2011 Microchip Technology Inc. DS39931D
PIC18F46J50
Data Sheet
28/44-Pin, Low-Power,
High-Performance USB Microcontrollers
with nanoWatt XLP Technology
DS39931D-page 2 2011 Microchip Technology Inc.
Information contained in this publication regarding device
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Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART,
PIC32 logo, rfPIC and UNI/O are registered trademarks of
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MXDEV, MXLAB, SEEVAL and The Embedded Control
Solutions Company are registered trademarks of Microchip
Technology Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard,
dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial
Programming, ICSP, Mindi, MiWi, MPASM, MPLAB Certified
logo, MPLIB, MPLINK, mTouch, Omniscient Code
Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,
PICtail, REAL ICE, rfLAB, Select Mode, Total Endurance,
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SQTP is a service mark of Microchip Technology Incorporated
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All other trademarks mentioned herein are property of their
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© 2011, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
ISBN: 978-1-61341-027-1
Note the following details of the code protection feature on Microch ip devices:
Microchip products meet the specification contained in their particular Microchip Data Sheet.
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Microchip received ISO/TS-16949:2002 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperiph erals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
2011 Microchip Technology Inc. DS39931D-page 3
PIC18F46J50 FAMILY
Power Management Features with
nanoWatt XLP™ for Extreme Low-Power:
Deep Sleep mode: CPU off, Peripherals off,
Currents Down to 13 nA and 850 nA with RTCC:
- Able to wake-up on external triggers,
programmable WDT or RTCC alarm
- Ultra Low-Power Wake-up (ULPWU)
Sleep mode: CPU off, Peripherals off, SRAM on,
Fast Wake-up, Currents Down to 105 nA, Typical
Idle: CPU off, Peripherals on, Currents Down to
2.3 A, Typical
Run: CPU on, Peripherals on, Currents Down to
6.2 A, Typical
Timer1 Oscillator w/RTCC: 1 A, 32 kHz, Typical
Watchdog Timer: 0.8 µA, 2V, Typical
S pecial Microcontroller Features:
Low-Power, High-Speed CMOS Flash Technology
C Compiler Optimized Architecture for Re-Entrant Code
Priority Levels for Interrupts
Self-Programmable under Software Control
8 x 8 Single-Cycle Hardware Multiplier
Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 131s
Single-Supply In-Circuit Serial Programming™
(ICSP™) via two pins
In-Circuit Debug (ICD) w/Three Breakpoints via 2 Pins
Operating Voltage Range of 2.0V to 3.6V
On-Chip 2.5V Regulator
Flash Program Memory of 10,000 Erase/Write
Cycles Minimum and 20-Year Data Retention
Universal Seri al Bus (USB) Features
USB V2.0 Compliant
Full Speed (12 Mbps) and Low Speed (1.5 Mbps)
Supports Control, Interrupt, Isochronous and Bulk
Transfers
Supports up to 32 Endpoints (16 bidirectional)
USB module can use any RAM Location on the
Device as USB Endpoint Buffers
On-Chip USB Transceiver with Crystal-less operation
Flexible Oscil lator Struc ture:
High-Precision Internal Oscillator (±0.15% typ.) for USB
Two External Clock modes, up to 48 MHz (12 MIPS)
Low-Power, 31 kHz Internal RC Oscillator
Tunable Internal Oscillator (31 kHz to 8 MHz, or
up to 48 MHz with PLL)
Secondary Oscillator using Timer1 @ 32 kHz
Fail-Safe Clock Monitor:
- Allows for safe shutdown if any clock stops
Two-Speed Oscillator Start-up
Programmable Reference Clock Output Generator
Peripheral Highl ight s:
Peripheral Pin Select:
- Allows independent I/O mapping of many
peripherals
- Continuous hardware integrity checking and
safety interlocks prevent unintentional
configuration changes
Hardware Real-Time Clock and Calendar (RTCC):
- Provides clock, calendar and alarm functions
High-Current Sink/Source 25 mA/25 mA
(PORTB and PORTC)
5.5V Tolerant Inputs (digital only pins)
Four Programmable External Interrupts
Four Input Change Interrupts
Two Enhanced Capture/Compare/PWM (ECCP)
modules:
- One, two or four PWM outputs
- Selectable polarity
- Programmable dead time
- Auto-shutdown and auto-restart
- Pulse steering control
Two Master Synchronous Serial Port (MSSP)
modules Supporting Three-Wire SPI (all four
modes) and I2C™ Master and Slave modes
Full-Duplex Master/Slave SPI DMA Engine
8-Bit Parallel Master Port/Enhanced Parallel
Slave Port
Two-Rail – Rail Analog Comparators with Input
Multiplexing
10-Bit, up to 13-Channel Analog-to-Digital (A/D)
Converter module:
- Auto-acquisition capability
- Conversion available during Sleep
- Self-calibration
High/Low-Voltage Detect module
Charge Time Measurement Unit (CTMU):
- Supports capacitive touch sensing for touch
screens and capacitive switches
- Provides a precise resolution time measure-
ment for both flow measurement and simple
temperature sensing
Two Enhanced USART modules:
- Supports RS-485, RS-232 and LIN/J2602
- Auto-Wake-up on Start bit
Auto-Baud Detect
28/44-Pin , Low-Power, High-Performance USB Microcontrollers
PIC18F46J50 FAMILY
DS39931D-page 4 2011 Microchip Technology Inc.
PIC18F/LF(1)
Device
Pins
Program
Memory (bytes)
SRAM (bytes)
Remappable
Pins
Timers
8/16-Bit
ECCP/(PWM)
EUSART
MSSP
10-Bit A/D (ch)
Comparators
Deep Sleep
PMP/PSP
CTMU
RTCC
USB
SPI w/DMA
I2C™
PIC18F24J50 28 16K 3776 16 2/3 2 2 2 Y Y 10 2 Y N Y Y Y
PIC18F25J50 28 32K 3776 16 2/3 2 2 2 Y Y 10 2 Y N Y Y Y
PIC18F26J50 28 64K 3776 16 2/3 2 2 2 Y Y 10 2 Y N Y Y Y
PIC18F44J50 44 16K 3776 22 2/3 2 2 2 Y Y 13 2 Y Y Y Y Y
PIC18F45J50 44 32K 3776 22 2/3 2 2 2 Y Y 13 2 Y Y Y Y Y
PIC18F46J50 44 64K 3776 22 2/3 2 2 2 Y Y 13 2 Y Y Y Y Y
PIC18LF24J50 28 16K 3776 16 2/3 2 2 2 Y Y 10 2 N N Y Y Y
PIC18LF25J50 28 32K 3776 16 2/3 2 2 2 Y Y 10 2 NNYYY
PIC18LF26J50 28 64K 3776 16 2/3 2 2 2 Y Y 10 2 NNYYY
PIC18LF44J50 44 16K 3776 22 2/3 2 2 2 Y Y 13 2 NYYYY
PIC18LF45J50 44 32K 3776 22 2/3 2 2 2 Y Y 13 2 NYYYY
PIC18LF46J50 44 64K 3776 22 2/3 2 2 2 Y Y 13 2 NYYYY
Note 1: See Section 1.3 “Details on Individual Fami ly De vi ces”, Section 4.6 “Deep Sleep Mode” and Section 27.3
“On-Chip Voltage Regulator” for details describing the functional differences between PIC18F and PIC18LF
variants in this device family.
2011 Microchip Technology Inc. DS39931D-page 5
PIC18F46J50 FAMILY
Pin Diagrams
PIC18F2XJ50
10
11
2
3
4
5
6
1
8
7
9
12
13
14 15
16
17
18
19
20
23
24
25
26
27
28
22
21
MCLR
RA0/AN0/C1INA/ULPWU/RP0
RA1/AN1/C2INA/RP1
RA2/AN2/VREF-/CVREF/C2INB
RA3/AN3/VREF+/C1INB
VDDCORE/VCAP(2)
RA5/AN4/SS1/HLVDIN/RCV/RP2
VSS
OSC1/CLKI/RA7
OSC2/CLKO/RA6
RC0/T1OSO/T1CKI/RP11
RC1/T1OSI/UOE/RP12
RC2/AN11/CTPLS/RP13
VUSB
RB7/KBI3/PGD/RP10
RB6/KBI2/PGC/RP9
RB5/KBI1/SDI1/SDA1/RP8
RB4/PMA1/KBI0/SCK1/SCL1/RP7
RB3/AN9/CTED2/VPO/RP6
RB2/AN8/CTED1/VMO/REFO/RP5
RB1/AN10/RTCC/RP4
RB0/AN12/INT0/RP3
VDD
VSS
RC7/RX1/DT1/SDO1/RP18
RC6/TX1/CK1/RP17
RC5/D+/VP
RC4/D-/VM
28-Pin SPDIP/SOIC/SSOP(1)
Legend: RPn represents remappable pins.
Note 1: Some input and output functions are routed through the Peripheral Pin Select (PPS) module and can be
dynamically assigned to any of the RPn pins. For a list of the input and output functions, see Table 10-13
and Table 10-14, respectively. For details on configuring the PPS module, see Section 10.7 “Peripheral
Pin Select (PP S) .
2: See Section 27.3 “On-Chip Voltage Regulator” for details on how to connect the VDDCORE/VCAP pin.
3: For the QFN package, it is recommended that the bottom pad be connected to VSS.
28-Pin QFN(1,3)
RC0/T1OSO/T1CKI/RP11
RB7/KBI3/PGD/RP10
RB6/KBI2/PGC/RP9
RB5/KBI1/SDI1/SDA1/RP8
RB4/KBI0/SCK1/SCL1/RP7
RB3/AN9/CTED2/VPO/RP6
RB2/AN8/CTED1/VMO/REFO/RP5
RB1/AN10/RTCC/RP4
RB0/AN12/INT0/RP3
VDD
VSS
RC7/RX1/DT1/SDO1/RP18
RC6/TX1/CK1/RP17
RC5/D+/VP
RC4/D-/VM
MCLR
RA0/AN0/C1INA/ULPWU/RP0
RA1/AN1/C2INA/RP1
RA2/AN2/VREF-/CVREF/C2INB
RA3/AN3/VREF+/C1INB
VDDCORE/VCAP(2)
RA5/AN4/SS1/HLVDIN/RCV/RP2
VSS
OSC1/CLKI/RA7
OSC2/CLKO/RA6
RC1/T1OSI/UOE/RP12
RC2/AN11/CTPLS/RP13
VUSB
= Pins are up to 5.5V tolerant
1011
2
3
6
1
18
19
20
21
22
12 13 14 15
8
7
16
17
232425262728
9
PIC18F2XJ50
5
4
PIC18F46J50 FAMILY
DS39931D-page 6 2011 Microchip Technology Inc.
Pin Diagrams (Continued)
44-Pin QFN(1,3,4)
RA3/AN3/VREF+/C1INB
RA2/AN2/VREF-/CVREF-/C2INB
RA1/AN1/C2INA/PMA7/RP1
RA0/AN0/C1INA/ULPWU/PMA6/RP0
MCLR
RB7/KBI3/PGD/RP10
RB6/KBI2/PGC/RP9
RB5/PMA0/KBI1/SDI1/SDA1/RP8
RB4/PMA1/KBI0/SCK1/SCL1/RP7
NC
RC6/PMA5/TX1/CK1/RP17
RC5/D+/VP
RC4/D-/VM
RD3/PMD3/RP20
RD2/PMD2/RP19
RD1/PMD1/SDA2
RD0/PMD0/SCL2
VUSB
RC2/AN11/CTPLS/RP13
RC1/T1OSI/UOE/RP12
RC0/T1OSO/T1CKI/RP11
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VSS
AVDD
RE2/AN7/PMCS
RE1/AN6/PMWR
RE0/AN5/PMRD
RA5/AN4/SS1/HLVDIN/RCV/RP2
VDDCORE/VCAP(2)
RC7/PMA4/RX1/DT1/SDO1/RP18
RD4/PMD4/RP21
RD5/PMD5/RP22
RD6/PMD6/RP23
VSS
VDD
RB0/AN12/INT0/RP3
RB1/AN10/PMBE/RTCC/RP4
RB2/AN8/CTED1/PMA3/VMO/REFO/RP5
RB3/AN9/CTED2/PMA2/VPO/RP6
RD7/PMD7/RP24 AVSS
VDD
AVDD
Legend: RPn represents remappable pins.
Note 1: Some input and output functions are routed through the Peripheral Pin Select (PPS) module and can be
dynamically assigned to any of the RPn pins. For a list of the input and output functions, see Table 10-13
and Table 10-14, respectively. For details on configuring the PPS module, see Section 10.7 “Peripheral
Pin Select (PP S) .
2: See Section 27.3 “On-Chip Voltage Regulator” for details on how to connect the VDDCORE/VCAP pin.
3: For the QFN package, it is recommended that the bottom pad be connected to VSS.
4: On 44-pin QFN devices, AVDD and AVSS reference sources are intended to be externally connected to VDD
and VSS levels. Other package types tie AVDD and AVSS to VDD and VSS internally.
= Pins are up to 5.5V tolerant
10
11
2
3
6
1
18
19
20
21
22
12
13
14
15
38
8
7
44
43
42
41
40
39
16
17
29
30
31
32
33
23
24
25
26
27
28
36
34
35
9
37
5
4
PIC18F4XJ50
2011 Microchip Technology Inc. DS39931D-page 7
PIC18F46J50 FAMILY
Pin Diagrams (Continued)
10
11
2
3
6
1
18
19
20
21
22
12
13
14
15
38
8
7
44
43
42
41
40
39
16
17
29
30
31
32
33
23
24
25
26
27
28
36
34
35
9
PIC18F4XJ50
37
RA3/AN3/VREF+/C1INB
RA2/AN2/VREF-/CVREF-/C2INB
RA1/AN1/C2INA/PMA7/RP1
RA0/AN0/C1INA/ULPWU/PMA6/RP0
MCLR
NC
RB7/KBI3/PGD/RP10
RB6/KBI2/PGC/RP9
RB5/PMA0/KBI1/SDI1/SDA1/RP8
RB4/PMA1/KBI0/SCK1/SCL1/RP7
NC
RC6/PMA5/TX1/CK1/RP17
RC5/D+/VP
RC4/D-/VM
RD3/PMD3/RP20
RD2/PMD2/RP19
RD1/PMD1/SDA2
RD0/PMD0/SCL2
VUSB
RC2/AN11/CTPLS/RP13
RC1/T1OSI/UOE/RP12
NC
NC
RC0/T1OSO/T1CKI/RP11
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VSS
VDD
RE2/AN7/PMCS
RE1/AN6/PMWR
RE0/AN5/PMRD
RA5/AN4/SS1/HLVDIN/RCV/RP2
VDDCORE/VCAP(2)
RC7/PMA4/RX1/DT1/SDO1/RP18
RD4/PMD4/RP21
RD5/PMD5/RP22
RD6/PMD6/RP23
VSS
VDD
RB0/AN12/INT0/RP3
RB1/AN10/PMBE/RTCC/RP4
RB2/AN8/CTED1/PMA3/VMO/REFO/RP5
RB3/AN9/CTED2/PMA2/VPO/RP6
44-Pin TQFP(1)
RD7/PMD7/RP24 5
4
Legend: RPn represents remappable pins.
Note 1: Some input and output functions are routed through the Peripheral Pin Select (PPS) module and can be
dynamically assigned to any of the RPn pins. For a list of the input and output functions, see Table 10-13
and Table 10-14, respectively. For details on configuring the PPS module, see Sectio n 10.7 “P eripheral
Pin Select (PP S) .
2: See Section 27.3 “On-Chip Voltage Regulator” for details on how to connect the VDDCORE/VCAP pin.
= Pins are up to 5.5V tolerant
PIC18F46J50 FAMILY
DS39931D-page 8 2011 Microchip Technology Inc.
Table of Contents
1.0 Device Overview ........................................................................................................................................................................ 11
2.0 Guidelines for Getting Started with PIC18FJ Microcontrollers ................................................................................................... 29
3.0 Oscillator Configurations ............................................................................................................................................................ 35
4.0 Low-Power Modes...................................................................................................................................................................... 47
5.0 Reset .......................................................................................................................................................................................... 63
6.0 Memory Organization ................................................................................................................................................................. 77
7.0 Flash Program Memory............................................................................................................................................................ 103
8.0 8 x 8 Hardware Multiplier.......................................................................................................................................................... 113
9.0 Interrupts .................................................................................................................................................................................. 115
10.0 I/O Ports ................................................................................................................................................................................... 131
11.0 Parallel Master Port (PMP)....................................................................................................................................................... 169
12.0 Timer0 Module ......................................................................................................................................................................... 195
13.0 Timer1 Module ......................................................................................................................................................................... 199
14.0 Timer2 Module ......................................................................................................................................................................... 211
15.0 Timer3 Module ......................................................................................................................................................................... 213
16.0 Timer4 Module ......................................................................................................................................................................... 223
17.0 Real-Time Clock and Calendar (RTCC)................................................................................................................................... 225
18.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 245
19.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 269
20.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 323
21.0 10-bit Analog-to-Digital Converter (A/D) Module ...................................................................................................................... 347
22.0 Universal Serial Bus (USB) ...................................................................................................................................................... 357
23.0 Comparator Module.................................................................................................................................................................. 385
24.0 Comparator Voltage Reference Module ................................................................................................................................... 391
25.0 High/Low Voltage Detect (HLVD)............................................................................................................................................. 395
26.0 Charge Time Measurement Unit (CTMU) ................................................................................................................................ 401
27.0 Special Features of the CPU.................................................................................................................................................... 417
28.0 Instruction Set Summary .......................................................................................................................................................... 435
29.0 Development Support............................................................................................................................................................... 485
30.0 Electrical Characteristics .......................................................................................................................................................... 489
31.0 Packaging Information.............................................................................................................................................................. 531
Appendix A: Revision History............................................................................................................................................................. 545
Appendix B: Device Differences......................................................................................................................................................... 545
The Microchip Web Site..................................................................................................................................................................... 559
Customer Change Notification Service .............................................................................................................................................. 559
Customer Support .............................................................................................................................................................................. 559
Reader Response .............................................................................................................................................................................. 560
Product Identification System............................................................................................................................................................. 561
2011 Microchip Technology Inc. DS39931D-page 9
PIC18F46J50 FAMILY
TO OUR VALUE D CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
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enhanced as new volumes and updates are introduced.
If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
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http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
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To determine if an errata sheet exists for a particular device, please check with one of the following:
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PIC18F46J50 FAMILY
DS39931D-page 10 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 11
PIC18F46J50 FAMILY
1.0 DEVICE OVERVIEW
This document contains device-specific information for
the following devices:
This family introduces a new line of low-voltage
Universal Serial Bus (USB) microcontrollers with the
main traditional advantage of all PIC18 microcontrollers,
namely, high computational performance and a rich
feature set at an extremely competitive price point.
These features make the PIC18F46J50 family a logical
choice for many high-performance applications, where
cost is a primary consideration.
1.1 Core Features
1.1.1 nanoWatt TECHNOLOGY
All of the devices in the PIC18F46J50 family incorpo-
rate a range of features that can significantly reduce
power consumption during operation. Key features are:
Alternate Run Modes: By clocking the controller
from the Timer1 source or the internal RC
oscillator, power consumption during code
execution can be reduced by as much as 90%.
Multiple Idle Modes: The controller can also run
with its CPU core disabled but the peripherals still
active. In these states, power consumption can be
reduced even further, to as little as 4% of normal
operational requirements.
On-the-Fly Mode Switching: The
power-managed modes are invoked by user code
during operation, allowing the users to incorporate
power-saving ideas into their application’s
software design.
1.1.2 UNIVERSAL SERIAL BUS (USB)
Devices in the PIC18F46J50 family incorporate a
fully-featured USB communications module with a
built-in transceiver that is compliant with the “USB
Specification Revision 2.0”. The module supports both
low-speed and full-speed communication for all
supported data transfer types.
1.1.3 OSCILLATOR OPTIONS AND
FEATURES
All of the devices in the PIC18F46J50 family offer five
different oscillator options, allowing users a range of
choices in developing application hardware. These
include:
Two Crystal modes, using crystals or ceramic
resonators.
Two External Clock modes, offering the option of
a divide-by-4 clock output.
An internal oscillator block, which provides an
8 MHz clock and an INTRC source (approxi-
mately 31 kHz, stable over temperature and VDD),
as well as a range of six user-selectable clock
frequencies, between 125 kHz to 4 MHz, for a
total of eight clock frequencies. This option frees
an oscillator pin for use as an additional general
purpose I/O.
A Phase Lock Loop (PLL) frequency multiplier,
available to the high-speed crystal, and external
and internal oscillators, providing a clock speed
up to 48 MHz.
Dual clock operation, allowing the USB module to
run from a high-frequency oscillator while the rest
of the microcontroller is clocked at a different
frequency.
The internal oscillator block provides a stable reference
source that gives the PIC18F46J50 family additional
features for robust operation:
Fail-Safe Clock Monitor: This option constantly
monitors the main clock source against a reference
signal provided by the internal oscillator. If a clock
failure occurs, the controller is switched to the
internal oscillator, allowing for continued low-speed
operation or a safe application shutdown.
Two-Speed Start-up: This option allows the
internal oscillator to serve as the clock source
from Power-on Reset (POR), or wake-up from
Sleep mode, until the primary clock source is
available.
1.1.4 EXPANDED MEMORY
The PIC18F46J50 family provides ample room for
application code, from 16 Kbytes to 64 Kbytes of code
space. The Flash cells for program memory are rated
to last in excess of 10000 erase/write cycles. Data
retention without refresh is conservatively estimated to
be greater than 20 years.
The Flash program memory is readable and writable
during normal operation. The PIC18F46J50 family also
provides plenty of room for dynamic application data
with up to 3.8 Kbytes of data RAM.
PI C18F24J50 PIC18LF24J50
PIC18F25J50 PIC18LF25J50
PIC18F26J50 PIC18LF26J50
PIC18F44J50 PIC18LF44J50
PIC18F45J50 PIC18LF45J50
PIC18F46J50 PIC18LF46J50
PIC18F46J50 FAMILY
DS39931D-page 12 2011 Microchip Technology Inc.
1.1.5 EXTENDED INSTRUCTION SET
The PIC18F46J50 family implements the optional
extension to the PIC18 instruction set, adding eight
new instructions and an Indexed Addressing mode.
Enabled as a device configuration option, the extension
has been specifically designed to optimize re-entrant
application code originally developed in high-level
languages, such as C.
1.1.6 EASY MIGRATION
Regardless of the memory size, all devices share the
same rich set of peripherals, allowing for a smooth
migration path as applications grow and evolve.
The consistent pinout scheme used throughout the
entire family also aids in migrating to the next larger
device.
The PIC18F46J50 family is also pin compatible with
other PIC18 families, such as the PIC18F4550,
PIC18F2450 and PIC18F45J10. This allows a new
dimension to the evolution of applications, allowing
developers to select different price points within
Microchip’s PIC18 portfolio, while maintaining the
same feature set.
1.2 Other Special Features
Communications: The PIC18F46J50 family
incorporates a range of serial and parallel com-
munication peripherals, including a fully featured
USB communications module that is compliant
with the “USB Spec ifi ca tio n Revis ion 2.0”. This
device also includes two independent Enhanced
USARTs and two Master Synchronous Serial Port
(MSSP) modules, capable of both Serial
Peripheral Interface (SPI) and I2C™ (Master and
Slave) modes of operation. The device also has a
parallel port and can be configured to serve as
either a Parallel Master Port (PMP) or as a
Parallel Slave Port (PSP).
ECCP Modules: All devices in the family incorpo-
rate three Enhanced Capture/Compare/PWM
(ECCP) modules to maximize flexibility in control
applications. Up to four different time bases may
be used to perform several different operations at
once. Each of the ECCPs offers up to four PWM
outputs, allowing for a total of eight PWMs. The
ECCPs also offer many beneficial features,
including polarity selection, programmable dead
time, auto-shutdown and restart and Half-Bridge
and Full-Bridge Output modes.
10-Bit A/D Converter: This module incorporates
programmable acquisition time, allowing for a
channel to be selected and a conversion to be
initiated without waiting for a sampling period, and
thus, reducing code overhead.
Extended Watchdog Timer (WDT): This
enhanced version incorporates a 16-bit prescaler,
allowing an extended time-out range that is stable
across operating voltage and temperature. See
Section 30.0 “Electrical Characteristics” for
time-out periods.
1.3 Details on Individual Family
Devices
Devices in the PIC18F46J50 family are available on
28-pin and 44-pin packages. Block diagrams for the
two groups are shown in Figure 1-1 and Figure 1-2.
The devices are differentiated from each other in two
ways:
Flash program memory (three sizes: 16 Kbytes
for the PIC18FX4J50, 32 Kbytes for
PIC18FX5J50 devices and 64 Kbytes for
PIC18FX6J50)
I/O ports (three bidirectional ports on 28-pin
devices, five bidirectional ports on 44-pin devices)
All other features for devices in this family are identical.
These are summarized in Ta b l e 1 - 1 and Tabl e 1 - 2.
The pinouts for the PIC18F2XJ50 devices are listed in
Table 1-3. The pinouts for the PIC18F4XJ50 devices
are shown in Tab l e 1 - 4.
The PIC18F46J50 family of devices provides an
on-chip voltage regulator to supply the correct voltage
levels to the core. Parts designated with an “F” part
number (such as PIC18F46J50) have the voltage
regulator enabled.
These parts can run from 2.15V-3.6V on VDD, but should
have the VDDCORE pin connected to VSS through a
low-ESR capacitor. Parts designated with an “LF” part
number (such as PIC18LF46J50) do not enable the volt-
age regulator. For “LF” parts, an external supply of
2.0V-2.7V has to be supplied to the VDDCORE pin while
2.0V-3.6V can be supplied to VDD (VDDCORE should
never exceed VDD).
For more details about the internal voltage regulator,
see Section 27.3 “On-Chip Voltage Regulator”.
2011 Microchip Technology Inc. DS39931D-page 13
PIC18F46J50 FAMILY
TABLE 1-1: DEVICE FEATURES FOR THE PIC18F2XJ50 (28-PIN DEVICES)
TABLE 1-2: DEVICE FEATURES FOR THE PIC18F4XJ50 (44-PIN DEVICES)
Features PIC18F24J50 PIC18F25J50 PIC18F26J50
Operating Frequency DC – 48 MHz DC – 48 MHz DC – 48 MHz
Program Memory (Bytes) 16K 32K 64K
Program Memory (Instructions) 8,192 16,384 32,768
Data Memory (Bytes) 3.8K 3.8K 3.8K
Interrupt Sources 30
I/O Ports Ports A, B, C
Timers 5
Enhanced Capture/Compare/PWM Modules 2
Serial Communications MSSP (2), Enhanced USART (2), USB
Parallel Communications (PMP/PSP) No
10-Bit Analog-to-Digital Module 10 Input Channels
Resets (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT
(PWRT, OST)
Instruction Set 75 Instructions, 83 with Extended Instruction Set Enabled
Packages 28-Pin QFN, SOIC, SSOP and SPDIP (300 mil)
Features PIC18F44J50 PIC18F45J50 PIC18F46J50
Operating Frequency DC – 48 MHz DC – 48 MHz DC – 48 MHz
Program Memory (Bytes) 16K 32K 64K
Program Memory (Instructions) 8,192 16,384 32,768
Data Memory (Bytes) 3.8K 3.8K 3.8K
Interrupt Sources 30
I/O Ports Ports A, B, C, D, E
Timers 5
Enhanced Capture/Compare/PWM Modules 2
Serial Communications MSSP (2), Enhanced USART (2), USB
Parallel Communications (PMP/PSP) Yes
10-Bit Analog-to-Digital Module 13 Input Channels
Resets (and Delays) POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT
(PWRT, OST)
Instruction Set 75 Instructions, 83 with Extended Instruction Set Enabled
Packages 44-Pin QFN and TQFP
PIC18F46J50 FAMILY
DS39931D-page 14 2011 Microchip Technology Inc.
FIGU RE 1- 1 : PIC1 8F 2XJ 50 ( 28 -P IN ) B LOC K DI AG R AM
Instruction
Decode and
Control
PORTA
Data Latch
Data Memory
(3.8 Kbytes)
Address Latch
Data Address<12>
12
Access
BSR FSR0
FSR1
FSR2
inc/dec
logic
Address
412 4
PCH PCL
PCLATH
8
31-Level Stack
Program Counter
PRODLPRODH
8 x 8 Multiply
8
BITOP
8
8
ALU<8>
Address Latch
Program Memory
(16 Kbytes-64 Kbytes)
Data Latch
20
8
8
Table Pointer<21>
inc/dec logic
21
8
Data Bus<8>
Table Latch
8
IR
12
3
PCLATU
PCU
Note 1: See Ta b le 1- 3 for I/O port pin descriptions.
2: BOR functionality is provided when the on-board voltage regulator is enabled.
EUSART1
Comparators
MSSP1
Timer2Timer1 Timer3Timer0
ECCP1
ADC
10-Bit
W
Instruct ion Bus <16>
STKPTR Bank
8
State Machine
Control Signals
Decode
8
8
EUSART2
ECCP2
ROM Latch
MSSP2
PORTC
RA0:RA7(1)
RC0:RC7(1)
PORTB
RB0:RB7(1)
Timer4
OSC1/CLKI
OSC2/CLKO
VDD,
8 MHz
INTOSC
VSS MCLR
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Brown-out
Reset(2)
Precision
Reference
Band Gap
INTRC
Oscillator
Regulator
Voltage
VDDCORE/VCAP
USB
CTMU
Timing
Generation
USB
Module
VUSB
HLVD
RTCC
2011 Microchip Technology Inc. DS39931D-page 15
PIC18F46J50 FAMILY
FIGU RE 1- 2 : PIC1 8F 4XJ 50 ( 44 -P IN ) B LOC K DI AG R AM
PRODLPRODH
8 x 8 Multiply
8
BITOP
8
8
ALU<8>
8
8
3
W8
8
8
Instruction
Decode and
Control
Data Latch
Address Latch
Data Address<12>
12
Access
BSR FSR0
FSR1
FSR2
inc/dec
logic
Address
412 4
PCH PCL
PCLATH
8
31-Level Stack
Program Counter
Address Latch
Program Memory
(16 Kbytes-64 Kbytes)
Data Latch
20
Table Pointer<21>
inc/dec logic
21
8
Data Bus<8>
Table Latch
8
IR
12
ROM Latch
PCLATU
PCU
Instruction Bus <16>
STKPTR Bank
State Machine
Control Signals
Decode
System Bus Interface
AD<15:0>, A<19:16>
(Multiplexed with PORTD
and PORTE)
PORTA
PORTC
PORTD
PORTE
RA0:RA7(1)
RC0:RC7(1)
RD0:RD7(1)
RE0:RE2(1)
PORTB
RB0:RB7(1)
EUSART1
Comparators
MSSP1
Timer2Timer1 Timer3Timer0
ECCP1
ADC
10-Bit
EUSART2
ECCP2 MSSP2
Timer4
Note 1: See Table 1-3 for I/O port pin descriptions.
2: The on-chip voltage regulator is always enabled by default.
Data Memory
(3.8 Kbytes)
USB
PMP
OSC1/CLKI
OSC2/CLKO
VDD,
8 MHz
INTOSC
VSS MCLR
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
Watchdog
Timer
Brown-out
Reset(2)
Precision
Reference
Band Gap
INTRC
Oscillator
Regulator
Voltage
VDDCORE/VCAP
Timing
Generation
USB
Module
VUSB
CTMU
HLVD
RTCC
PIC18F46J50 FAMILY
DS39931D-page 16 2011 Microchip Technology Inc.
TABLE 1-3: PIC18F2XJ50 PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number
Pin
Type Buffer
Type Description
28-SPDIP/
SSOP/
SOIC 28-QFN
MCLR 1 26 I ST Master Clear (Reset) input. This pin is an
active-low Reset to the device.
OSC1/CLKI/RA7
OSC1
CLKI
RA7(1)
96
I
I
I/O
ST
CMOS
TTL
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source
input. ST buffer when configured in RC mode;
CMOS otherwise. Main oscillator input
connection.
External clock source input; always associated
with pin function, OSC1 (see related
OSC1/CLKI pins).
Digital I/O.
OSC2/CLKO/RA6
OSC2
CLKO
RA6(1)
10 7
O
O
I/O
TTL
Oscillator crystal or clock output.
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
Main oscillator feedback output connection.
In RC mode, OSC2 pin outputs CLKO, which
has 1/4 the frequency of OSC1 and denotes
the instruction cycle rate.
Digital I/O.
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 17
PIC18F46J50 FAMILY
PORTA is a bidirectional I/O port.
RA0/AN0/C1INA/ULPWU/RP0
RA0
AN0
C1INA
ULPWU
RP0
227
I/O
I
I
I
I/O
DIG
Analog
Analog
Analog
DIG
Digital I/O.
Analog Input 0.
Comparator 1 Input A.
Ultra Low-Power Wake-up input.
Remappable Peripheral Pin 0 input/output.
RA1/AN1/C2INA/RP1
RA1
AN1
C2INA
RP1
328
I
O
I
I/O
DIG
Analog
Analog
DIG
Digital I/O.
Analog Input 1.
Comparator 2 Input A.
Remappable Peripheral Pin 1 input/output.
RA2/AN2/VREF-/CVREF/C2INB
RA2
AN2
VREF-
CVREF
C2INB
41
I/O
I
O
I
I
DIG
Analog
Analog
Analog
Analog
Digital I/O.
Analog Input 2.
A/D reference voltage (low) input.
Comparator reference voltage output.
Comparator 2 Input B.
RA3/AN3/VREF+/C1INB
RA3
AN3
VREF+
C1INB
52
I/O
I
I
I
DIG
Analog
Analog
Analog
Digital I/O.
Analog Input 3.
A/D reference voltage (high) input.
Comparator 1 Input B.
RA5/AN4/SS1/HLVDIN/
RCV/RP2
RA5
AN4
SS1
HLVDIN
RCV
RP2
74
I/O
I
I
I
I
I/O
DIG
Analog
TTL
Analog
Analog
DIG
Digital I/O.
Analog Input 4.
SPI slave select input.
Low-Voltage Detect (LVD) input.
External USB transceiver RCV input.
Remappable Peripheral Pin 2 input/output.
RA6(1)
RA7(1) See the OSC2/CLKO/RA6 pin.
See the OSC1/CLKI/RA7 pin.
TABLE 1-3: PIC18F2XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type Buffer
Type Description
28-SPDIP/
SSOP/
SOIC 28-QFN
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
PIC18F46J50 FAMILY
DS39931D-page 18 2011 Microchip Technology Inc.
PORTB is a bidirectional I/O port. PORTB can be
software programmed for internal weak pull-ups
on all inputs.
RB0/AN12/INT0/RP3
RB0
AN12
INT0
RP3
21 18
I/O
I
I
I/O
DIG
Analog
ST
DIG
Digital I/O.
Analog Input 12.
External Interrupt 0.
Remappable Peripheral Pin 3 input/output.
RB1/AN10/RTCC/RP4
RB1
AN10
RTCC
RP4
22 19
I/O
I
O
I/O
DIG
Analog
DIG
DIG
Digital I/O.
Analog Input 10.
Real-Time Clock Calendar (RTCC) output.
Remappable Peripheral Pin 4 input/output.
RB2/AN8/CTED1/VMO/
REFO/RP5
RB2
AN8
CTED1
VMO
REFO
RP5
23 20
I/O
I
I
O
O
I/O
DIG
Analog
ST
DIG
DIG
DIG
Digital I/O.
Analog Input 8.
CTMU Edge 1 input.
External USB transceiver D- data output.
Reference output clock.
Remappable Peripheral Pin 5 input/output.
RB3/AN9/CTED2/VPO/RP6
RB3
AN9
CTED2
VPO
RP6
24 21
I/O
I
I/O
O
I
DIG
Analog
ST
DIG
DIG
Digital I/O.
Analog Input 9.
CTMU Edge 2 input.
External USB transceiver D+ data output.
Remappable Peripheral Pin 6 input/output.
TABLE 1-3: PIC18F2XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type Buffer
Type Description
28-SPDIP/
SSOP/
SOIC 28-QFN
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 19
PIC18F46J50 FAMILY
PORTB (continued)
RB4/KBI0/SCK1/SCL1/RP7
RB4
KBI0
SCK1
SCL1
RP7
25 22
I/O
I
I/O
I/O
I/O
DIG
TTL
DIG
I2C
DIG
Digital I/O.
Interrupt-on-change pin.
Synchronous serial clock input/output.
I2C clock input/output.
Remappable Peripheral Pin 7 input/output.
RB5/KBI1/SDI1/SDA1/RP8
RB5
KBI1
SDI1
SDA1
RP8
26 23
I/O
I
I
I/O
I/O
DIG
TTL
ST
I2C
DIG
Digital I/O.
Interrupt-on-change pin.
SPI data input.
I2C™ data input/output.
Remappable Peripheral Pin 8 input/output.
RB6/KBI2/PGC/RP9
RB6
KBI2
PGC
RP9
27 24
I/O
I
I
I/O
DIG
TTL
ST
DIG
Digital I/O.
Interrupt-on-change pin.
ICSP™ clock input.
Remappable Peripheral Pin 9 input/output.
RB7/KBI3/PGD/RP10
RB7
KBI3
PGD
RP10
28 25
I/O
I
I/O
I/O
DIG
TTL
ST
DIG
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming
data pin.
Remappable Peripheral Pin 10 input/output.
TABLE 1-3: PIC18F2XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type Buffer
Type Description
28-SPDIP/
SSOP/
SOIC 28-QFN
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
PIC18F46J50 FAMILY
DS39931D-page 20 2011 Microchip Technology Inc.
PORTC is a bidirectional I/O port.
RC0/T1OSO/T1CKI/RP11
RC0
T1OSO
T1CKI
RP11
11 8
I/O
O
I
I/O
ST
Analog
ST
DIG
Digital I/O.
Timer1 oscillator output.
Timer1 external digital clock input.
Remappable Peripheral Pin 11 input/output.
RC1/T1OSI/UOE/RP12
RC1
T1OSI
UOE
RP12
12 9
I/O
I
O
I/O
ST
Analog
DIG
DIG
Digital I/O.
Timer1 oscillator input.
External USB transceiver NOE output.
Remappable Peripheral Pin 12 input/output.
RC2/AN11/CTPLS/RP13
RC2
AN11
CTPLS
RP13
13 10
I/O
I
O
I/O
ST
Analog
DIG
DIG
Digital I/O.
Analog Input 11.
CTMU pulse generator output.
Remappable Peripheral Pin 13 input/output.
RC4/D-/VM
RC4
D-
VM
15 12
I
I/O
I
TTL
TTL
Digital I.
USB bus minus line input/output.
External USB transceiver FM input.
RC5/D+/VP
RC5
D+
VP
16 13
I
I/O
I
TTL
DIG
TTL
Digital I.
USB bus plus line input/output.
External USB transceiver VP input.
RC6/TX1/CK1/RP17
RC6
TX1
CK1
RP17
17 14
I/O
O
I/O
I/O
ST
DIG
ST
DIG
Digital I/O.
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related
RX1/DT1).
Remappable Peripheral Pin 17 input/output.
RC7/RX1/DT1/SDO1/RP18
RC7
RX1
DT1
SDO1
RP18
18 15
I/O
I
I/O
O
I/O
ST
ST
ST
DIG
DIG
Digital I/O.
Asynchronous serial receive data input.
Synchronous serial data output/input.
SPI data output.
Remappable Peripheral Pin 18 input/output.
TABLE 1-3: PIC18F2XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type Buffer
Type Description
28-SPDIP/
SSOP/
SOIC 28-QFN
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 21
PIC18F46J50 FAMILY
VSS1 8 5 P Ground reference for logic and I/O pins.
VSS21916
VDD 20 17 P Positive supply for peripheral digital logic and I/O
pins.
VDDCORE/VCAP
VDDCORE
VCAP
63
P
P
Core logic power or external filter capacitor
connection.
Positive supply for microcontroller core logic
(regulator disabled).
External filter capacitor connection (regulator
enabled).
VUSB 14 11 P USB voltage input pin.
TABLE 1-3: PIC18F2XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
Pin
Type Buffer
Type Description
28-SPDIP/
SSOP/
SOIC 28-QFN
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
PIC18F46J50 FAMILY
DS39931D-page 22 2011 Microchip Technology Inc.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
MCLR 18 18 I ST Master Clear (Reset) input; this is an active-low
Reset to the device.
OSC1/CLKI/RA7
OSC1
CLKI
RA7(1)
32 30
I
I
I/O
ST
CMOS
TTL
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source
input. ST buffer when configured in RC mode;
otherwise CMOS. Main oscillator input
connection.
External clock source input; always associated
with pin function, OSC1 (see related OSC1/CLKI
pins).
Digital I/O.
OSC2/CLKO/RA6
OSC2
CLKO
RA6(1)
33 31
O
O
I/O
TTL
Oscillator crystal or clock output.
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
Main oscillator feedback output connection
in RC mode, OSC2 pin outputs CLKO, which
has 1/4 the frequency of OSC1 and denotes
the instruction cycle rate.
Digital I/O.
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 23
PIC18F46J50 FAMILY
PORTA is a bidirectional I/O port.
RA0/AN0/C1INA/ULPWU/PMA6/
RP0
RA0
AN0
C1INA
ULPWU
PMA6
RP0
19 19
I/O
I
I
I
O
I/O
DIG
Analog
Analog
Analog
DIG
DIG
Digital I/O.
Analog Input 0.
Comparator 1 Input A.
Ultra Low-Power Wake-up input.
Parallel Master Port digital output.
Remappable Peripheral Pin 0 input/output.
RA1/AN1/C2INA/PMA7/RP1
RA1
AN1
C2INA
PMA7
RP1
20 20
I
O
I
O
I/O
DIG
Analog
Analog
DIG
DIG
Digital I/O.
Analog Input 1.
Comparator 2 Input A.
Parallel Master Port digital output.
Remappable Peripheral Pin 1 input/output.
RA2/AN2/VREF-/CVREF/C2INB
RA2
AN2
VREF-
CVREF
C2INB
21 21
I/O
I
O
I
I
DIG
Analog
Analog
Analog
Analog
Digital I/O.
Analog Input 2.
A/D reference voltage (low) input.
Comparator reference voltage output.
Comparator 2 Input B.
RA3/AN3/VREF+/C1INB
RA3
AN3
VREF+
C1INB
22 22
I/O
I
I
I
DIG
Analog
Analog
Analog
Digital I/O.
Analog Input 3.
A/D reference voltage (high) input.
Comparator 1 Input B.
RA5/AN4/SS1/HLVDIN/RCV/RP2
RA5
AN4
SS1
HLVDIN
RCV
RP2
24 24
I/O
I
I
I
I
I/O
DIG
Analog
TTL
Analog
Analog
DIG
Digital I/O.
Analog Input 4.
SPI slave select input.
Low-Voltage Detect (LVD) input.
External USB transceiver RCV input.
Remappable Peripheral Pin 2 input/output.
RA6(1)
RA7(1) See the OSC2/CLKO/RA6 pin.
See the OSC1/CLKI/RA7 pin.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
PIC18F46J50 FAMILY
DS39931D-page 24 2011 Microchip Technology Inc.
PORTB is a bidirectional I/O port. PORTB can be
software programmed for internal weak pull-ups on
all inputs.
RB0/AN12/INT0/RP3
RB0
AN12
INT0
RP3
98
I/O
I
I
I/O
DIG
Analog
ST
DIG
Digital I/O.
Analog Input 12.
External Interrupt 0.
Remappable Peripheral Pin 3 input/output.
RB1/AN10/PMBE/RTCC/RP4
RB1
AN10
PMBE
RTCC
RP4
10 9
I/O
I
O
O
I/O
DIG
Analog
DIG
DIG
DIG
Digital I/O.
Analog Input 10.
Parallel Master Port byte enable.
Real-Time Clock Calendar (RTCC) output.
Remappable Peripheral Pin 4 Input/output.
RB2/AN8/CTED1/PMA3/VMO/
REFO/RP5
RB2
AN8
CTED1
PMA3
VMO
REFO
RP5
11 10
I/O
I
I
O
O
O
I/O
DIG
Analog
ST
DIG
DIG
DIG
DIG
Digital I/O.
Analog Input 8.
CTMU Edge 1 input.
Parallel Master Port address.
External USB transceiver D- data output.
Reference output clock.
Remappable Peripheral Pin 5 input/output.
RB3/AN9/CTED2/PMA2/VPO/
RP6
RB3
AN9
CTED2
PMA2
VPO
RP6
12 11
I/O
I
I
O
O
I/O
DIG
Analog
ST
DIG
DIG
DIG
Digital I/O.
Analog Input 9.
CTMU Edge 2 input.
Parallel Master Port address.
External USB transceiver D+ data output.
Remappable Peripheral Pin 6 input/output.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 25
PIC18F46J50 FAMILY
PORTB (continued)
RB4/PMA1/KBI0/SCK1/SCL1/RP7
RB4
PMA1
KBI0
SCK1
SCL1
RP7
14 14
I/O
I/O
I
I/O
I/O
I/O
DIG
DIG
TTL
DIG
I2C
DIG
Digital I/O.
Parallel Master Port address.
Interrupt-on-change pin.
Synchronous serial clock input/output.
I2C clock input/output.
Remappable Peripheral Pin 7 input/output.
RB5/PMA0/KBI1/SDI1/SDA1/RP8
RB5
PMA0
KBI1
SDI1
SDA1
RP8
15 15
I/O
I/O
I
I
I/O
I/O
DIG
DIG
TTL
ST
I2C
DIG
Digital I/O.
Parallel Master Port address.
Interrupt-on-change pin.
SPI data input.
I2C™ data input/output.
Remappable Peripheral Pin 8 input/output.
RB6/KBI2/PGC/RP9
RB6
KBI2
PGC
RP9
16 16
I/O
I
I
I/O
DIG
TTL
ST
DIG
Digital I/O.
Interrupt-on-change pin.
ICSP™ clock input.
Remappable Peripheral Pin 9 input/output.
RB7/KBI3/PGD/RP10
RB7
KBI3
PGD
RP10
17 17
I/O
I
I/O
I/O
DIG
TTL
ST
DIG
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming
data pin.
Remappable Peripheral Pin 10 input/output.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
PIC18F46J50 FAMILY
DS39931D-page 26 2011 Microchip Technology Inc.
PORTC is a bidirectional I/O port.
RC0/T1OSO/T1CKI/RP11
RC0
T1OSO
T1CKI
RP11
34 32
I/O
O
I
I/O
ST
Analog
ST
DIG
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
Remappable Peripheral Pin 11 input/output.
RC1/T1OSI/UOE/RP12
RC1
T1OSI
UOE
RP12
35 35
I/O
I
O
I/O
ST
Analog
DIG
DIG
Digital I/O.
Timer1 oscillator input.
External USB transceiver NOE output.
Remappable Peripheral Pin 12 input/output.
RC2/AN11/CTPLS/RP13
RC2
AN11
CTPLS
RP13
36 36
I/O
I
O
I/O
ST
Analog
DIG
DIG
Digital I/O.
Analog Input 11.
CTMU pulse generator output.
Remappable Peripheral Pin 13 input/output.
RC4/D-/VM
RC4
D-
VM
42 42
I
O
I
TTL
TTL
Digital I.
USB bus minus line input/output.
External USB transceiver FM input.
RC5/D+/VP
RC5
D+
VP
43 43
I
I/O
I
TTL
DIG
TTL
Digital I.
USB bus plus line input/output.
External USB transceiver VP input.
RC6/PMA5/TX1/CK1/RP17
RC6
PMA5
TX1
CK1
RP17
44 44
I/O
O
O
I/O
I/O
ST
DIG
DIG
ST
DIG
Digital I/O.
Parallel Master Port address.
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related
RX1/DT1).
Remappable Peripheral Pin 17 input/output.
RC7/PMA4/RX1/DT1/SDO1/RP18
RC7
PMA4
RX1
DT1
SDO1
RP18
11
I/O
O
I
I/O
O
I/O
ST
DIG
ST
ST
DIG
DIG
Digital I/O.
Parallel Master Port address.
EUSART1 asynchronous receive.
EUSART1 synchronous data output/input (see
related TX1/CK1).
SPI data output.
Remappable Peripheral Pin 18 input/output.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 27
PIC18F46J50 FAMILY
PORTD is a bidirectional I/O port.
RD0/PMD0/SCL2
RD0
PMD0
SCL2
38 38
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
I2C™ data input/output.
RD1/PMD1/SDA2
RD1
PMD1
SDA2
39 39
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
I2C data input/output.
RD2/PMD2/RP19
RD2
PMD2
RP19
40 40
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
Remappable Peripheral Pin 19 input/output.
RD3/PMD3/RP20
RD3
PMD3
RP20
41 41
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
Remappable Peripheral Pin 20 input/output.
RD4/PMD4/RP21
RD4
PMD4
RP21
22
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
Remappable Peripheral Pin 21 input/output.
RD5/PMD5/RP22
RD5
PMD5
RP22
33
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
Remappable Peripheral Pin 22 input/output.
RD6/PMD6/RP23
RD6
PMD6
RP23
44
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
Remappable Peripheral Pin 23 input/output.
RD7/PMD7/RP24
RD7
PMD7
RP24
55
I/O
I/O
I/O
ST
DIG
DIG
Digital I/O.
Parallel Master Port data.
Remappable Peripheral Pin 24 input/output.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
PIC18F46J50 FAMILY
DS39931D-page 28 2011 Microchip Technology Inc.
PORTE is a bidirectional I/O port.
RE0/AN5/PMRD
RE0
AN5
PMRD
25 25
I/O
I
I/O
ST
Analog
DIG
Digital I/O.
Analog Input 5.
Parallel Master Port input/output.
RE1/AN6/PMWR
RE1
AN6
PMWR
26 26
I/O
I
I/O
ST
Analog
DIG
Digital I/O.
Analog Input 6.
Parallel Master Port write strobe.
RE2/AN7/PMCS
RE2
AN7
PMCS
27 27
I/O
I
O
ST
Analog
Digital I/O.
Analog Input 7.
Parallel Master Port chip select.
VSS1 6 6 P Ground reference for logic and I/O pins.
VSS23129
AVSS1 30 P Ground reference for analog modules.
VDD1 8 7 P Positive supply for peripheral digital logic and
I/O pins.
VDD22928P
VDDCORE/VCAP
VDDCORE
VCAP
23 23
P
P
Core logic power or external filter capacitor
connection.
Positive supply for microcontroller core logic
(regulator disabled).
External filter capacitor connection (regulator
enabled).
AVDD1 7 P Positive supply for analog modules.
AVDD2 28 Positive supply for analog modules.
VUSB 37 37 P USB voltage input pin.
TABLE 1-4: PIC18F4XJ50 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number Pin
Type Buffer
Type Description
44-
QFN 44-
TQFP
Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog = Analog input
I = Input O = Output
P = Power OD = Open-Drain (no P diode to VDD)
DIG = Digital output I2C™ = Open-Drain, I2C-specific
Note 1: RA7 and RA6 will be disabled if OSC1 and OSC2 are used for the clock function.
2011 Microchip Technology Inc. DS39931D-page 29
PIC18F46J50 FAMILY
2.0 GUIDELINES FOR GETTING
STARTED WITH PIC18FJ
MICROCONTROLLERS
2.1 Basic Connection Requirements
Getting started with the PIC18F46J50 family family of
8-bit microcontrollers requires attention to a minimal
set of device pin connections before proceeding with
development.
The following pins must always be connected:
•All V
DD and VSS pins
(see Section 2.2 “Power Supply Pins”)
•All AV
DD and AVSS pins (if present), regardless of
whether or not the analog device features are used
(see Section 2.2 “Power Supply Pins”)
•MCLR
pin
(see Section 2.3 “Master Clear (MCLR) Pin”)
•V
CAP/VDDCORE pin
(see Section 2.4 “Voltage Regulator Pins
(VCAP/VDDCORE)”)
These pins must also be connected if they are being
used in the end application:
PGC/PGD pins used for In-Circuit Serial
Programming™ (ICSP™) and debugging purposes
(see Section 2.5 “ICSP Pins”)
OSCI and OSCO pins when an external oscillator
source is used
(see Section 2.6 “External Oscillator Pins”)
Additionally, the following pins may be required:
•V
REF+/VREF- pins are used when external voltage
reference for analog modules is implemented
The minimum mandatory connections are shown in
Figure 2-1.
FIGURE 2-1: RECOMMENDED
MINIMUM CONNECTIONS
Note: The AVDD and AVSS pins must always be
connected, regardless of whether any of
the analog modules are being used.
PIC18FXXJXX
VDD
VSS
VDD
VSS
VSS
VDD
AVDD
AVSS
VDD
VSS
C1
R1
VDD
MCLR
VCAP/VDDCORE
R2 VUSB
(3)
C7
C2(2)
C3(2)
C4(2)
C5(2)
C6(2)
Key (all values are recommendations):
C1 through C6: 0.1 F, 20V ceramic
C7: 10 F, 6.3V or greater, tantalum or 10v or greater
ceramic
R1: 10 k
R2: 100 to 470
Note 1: See Section 2.4 “Voltage Regulator Pins
(VCAP/VDDCORE)” for explanation of
VCAP/VDDCORE pin connections.
2: The example shown is for a PIC18F device
with five VDD/VSS and AVDD/AVSS pairs.
Other devices may have more or less pairs;
adjust the number of decoupling capacitors
appropriately.
3: See Section 22.2.2.1 “Internal Transceiver.
(1)
PIC18F46J50 FAMILY
DS39931D-page 30 2011 Microchip Technology Inc.
2.2 Power Supply Pins
2.2.1 DECOUPLING CAPACITORS
The use of decoupling capacitors on every pair of
power supply pins, such as VDD, VSS, AVDD and
AVSS, is required.
Consider the following criteria when using decoupling
capacitors:
Value and type of capacitor: A 0.1 F (100 nF),
10-20V capacitor is recommended. The capacitor
should be a low-ESR device, with a resonance
frequency in the range of 200 MHz and higher.
Ceramic capacitors are recommended.
Placement on the printed circuit board: The
decoupling capacitors should be placed as close
to the pins as possible. It is recommended to
place the capacitors on the same side of the
board as the device. If space is constricted, the
capacitor can be placed on another layer on the
PCB using a via; however, ensure that the trace
length from the pin to the capacitor is no greater
than 0.25 inch (6 mm).
Handling high-frequency noise: If the board is
experiencing high-frequency noise (upward of
tens of MHz), add a second ceramic type capaci-
tor in parallel to the above described decoupling
capacitor. The value of the second capacitor can
be in the range of 0.01 F to 0.001 F. Place this
second capacitor next to each primary decoupling
capacitor. In high-speed circuit designs, consider
implementing a decade pair of capacitances as
close to the power and ground pins as possible
(e.g., 0.1 F in parallel with 0.001 F).
Maximizing performance: On the board layout
from the power supply circuit, run the power and
return traces to the decoupling capacitors first,
and then to the device pins. This ensures that the
decoupling capacitors are first in the power chain.
Equally important is to keep the trace length
between the capacitor and the power pins to a
minimum, thereby reducing PCB trace
inductance.
2.2.2 BULK CAPACITORS
On boards with power traces running longer than
six inches in length, it is suggested to use a larger
energy storing capacitor for integrated circuits, includ-
ing microcontrollers, to supply a local power source.
The value of this capacitor should be determined based
on the trace resistance that connects the power supply
source to the device, and the maximum current drawn
by the device in the application. In other words, select
the capacitor so that it meets the acceptable voltage
sag at the device. Typical values range from 4.7 F to
47 F.
2.3 Master Clear (MCLR) Pin
The MCLR pin provides two specific device
functions: Device Reset, and Device Programming
and Debugging. If programming and debugging are
not required in the end application, a direct
connection to VDD may be all that is required. The
addition of other components, to help increase the
application’s resistance to spurious Resets from
voltage sags, may be beneficial. A typical
configuration is shown in Figure 2-1. Other circuit
designs may be implemented, depending on the
application’s requirements.
During programming and debugging, the resistance
and capacitance that can be added to the pin must
be considered. Device programmers and debuggers
drive the MCLR pin. Consequently, specific voltage
levels (VIH and VIL) and fast signal transitions must
not be adversely affected. Therefore, specific values
of R1 and C1 will need to be adjusted based on the
application and PCB requirements. For example, it is
recommended that the capacitor, C1, be isolated
from the MCLR pin during programming and
debugging operations by using a jumper (Figure 2-2).
The jumper is replaced for normal run-time
operations.
Any components associated with the MCLR pin
should be placed within 0.25 inch (6 mm) of the pin.
FIGURE 2-2: EXAMPLE OF MCLR PIN
CONNECTIONS
Note 1: R1  10 k is recommended. A suggested
starting value is 10 k. Ensure that the
MCLR pin VIH and VIL specifications are met.
2: R2  470 will limit any current flowing into
MCLR from the external capacitor, C, in the
event of MCLR pin breakdown, due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS). Ensure that the MCLR pin
VIH and VIL specifications are met.
C1
R2
R1
VDD
MCLR
PIC18FXXJXX
JP
2011 Microchip Technology Inc. DS39931D-page 31
PIC18F46J50 FAMILY
2.4 Voltage Regulator Pins
(VCAP/VDDCORE)
On “F” devices, a low-ESR (< 5) capacitor is required
on the VCAP/VDDCORE pin to stabilize the voltage
regulator output voltage. The VCAP/VDDCORE pin must
not be connected to VDD or any other voltage source on
an “F” device. The VCAP/VDDCORE pin should only be
connected to a 10 µF capacitor to ground. The type can
be ceramic or tantalum. Suitable example capacitors
are provided in Table 2-1.
Designers may use Figure 2-3 to evaluate ESR
equivalence of candidate devices. It is recommended
that the trace length not exceed 0.25 inch (6 mm).
Refer to Section 30.0 “Electrical Characteristics” for
additional information.
On “LF” devices, the internal core voltage regulator is
disabled. On these devices, the VCAP/VDDCORE pin
must be externally connected to a suitable VDDCORE
level voltage source at the circuit board level. Refer to
Section 30.0 “Electrical Characteristics” for the
allowed VDDCORE voltage range. Good power supply
bypassing practices should be used for the supply
source providing the VCAP/VDDCORE voltage.
It is recommended to use a 0.1 µF ceramic capacitor
between VCAP/VDDCORE and ground, placed as close
to the VCAP/VDDCORE and VSS pins as possible.
FIGURE 2-3: FREQUENCY vs. ESR
PERFORMANCE FOR
SUGGESTED VCAP
.
10
1
0.1
0.01
0.001 0.01 0.1 1 10 100 1000 10,000
Frequ en cy (MH z)
ESR ()
Note: Typical data measurement at 25°C, 0V DC bias.
TABLE 2-1: SUITABLE CAPACITOR EQUIVALENTS
Make Part # Nominal
Capacitance Base Tolerance Rated Voltage Temp. Range
TDK C3216X7R1C106K 10 µF ±10% 16V -55 to +125ºC
TDK C3216X5R1C106K 10 µF ±10% 16V -55 to +85ºC
Panasonic ECJ-3YX1C106K 10 µF ±10% 16V -55 to +125ºC
Panasonic ECJ-4YB1C106K 10 µF ±10% 16V -55 to +85ºC
Murata GRM32DR71C106KA01L 10 µF ±10% 16V -55 to +125ºC
Murata GRM31CR61C106KC31L 10 µF ±10% 16V -55 to +85ºC
PIC18F46J50 FAMILY
DS39931D-page 32 2011 Microchip Technology Inc.
2.4.1 CONSIDERATIONS FOR CERAMIC
CAPACITORS
In recent years, large value, low-voltage, surface-mount
ceramic capacitors have become very cost effective in
sizes up to a few tens of microfarad. The low-ESR, small
physical size and other properties make ceramic
capacitors very attractive in many types of applications.
Ceramic capacitors are suitable for use with the
VDDCORE voltage regulator of this microcontroller.
However, some care is needed in selecting the capac-
itor to ensure that it maintains sufficient capacitance
over the intended operating range of the application.
Typical low-cost, 10 µF ceramic capacitors are available
in X5R, X7R and Y5V dielectric ratings (other types are
also available, but are less common). The initial toler-
ance specifications for these types of capacitors are
often specified as ±10% to ±20% (X5R and X7R), or
-20%/+80% (Y5V). However, the effective capacitance
that these capacitors provide in an application circuit will
also vary based on additional factors, such as the
applied DC bias voltage and the temperature. The total
in-circuit tolerance is, therefore, much wider than the
initial tolerance specification.
The X5R and X7R capacitors typically exhibit satisfac-
tory temperature stability (ex: ±15% over a wide
temperature range, but consult the manufacturer’s data
sheets for exact specifications). However, Y5V capaci-
tors typically have extreme temperature tolerance
specifications of +22%/-82%. Due to the extreme
temperature tolerance, a 10 µF nominal rated Y5V type
capacitor may not deliver enough total capacitance to
meet minimum VDDCORE voltage regulator stability and
transient response requirements. Therefore, Y5V
capacitors are not recommended for use with the
VDDCORE regulator if the application must operate over
a wide temperature range.
In addition to temperature tolerance, the effective
capacitance of large value ceramic capacitors can vary
substantially, based on the amount of DC voltage
applied to the capacitor. This effect can be very signifi-
cant, but is often overlooked or is not always
documented.
A typical DC bias voltage vs. capacitance graph for
X7R type and Y5V type capacitors is shown in
Figure 2-4.
FIGURE 2-4: DC BIAS VOLTAGE vs.
CAPACITANCE
CHARACTERISTICS
When selecting a ceramic capacitor to be used with the
VDDCORE voltage regulator, it is suggested to select a
high-voltage rating, so that the operating voltage is a
small percentage of the maximum rated capacitor volt-
age. For example, choose a ceramic capacitor rated at
16V for the 2.5V VDDCORE voltage. Suggested
capacitors are shown in Table 2-1.
2.5 ICSP Pins
The PGC and PGD pins are used for In-Circuit Serial
Programming™ (ICSP™) and debugging purposes. It
is recommended to keep the trace length between the
ICSP connector and the ICSP pins on the device as
short as possible. If the ICSP connector is expected to
experience an ESD event, a series resistor is recom-
mended, with the value in the range of a few tens of
ohms, not to exceed 100.
Pull-up resistors, series diodes, and capacitors on the
PGC and PGD pins are not recommended as they will
interfere with the programmer/debugger communica-
tions to the device. If such discrete components are an
application requirement, they should be removed from
the circuit during programming and debugging. Alter-
natively, refer to the AC/DC characteristics and timing
requirements information in the respective device
Flash programming specification for information on
capacitive loading limits, and pin input voltage high
(VIH) and input low (VIL) requirements.
For device emulation, ensure that the “Communication
Channel Select” (i.e., PGCx/PGDx pins), programmed
into the device, matches the physical connections for
the ICSP to the Microchip debugger/emulator tool.
For more information on available Microchip
development tools connection requirements, refer to
Section 29.0 “Development Support”.
-80
-70
-60
-50
-40
-30
-20
-10
0
10
5 1011121314151617
DC Bias Voltage (VDC)
Capacitance Change (%)
01234 67 89
16V Capacitor
10V Capacitor
6.3V Capacitor
2011 Microchip Technology Inc. DS39931D-page 33
PIC18F46J50 FAMILY
2.6 External Oscillator Pins
Many microcontrollers have options for at least two
oscillators: a high-frequency primary oscillator and a
low-frequency secondary oscillator (refer to
Section 3.0 “Oscillator Configurations” for details).
The oscillator circuit should be placed on the same
side of the board as the device. Place the oscillator
circuit close to the respective oscillator pins with no
more than 0.5 inch (12 mm) between the circuit
components and the pins. The load capacitors should
be placed next to the oscillator itself, on the same side
of the board.
Use a grounded copper pour around the oscillator cir-
cuit to isolate it from surrounding circuits. The
grounded copper pour should be routed directly to the
MCU ground. Do not run any signal traces or power
traces inside the ground pour. Also, if using a two-sided
board, avoid any traces on the other side of the board
where the crystal is placed.
Layout suggestions are shown in Figure 2-5. In-line
packages may be handled with a single-sided layout
that completely encompasses the oscillator pins. With
fine-pitch packages, it is not always possible to com-
pletely surround the pins and components. A suitable
solution is to tie the broken guard sections to a mirrored
ground layer. In all cases, the guard trace(s) must be
returned to ground.
In planning the application’s routing and I/O assign-
ments, ensure that adjacent port pins, and other
signals in close proximity to the oscillator, are benign
(i.e., free of high frequencies, short rise and fall times,
and other similar noise).
For additional information and design guidance on
oscillator circuits, please refer to these Microchip
Application Notes, available at the corporate web site
(www.microchip.com):
AN826, Crystal Oscillator Ba sics and Crystal
Selection for rfPIC™ and PICmicro® Devices”
AN849, “Basic PICmicro® Oscillator Design”
AN943, “Practical PICmicro® Oscillator Analysis
and Design”
AN949, “Ma king Your Oscillator Work
2.7 Unused I/Os
Unused I/O pins should be configured as outputs and
driven to a logic low state. Alternatively, connect a 1 k
to 10 k resistor to VSS on unused pins and drive the
output to logic low.
FIGURE 2-5: SUGGESTED PLACEMENT
OF THE OSCILLATOR
CIRCUIT
GND
`
`
`
OSC1
OSC2
T1OSO
T1OS I
Copper Pour Primary Oscillator
Crystal
Timer1 Oscillator
Crystal
DEVICE PINS
Primary
Oscillator
C1
C2
T1 Oscillator: C1 T1 Oscillator: C2
(tied to ground)
Single-Sided and In-Line Layouts:
Fine-Pitch (Dual-Sided) Layouts:
GND
OSCO
OSCI
Bottom Layer
Copper Pour
Oscillator
Crystal
Top Layer Copper Pour
C2
C1
DEVICE PINS
(tied to ground)
(tied to ground)
PIC18F46J50 FAMILY
DS39931D-page 34 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 35
PIC18F46J50 FAMILY
3.0 OSCILLATOR
CONFIGURATIONS
3.1 Overview
Devices in the PIC18F46J50 family incorporate a
different oscillator and microcontroller clock system
than general purpose PIC18F devices. Besides the
USB module, with its unique requirements for a stable
clock source, make it necessary to provide a separate
clock source that is compliant with both USB low-speed
and full-speed specifications.
The PIC18F46J50 family has additional prescalers and
postscalers, which have been added to accommodate
a wide range of oscillator frequencies. Figure 3-1
provides an overview of the oscillator structure.
Other oscillator features used in PIC18 enhanced
microcontrollers, such as the internal oscillator block
and clock switching, remain the same. They are
discussed later in this chapter.
3.1.1 OSCILLATOR CONTROL
The operation of the oscillator in PIC18F46J50 family
devices is controlled through three Configuration regis-
ters and two control registers. Configuration registers,
CONFIG1L, CONFIG1H and CONFIG2L, select the
oscillator mode, PLL prescaler and CPU divider
options. As Configuration bits, these are set when the
device is programmed and left in that configuration until
the device is reprogrammed.
The OSCCON register (Register 3-2) selects the Active
Clock mode; it is primarily used in controlling clock
switching in power-managed modes. Its use is
discussed in Section 3.5.1 “Oscillator Control
Register”.
The OSCTUNE register (Register 3-1) is used to trim the
INTOSC frequency source, and select the
low-frequency clock source that drives several special
features. The OSCTUNE register is also used to activate
or disable the Phase Locked Loop (PLL). Its use is
described in Section 3.2.5.1 “OSCTUNE Register”.
3.2 Oscillator Types
PIC18F46J50 family devices can be operated in eight
distinct oscillator modes. Users can program the
FOSC<2:0> Configuration bits to select one of the
modes listed in Ta b l e 3 - 1 . For oscillator modes which
produce a clock output (CLKO) on pin RA6, the output
frequency will be one fourth of the peripheral clock
frequency. The clock output stops when in Sleep mode,
but will continue during Idle mode (see Figure 3-1).
TABLE 3-1: OSCILLATOR MODES
Mode Descript ion
ECPLL External Clock Input mode, the PLL can
be enabled or disabled in software,
CLKO on RA6, apply external clock
signal to RA7.
EC External Clock Input mode, the PLL is
always disabled, CLKO on RA6, apply
external clock signal to RA7.
HSPLL High-Speed Crystal/Resonator mode,
PLL can be enabled or disabled in
software, crystal/resonator connected
between RA6 and RA7.
HS High-Speed Crystal/Resonator mode,
PLL always disabled, crystal/resonator
connected between RA6 and RA7.
INTOSCPLLO Internal Oscillator mode, PLL can be
enabled or disabled in software, CLKO
on RA6, port function on RA7, the
internal oscillator block is used to derive
both the primary clock source and the
postscaled internal clock.
INTOSCPLL Internal Oscillator mode, PLL can be
enabled or disabled in software, port
function on RA6 and RA7, the internal
oscillator block is used to derive both the
primary clock source and the postscaled
internal clock.
INTOSCO Internal Oscillator mode, PLL is always
disabled, CLKO on RA6, port function on
RA7, the output of the INTOSC
postscaler serves as both the postscaled
internal clock and the primary clock
source.
INTOSC Internal Oscillator mode, PLL is always
disabled, port function on RA6 and RA7,
the output of the INTOSC postscaler
serves as both the postscaled internal
clock and the primary clock source.
PIC18F46J50 FAMILY
DS39931D-page 36 2011 Microchip Technology Inc.
3.2.1 OSCILLATOR MODES AND
USB OPERATION
Because of the unique requirements of the USB module,
a different approach to clock operation is necessary. In
order to use the USB module, a fixed 6 MHz or 48 MHz
clock must be internally provided to the USB module for
operation in either Low-Speed or Full-Speed mode,
respectively. The microcontroller core need not be
clocked at the same frequency as the USB module.
A network of MUXes, clock dividers and a fixed 96 MHz
output PLL have been provided, which can be used to
derive various microcontroller core and USB module
frequencies. Figure 3-1 helps in understanding the
oscillator structure of the PIC18F46J50 family of
devices.
FIGURE 3- 1 : PIC18F 46 J50 FAM IL Y CLOCK D IA GRA M
OSC1
OSC2
Primar y Osc illa to r
CPU
Peripherals
IDLE
INTOSC Postscaler
8 MHz
4 MHz
2 MHz
1 MHz
500 kHz
125 kHz
250 kHz
111
110
101
100
011
010
001
000
31 kHz
INTRC
31 kHz
Internal
Oscillator
Block
8 MHz
8 MHz
0
1
OSCTUNE<7>
PLLDIV<2:0>
CPU Divider
1
2
3
6
USB Modul e
4 MHz
WDT, PWRT, FSCM
and Two-Speed Start-up
OSCCON<6:4>
PLLEN
1
0
FOSC2
1
0
PLL Prescaler
96 MHz
PLL(1) 2
1
0
FSEN
8 10
11
4
CPDIV<1:0>
00
01
10
11
CPDIV<1:0>
(Note 2)
00
FOSC<2:1>
Other
00
01
OSCCON<1:0>
11
4
RA6
CLKO
Enabled Modes
Timer1 Clock(3)
Postscaled
Internal Clock
T1OSI
T1OSO
Secondary Os cillato r
T1OSCEN
Clock
Needs 48 MHz for FS
Needs 6 MHz for LS
Note 1: The PLL requires a 4 MHz input and it produces a 96 MHz output. The PLL will not be available until the PLLEN bit in
the OSCTUNE register is set. Once the PLLEN bit is set, the PLL requires up to trc to lock. During this time, the
device continues to be clocked at the PLL bypassed frequency.
2: In order to use the USB module in Full-Speed mode, this node must be run at 48 MHz. For Low-Speed mode, this node
may be run at either 48 MHz or 24 MHz, but the CPDIV bits must be set such that the USB module is clocked at 6 MHz.
3: Selecting the Timer1 clock or postscaled internal clock will turn off the primary oscillator (unless required by the
reference clock described in Section 3.6 “Reference Clock Output”) and the PLL.
4: The USB module cannot be used to communicate unless the primary clock source is selected.
12
10
6
5
4
3
2
1
000
001
010
011
100
101
110
111
48 MHz
Primary Clock
Source(4)
2011 Microchip Technology Inc. DS39931D-page 37
PIC18F46J50 FAMILY
3.2.2 CRYSTAL OSCILLATOR/CERAMIC
RESONATORS
In HS and HSPLL Oscillator modes, a crystal or
ceramic resonator is connected to the OSC1 and
OSC2 pins to establish oscillation. Figure 3-2 displays
the pin connections.
The oscillator design requires the use of a parallel
resonant crystal.
FIGU RE 3-2: CRYSTAL/CERAMI C
RES ONAT OR OP ERA TIO N
(HS OR HSPLL
CONFIGURATION)
TABLE 3-2: CAPACITOR SELECTION FOR
CERAMIC RESO NATORS
T ABLE 3-3: CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
An internal postscaler allows users to select a clock
frequency other than that of the crystal or resonator.
Frequency division is determined by the CPDIV
Configuration bits. Users may select a clock frequency
of the oscillator frequency, or 1/2, 1/3 or 1/6 of the
frequency.
Note: Use of a series resonant crystal may give a
frequency out of the crystal manufacturer’s
specifications.
Typical Capacitor Values Used:
Mode Freq OSC1 OSC2
HS 8.0 MHz
16.0 MHz
27 pF
22 pF
27 pF
22 pF
Capacitor values are for design guidance only.
These capacitors were tested with the resonators
listed below for basic start-up and operation. These
values are not optimiz ed.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application.
See the notes following Tabl e 3 - 3 for additional
information.
Resonators Used:
4.0 MHz
8.0 MHz
16.0 MHz
Note 1: See Table 3-2 and Table 3-3 for initial values
of C1 and C2.
2: A series resistor (RS) may be required to
avoid overdriving crystals with low drive level
specification.
C1
(1)
C2
(1)
XTAL
OSC2
OSC1
R
F
Sleep
To
Logic
R
S
(2)
Internal
PIC18F46J50
Osc Type Crystal
Freq
Typical Cap acitor V alu es
Tested:
C1 C2
HS 4 MHz 27 pF 27 pF
8 MHz 22 pF 22 pF
16 MHz 18 pF 18 pF
Capacitor values are for design guidance only.
These capacitors were tested with the crystals listed
below for basic start-up and operation. These values
are not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application.
See the notes following this table for additional
information.
Crystals Used:
4 MHz
8 MHz
16 MHz
Note 1: Higher capacitance not only increases
the stability of the oscillator, but also
increases the start-up time.
2: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external
components.
3: Rs may be required to avoid overdriving
crystals with a low drive level specification.
4: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
PIC18F46J50 FAMILY
DS39931D-page 38 2011 Microchip Technology Inc.
3.2.3 EXTERNAL CLOCK INPUT
The EC and ECPLL Oscillator modes require an
external clock source to be connected to the OSC1 pin.
There is no oscillator start-up time required after a
Power-on Reset (POR) or after an exit from Sleep mode.
In the EC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. In the ECPLL
Oscillator mode, the PLL output divided by 4 is available
on the OSC2 pin This signal may be used for test pur-
poses or to synchronize other logic. Figure 3-3 displays
the pin connections for the EC Oscillator mode.
FIGURE 3-3: EXTERNAL CLOCK INPUT
OPER ATI ON (E C AND
ECPL L CON FIGUR ATION)
3.2.4 PLL FREQUENCY MULTIPLIER
PIC18F46J50 family devices include a PLL circuit. This
is provided specifically for USB applications with lower
speed oscillators and can also be used as a
microcontroller clock source.
The PLL can be enabled in HSPLL, ECPLL,
INTOSCPLL and INTOSCPLLO Oscillator modes by
setting the PLLEN bit (OSCTUNE<6>). It is designed
to produce a fixed 96 MHz reference clock from a
fixed 4 MHz input. The output can then be divided and
used for both the USB and the microcontroller core
clock. Because the PLL has a fixed frequency input
and output, there are eight prescaling options to
match the oscillator input frequency to the PLL. This
prescaler allows the PLL to be used with crystals, res-
onators and external clocks, which are integer multiple
frequencies of 4 MHz. For example, a 12 MHz crystal
could be used in a Prescaler Divide-by-Three mode to
drive the PLL.
There is also a CPU divider, which can be used to derive
the microcontroller clock from the PLL. This allows the
USB peripheral and microcontroller to use the same
oscillator input and still operate at different clock speeds.
The CPU divider can reduce the incoming frequency by
a factor of 1, 2, 3 or 6.
3.2.5 INTERNAL OSCILLATOR BLOCK
The PIC18F46J50 family devices include an internal
oscillator block which generates two different clock
signals; either can be used as the microcontrollers
clock source. The internal oscillator may eliminate the
need for external oscillator circuits on the OSC1 and/or
OSC2 pins.
The main output (INTOSC) is an 8 MHz clock source
which can be used to directly drive the device clock. It
also drives the INTOSC postscaler which can provide a
range of clock frequencies from 31 kHz to 8 MHz.
Additionally, the INTOSC may be used in conjunction
with the PLL to generate clock frequencies up to
48 MHz.
The other clock source is the internal RC oscillator
(INTRC) which provides a nominal 31 kHz output.
INTRC is enabled if it is selected as the device clock
source. It is also enabled automatically when any of the
following are enabled:
Power-up Timer
Fail-Safe Clock Monitor
Watchdog Timer
Two-Speed Start-up
These features are discussed in larger detail in
Section 27.0 “Special Features of the CPU”.
The clock source frequency (INTOSC direct, INTRC
direct or INTOSC postscaler) is selected by configuring
the IRCF bits of the OSCCON register (Page 43).
OSC1/CLKI
OSC2/CLKO
FOSC/4
Clock from
Ext. System PIC18F46J50
2011 Microchip Technology Inc. DS39931D-page 39
PIC18F46J50 FAMILY
3.2.5.1 OSCTUNE Register
The internal oscillator’s output has been calibrated at
the factory but can be adjusted in the user’s applica-
tion. This is done by writing to the OSCTUNE register
(Register 3-1). The tuning sensitivity is constant
throughout the tuning range.
When the OSCTUNE register is modified, the INTOSC
frequency will begin shifting to the new frequency.
Code execution continues during this shift. There is no
indication that the shift has occurred.
The OSCTUNE register also contains the INTSRC bit.
The INTSRC bit allows users to select which internal
oscillator provides the clock source when the 31 kHz
frequency option is selected. This is covered in larger
detail in Section 3.5.1 “Oscillator Control Register”.
The PLLEN bit, contained in the OSCTUNE register,
can be used to enable or disable the internal 96 MHz
PLL when running in one of the PLL type oscillator
modes (e.g., INTOSCPLL). Oscillator modes that do
not contain “PLL” in their name cannot be used with
the PLL. In these modes, the PLL is always disabled
regardless of the setting of the PLLEN bit.
When configured for one of the PLL enabled modes, set-
ting the PLLEN bit does not immediately switch the
device clock to the PLL output. The PLL requires up to
electrical parameter, trc, to start-up and lock, during
which time, the device continues to be clocked. Once the
PLL output is ready, the microcontroller core will
automatically switch to the PLL derived frequency.
3.2.5.2 Internal Oscillator Output Frequency
and Drift
The internal oscillator block is calibrated at the factory
to produce an INTOSC output frequency of 8.0 MHz.
However, this frequency may drift as VDD or tempera-
ture changes, which can affect the controller operation
in a variety of ways.
The low-frequency INTRC oscillator operates indepen-
dently of the INTOSC source. Any changes in INTOSC
across voltage and temperature are not necessarily
reflected by changes in INTRC and vice versa.
3.2.5.3 Compensating for INTOSC Drift
It is possible to adjust the INTOSC frequency by
modifying the value in the OSCTUNE register. This has
no effect on the INTRC clock source frequency.
Tuning the INTOSC source requires knowing when to
make the adjustment, in which direction it should be
made and in some cases, how large a change is
needed. When using the EUSART, for example, an
adjustment may be required when it begins to generate
framing errors or receives data with errors while in
Asynchronous mode. Framing errors indicate that the
device clock frequency is too high; to adjust for this,
decrement the value in OSCTUNE to reduce the clock
frequency. On the other hand, errors in data may sug-
gest that the clock speed is too low; to compensate,
increment OSCTUNE to increase the clock frequency.
It is also possible to verify device clock speed against
a reference clock. Two timers may be used: one timer
is clocked by the peripheral clock, while the other is
clocked by a fixed reference source, such as the
Timer1 oscillator. Both timers are cleared, but the timer
clocked by the reference generates interrupts. When
an interrupt occurs, the internally clocked timer is read
and both timers are cleared. If the internally clocked
timer value is greater than expected, then the internal
oscillator block is running too fast. To adjust for this,
decrement the OSCTUNE register.
Finally, an ECCP module can use free-running Timer1
(or Timer3), clocked by the internal oscillator block and
an external event with a known period (i.e., AC power
frequency). The time of the first event is captured in the
CCPRxH:CCPRxL registers and is recorded for use
later. When the second event causes a capture, the
time of the first event is subtracted from the time of the
second event. Since the period of the external event is
known, the time difference between events can be
calculated.
If the measured time is greater than the calculated time,
the internal oscillator block is running too fast; to
compensate, decrement the OSCTUNE register. If the
measured time is less than the calculated time, the inter-
nal oscillator block is running too slow; to compensate,
increment the OSCTUNE register.
PIC18F46J50 FAMILY
DS39931D-page 40 2011 Microchip Technology Inc.
3.3 Oscillator Settings for USB
When the PIC18F46J50 family devices are used for
USB connectivity, a 6 MHz or 48 MHz clock must be
provided to the USB module for operation in either
Low-Speed or Full-Speed modes, respectively. This
may require some forethought in selecting an oscillator
frequency and programming the device.
The full range of possible oscillator configurations
compatible with USB operation is shown in Table 3-5.
3.3.1 LOW-SPEED OPERATION
The USB clock for Low-Speed mode is derived from the
primary oscillator or from the 96 MHz PLL. In order to
operate the USB module in Low-Speed mode, a 6 MHz
clock must be provided to the USB module. Due to the
way the clock dividers have been implemented in the
PIC18F46J50 family, the microcontroller core must run
at 24 MHz in order for the USB module to get the 6 MHz
clock needed for low-speed USB operation. Several
clocking schemes could be used to meet these two
required conditions. See Ta b l e 3 - 4 and Tab l e 3-5 for
possible combinations which can be used for
low-speed USB operation.
TABLE 3-4: CLOCK FOR LOW-SPEED USB
REGISTER 3-1: OSCTUNE: OSCILLATOR TUNI NG REGISTER (ACCESS F9Bh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
INTSRC PLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 INTSRC: Internal Oscillator Low-Frequency Source Select bit
1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)
0 = 31 kHz device clock derived directly from INTRC internal oscillator
bit 6 PLLEN: Frequency Multiplier Enable bit
1 = 96 MHz PLL is enabled
0 = 96 MHz PLL is disabled
bit 5-0 TUN<5:0>: Frequency Tuning bits
011111 = Maximum frequency
011110
000001
000000 = Center frequency; oscillator module is running at the calibrated frequency
111111
100000 = Minimum frequency
Clock
Input CPU
Clock CPDIV<1:0> USB Clock
48 24 10 48/8 = 6 MHz
24 24 11 24/4 = 6 MHz
2011 Microchip Technology Inc. DS39931D-page 41
PIC18F46J50 FAMILY
TABLE 3-5: OSCILLATOR CONFIGURATION OPTIONS FOR USB OPERATION
Input Oscillator
Frequency PLL Division
(PLLDIV<2:0>) Clock Mode
(FOSC<2:0>) MCU Clock Division
(CPDIV<1:0>) Microcontroller
Clock Frequency
48 MHz N/A EC
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
48 MHz 12 (000)ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
40 MHz 10 (001)ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
24 MHz 6 (010)ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
24 MHz N/A EC
None (11)24 MHz
2 (10)12MHz
3 (01)8MHz
6 (00)4MHz
20 MHz 5 (011)ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
16 MHz 4 (100) HSPLL, ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
12 MHz 3 (101) HSPLL, ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
8MHz 2 (110)
HSPLL, ECPLL,
INTOSCPLL/
INTOSCPLLO
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
4MHz 1 (111) HSPLL, ECPLL
None (11)48MHz
2 (10)24 MHz
3 (01)16MHz
6 (00)8MHz
Legend: All clock frequencies, except 24 MHz, are exclusively associated with full-speed USB operation (USB clock of 48 MHz).
Bold text highlights the clock selections that are compatible with low-speed USB operation (system clock of 24 MHz,
USB clock of 6 MHz).
PIC18F46J50 FAMILY
DS39931D-page 42 2011 Microchip Technology Inc.
3.4 USB Fr om INTO S C
The 8 MHz INTOSC included in all PIC18F46J50 family
devices is extremely accurate. When the 8 MHz
INTOSC is used with the 96 MHz PLL, it may be used
to derive the USB module clock. The high accuracy of
the INTOSC will allow the application to meet
low-speed USB signal rate specifications.
3.5 Clock Sources and Oscillator
Switching
Like previous PIC18 enhanced devices, the
PIC18F46J50 family includes a feature that allows the
device clock source to be switched from the main
oscillator to an alternate, low-frequency clock source.
PIC18F46J50 family devices offer two alternate clock
sources. When an alternate clock source is enabled,
the various power-managed operating modes are
available.
Essentially, there are three clock sources for these
devices:
Primary Oscillators
Secondary Oscillators
Internal Oscillator Block
The Primary Oscillators include the External Crystal
and Resonator modes, the External Clock modes and
the internal oscillator block. The particular mode is
defined by the FOSC<2:0> Configuration bits. The
details of these modes are covered earlier in this
chapter.
The Secondary Oscillators are external sources that
are not connected to the OSC1 or OSC2 pins. These
sources may continue to operate even after the
controller is placed in a power-managed mode.
PIC18F46J50 family devices offer the Timer1 oscillator
as a secondary oscillator. This oscillator, in all
power-managed modes, is often the time base for
functions, such as a Real-Time Clock (RTC). Most often,
a 32.768 kHz watch crystal is connected between the
RC0/T1OSO/T1CKI/RP11 and RC1/T1OSI/UOE/RP12
pins. Like the HS Oscillator mode circuits, loading
capacitors are also connected from each pin to ground.
The Timer1 oscillator is discussed in larger detail in
Section 13.5 “Timer1 Oscillator”.
In addition to being a primary clock source, the
postscaled internal clock is available as a
power-managed mode clock source. The INTRC
source is also used as the clock source for several
special features, such as the WDT and Fail-Safe Clock
Monitor (FSCM).
3.5.1 OSCILLATOR CONTROL REGISTER
The OSCCON register (Register 3-2) controls several
aspects of the device clock’s operation, both in
full-power operation and in power-managed modes.
The System Clock Select bits, SCS<1:0>, select the
clock source. The available clock sources are the
primary clock (defined by the FOSC<2:0> Configura-
tion bits), the secondary clock (Timer1 oscillator) and
the postscaled internal clock.The clock source changes
immediately, after one or more of the bits is written to,
following a brief clock transition interval. The SCS bits
are cleared on all forms of Reset.
The Internal Oscillator Frequency Select bits,
IRCF<2:0>, select the frequency output provided on
the postscaled internal clock line. The choices are the
INTRC source, the INTOSC source (8 MHz) or one of
the frequencies derived from the INTOSC postscaler
(31 kHz to 4 MHz). If the postscaled internal clock is
supplying the device clock, changing the states of
these bits will have an immediate change on the inter-
nal oscillator’s output. On device Resets, the default
output frequency of the INTOSC postscaler is set at
4MHz.
When an output frequency of 31 kHz is selected
(IRCF<2:0> = 000), users may choose the internal
oscillator, which acts as the source. This is done with
the INTSRC bit in the OSCTUNE register
(OSCTUNE<7>). Setting this bit selects INTOSC as a
31.25 kHz clock source by enabling the divide-by-256
output of the INTOSC postscaler. Clearing INTSRC
selects INTRC (nominally 31 kHz) as the clock source.
This option allows users to select the tunable and more
precise INTOSC as a clock source, while maintaining
power savings with a very low clock speed. Regardless
of the setting of INTSRC, INTRC always remains the
clock source for features such as the WDT and the
FSCM.
The OSTS and T1RUN bits indicate which clock source
is currently providing the device clock. The OSTS bit
indicates that the Oscillator Start-up Timer (OST) has
timed out and the primary clock is providing the device
clock in primary clock modes. The T1RUN bit
(T1CON<6>) indicates when the Timer1 oscillator is
providing the device clock in secondary clock modes.
In power-managed modes, only one of these bits will
be set at any time. If none of these bits are set, the
INTRC is providing the clock or the internal oscillator
block has just started and is not yet stable.
The IDLEN bit determines if the device goes into Sleep
mode, or one of the Idle modes, when the SLEEP
instruction is executed.
2011 Microchip Technology Inc. DS39931D-page 43
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The use of the flag and control bits in the OSCCON
register is discussed in more detail in Section 4.0
“Low-Power Modes”.
3.5.2 OSCILLATOR TRANSITIONS
PIC18F46J50 family devices contain circuitry to
prevent clock “glitches” when switching between clock
sources. A short pause in the device clock occurs dur-
ing the clock switch. The length of this pause is the sum
of two cycles of the old clock source and three to four
cycles of the new clock source. This formula assumes
that the new clock source is stable.
Clock transitions are discussed in more detail in
Section 4.1.2 “Entering Power-Managed Modes”.
Note 1: The Timer1 crystal driver is enabled by
setting the T1OSCEN bit in the Timer1
Control register (T1CON<3>). If the
Timer1 oscillator is not enabled, then any
attempt to select the Timer1 clock source
will be ignored.
2: If Timer1 is driving a crystal, it is recom-
mended that the Timer1 oscillator be
operating and stable prior to switching to
it as the clock source; otherwise, a very
long delay may occur while the Timer1
oscillator starts.
REGISTER 3-2: OSCCON: OSCILLATOR CONTROL REGISTER (ACCESS FD3h)
R/W-0 R/W-1 R/W-1 R/W-0 R-1(1) U-1 R/W-0 R/W-0
IDLEN IRCF2 IRCF1 IRCF0 OSTS —SCS1SCS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IDLEN: Idle Enable bit
1 = Device enters Idle mode on SLEEP instruction
0 = Device enters Sleep mode on SLEEP instruction
bit 6-4 IRCF<2:0>: Internal Oscillator Frequency Select bits
111 = 8 MHz (INTOSC drives clock directly)
110 = 4 MHz(2)
101 = 2 MHz
100 = 1 MHz
011 = 500 kHz
010 = 250 kHz
001 = 125 kHz
000 = 31 kHz (from either INTOSC/256 or INTRC directly)(3)
bit 3 OSTS: Oscillator Start-up Time-out Status bit(1)
1 = Oscillator Start-up Timer time-out has expired; primary oscillator is running
0 = Oscillator Start-up Timer time-out is running; primary oscillator is not ready
bit 2 Unimplemented: Read as ‘1
bit 1-0 SCS<1:0>: System Clock Select bits
11 = Postscaled internal clock (INTRC/INTOSC derived)
10 = Reserved
01 = Timer1 oscillator(4)
00 = Primary clock source (INTOSC postscaler output when FOSC<2:0> = 001 or 000)
00 = Primary clock source (CPU divider output for other values of FOSC<2:0>)
Note 1: Reset value is0’ when Two-Speed Start-up is enabled and ‘1’ if disabled.
2: Default output frequency of INTOSC on Reset (4 MHz).
3: Source selected by the INTSRC bit (OSCTUNE<7>).
4: Application firmware should first enable the Timer1 oscillator crystal driver by setting the T1OSCEN bit.
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DS39931D-page 44 2011 Microchip Technology Inc.
3.6 Reference Clock Output
In addition to the peripheral clock/4 output in certain
oscillator modes, the device clock in the PIC18F46J50
family can also be configured to provide a reference
clock output signal to a port pin. This feature is avail-
able in all oscillator configurations and allows the user
to select a greater range of clock submultiples to drive
external devices in the application.
This reference clock output is controlled by the
REFOCON register (Register 3-3). Setting the ROON
bit (REFOCON<7>) makes the clock signal available
on the REFO (RB2) pin. The RODIV<3:0> bits enable
the selection of 16 different clock divider options.
The ROSSLP and ROSEL bits (REFOCON<5:4>)
control the availability of the reference output during
Sleep mode. The ROSEL bit determines if the oscillator
is on OSC1 and OSC2, or the current system clock
source is used for the reference clock output. The
ROSSLP bit determines if the reference source is
available on RB2 when the device is in Sleep mode.
To use the reference clock output in Sleep mode, both
the ROSSLP and ROSEL bits must be set. The device
clock must also be configured for an EC or HS mode;
otherwise, the oscillator on OSC1 and OSC2 will be
powered down when the device enters Sleep mode.
Clearing the ROSEL bit allows the reference output
frequency to change as the system clock changes
during any clock switches.
REGISTER 3-3: REFOCON: REFERENCE OSCILLATOR CONTROL REGISTER (BANKED F3Dh)
R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ROON ROSSLP ROSEL RODIV3 RODIV2 RODIV1 RODIV0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ROON: Reference Oscillator Output Enable bit
1 = Reference oscillator is enabled on REFO pin
0 = Reference oscillator is disabled
bit 6 Unimplemented: Read as ‘0
bit 5 ROSSLP: Reference Oscillator Output Stop in Sleep bit
1 = Reference oscillator continues to run in Sleep
0 = Reference oscillator is disabled in Sleep
bit 4 ROSEL: Reference Oscillator Source Select bit
1 = Primary oscillator crystal/resonator is used as the base clock(1)
0 = System clock (FOSC) is used as the base clock; base clock reflects any clock switching of the device
bit 3-0 RODIV<3:0>: Reference Oscillator Divisor Select bits
1111 = Base clock value divided by 32,768
1110 = Base clock value divided by 16,384
1101 = Base clock value divided by 8,192
1100 = Base clock value divided by 4,096
1011 = Base clock value divided by 2,048
1010 = Base clock value divided by 1,024
1001 = Base clock value divided by 512
1000 = Base clock value divided by 256
0111 = Base clock value divided by 128
0110 = Base clock value divided by 64
0101 = Base clock value divided by 32
0100 = Base clock value divided by 16
0011 = Base clock value divided by 8
0010 = Base clock value divided by 4
0001 = Base clock value divided by 2
0000 = Base clock value
Note 1: The crystal oscillator must be enabled using the FOSC<2:0> bits. The crystal maintains the operation in
Sleep mode.
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3.7 Effects of Power-Managed Modes
on Various Clock Sources
When the PRI_IDLE mode is selected, the designated
primary oscillator continues to run without interruption.
For all other power-managed modes, the oscillator
using the OSC1 pin is disabled. Unless the USB
module is enabled, the OSC1 pin (and OSC2 pin if
used by the oscillator) will stop oscillating.
In secondary clock modes (SEC_RUN and
SEC_IDLE), the Timer1 oscillator is operating and
providing the device clock. The Timer1 oscillator may
also run in all power-managed modes if required to
clock Timer1 or Timer3.
In internal oscillator modes (RC_RUN and RC_IDLE),
the internal oscillator block provides the device clock
source. The 31 kHz INTRC output can be used directly
to provide the clock and may be enabled to support
various special features regardless of the
power-managed mode (see Sect io n 27. 2 “Watch dog
Timer (WDT), Section 27.4 “Two-Speed Start-up”
and Section 27.5 “Fail-Safe Clo ck Moni tor” for more
information on WDT, FSCM and Two-Speed Start-up).
The INTOSC output at 8 MHz may be used directly to
clock the device or may be divided down by the post-
scaler. The INTOSC output is disabled if the clock is
provided directly from the INTRC output.
If Sleep mode is selected, all clock sources which are
no longer required are stopped. Since all the transistor
switching currents have been stopped, Sleep mode
achieves the lowest current consumption of the device
(only leakage currents) outside of Deep Sleep.
Sleep mode should not be invoked while the USB
module is enabled and operating in Full-Power mode.
Before Sleep mode is selected, the USB module should
be put in the suspend state. This is accomplished by
setting the SUSPND bit in the UCON register.
Enabling any on-chip feature that will operate during
Sleep mode increases the current consumed during
Sleep mode. The INTRC is required to support WDT
operation. The Timer1 oscillator may be operating to
support a RTC. Other features may be operating that
do not require a device clock source (i.e., MSSP slave,
PMP, INTx pins, etc.). Peripherals that may add
significant current consumption are listed in
Section 30.2 “DC Characteristics: Power-Down and
Supply Current PIC18F46J50 Family (Industrial)”.
3.8 Power-up Delays
Power-up delays are controlled by two timers so that no
external Reset circuitry is required for most applica-
tions. The delays ensure that the device is kept in
Reset until the device power supply is stable under
normal circumstances and the primary clock is operat-
ing and stable. For additional information on power-up
delays, see Section 5.6 “Power-up Timer (PWRT)”.
The first timer is the Power-up Timer (PWRT), which
provides a fixed delay on power-up (Parameter 33,
Table 30-14).
The second timer is the Oscillator Start-up Timer
(OST), intended to keep the chip in Reset until the
crystal oscillator is stable (HS mode). The OST does
this by counting 1024 oscillator cycles before allowing
the oscillator to clock the device.
There is a delay of interval, T
CSD (Parameter 38,
Table 30-14), following POR, while the controller
becomes ready to execute instructions. This delay runs
concurrently with any other delays. This may be the only
delay that occurs when any of the internal oscillator or
EC modes are used as the primary clock source.
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DS39931D-page 46 2011 Microchip Technology Inc.
NOTES:
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4.0 LOW-POWER MODES
The PIC18F46J50 family devices can manage power
consumption through clocking to the CPU and the
peripherals. In general, reducing the clock frequency
and number of circuits being clocked reduce power
consumption.
For managing power in an application, the primary
modes of operation are:
Run Mode
Idle Mode
Sleep Mode
Deep Sleep Mode
Additionally, there is an Ultra Low-Power Wake-up
(ULPWU) mode for generating an interrupt-on-change
on RA0.
These modes define which portions of the device are
clocked and at what speed.
The Run and Idle modes can use any of the three
available clock sources (primary, secondary or
internal oscillator blocks).
The Sleep mode does not use a clock source.
The ULPWU mode on RA0 allows a slow falling voltage
to generate an interrupt-on-change on RA0 without
excess current consumption. See Section 4.7 “Ultra
Low-Power Wake-up”.
The power-managed modes include several
power-saving features offered on previous PIC®
devices, such as clock switching, ULPWU and Sleep
mode. In addition, the PIC18F46J50 family devices add
a new power-managed Deep Sleep mode.
4.1 Selecting Power-Managed Modes
Selecting a power-managed mode requires these
decisions:
Will the CPU be clocked?
If so, which clock source will be used?
The IDLEN bit (OSCCON<7>) controls CPU clocking
and the SCS<1:0> bits (OSCCON<1:0>) select the
clock source. The individual modes, bit settings, clock
sources and affected modules are summarized in
Table 4-1.
4.1.1 CLOCK SOURCES
The SCS<1:0> bits allow the selection of one of three
clock sources for power-managed modes. They are:
Primary clock source – Defined by the
FOSC<2:0> Configuration bits
Timer1 clock – Provided by the secondary
oscillator
Postscaled internal clock – Derived from the
internal oscillator block
4.1.2 ENTERING POWER-MANAGED
MODES
Switching from one clock source to another begins by
loading the OSCCON register. The SCS<1:0> bits
select the clock source.
Changing these bits causes an immediate switch to the
new clock source, assuming that it is running. The
switch also may be subject to clock transition delays.
These delays are discussed in Section 4.1.3 “Clock
Transitions and Status Indicators” and subsequent
sections.
Entry to the power-managed Idle or Sleep modes is
triggered by the execution of a SLEEP instruction. The
actual mode that results depends on the status of the
IDLEN bit.
Depending on the current mode and the mode being
switched to, a change to a power-managed mode does
not always require setting all of these bits. Many transi-
tions may be done by changing the oscillator select
bits, the IDLEN bit, or the DSEN bit prior to issuing a
SLEEP instruction.
If the IDLEN and DSEN bits are already configured
correctly, it only may be necessary to perform a SLEEP
instruction to switch to the desired mode.
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DS39931D-page 48 2011 Microchip Technology Inc.
TABLE 4-1: LOW-POWER MODES
4.1.3 CLOCK TRANSITIONS AND STATUS
INDICATORS
The length of the transition between clock sources is
the sum of two cycles of the old clock source and three
to four cycles of the new clock source. This formula
assumes that the new clock source is stable.
Two bits indicate the current clock source and its
status: OSTS (OSCCON<3>) and T1RUN
(T1CON<6>). In general, only one of these bits will be
set in a given power-managed mode. When the OSTS
bit is set, the primary clock would be providing the
device clock. When the T1RUN bit is set, the Timer1
oscillator would be providing the clock. If neither of
these bits is set, INTRC would be clocking the device.
4.1.4 MULTIPLE SLEEP COMMANDS
The power-managed mode that is invoked with the
SLEEP instruction is determined by the setting of the
IDLEN and DSEN bits at the time the instruction is exe-
cuted. If another SLEEP instruction is executed, the
device will enter the power-managed mode specified
by IDLEN and DSEN at that time. If IDLEN or DSEN
have changed, the device will enter the new
power-managed mode specified by the new setting.
4.2 Run Modes
In the Run modes, clocks to both the core and
peripherals are active. The difference between these
modes is the clock source.
4.2.1 PRI_RUN MODE
The PRI_RUN mode is the normal, full-power execu-
tion mode of the microcontroller. This is also the default
mode upon a device Reset unless Two-Speed Start-up
is enabled (see Section 27.4 “Two-Speed Start-up”
for details). In this mode, the OSTS bit is set (see
Section 3.5.1 “Oscillator Control Regis ter”).
4.2.2 SEC_RUN MODE
The SEC_RUN mode is the compatible mode to the
“clock switching” feature offered in other PIC18
devices. In this mode, the CPU and peripherals are
clocked from the Timer1 oscillator. This gives users the
option of low-power consumption while still using a
high-accuracy clock source.
SEC_RUN mode is entered by setting the SCS<1:0>
bits to ‘01’. The device clock source is switched to the
Timer1 oscillator (see Figure 4-1), the primary
oscillator is shut down, the T1RUN bit (T1CON<6>) is
set and the OSTS bit is cleared.
Mode D SCONH<7> OSCCO N<7,1: 0> Module Clocking Available Clock and Osc illator Source
DSEN(1) IDLEN(1) SCS<1:0> CPU Peripherals
Sleep 00N/A Off Off Timer1 oscillator and/or RTCC may optionally be
enabled
Deep Sleep 10N/A Off(2) Off RTCC can run uninterrupted using the Timer1 or
internal low-power RC oscillator
PRI_RUN 0N/A 00 Clocked Clocked The normal, full-power execution mode; primary
clock source (defined by FOSC<2:0>)
SEC_RUN 0N/A 01 Clocked Clocked Secondary – Timer1 oscillator
RC_RUN 0N/A 11 Clocked Clocked Postscaled internal clock
PRI_IDLE 0100Off Clocked Primary clock source (defined by FOSC<2:0>)
SEC_IDLE 0101Off Clocked Secondary – Timer1 oscillator
RC_IDLE 0111Off Clocked Postscaled internal clock
Note 1: IDLEN and DSEN reflect their values when the SLEEP instruction is executed.
2: Deep Sleep turns off the voltage regulator for ultra low-power consumption. See Section 4.6 “Deep Sleep
Mode” for more information.
Note: Executing a SLEEP instruction does not
necessarily place the device into Sleep
mode. It acts as the trigger to place the
controller into either the Sleep or Deep
Sleep mode, or one of the Idle modes,
depending on the setting of the IDLEN bit.
Note: The Timer1 oscillator should already be
running prior to entering SEC_RUN
mode. If the T1OSCEN bit is not set when
the SCS<1:0> bits are set to ‘01’, entry to
SEC_RUN mode will not occur. If the
Timer1 oscillator is enabled, but not yet
running, device clocks will be delayed until
the oscillator has started. In such situa-
tions, initial oscillator operation is far from
stable and unpredictable operation may
result.
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On transitions from SEC_RUN mode to PRI_RUN
mode, the peripherals and CPU continue to be clocked
from the Timer1 oscillator while the primary clock is
started. When the primary clock becomes ready, a
clock switch back to the primary clock occurs (see
Figure 4-2). When the clock switch is complete, the
T1RUN bit is cleared, the OSTS bit is set and the
primary clock would be providing the clock. The IDLEN
and SCS bits are not affected by the wake-up; the
Timer1 oscillator continues to run.
FIGURE 4-1: TRANSITION TI MING FOR ENTRY TO SEC _RUN MOD E
FIGU RE 4-2: TRANSIT ION T I MING FR OM SEC_ RUN MO DE TO PRI_RU N MODE ( HSPLL )
Q4Q3Q2
OSC1
Peripheral
Program
Q1
T1OSI
Q1
Counter
Clock
CPU
Clock
PC + 2PC
123 n-1n
Clock Transition
Q4Q3Q2 Q1 Q3Q2
PC + 4
Q1 Q3 Q4
OSC1
Peripheral
Program PC
T1OSI
PLL Clock
Q1
PC + 4
Q2
Output
Q3 Q4 Q1
CPU Clock
PC + 2
Clock
Counter
Q2 Q2 Q3
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
SCS<1:0> Bits Changed
TPLL(1)
12 n-1n
Clock
OSTS Bit Set
Transition
TOST(1)
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DS39931D-page 50 2011 Microchip Technology Inc.
4.2.3 RC_RUN MODE
In RC_RUN mode, the CPU and peripherals are
clocked from the internal oscillator; the primary clock is
shut down. This mode provides the best power conser-
vation of all the Run modes while still executing code.
It works well for user applications, which are not highly
timing-sensitive or do not require high-speed clocks at
all times.
This mode is entered by setting the SCS<1:0> bits
(OSCCON<1:0>) to ‘11’. When the clock source is
switched to the internal oscillator block (see
Figure 4-3), the primary oscillator is shutdown and the
OSTS bit is cleared.
On transitions from RC_RUN mode to PRI_RUN mode,
the device continues to be clocked from the INTOSC
block while the primary clock is started. When the
primary clock becomes ready, a clock switch to the
primary clock occurs (see Figure 4-4). When the clock
switch is complete, the OSTS bit is set and the primary
clock is providing the device clock. The IDLEN and
SCS bits are not affected by the switch. The INTRC
clock source will continue to run if either the WDT or the
FSCM is enabled.
FIGU RE 4- 3 : TRANSIT ION TIMING TO RC _R UN MO DE
FIGURE 4-4: TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE
Q4Q3Q2
OSC1
Peripheral
Program
Q1
INTRC
Q1
Counter
Clock
CPU
Clock
PC + 2PC
123 n-1n
Clock Transition
Q4Q3Q2 Q1 Q3Q2
PC + 4
Q1 Q3 Q4
OSC1
Peripheral
Program PC
INTRC
PLL Clock
Q1
PC + 4
Q2
Output
Q3 Q4 Q1
CPU Clock
PC + 2
Clock
Counter
Q2 Q2 Q3
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
SCS<1:0> Bits Changed
TPLL(1)
12 n-1n
Clock
OSTS Bit Set
Transition
TOST(1)
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4.3 Sleep Mode
The power-managed Sleep mode is identical to the
legacy Sleep mode offered in all other PIC devices. It is
entered by clearing the IDLEN bit (the default state on
device Reset) and executing the SLEEP instruction.
This shuts down the selected oscillator (Figure 4-5). All
clock source status bits are cleared.
Entering the Sleep mode from any other mode does not
require a clock switch. This is because no clocks are
needed once the controller has entered Sleep mode. If
the WDT is selected, the INTRC source will continue to
operate. If the Timer1 oscillator is enabled, it will also
continue to run.
When a wake event occurs in Sleep mode (by interrupt,
Reset or WDT time-out), the device will not be clocked
until the clock source selected by the SCS<1:0> bits
becomes ready (see Figure 4-6), or it will be clocked
from the internal oscillator if either the Two-Speed
Start-up or the FSCM are enabled (see Section 27.0
“Special Features of the CPU”). In either case, the
OSTS bit is set when the primary clock is providing the
device clocks. The IDLEN and SCS bits are not
affected by the wake-up.
FIGURE 4-5: T RANSITION T IMING FOR ENTRY TO SLEEP MODE
FIGURE 4-6: T RANSITION T IMING FOR W AKE FROM SLEEP (HSPLL)
Q4Q3Q2
OSC1
Peripheral
Sleep
Program
Q1Q1
Counter
Clock
CPU
Clock
PC + 2PC
Q3 Q4 Q1 Q2
OSC1
Peripheral
Program PC
PLL Clock
Q3 Q4
Output
CPU Clock
Q1 Q2 Q3 Q4 Q1 Q2
Clock
Counter PC + 6PC + 4
Q1 Q2 Q3 Q4
Wake Event
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
TOST(1) TPLL(1)
OSTS Bit Set
PC + 2
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4.4 Idle Modes
The Idle modes allow the controller’s CPU to be
selectively shut down while the peripherals continue to
operate. Selecting a particular Idle mode allows users
to further manage power consumption.
If the IDLEN bit is set to1’ when a SLEEP instruction is
executed, the peripherals will be clocked from the clock
source selected using the SCS<1:0> bits; however, the
CPU will not be clocked. The clock source status bits are
not affected. Setting IDLEN and executing a SLEEP
instruction provides a quick method of switching from a
given Run mode to its corresponding Idle mode.
If the WDT is selected, the INTRC source will continue
to operate. If the Timer1 oscillator is enabled, it will also
continue to run.
Since the CPU is not executing instructions, the only
exits from any of the Idle modes are by interrupt, WDT
time-out or a Reset. When the CPU begins executing
code, it resumes with the same clock source for the
current Idle mode. For example, when waking from
RC_IDLE mode, the internal oscillator block will clock
the CPU and peripherals (in other words, RC_RUN
mode). The IDLEN and SCS bits are not affected by the
wake-up.
While in any Idle or Sleep mode, a WDT time-out will
result in a WDT wake-up to the Run mode currently
specified by the SCS<1:0> bits.
4.4.1 PRI_IDLE MODE
This mode is unique among the three low-power Idle
modes, in that it does not disable the primary device
clock. For timing-sensitive applications, this allows for
the fastest resumption of device operation with its more
accurate primary clock source, since the clock source
does not have to “warm up” or transition from another
oscillator.
PRI_IDLE mode is entered from PRI_RUN mode by
setting the IDLEN bit and executing a SLEEP instruc-
tion. If the device is in another Run mode, set IDLEN
first, then set the SCS bits to ‘00’ and execute SLEEP.
Although the CPU is disabled, the peripherals continue
to be clocked from the primary clock source specified
by the FOSC<1:0> Configuration bits. The OSTS bit
remains set (see Figure 4-7).
When a wake event occurs, the CPU is clocked from the
primary clock source. After the wake-up, the OSTS bit
remains set. The IDLEN and SCS bits are not affected
by the wake-up (see Figure 4-8).
4.4.2 SEC_IDLE MODE
In SEC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the Timer1
oscillator. This mode is entered from SEC_RUN by set-
ting the IDLEN bit and executing a SLEEP instruction. If
the device is in another Run mode, set IDLEN first, then
set SCS<1:0> to ‘01’ and execute SLEEP. When the
clock source is switched to the Timer1 oscillator, the
primary oscillator is shut down (unless some other
peripheral is still requesting it), the OSTS bit is cleared
and the T1RUN bit is set.
When a wake event occurs, the peripherals continue to
be clocked from the Timer1 oscillator. After a wake
event, the CPU begins executing code being clocked
by the Timer1 oscillator. The IDLEN and SCS bits are
not affected by the wake-up; the Timer1 oscillator
continues to run (see Figure 4-8).
FIGURE 4-7: TRANSITION TIMING FOR ENTRY TO IDLE MODE
Note: The Timer1 oscillator should already be
running prior to entering SEC_IDLE
mode. If the T1OSCEN bit is not set when
the SLEEP instruction is executed, the
SLEEP instruction will be ignored and
entry to SEC_IDLE mode will not occur. If
the Timer1 oscillator is enabled, but not
yet running, peripheral clocks will be
delayed until the oscillator has started. In
such situations, initial oscillator operation
is far from stable and unpredictable
operation may result.
Q1
Peripheral
Program PC PC + 2
OSC1
Q3 Q4 Q1
CPU Clock
Clock
Counter
Q2
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FIGURE 4-8: T RANSITION TIMING FOR W AKE FROM IDLE TO RUN MODE
4.4.3 RC_IDLE MODE
In RC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the internal
oscillator block. This mode allows for controllable
power conservation during Idle periods.
From RC_RUN, this mode is entered by setting the
IDLEN bit and executing a SLEEP instruction. If the
device is in another Run mode, first set IDLEN, then
clear the SCS bits and execute SLEEP. When the clock
source is switched to the INTOSC block, the primary
oscillator is shutdown and the OSTS bit is cleared.
When a wake event occurs, the peripherals continue to
be clocked from the internal oscillator block. After a wake
event, the CPU begins executing code being clocked by
the INTRC. The IDLEN and SCS bits are not affected by
the wake-up. The INTRC source will continue to run if
either the WDT or the FSCM is enabled.
4.5 Exiting Idle and Sleep Modes
An exit from Sleep mode, or any of the Idle modes, is
triggered by an interrupt, a Reset or a WDT time-out.
This section discusses the triggers that cause exits
from power-managed modes. The clocking subsystem
actions are discussed in each of the power-managed
modes sections (see Section 4.2 “Run Modes”,
Section 4.3 “Sleep Mode” and Section 4.4 “Idle
Modes”).
4.5.1 EXIT BY INTERRUPT
Any of the available interrupt sources can cause the
device to exit from an Idle mode, or the Sleep mode, to
a Run mode. To enable this functionality, an interrupt
source must be enabled by setting its enable bit in one
of the INTCON or PIE registers. The exit sequence is
initiated when the corresponding interrupt flag bit is set.
On all exits from Idle or Sleep modes by interrupt, code
execution branches to the interrupt vector if the
GIE/GIEH bit (INTCON<7>) is set. Otherwise, code
execution continues or resumes without branching
(see Section 9.0 “Interrupts”).
4.5.2 EXIT BY WDT TIME-OUT
A WDT time-out will cause different actions depending
on which power-managed mode the device is, when
the time-out occurs.
If the device is not executing code (all Idle modes and
Sleep mode), the time-out will result in an exit from the
power-managed mode (see Section 4.2 “Run
Modes” and Section 4.3 “Sleep Mode”). If the device
is executing code (all Run modes), the time-out will
result in a WDT Reset (see Section 27.2 “Watchdog
Timer (WDT)”).
The WDT and postscaler are cleared by one of the
following events:
Executing a SLEEP or CLRWDT instruction
The loss of a currently selected clock source (if
the FSCM is enabled)
4.5.3 EXIT BY RESET
Exiting an Idle or Sleep mode by Reset automatically
forces the device to run from the INTRC.
OSC1
Peripheral
Program PC
CPU Clock
Q1 Q3 Q4
Clock
Counter
Q2
Wake Event
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DS39931D-page 54 2011 Microchip Technology Inc.
4.5.4 EXIT WITHOUT AN OSCILLATOR
START-UP DELAY
Certain exits from power-managed modes do not
invoke the OST at all. There are two cases:
PRI_IDLE mode (where the primary clock source
is not stopped) and the primary clock source is
the EC mode
PRI_IDLE mode and the primary clock source is
the ECPLL mode
In these instances, the primary clock source either
does not require an oscillator start-up delay, since it is
already running (PRI_IDLE), or normally does not
require an oscillator start-up delay (EC).
4.6 Deep Sleep Mode
Deep Sleep mode brings the device into its lowest
power consumption state without requiring the use of
external switches to remove power from the device.
During Deep Sleep, the on-chip VDDCORE voltage reg-
ulator is powered down, effectively disconnecting
power to the core logic of the microcontroller.
On devices that support it, the Deep Sleep mode is
entered by:
Setting the REGSLP (WDTCON<7>) bit
Clearing the IDLEN bit
Clearing the GIE bit
Setting the DSEN bit (DSCONH<7>)
Executing the SLEEP instruction immediately after
setting DSEN (no delay or interrupts in between)
In order to minimize the possibility of inadvertently enter-
ing Deep Sleep, the DSEN bit is cleared in hardware,
two instruction cycles after having been set. Therefore,
in order to enter Deep Sleep, the SLEEP instruction must
be executed in the immediate instruction cycle after set-
ting DSEN. If DSEN is not set when Sleep is executed,
the device will enter conventional Sleep mode instead.
During Deep Sleep, the core logic circuitry of the
microcontroller is powered down to reduce leakage
current. Therefore, most peripherals and functions of
the microcontroller become unavailable during Deep
Sleep. However, a few specific peripherals and func-
tions are powered directly from the VDD supply rail of
the microcontroller, and therefore, can continue to
function in Deep Sleep.
Entering Deep Sleep mode clears the DSWAKEL
register. However, if the Real-Time Clock and Calendar
(RTCC) is enabled prior to entering Deep Sleep, it will
continue to operate uninterrupted.
The device has a dedicated Brown-out Reset (DSBOR)
and Watchdog Timer Reset (DSWDT) for monitoring
voltage and time-out events in Deep Sleep. The
DSBOR and DSWDT are independent of the standard
BOR and WDT used with other power-managed modes
(Run, Idle and Sleep).
When a wake event occurs in Deep Sleep mode (by
MCLR Reset, RTCC alarm, INT0 interrupt, ULPWU or
DSWDT), the device will exit Deep Sleep mode and
perform a Power-on Reset (POR). When the device is
released from Reset, code execution will resume at the
device’s Reset vector.
4.6.1 PREPARING FOR DEEP SLEEP
Because VDDCORE could fall below the SRAM retention
voltage while in Deep Sleep mode, SRAM data could
be lost in Deep Sleep. Exiting Deep Sleep mode
causes a POR; as a result, most Special Function
Registers (SFRs) will reset to their default POR values.
Applications needing to save a small amount of data
throughout a Deep Sleep cycle can save the data to the
general purpose DSGPR0 and DSGPR1 registers. The
contents of these registers are preserved while the
device is in Deep Sleep, and will remain valid throughout
an entire Deep Sleep entry and wake-up sequence.
Note: Since Deep Sleep mode powers down the
microcontroller by turning off the on-chip
VDDCORE voltage regulator, Deep Sleep
capability is available only on PIC18FXXJ
members in the device family. The on-chip
voltage regulator is not available on
PIC18LFXXJ members of the device
family, and therefore, they do not support
Deep Sleep.
2011 Microchip Technology Inc. DS39931D-page 55
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4.6.2 I/O PINS DURING DEEP SLEEP
During Deep Sleep, the general purpose I/O pins will
retain their previous states.
Pins that are configured as inputs (TRIS bit set) prior to
entry into Deep Sleep will remain high impedance
during Deep Sleep.
Pins that are configured as outputs (TRIS bit clear)
prior to entry into Deep Sleep will remain as output pins
during Deep Sleep. While in this mode, they will drive
the output level determined by their corresponding LAT
bit at the time of entry into Deep Sleep.
When the device wakes back up, the I/O pin behavior
depends on the type of wake up source.
If the device wakes back up by an RTCC alarm, INT0
interrupt, DSWDT or ULPWU event, all I/O pins will
continue to maintain their previous states, even after the
device has finished the POR sequence and is executing
application code again. Pins configured as inputs during
Deep Sleep will remain high impedance, and pins
configured as outputs will continue to drive their previous
value.
After waking up, the TRIS and LAT registers will be
reset, but the I/O pins will still maintain their previous
states. If firmware modifies the TRIS and LAT values
for the I/O pins, they will not immediately go to the
newly configured states. Once the firmware clears the
RELEASE bit (DSCONL<0>), the I/O pins will be
“released”. This causes the I/O pins to take the states
configured by their respective TRIS and LAT bit values.
If the Deep Sleep BOR (DSBOR) circuit is enabled, and
VDD drops below the DSBOR and VDD rail POR thresh-
olds, the I/O pins will be immediately released similar to
clearing the RELEASE bit. All previous state informa-
tion will be lost, including the general purpose DSGPR0
and DSGPR1 contents. See Section 4.6.5 “Deep
Sleep Brown-Out Reset (DSBOR)” for additional
details regarding this scenario
If a MCLR Reset event occurs during Deep Sleep, the
I/O pins will also be released automatically, but in this
case, the DSGPR0 and DSGPR1 contents will remain
valid.
In all other Deep Sleep wake-up cases, application
firmware needs to clear the RELEASE bit in order to
reconfigure the I/O pins.
4.6.3 DEEP SLEEP WAKE-UP SOURCES
The device can be awakened from Deep Sleep mode by
a MCLR, POR, RTCC, INT0 I/O pin interrupt, DSWDT or
ULPWU event. After waking, the device performs a
POR. When the device is released from Reset, code
execution will begin at the device’s Reset vector.
The software can determine if the wake-up was caused
from an exit from Deep Sleep mode by reading the DS
bit (WDTCON<3>). If this bit is set, the POR was
caused by a Deep Sleep exit. The DS bit must be
manually cleared by the software.
The software can determine the wake event source by
reading the DSWAKEH and DSWAKEL registers.
When the application firmware is done using the
DSWAKEH and DSWAKEL status registers, individual
bits do not need to be manually cleared before entering
Deep Sleep again. When entering Deep Sleep mode,
these registers are automatically cleared.
4.6.3.1 Wake-up Event Considerations
Deep Sleep wake-up events are only monitored while
the processor is fully in Deep Sleep mode. If a wake-up
event occurs before Deep Sleep mode is entered, the
event status will not be reflected in the DSWAKE
registers. If the wake-up source asserts prior to entering
Deep Sleep, the CPU will either go to the interrupt vector
(if the wake source has an interrupt bit and the interrupt
is fully enabled) or will abort the Deep Sleep entry
sequence by executing past the SLEEP instruction if the
interrupt was not enabled. In this case, a wake-up event
handler should be placed after the SLEEP instruction to
process the event and re-attempt entry into Deep Sleep,
if desired.
When the device is in Deep Sleep with more than one
wake-up source simultaneously enabled, only the first
wake-up source to assert will be detected and logged
in the DSWAKEH/DSWAKEL status registers.
4.6.4 DEEP SLEEP WATCHDOG TIMER
(DSWDT)
Deep Sleep has its own dedicated WDT (DSWDT) with
a postscaler for time-outs of 2.1 ms to 25.7 days,
configurable through the bits, DSWDTPS<3:0>.
The DSWDT can be clocked from either the INTRC or
the T1OSC/T1CKI input. If the T1OSC/T1CKI source
will be used with a crystal, the T1OSCEN bit in the
T1CON register needs to be set prior to entering Deep
Sleep. The reference clock source is configured through
the DSWDTOSC bit.
DSWDT is enabled through the DSWDTEN bit. Entering
Deep Sleep mode automatically clears the DSWDT. See
Section 27.0 “Special Features of the CPU” for more
information.
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4.6.5 DEEP SLEEP BROWN-OUT RESET
(DSBOR)
The Deep Sleep module contains a dedicated Deep Sleep
BOR (DSBOR) circuit. This circuit may be optionally
enabled through the DSBOREN Configuration bit.
The DSBOR circuit monitors the VDD supply rail
voltage. The behavior of the DSBOR circuit is
described in Section 5.4 “Brown-out Reset (BOR)”.
4.6.6 RTCC PERIPHERAL AND DEEP
SLEEP
The RTCC can operate uninterrupted during Deep
Sleep mode. It can wake the device from Deep Sleep
by configuring an alarm.
The RTCC clock source is configured with the
RTCOSC bit (CONFIG3L<1>). The available reference
clock sources are the INTRC and T1OSC/T1CKI. If the
INTRC is used, the RTCC accuracy will directly depend
on the INTRC tolerance.For more information on
configuring the RTCC peripheral, see Section 17.0
“Real-Time Clock and Calendar (RTCC)” .
4.6.7 TYPICAL DEEP SLEEP SEQUENCE
This section gives the typical sequence for using the Deep
Sleep mode. Optional steps are indicated, and additional
information is given in notes at the end of the procedure.
1. Enable DSWDT (optional).(1)
2. Configure DSWDT clock source (optional).(2)
3. Enable DSBOR (optional).(1)
4. Enable RTCC (optional).(3)
5. Configure the RTCC peripheral (optional).(3)
6. Configure the ULPWU peripheral (optional).(4)
7. Enable the INT0 Interrupt (optional).
8. Context save SRAM data by writing to the
DSGPR0 and DSGPR1 registers (optional).
9. Set the REGSLP bit (WDTCON<7>) and clear
the IDLEN bit (OSCCON<7>).
10. If using an RTCC alarm for wake-up, wait until
the RTCSYNC bit (RTCCFG<4>) is clear.
11. Enter Deep Sleep mode by setting the DSEN bit
(DSCONH<7>) and issuing a SLEEP instruction.
These two instructions must be executed
back-to-back.
12. Once a wake-up event occurs, the device will
perform a Power-on Reset sequence. Code
execution resumes at the device’s Reset vector.
13. Determine if the device exited Deep Sleep by
reading the Deep Sleep bit, DS (WDTCON<3>).
This bit will be set if there was an exit from Deep
Sleep mode.
14. Clear the Deep Sleep bit, DS (WDTCON<3>).
15. Determine the wake-up source by reading the
DSWAKEH and DSWAKEL registers.
16. Determine if a DSBOR event occurred during
Deep Sleep mode by reading the DSBOR bit
(DSCONL<1>).
17. Read the DSGPR0 and DSGPR1 Context Save
registers (optional).
18. Clear the RELEASE bit (DSCONL<0>).
4.6.8 DEEP SLEEP FAULT DETECTION
If during Deep Sleep, the device is subjected to
unusual operating conditions, such as an Electrostatic
Discharge (ESD) event, it is possible that internal cir-
cuit states used by the Deep Sleep module could
become corrupted. If this were to happen, the device
may exhibit unexpected behavior, such as a failure to
wake back up.
In order to prevent this type of scenario from occurring,
the Deep Sleep module includes automatic
self-monitoring capability. During Deep Sleep, critical
internal nodes are continuously monitored in order to
detect possible Fault conditions (which would not
ordinarily occur). If a Fault condition is detected, the
circuitry will set the DSFLT status bit (DSWAKEL<7>)
and automatically wake the microcontroller from Deep
Sleep, causing a POR.
During Deep Sleep, the Fault detection circuitry is
always enabled and does not require any specific
configuration prior to entering Deep Sleep.
Note 1: DSWDT and DSBOR are enabled
through the devices’ Configuration bits.
For more information, see Section 27.1
“Configuration Bits”.
2: The DSWDT and RTCC clock sources
are selected through the devices’ Con-
figuration bits. For more information, see
Secti on 2 7. 1 “C onfi gu rat io n Bits”.
3: For more information, see Section 17.0
“Real-Time Clock and Calendar
(RTCC)”.
4: For more information on configuring this
peripheral, see Section 4.7 “Ultra
Low-Power Wake-up”.
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4.6.9 DEEP SLEEP MODE REGISTERS
Deep Sleep mode registers are provided in
Register 4-1 through Register 4-6.
REGISTER 4-1: DSCONH: DEEP SLEEP CONTROL HIGH BYTE REGISTER (BANKED F4Dh)
R/W-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0
DSEN(1) r DSULPEN RTCWDIS
bit 7 bit 0
Legend: r = Reserved bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 DSEN: Deep Sleep Enable bit(1)
1 = Deep Sleep mode is entered on a SLEEP command
0 = Sleep mode is entered on a SLEEP command
bit 6-3 Unimplemented: Read as ‘0
bit 2 Reserved: Always write ‘0 to this bit
bit 1 DSULPEN: Ultra Low-Power Wake-up Module Enable bit
1 = ULPWU module is enabled in Deep Sleep
0 = ULPWU module is disabled in Deep Sleep
bit 0 RTCWDIS: RTCC Wake-up Disable bit
1 = Wake-up from RTCC is disabled
0 = Wake-up from RTCC is enabled
Note 1: In order to enter Deep Sleep, Sleep must be executed immediately after setting DSEN.
REGISTER 4-2: DSCONL: DEEP SLEEP CONTROL LOW BYTE REGISTER (BANKED F4Ch)
U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0(1) R/W-0(1)
ULPWDIS DSBOR RELEASE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-3 Unimplemented: Read as ‘0
bit 2 ULPWDIS: Ultra Low-Power Wake-up Disable bit
1 = ULPWU wake-up source is disabled
0 = ULPWU wake-up source is enabled (must also set DSULPEN = 1)
bit 1 DSBOR: Deep Sleep BOR Event Status bit
1 = DSBOREN was enabled and VDD dropped below the DSBOR arming voltage during Deep Sleep,
but did not fall below VDSBOR
0 = DSBOREN was disabled or VDD did not drop below the DSBOR arming voltage during Deep Sleep
bit 0 RELEASE: I/O Pin State Release bit
Upon waking from Deep Sleep, the I/O pins maintain their previous states. Clearing this bit will
release the I/O pins and allow their respective TRIS and LAT bits to control their states.
Note 1: This is the value when VDD is initially applied.
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REGISTER 4-3: DSGPR0: DEEP SLEEP PERSISTENT GENERAL PURPOSE REGISTER 0
(BANKED F4Eh)
R/W-xxxx(1)
Deep Sleep Persistent General Purpose bits
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 Deep Sleep Persistent General Purpose bits
Contents are retained even in Deep Sleep mode.
Note 1: All register bits are maintained unless: VDDCORE drops below the normal BOR threshold outside of Deep
Sleep or the device is in Deep Sleep and the dedicated DSBOR is enabled and VDD drops below the
DSBOR threshold, or DSBOR is enabled or disabled, but VDD is hard cycled to near VSS.
REGISTER 4-4: DSGPR1: DEEP SLEEP PERSISTENT GENERAL PURPOSE REGISTER 1
(BANKED F4Fh)
R/W-xxxx(1)
Deep Sleep Persistent General Purpose bits
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 Deep Sleep Persistent General Purpose bits
Contents are retained even in Deep Sleep mode.
Note 1: All register bits are maintained unless: VDDCORE drops below the normal BOR threshold outside of Deep
Sleep or the device is in Deep Sleep and the dedicated DSBOR is enabled and VDD drops below the
DSBOR threshold, or DSBOR is enabled or disabled, but VDD is hard cycled to near VSS.
2011 Microchip Technology Inc. DS39931D-page 59
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REGISTER 4-5: DSWAKEH: DEEP SLEEP WAKE HIGH BYTE REGISTER (BANKED F4Bh)
U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0
—DSINT0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-1 Unimplemented: Read as ‘0
bit 0 DSINT0: Interrupt-on-Change bit
1 = Interrupt-on-change was asserted during Deep Sleep
0 = Interrupt-on-change was not asserted during Deep Sleep
REGISTER 4-6: DSWAKEL: DEEP SLEEP WAKE LOW BYTE REGISTER (BANKED F4Ah)
R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-1
DSFLT DSULP DSWDT DSRTC DSMCLR DSPOR
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 DSFLT: Deep Sleep Fault Detected bit
1 = A Deep Sleep Fault was detected during Deep Sleep
0 = A Deep Sleep Fault was not detected during Deep Sleep
bit 6 Unimplemented: Read as ‘0
bit 5 DSULP: Ultra Low-Power Wake-up Status bit
1 = An Ultra Low-Power Wake-up event occurred during Deep Sleep
0 = An Ultra Low-Power Wake-up event did not occur during Deep Sleep
bit 4 DSWDT: Deep Sleep Watchdog Timer Time-out bit
1 = The Deep Sleep Watchdog Timer timed out during Deep Sleep
0 = The Deep Sleep Watchdog Timer did not time out during Deep Sleep
bit 3 DSRTC: Real-Time Clock and Calendar Alarm bit
1 = The Real-Time Clock/Calendar triggered an alarm during Deep Sleep
0 = The Real-Time Clock /Calendar did not trigger an alarm during Deep Sleep
bit 2 DSMCLR: MCLR Event bit
1 = The MCLR pin was asserted during Deep Sleep
0 = The MCLR pin was not asserted during Deep Sleep
bit 1 Unimplemented: Read as ‘0
bit 0 DSPOR: Power-on Reset Event bit
1 = The VDD supply POR circuit was active and a POR event was detected(1)
0 = The VDD supply POR circuit was not active, or was active, but did not detect a POR event
Note 1: Unlike the other bits in this register, this bit can be set outside of Deep Sleep.
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DS39931D-page 60 2011 Microchip Technology Inc.
4.7 Ultra Low-Power Wake-up
The Ultra Low-Power Wake-up (ULPWU) on RA0 allows
a slow falling voltage to generate an interrupt-on-change
without excess current consumption.
Follow these steps to use this feature:
1. Configure a remappable output pin to output the
ULPOUT signal.
2. Map an INTx interrupt-on-change input function to
the same pin as used for the ULPOUT output func-
tion. Alternatively, in Step 1, configure ULPOUT to
output onto a PORTB interrupt-on-change pin.
3. Charge the capacitor on RA0 by configuring the
RA0 pin to an output and setting it to ‘1’.
4. Enable interrupt-on-change (PIE bit) for the
corresponding pin selected in Step 2.
5. Stop charging the capacitor by configuring RA0
as an input.
6. Discharge the capacitor by setting the ULPEN
and ULPSINK bits in the WDTCON register.
7. Configure Sleep mode.
8. Enter Sleep mode.
When the voltage on RA0 drops below VIL, an interrupt
will be generated, which will cause the device to
wake-up and execute the next instruction.
This feature provides a low-power technique for
periodically waking up the device from Sleep mode.
The time-out is dependent on the discharge time of the
RC circuit on RA0.
When the ULPWU module causes the device to
wake-up from Sleep mode, the WDTCON<ULPLVL>
bit is set. When the ULPWU module causes the device
to wake-up from Deep Sleep, the DSULP
(DSWAKEL<5>) bit is set. Software can check these
bits upon wake-up to determine the wake-up source.
Also in Sleep mode, only the remappable output func-
tion, ULPWU, will output this bit value to an RPn pin for
externally detecting wake-up events.
See Example 4-1 for initializing the ULPWU module.
A series resistor between RA0 and the external
capacitor provides overcurrent protection for the
RA0/AN0/C1INA/ULPWU/RP0 pin and can allow for
software calibration of the time-out (see Figure 4-9).
FIGURE 4-9: SERIAL RESISTOR
A timer can be used to measure the charge time and
discharge time of the capacitor. The charge time can
then be adjusted to provide the desired interrupt delay.
This technique will compensate for the affects of
temperature, voltage and component accuracy. The
ULPWU peripheral can also be configured as a simple
Programmable Low-Voltage Detect (LVD) or
temperature sensor.
Note: For module-related bit definitions, see the
WDTCON register in Section 27.2
“Watchdog Timer (WDT)” and the
DSWAKEL register (Register 4-6).
Note: For more information, refer to AN879,
Using the Microchip Ultra Low-Power
Wake-up Module” application note
(DS00879).
R1
C1
RA0
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EXAMPLE 4-1: ULTRA LOW-POWER WAKE-UP INITIALIZATION
//*********************************************************************************
//Configure a remappable output pin with interrupt capability
//for ULPWU function (RP21 => RD4/INT1 in this example)
//*********************************************************************************
RPOR21 = 13;// ULPWU function mapped to RP21/RD4
RPINR1 = 21;// INT1 mapped to RP21 (RD4)
//***************************
//Charge the capacitor on RA0
//***************************
TRISAbits.TRISA0 = 0;
LATAbits.LATA0 = 1;
for(i = 0; i < 10000; i++) Nop();
//**********************************
//Stop Charging the capacitor on RA0
//**********************************
TRISAbits.TRISA0 = 1;
//*****************************************
//Enable the Ultra Low Power Wakeup module
//and allow capacitor discharge
//*****************************************
WDTCONbits.ULPEN = 1;
WDTCONbits.ULPSINK = 1;
//******************************************
//Enable Interrupt for ULPW
//******************************************
//For Sleep
//(assign the ULPOUT signal in the PPS module to a pin
//which has also been assigned an interrupt capability,
//such as INT1)
INTCON3bits.INT1IF = 0;
INTCON3bits.INT1IE = 1;
//********************
//Configure Sleep Mode
//********************
//For Sleep
OSCCONbits.IDLEN = 0;
//For Deep Sleep
OSCCONbits.IDLEN = 0; // enable deep sleep
DSCONHbits.DSEN = 1; // Note: must be set just before executing Sleep();
//****************
//Enter Sleep Mode
//****************
Sleep();
// for sleep, execution will resume here
// for deep sleep, execution will restart at reset vector (use WDTCONbits.DS to detect)
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NOTES:
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5.0 RESET
The PIC18F46J50 family of devices differentiate
among various kinds of Reset:
a) Power-on Reset (POR)
b) MCLR Reset during normal operation
c) MCLR Reset during power-managed modes
d) Watchdog Timer (WDT) Reset (during
execution)
e) Configuration Mismatch (CM)
f) Brown-out Reset (BOR)
g) RESET Instruction
h) Stack Full Reset
i) Stack Underflow Reset
j) Deep Sleep Reset
This section discusses Resets generated by MCLR,
POR and BOR, and covers the operation of the various
start-up timers.
For information on WDT Resets, see Section 27.2
“Watchdog Timer (WDT)”. For Stack Reset events,
see Section 6.1.4.4 “Stack Full and Underflow
Resets” and for Deep Sleep mode, see Section 4.6
“Deep Sleep Mode”.
Figure 5-1 provides a simplified block diagram of the
on-chip Reset circuit.
5.1 RCON Register
Device Reset events are tracked through the RCON
register (Register 5-1). The lower five bits of the register
indicate that a specific Reset event has occurred. In
most cases, these bits can only be set by the event and
must be cleared by the application after the event. The
state of these flag bits, taken together, can be read to
indicate the type of Reset that just occurred. This is
described in more detail in Section 5.7 “Reset State of
Registers”.
FIGURE 5-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
External Reset
MCLR
VDD
WDT
Time-out
VDD Rise
Detect
PWRT
INTRC
POR Pulse
Chip_Reset
Brown-out
Reset(1)
RESET Instruction
Stack
Pointer
Stack Full/Underflow Reset
Sleep
( )_IDLE
PWRT
S
RQ
Configuration Word Mismatch
Deep Sleep Reset
Note 1: The VDD monitoring BOR circuit can be enabled or disabled on “LF” devices based on the DSBOREN
(CONFIG3L<2>) Configuration bit. On “F” devices, the VDD monitoring BOR circuit is only enabled during Deep
Sleep mode by DSBOREN (CONFIG3L<2>).
2: The VDDCORE monitoring BOR circuit is only implemented on “F” devices. It is always used, except while in Deep
Sleep mode. The VDDCORE monitoring BOR circuit has a trip point threshold of VBOR (Parameter D005).
VDDCORE
Brown-out
Reset(2)
F: 5-Bit Ripple Counter
LF: 11-Bit Ripple Counter
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REGISTER 5-1: RCON: RESET CONTROL REGISTER (ACCESS FD0h)
R/W-0 U-0 R/W-1 R/W-1 R-1 R-1 R/W-0 R/W-0
IPEN —CMRI TO PD POR BOR
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6 Unimplemented: Read as ‘0
bit 5 CM: Configuration Mismatch Flag bit
1 = A Configuration Mismatch Reset has not occurred
0 = A Configuration Mismatch Reset has occurred (must be set in software after a Configuration
Mismatch Reset occurs)
bit 4 RI: RESET Instruction Flag bit
1 = The RESET instruction was not executed (set by firmware only)
0 = The RESET instruction was executed causing a device Reset (must be set in software after a
Brown-out Reset occurs)
bit 3 TO: Watchdog Time-out Flag bit
1 = Set by power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 2 PD: Power-Down Detection Flag bit
1 = Set by power-up or by the CLRWDT instruction
0 = Set by execution of the SLEEP instruction
bit 1 POR: Power-on Reset Status bit
1 = A Power-on Reset has not occurred (set by firmware only)
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0 BOR: Brown-out Reset Status bit
1 = A Brown-out Reset has not occurred (set by firmware only)
0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)
Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent
Power-on Resets may be detected.
2: If the on-chip voltage regulator is disabled, BOR remains ‘0’ at all times. See Section 5.4.1 “Detecting
BOR” for more information.
3: Brown-out Reset is said to have occurred when BOR is ‘0’ and POR is ‘1’ (assuming that POR was set to
1’ by software immediately after a Power-on Reset).
2011 Microchip Technology Inc. DS39931D-page 65
PIC18F46J50 FAMILY
5.2 Master Clear (MCLR)
The Master Clear Reset (MCLR) pin provides a method
for triggering a hard external Reset of the device. A
Reset is generated by holding the pin low. PIC18
extended microcontroller devices have a noise filter in
the MCLR Reset path, which detects and ignores small
pulses.
The MCLR pin is not driven low by any internal Resets,
including the WDT.
5.3 Power-on Reset (POR)
A POR condition is generated on-chip whenever VDD
rises above a certain threshold. This allows the device
to start in the initialized state when VDD is adequate for
operation.
To take advantage of the POR circuitry, tie the MCLR
pin through a resistor (1 k to 10 k) to VDD. This will
eliminate external RC components usually needed to
create a POR delay.
When the device starts normal operation (i.e., exits the
Reset condition), device operating parameters
(voltage, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
POR events are captured by the POR bit (RCON<1>).
The state of the bit is set to ‘0’ whenever a Power-on
Reset occurs; it does not change for any other Reset
event. POR is not reset to ‘1’ by any hardware event.
To capture multiple events, the user manually resets
the bit to ‘1’ in software following any POR.
5.4 Brown-out Reset (BOR)
The “F” devices in the PIC18F46J50 family incorporate
two types of BOR circuits: one which monitors
VDDCORE and one which monitors VDD. Only one BOR
circuit can be active at a time. When in normal Run
mode, Idle or normal Sleep modes, the BOR circuit that
monitors VDDCORE is active and will cause the device
to be held in BOR if VDDCORE drops below VBOR
(Parameter D005). Once VDDCORE rises back above
VBOR, the device will be held in Reset until the
expiration of the Power-up Timer, with period, TPWRT
(Parameter 33).
During Deep Sleep operation, the on-chip core voltage
regulator is disabled and VDDCORE is allowed to drop to
VSS. If the Deep Sleep BOR circuit is enabled by the
DSBOREN bit (CONFIG3L<2> = 1), it will monitor VDD.
If VDD drops below the VDSBOR threshold, the device
will be held in a Reset state similar to POR. All registers
will be set back to their Power-on Reset values and the
contents of the DSGPR0 and DSGPR1 holding regis-
ters will be lost. Additionally, if any I/O pins had been
configured as outputs during Deep Sleep, these pins
will be tri-stated and the device will no longer be held in
Deep Sleep. Once the VDD voltage recovers back
above the VDSBOR threshold, and once the core
voltage regulator achieves a VDDCORE voltage above
VBOR, the device will begin executing code again
normally, but the DS bit in the WDTCON register will
not be set. The device behavior will be similar to hard
cycling all power to the device.
On “LF” devices (ex: PIC18LF46J50), the VDDCORE
BOR circuit is always disabled because the internal
core voltage regulator is disabled. Instead of monitor-
ing VDDCORE, PIC18LF devices in this family can still
use the VDD BOR circuit to monitor VDD excursions
below the VDSBOR threshold. The VDD BOR circuit can
be disabled by setting the DSBOREN bit = 0.
The VDD BOR circuit is enabled when DSBOREN = 1
on “LF” devices, or on “F” devices while in Deep Sleep
with DSBOREN = 1. When enabled, the VDD BOR cir-
cuit is extremely low power (typ. 40nA) during normal
operation, above ~2.3V on VDD. If VDD drops below this
DSBOR arming level when the VDD BOR circuit is
enabled, the device may begin to consume additional
current (typ. 50 A) as internal features of the circuit
power-up. The higher current is necessary to achieve
more accurate sensing of the VDD level. However, the
device will not enter Reset until VDD falls below the
VDSBOR threshold.
5.4.1 DETECTING BOR
The BOR bit always resets to ‘0’ on any VDDCORE BOR
or POR event. This makes it difficult to determine if a
Brown-out Reset event has occurred just by reading
the state of BOR alone. A more reliable method is to
simultaneously check the state of both POR and BOR.
This assumes that the POR bit is reset to ‘1’ in software
immediately after any Power-on Reset event. If BOR is
0’ while POR is ‘1’, it can be reliably assumed that a
Brown-out Reset event has occurred.
If the voltage regulator is disabled (LF device), the
VDDCORE BOR functionality is disabled. In this case,
the BOR bit cannot be used to determine a Brown-out
Reset event. The BOR bit is still cleared by a Power-on
Reset event.
PIC18F46J50 FAMILY
DS39931D-page 66 2011 Microchip Technology Inc.
5.5 Configuration Mismatch (CM)
The Configuration Mismatch (CM) Reset is designed to
detect, and attempt to recover from, random memory
corrupting events. These include Electrostatic
Discharge (ESD) events, which can cause widespread
single-bit changes throughout the device, and result in
catastrophic failure.
In PIC18FXXJ Flash devices, the device Configuration
registers (located in the configuration memory space)
are continuously monitored during operation by com-
paring their values to complimentary shadow registers.
If a mismatch is detected between the two sets of
registers, a CM Reset automatically occurs. These
events are captured by the CM bit (RCON<5>). The
state of the bit is set to ‘0’ whenever a CM event occurs;
it does not change for any other Reset event.
A CM Reset behaves similarly to a MCLR, RESET
instruction, WDT time-out or Stack Event Resets. As
with all hard and power Reset events, the device
Configuration Words are reloaded from the Flash
Configuration Words in program memory as the device
restarts.
5.6 Power-up Timer (PWRT)
PIC18F46J50 family devices incorporate an on-chip
PWRT to help regulate the POR process. The PWRT is
always enabled. The main function is to ensure that the
device voltage is stable before code is executed.
The Power-up Timer (PWRT) of the PIC18F46J50 fam-
ily devices is a 5-bit counter which uses the INTRC
source as the clock input. This yields an approximate
time interval of 32 x 32 s = 1 ms. While the PWRT is
counting, the device is held in Reset.
The power-up time delay depends on the INTRC clock
and will vary from chip-to-chip due to temperature and
process variation. See DC Parameter 33 (TPWRT) for
details.
5.6.1 TIME-OUT SEQUENCE
The PWRT time-out is invoked after the POR pulse has
cleared. The total time-out will vary based on the status
of the PWRT. Figure 5-2, Figure 5-3, Figure 5-4 and
Figure 5-5 all depict time-out sequences on power-up
with the PWRT.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, the PWRT will expire. Bringing
MCLR high will begin execution immediately if a clock
source is available (Figure 5-4). This is useful for
testing purposes, or to synchronize more than one
PIC18F device operating in parallel.
FIGURE 5-2: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)
TPWRT
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
2011 Microchip Technology Inc. DS39931D-page 67
PIC18F46J50 FAMILY
FIGURE 5-3: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
FIGURE 5-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
FIGURE 5-5: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > T PWRT)
TPWRT
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
TPWRT
VDD
MCLR
INTERNAL POR
PWRT TIME-OUT
INTERNAL RESET
0V 1V
3.3V
TPWRT
PIC18F46J50 FAMILY
DS39931D-page 68 2011 Microchip Technology Inc.
5.7 Reset State of Registers
Most registers are unaffected by a Reset. Their status
is unknown on POR and unchanged by all other
Resets. The other registers are forced to a “Reset
state” depending on the type of Reset that occurred.
Most registers are not affected by a WDT wake-up,
since this is viewed as the resumption of normal
operation. Status bits from the RCON register (CM, RI,
TO, PD, POR and BOR) are set or cleared differently in
different Reset situations, as indicated in Tab l e 5 -1.
These bits are used in software to determine the nature
of the Reset.
Table 5-2 describes the Reset states for all of the
Special Function Registers. These are categorized by
POR and BOR, MCLR and WDT Resets and WDT
wake-ups.
TABLE 5-1: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR
RCON REGISTER
Condition Program
Counter(1) RCON Register STKPTR Register
CM RI TO PD POR BOR STKFUL STKUNF
Power-on Reset 0000h 111100 0 0
RESET instruction 0000h u0uuuu u u
Brown-out Reset 0000h 1111u0 u u
Configuration Mismatch Reset 0000h 0uuuuu u u
MCLR Reset during
power-managed Run modes
0000h uu1uuu u u
MCLR Reset during
power-managed Idle modes and
Sleep mode
0000h uu10uu u u
MCLR Reset during full-power
execution
0000h uuuuuu u u
Stack Full Reset (STVREN = 1) 0000h uuuuuu 1 u
Stack Underflow Reset
(STVREN = 1)
0000h uuuuuu u 1
Stack Underflow Error (not an
actual Reset, STVREN = 0)
0000h uuuuuu u 1
WDT time-out during full-power
or power-managed Run modes
0000h uu0uuu u u
WDT time-out during
power-managed Idle or Sleep
modes
PC + 2 uu00uu u u
Interrupt exit from
power-managed modes
PC + 2 uuu0uu u u
Legend: u = unchanged
Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bit is set, the PC is loaded with the
interrupt vector (0008h or 0018h).
2011 Microchip Technology Inc. DS39931D-page 69
PIC18F46J50 FAMILY
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
TOSU PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu(1)
TOSH PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu(1)
TOSL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu(1)
STKPTR PIC18F2XJ50 PIC18F4XJ50 00-0 0000 uu-0 0000 uu-u uuuu(1)
PCLATU PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
PCLATH PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PCL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 PC + 2(2)
TBLPTRU PIC18F2XJ50 PIC18F4XJ50 --00 0000 --00 0000 --uu uuuu
TBLPTRH PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TBLPTRL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TABLAT PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PRODH PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
PRODL PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
INTCON PIC18F2XJ50 PIC18F4XJ50 0000 000x 0000 000u uuuu uuuu(3)
INTCON2 PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu(3)
INTCON3 PIC18F2XJ50 PIC18F4XJ50 1100 0000 1100 0000 uuuu uuuu(3)
INDF0 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
POSTINC0 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
POSTDEC0 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
PREINC0 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
PLUSW0 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
FSR0H PIC18F2XJ50 PIC18F4XJ50 ---- 0000 ---- 0000 ---- uuuu
FSR0L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
WREG PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
INDF1 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
POSTINC1 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
POSTDEC1 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
PREINC1 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
PLUSW1 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
FSR1H PIC18F2XJ50 PIC18F4XJ50 ---- 0000 ---- 0000 ---- uuuu
FSR1L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
BSR PIC18F2XJ50 PIC18F4XJ50 ---- 0000 ---- 0000 ---- uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
PIC18F46J50 FAMILY
DS39931D-page 70 2011 Microchip Technology Inc.
INDF2 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
POSTINC2 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
POSTDEC2 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
PREINC2 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
PLUSW2 PIC18F2XJ50 PIC18F4XJ50 N/A N/A N/A
FSR2H PIC18F2XJ50 PIC18F4XJ50 ---- 0000 ---- 0000 ---- uuuu
FSR2L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
STATUS PIC18F2XJ50 PIC18F4XJ50 ---x xxxx ---u uuuu ---u uuuu
TMR0H PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TMR0L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
T0CON PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
OSCCON PIC18F2XJ50 PIC18F4XJ50 0110 q100 0110 q100 uuuu q1uu
CM1CON PIC18F2XJ50 PIC18F4XJ50 0001 1111 0001 1111 uuuu uuuu
CM2CON PIC18F2XJ50 PIC18F4XJ50 0001 1111 0001 1111 uuuu uuuu
RCON(4) PIC18F2XJ50 PIC18F4XJ50 0-11 11qq 0-qq qquu u-qq qquu
TMR1H PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
TMR1L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
T1CON PIC18F2XJ50 PIC18F4XJ50 0000 0000 uuuu uuuu uuuu uuuu
TMR2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PR2 PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
T2CON PIC18F2XJ50 PIC18F4XJ50 -000 0000 -000 0000 -uuu uuuu
SSP1BUF PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
SSP1ADD PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SSP1MSK PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
SSP1STAT PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SSP1CON1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SSP1CON2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
ADRESH PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
ADRESL PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
ADCON0 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
ADCON1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
WDTCON PIC18F2XJ50 PIC18F4XJ50 1qq- q000 1qq- 0000 uqq- uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
2011 Microchip Technology Inc. DS39931D-page 71
PIC18F46J50 FAMILY
PSTR1CON PIC18F2XJ50 PIC18F4XJ50 00-0 0001 00-0 0001 uu-u uuuu
ECCP1AS PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
ECCP1DEL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
CCPR1H PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
CCPR1L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
CCP1CON PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PSTR2CON PIC18F2XJ50 PIC18F4XJ50 00-0 0001 00-0 0001 uu-u uuuu
ECCP2AS PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
ECCP2DEL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
CCPR2H PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
CCPR2L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
CCP2CON PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
CTMUCONH PIC18F2XJ50 PIC18F4XJ50 0-00 000- 0-00 000- u-uu uuu-
CTMUCONL PIC18F2XJ50 PIC18F4XJ50 0000 00xx 0000 00xx uuuu uuuu
CTMUICON PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SPBRG1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
RCREG1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TXREG1 PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx 0000 0000 uuuu uuuu
TXSTA1 PIC18F2XJ50 PIC18F4XJ50 0000 0010 0000 0010 uuuu uuuu
RCSTA1 PIC18F2XJ50 PIC18F4XJ50 0000 000x 0000 000x uuuu uuuu
SPBRG2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
RCREG2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TXREG2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TXSTA2 PIC18F2XJ50 PIC18F4XJ50 0000 0010 0000 0010 uuuu uuuu
EECON2 PIC18F2XJ50 PIC18F4XJ50 ---- ---- ---- ---- ---- ----
EECON1 PIC18F2XJ50 PIC18F4XJ50 --00 x00- --00 q00- --00 u00-
IPR3 PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
PIR3 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu(3)
PIE3 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
IPR2 PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
PIR2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu(3)
PIE2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
PIC18F46J50 FAMILY
DS39931D-page 72 2011 Microchip Technology Inc.
IPR1 PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
PIR1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu(3)
PIE1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
RCSTA2 PIC18F2XJ50 PIC18F4XJ50 0000 000x 0000 000x uuuu uuuu
OSCTUNE PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
T1GCON PIC18F2XJ50 PIC18F4XJ50 0000 0x00 0000 0x00 uuuu uxuu
RTCVALH PIC18F2XJ50 PIC18F4XJ50 0xxx xxxx 0uuu uuuu 0uuu uuuu
RTCVALL PIC18F2XJ50 PIC18F4XJ50 0xxx xxxx 0uuu uuuu 0uuu uuuu
T3GCON PIC18F2XJ50 PIC18F4XJ50 0000 0x00 uuuu uxuu uuuu uxuu
TRISE(5) PIC18F4XJ50 ---- -111 ---- -111 ---- -uuu
TRISD(5) PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
TRISC PIC18F2XJ50 PIC18F4XJ50 11-- -111 11-- -111 uu-- -uuu
TRISB PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
TRISA PIC18F2XJ50 PIC18F4XJ50 111- 1111 111- 1111 uuu- uuuu
ALRMCFG PIC18F2XJ50 PIC18F4XJ50 0000 0000 uuuu uuuu uuuu uuuu
ALRMRPT PIC18F2XJ50 PIC18F4XJ50 0000 0000 uuuu uuuu uuuu uuuu
ALRMVALH PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
ALRMVALL PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
LATE(5) PIC18F4XJ50 ---- -xxx ---- -uuu ---- -uuu
LATD(5) PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
LATC PIC18F2XJ50 PIC18F4XJ50 xx-- -xxx uu-- -uuu uu-- -uuu
LATB PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
LATA PIC18F2XJ50 PIC18F4XJ50 xxx- xxxx uuu- uuuu uuu- uuuu
DMACON1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
DMACON2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
HLVDCON PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PORTE(5) PIC18F4XJ50 00-- -xxx uu-- -uuu uu-- -uuu
PORTD(5) PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
PORTC PIC18F2XJ50 PIC18F4XJ50 xxxx -xxx uuuu -uuu uuuu -uuu
PORTB PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
PORTA PIC18F2XJ50 PIC18F4XJ50 xxx- xxxx uuu- uuuu uuu- uuuu
SPBRGH1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
2011 Microchip Technology Inc. DS39931D-page 73
PIC18F46J50 FAMILY
BAUDCON1 PIC18F2XJ50 PIC18F4XJ50 0100 0-00 0100 0-00 uuuu u-uu
SPBRGH2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
BAUDCON2 PIC18F2XJ50 PIC18F4XJ50 0100 0-00 0100 0-00 uuuu u-uu
TMR3H PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
TMR3L PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
T3CON PIC18F2XJ50 PIC18F4XJ50 0000 0000 uuuu uuuu uuuu uuuu
TMR4 PIC18F2XJ50 PIC18F4XJ50 0000 0000 uuuu uuuu uuuu uuuu
PR4 PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
T4CON PIC18F2XJ50 PIC18F4XJ50 -000 0000 -000 0000 -uuu uuuu
SSP2BUF PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx uuuu uuuu uuuu uuuu
SSP2ADD PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SSP2MSK PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SSP2STAT PIC18F2XJ50 PIC18F4XJ50 1111 1111 1111 1111 uuuu uuuu
SSP2CON1 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
SSP2CON2 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
CMSTAT PIC18F2XJ50 PIC18F4XJ50 ---- --11 ---- --11 ---- --uu
PMADDRH(5) PIC18F4XJ50 -000 0000 -000 0000 -uuu uuuu
PMDOUT1H(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMADDRL(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDOUT1L(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDIN1H(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDIN1L(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TXADDRL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TXADDRH PIC18F2XJ50 PIC18F4XJ50 ---- 0000 ---- 0000 ---- uuuu
RXADDRL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
RXADDRH PIC18F2XJ50 PIC18F4XJ50 ---- 0000 ---- 0000 ---- uuuu
DMABCL PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
DMABCH PIC18F2XJ50 PIC18F4XJ50 ---- --00 ---- --00 ---- --uu
UCON PIC18F2XJ50 PIC18F4XJ50 -0x0 000- -0x0 000- -uuu uuu-
USTAT PIC18F2XJ50 PIC18F4XJ50 -xxx xxx- -xxx xxx- -uuu uuu-
UEIR PIC18F2XJ50 PIC18F4XJ50 0--0 0000 0--0 0000 u--u uuuu
UIR PIC18F2XJ50 PIC18F4XJ50 -000 0000 -000 0000 -uuu uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
PIC18F46J50 FAMILY
DS39931D-page 74 2011 Microchip Technology Inc.
UFRMH PIC18F2XJ50 PIC18F4XJ50 ---- -xxx ---- -xxx ---- -uuu
UFRML PIC18F2XJ50 PIC18F4XJ50 xxxx xxxx xxxxx xxxx uuuu uuuu
PMCONH(5) PIC18F4XJ50 0--0 0000 0--0 0000 u--u uuuu
PMCONL(5) PIC18F4XJ50 000- 0000 000- 0000 uuu- uuuu
PMMODEH(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMMODEL(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDOUT2H(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDOUT2L(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDIN2H(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMDIN2L(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMEH(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMEL(5) PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
PMSTATH PIC18F4XJ50 00-- 0000 00-- 0000 uu-- uuuu
PMSTATL PIC18F4XJ50 10-- 1111 10-- 1111 uu-- uuuu
CVRCON PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
TCLKCON PIC18F2XJ50 PIC18F4XJ50 ---0 --00 ---0 --uu ---u --uu
DSGPR1(6) PIC18F2XJ50 PIC18F4XJ50 uuuu uuuu uuuu uuuu uuuu uuuu
DSGPR0(6) PIC18F2XJ50 PIC18F4XJ50 uuuu uuuu uuuu uuuu uuuu uuuu
DSCONH(6) PIC18F2XJ50 PIC18F4XJ50 0--- -000 0--- -uuu u--- -uuu
DSCONL(6) PIC18F2XJ50 PIC18F4XJ50 ---- -000 ---- -u00 ---- -uuu
DSWAKEH(6) PIC18F2XJ50 PIC18F4XJ50 ---- ---0 ---- ---0 ---- ---u
DSWAKEL(6) PIC18F2XJ50 PIC18F4XJ50 0-00 00-1 0-00 00-0 u-uu uu-u
ANCON1 PIC18F2XJ50 PIC18F4XJ50 00-0 0000 00-0 0000 uu-u uuuu
ANCON0 PIC18F2XJ50 PIC18F4XJ50 0000 0000 0000 0000 uuuu uuuu
ODCON1 PIC18F2XJ50 PIC18F4XJ50 ---- --00 ---- --uu ---- --uu
ODCON2 PIC18F2XJ50 PIC18F4XJ50 ---- --00 ---- --uu ---- --uu
ODCON3 PIC18F2XJ50 PIC18F4XJ50 ---- --00 ---- --uu ---- --uu
RTCCFG PIC18F2XJ50 PIC18F4XJ50 0-00 0000 u-uu uuuu u-uu uuuu
RTCCAL PIC18F2XJ50 PIC18F4XJ50 0000 0000 uuuu uuuu uuuu uuuu
REFOCON PIC18F2XJ50 PIC18F4XJ50 0-00 0000 0-00 0000 u-uu uuuu
PADCFG1 PIC18F2XJ50 PIC18F4XJ50 ---- -000 ---- -000 ---- -uuu
UCFG PIC18F2XJ50 PIC18F4XJ50 00-0 0000 00-0 0000 uu-u uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
2011 Microchip Technology Inc. DS39931D-page 75
PIC18F46J50 FAMILY
UADDR PIC18F2XJ50 PIC18F4XJ50 -000 0000 -uuu uuuu -uuu uuuu
UEIE PIC18F2XJ50 PIC18F4XJ50 0--0 0000 0--0 0000 u--u uuuu
UIE PIC18F2XJ50 PIC18F4XJ50 -000 0000 -000 0000 -uuu uuuu
UEP15 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP14 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP13 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP12 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP11 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP10 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP9 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP8 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP7 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP6 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP5 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP4 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP3 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP2 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP1 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
UEP0 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
PPSCON PIC18F2XJ50 PIC18F4XJ50 ---- ---0 ---- ---0 ---- ---u
RPINR24 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR23 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR22 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR21 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR17 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR16 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR13 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR12 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR8 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR7 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR6 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR4 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
PIC18F46J50 FAMILY
DS39931D-page 76 2011 Microchip Technology Inc.
RPINR3 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR2 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPINR1 PIC18F2XJ50 PIC18F4XJ50 ---1 1111 ---1 1111 ---u uuuu
RPOR24 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR23 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR22 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR21 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR20 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR19 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR18 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR17 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR13 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR12 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR11 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR10 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR9 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR8 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR7 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR6 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR5 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR4 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR3 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR2 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR1 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
RPOR0 PIC18F2XJ50 PIC18F4XJ50 ---0 0000 ---0 0000 ---u uuuu
TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Register Applicable Devices
Power-on Reset,
Brown-out Reset,
Wake From Deep
Sleep
MCLR Rese ts
WDT Reset
RESET Instruction
Stack Reset s
CM Resets
W ake-up via WDT
or Interrupt
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as ‘0’, q = value depends on condition.
Note 1: When the wake-up is due to an interrupt and the GIEH (and GIEL if low priority) bit(s) are set, the TOSU,
TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the
next location in the hardware stack.
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt
vector (0008h or 0018h).
3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
4: See Ta bl e 5 - 1 for Reset value for specific condition.
5: Not implemented on PIC18F2XJ50 devices.
6: Not implemented on “LF” devices.
2011 Microchip Technology Inc. DS39931D-page 77
PIC18F46J50 FAMILY
6.0 MEMORY ORGANIZATION
There are two types of memory in PIC18 Flash
microcontrollers:
Program Memory
Data RAM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for
concurrent access of the two memory spaces.
Section 7.0 “Flash Program Memory” provides
additional information on the operation of the Flash
program memory.
6.1 Program Memory Organization
PIC18 microcontrollers implement a 21-bit Program
Counter, which is capable of addressing a 2-Mbyte
program memory space. Accessing a location between
the upper boundary of the physically implemented
memory and the 2-Mbyte address returns all ‘0’s (a
NOP instruction).
The PIC18F46J50 family offers a range of on-chip
Flash program memory sizes, from 16 Kbytes (up to
8,192 single-word instructions) to 64 Kbytes
(32,768 single-word instructions).
Figure 6-1 provides the program memory maps for
individual family devices.
FIGURE 6- 1 : MEMORY MA PS FOR PIC 18F46 J5 0 F AMIL Y DE VIC ES
Note: Sizes of memory areas are not to scale. Sizes of program memory areas are enhanced to show detail.
Unimplemented
Read as ‘0
Unimplemented
Read as ‘0
Unimplemented
Read as ‘0
000000h
1FFFFFF
003FFFh
007FFFh
00FFFFh
PC<20:0>
Stack Level 1
Stack Level 31
CALL, CALLW, RCALL,
RETURN, RET FIE , RETLW,
21
User Memory Space
On-Chip
Memory
On-Chip
Memory
On-Chip
Memory
ADDULNK, SUBULNK
Config. Words
Config. Words
Config. Words
PIC18FX4J50 PIC18FX5J50 PIC18FX6J50
PIC18F46J50 FAMILY
DS39931D-page 78 2011 Microchip Technology Inc.
6.1.1 HARD MEMORY VECTORS
All PIC18 devices have a total of three hard-coded
return vectors in their program memory space. The
Reset vector address is the default value to which the
Program Counter returns on all device Resets; it is
located at 0000h.
PIC18 devices also have two interrupt vector
addresses for handling high-priority and low-priority
interrupts. The high-priority interrupt vector is located at
0008h and the low-priority interrupt vector at 0018h.
Figure 6-2 provides their locations in relation to the
program memory map.
FIGU RE 6-2: HARD VECTOR AN D
CONFIGURATION WORD
LOCATIONS FOR
PIC18F 46 J50 FAM ILY
DEVICES
6.1.2 FLASH CONFIGURATION WORDS
Because PIC18F46J50 family devices do not have
persistent configuration memory, the top four words of
on-chip program memory are reserved for configuration
information. On Reset, the configuration information is
copied into the Configuration registers.
The Configuration Words are stored in their program
memory location in numerical order, starting with the
lower byte of CONFIG1 at the lowest address and
ending with the upper byte of CONFIG4.
Table 6-1 provides the actual addresses of the Flash
Configuration Word for devices in the PIC18F46J50
family. Figure 6-2 displays their location in the memory
map with other memory vectors.
Additional details on the device Configuration Words
are provided in Secti on 27.1 “Configuration Bits”.
TABLE 6-1: FLASH CONFIGURATION
WORD FOR PIC18F46J50
FAMILY DEVICES
Reset Vector
Low-Priority Interrupt Vector
0000h
0018h
On-Chip
Program Memory
High-Priority Interrupt Vector 0008h
1FFFFFh
(Top of Memory)
(Top of Memory-7)
Flash Configuration Words
Read as ‘0
Legend: (Top of Memory) represents upper boundary
of on-chip program memory space (see
Figure 6-1 for device-specific values).
Shaded area represents unimplemented
memory. Areas are not shown to scale.
Device Program
Memory
(Kbytes)
Configuration
Word
Addresses
PIC18F24J50 16 3FF8h to 3FFFh
PIC18F44J50
PIC18F25J50 32 7FF8h to 7FFFh
PIC18F45J50
PIC18F26J50 64 FFF8h to FFFFh
PIC18F46J50
2011 Microchip Technology Inc. DS39931D-page 79
PIC18F46J50 FAMILY
6.1.3 PROGRAM COUNTER
The Program Counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 21 bits wide
and is contained in three separate 8-bit registers. The
low byte, known as the PCL register, is both readable
and writable. The high byte, or PCH register, contains
the PC<15:8> bits; it is not directly readable or writable.
Updates to the PCH register are performed through the
PCLATH register. The upper byte is called PCU. This
register contains the PC<20:16> bits; it is also not
directly readable or writable. Updates to the PCU
register are performed through the PCLATU register.
The contents of PCLATH and PCLATU are transferred
to the Program Counter by any operation that writes to
PCL. Similarly, the upper 2 bytes of the Program
Counter are transferred to PCLATH and PCLATU by an
operation that reads PCL. This is useful for computed
offsets to the PC (see Section 6.1.6.1 “Computed
GOTO”).
The PC addresses bytes in the program memory. To
prevent the PC from becoming misaligned with word
instructions, the Least Significant bit (LSb) of PCL is
fixed to a value of 0’. The PC increments by two to
address sequential instructions in the program
memory.
The CALL, RCALL, GOTO and program branch
instructions write to the Program Counter directly. For
these instructions, the contents of PCLATH and
PCLATU are not transferred to the Program Counter.
6.1.4 RETURN ADDRESS STACK
The return address stack allows any combination of up
to 31 program calls and interrupts to occur. The PC is
pushed onto the stack when a CALL or RCALL instruc-
tion is executed, or an interrupt is Acknowledged. The
PC value is pulled off of the stack on a RETURN,
RETLW or a RETFIE instruction (and on ADDULNK and
SUBULNK instructions if the extended instruction set is
enabled). PCLATU and PCLATH are not affected by
any of the RETURN or CALL instructions.
The stack operates as a 31-word by 21-bit RAM and a
5-bit Stack Pointer (SP), STKPTR. The stack space is
not part of either program or data space. The Stack
Pointer is readable and writable and the address on the
top of the stack is readable and writable through the
Top-of-Stack Special Function Registers (SFRs). Data
can also be pushed to, or popped from the stack, using
these registers.
A CALL type instruction causes a push onto the stack.
The Stack Pointer is first incremented and the location
pointed to by the Stack Pointer is written with the
contents of the PC (already pointing to the instruction
following the CALL). A RETURN type instruction causes
a pop from the stack. The contents of the location
pointed to by the STKPTR are transferred to the PC
and then the Stack Pointer is decremented.
The Stack Pointer is initialized to ‘00000 after all
Resets. There is no RAM associated with the location
corresponding to a Stack Pointer value of ‘00000’; this
is only a Reset value. Status bits indicate if the stack is
full, has overflowed or has underflowed.
6.1.4.1 Top-of-Stack Access
Only the top of the return address stack (TOS) is read-
able and writable. A set of three registers,
TOSU:TOSH:TOSL, holds the contents of the stack
location pointed to by the STKPTR register
(Figure 6-3). This allows users to implement a software
stack if necessary. After a CALL, RCALL or interrupt
(and ADDULNK and SUBULNK instructions if the
extended instruction set is enabled), the software can
read the pushed value by reading the
TOSU:TOSH:TOSL registers. These values can be
placed on a user-defined software stack. At return time,
the software can return these values to
TOSU:TOSH:TOSL and do a return.
The user must disable the Global Interrupt Enable bits
while accessing the stack to prevent inadvertent stack
corruption.
FI GURE 6- 3: RETUR N ADDR ESS ST A CK AND AS SOCIAT ED RE GIS T ERS
00011
001A34h
11111
11110
11101
00010
00001
00000
00010
Return Address Stack <20:0>
To p - o f - St a c k
000D58h
TOSLTOSHTOSU
34h1Ah00h
STKPTR<4:0>
Top-of-Stack Registers Stack Pointer
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6.1.4.2 Return Stack Pointer (STKPTR)
The STKPTR register (Register 6-1) contains the Stack
Pointer value, the STKFUL (Stack Full) and the
STKUNF (Stack Underflow) status bits. The value of
the Stack Pointer can be 0 through 31. The Stack
Pointer increments before values are pushed onto the
stack and decrements after values are popped off the
stack. On Reset, the Stack Pointer value will be zero.
The user may read and write the Stack Pointer value.
This feature can be used by a Real-Time Operating
System (RTOS) for return stack maintenance.
After the PC is pushed onto the stack 31 times (without
popping any values off the stack), the STKFUL bit is
set. The STKFUL bit is cleared by software or by a
Power-on Reset (POR).
The action that takes place when the stack becomes
full depends on the state of the Stack Overflow Reset
Enable (STVREN) Configuration bit.
Refer to Section 27.1 “Confi guration Bit s” for device
Configuration bits’ description.
If STVREN is set (default), the 31st push will push the
(PC + 2) value onto the stack, set the STKFUL bit and
reset the device. The STKFUL bit will remain set and
the Stack Pointer will be set to zero.
If STVREN is cleared, the STKFUL bit will be set on the
31st push and the Stack Pointer will increment to 31.
Any additional pushes will not overwrite the 31st push
and the STKPTR will remain at 31.
When the stack has been popped enough times to
unload the stack, the next pop will return zero to the PC
and set the STKUNF bit, while the Stack Pointer
remains at zero. The STKUNF bit will remain set until
cleared by software or until a POR occurs.
6.1.4.3 PUSH and POP Instructions
Since the Top-of-Stack is readable and writable, the
ability to push values onto the stack and pull values off
the stack, without disturbing normal program execution
is necessary. The PIC18 instruction set includes two
instructions, PUSH and POP, that permit the TOS to be
manipulated under software control. TOSU, TOSH and
TOSL can be modified to place data or a return address
on the stack.
The PUSH instruction places the current PC value onto
the stack. This increments the Stack Pointer and loads
the current PC value onto the stack.
The POP instruction discards the current TOS by
decrementing the Stack Pointer. The previous value
pushed onto the stack then becomes the TOS value.
Note: Returning a value of zero to the PC on an
underflow has the effect of vectoring the
program to the Reset vector, where the
stack conditions can be verified and
appropriate actions can be taken. This is
not the same as a Reset, as the contents
of the SFRs are not affected.
REGISTER 6-1: STKPTR: STACK POINTER REGISTER (ACCESS FFCh)
R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
STKFUL(1) STKUNF(1) SP4 SP3 SP2 SP1 SP0
bit 7 bit 0
Legend: C = Clearable bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 STKFUL: Stack Full Flag bit(1)
1 = Stack became full or overflowed
0 = Stack has not become full or overflowed
bit 6 STKUNF: Stack Underflow Flag bit(1)
1 = Stack underflow occurred
0 = Stack underflow did not occur
bit 5 Unimplemented: Read as ‘0
bit 4-0 SP<4:0>: Stack Pointer Location bits
Note 1: Bits 7 and 6 are cleared by user software or by a POR.
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6.1.4.4 Stack Full and Underflow Resets
Device Resets on stack overflow and stack underflow
conditions are enabled by setting the STVREN bit in
Configuration Register 1L. When STVREN is set, a full
or underflow condition sets the appropriate STKFUL or
STKUNF bit and then causes a device Reset. When
STVREN is cleared, a full or underflow condition sets
the appropriate STKFUL or STKUNF bit, but does not
cause a device Reset. The STKFUL or STKUNF bits
are cleared by the user software or a POR.
6.1.5 FAST REGISTER STACK (FRS)
A Fast Register Stack (FRS) is provided for the
STATUS, WREG and BSR registers to provide a “fast
return” option for interrupts. This stack is only one level
deep and is neither readable nor writable. It is loaded
with the current value of the corresponding register
when the processor vectors for an interrupt. All inter-
rupt sources push values into the Stack registers. The
values in the registers are then loaded back into the
working registers if the RETFIE,FAST instruction is
used to return from the interrupt.
If both low-priority and high-priority interrupts are
enabled, the Stack registers cannot be used reliably to
return from low-priority interrupts. If a high-priority
interrupt occurs while servicing a low-priority interrupt,
the Stack register values stored by the low-priority
interrupt will be overwritten. In these cases, users must
save the key registers in software during a low-priority
interrupt.
If interrupt priority is not used, all interrupts may use the
FRS for returns from interrupt. If no interrupts are used,
the FRS can be used to restore the STATUS, WREG
and BSR registers at the end of a subroutine call. To
use the Fast Register Stack for a subroutine call, a
CALL label, FAST instruction must be executed to
save the STATUS, WREG and BSR registers to the
Fast Register Stack. A RETURN,FAST instruction is
then executed to restore these registers from the FRS.
Example 6-1 provides a source code example that
uses the FRS during a subroutine call and return.
EXAMPLE 6-1: FAST REGISTER STACK
CODE EXAMPLE
6.1.6 LOOK-UP TABLES IN PROGRAM
MEMORY
There may be programming situations that require the
creation of data structures or look-up tables in program
memory. For PIC18 devices, look-up tables can be
implemented in two ways:
Computed GOTO
Table Reads
6.1.6.1 Computed GOTO
A computed GOTO is accomplished by adding an offset
to the PC. An example is shown in Example 6-2.
A look-up table can be formed with an ADDWF PCL
instruction and a group of RETLW nn instructions. The
W register is loaded with an offset into the table before
executing a call to that table. The first instruction of the
called routine is the ADDWF PCL instruction. The next
executed instruction will be one of the RETLW nn
instructions that returns the value, ‘nn’, to the calling
function.
The offset value (in WREG) specifies the number of
bytes that the PC should advance and should be
multiples of 2 (LSb = 0).
In this method, only one byte may be stored in each
instruction location, room on the return address stack is
required.
EXAMPLE 6-2: COMPUTED GOTO USING
AN OFFSET V ALUE
6.1.6.2 Table Reads
A better method of storing data in program memory
allows two bytes to be stored in each instruction
location.
Look-up table data may be stored two bytes per
program word while programming. The Table Pointer
(TBLPTR) specifies the byte address, and the Table
Latch (TABLAT) contains the data that is read from the
program memory. Data is transferred from program
memory one byte at a time.
Table read operation is discussed further in
Section 7.1 “Table Reads and Table Writes”.
CALL SUB1, FAST ;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
SUB1
RETURN FAST ;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
MOVF OFFSET, W
CALL TABLE
ORG nn00h
TABLE ADDWF PCL
RETLW nnh
RETLW nnh
RETLW nnh
.
.
.
PIC18F46J50 FAMILY
DS39931D-page 82 2011 Microchip Technology Inc.
6.2 PIC18 Instruction Cycle
6.2.1 CLOCKING SCHEME
The microcontroller clock input, whether from an
internal or external source, is internally divided by four
to generate four non-overlapping quadrature clocks
(Q1, Q2, Q3 and Q4). Internally, the PC is incremented
on every Q1; the instruction is fetched from the pro-
gram memory and latched into the Instruction Register
(IR) during Q4. The instruction is decoded and exe-
cuted during the following Q1 through Q4. Figure 6-4
illustrates the clocks and instruction execution flow.
6.2.2 INSTRUCTION FLOW/PIPELINING
An “Instruction Cycle” consists of four Q cycles, Q1
through Q4. The instruction fetch and execute are pipe-
lined in such a manner that a fetch takes one instruction
cycle, while the decode and execute takes another
instruction cycle. However, due to the pipelining, each
instruction effectively executes in one cycle. If an
instruction causes the PC to change (e.g., GOTO), then
two cycles are required to complete the instruction
(Example 6-3).
A fetch cycle begins with the PC incrementing in Q1.
In the execution cycle, the fetched instruction is latched
into the IR in the Q1 cycle. This instruction is then
decoded and executed during the Q2, Q3 and Q4
cycles. Data memory is read during Q2 (operand read)
and written during Q4 (destination write).
FIGU RE 6-4 : CLOC K/INST RUCT IO N C YC LE
EXAMPLE 6-3: INSTRUCTION PIPELINE FLOW
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
Q1
Q2
Q3
Q4
PC
OSC2/CLKO
(RC mode)
PC PC + 2 PC + 4
Fetch INST (PC)
Execute INST (PC – 2)
Fetch INST (PC + 2)
Execute INST (PC)
Fetch INST (PC + 4)
Execute INST (PC + 2)
Internal
Phase
Clock
Note: All instructions are single-cycle, except for any program branches. These take two cycles since the
fetch instruction is “flushed” from the pipeline while the new instruction is being fetched and then exe-
cuted.
TCY0TCY1TCY2TCY3TCY4TCY5
1. MOVLW 55h Fetch 1 Execute 1
2. MOVWF LATB Fetch 2 Execute 2
3. BRA SUB_1 Fetch 3 Execute 3
4. BSF LATA, 3 (Forced NOP) Fetch 4 Flush (NOP)
5. Instruction @ address SUB_1 Fetch SUB_1 Execute SUB_1
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6.2.3 INSTRUCTIONS IN PROGRAM
MEMORY
The program memory is addressed in bytes. Instruc-
tions are stored as 2 bytes or 4 bytes in program
memory. The Least Significant Byte (LSB) of an
instruction word is always stored in a program memory
location with an even address (LSB = 0). To maintain
alignment with instruction boundaries, the PC
increments in steps of 2 and the LSB will always read
0’ (see Section 6.1.3 “Program Counter”).
Figure 6-5 provides an example of how instruction
words are stored in the program memory.
The CALL and GOTO instructions have the absolute
program memory address embedded into the instruc-
tion. Since instructions are always stored on word
boundaries, the data contained in the instruction is a
word address. The word address is written to PC<20:1>,
which accesses the desired byte address in program
memory. Instruction #2 in Figure 6-5 displays how the
instruction, GOTO 0006h, is encoded in the program
memory. Program branch instructions, which encode a
relative address offset, operate in the same manner. The
offset value stored in a branch instruction represents the
number of single-word instructions that the PC will be
offset by. Section 28.0 “Instruction Set Summary”
provides further details of the instruction set.
FIGURE 6-5: INSTRUCTIONS IN PROGRAM MEMORY
6.2.4 TWO-WORD INSTRUCTIONS
The standard PIC18 instruction set has four, two-word
instructions: CALL, MOVFF, GOTO and LSFR. In all
cases, the second word of the instructions always has
1111’ as its four Most Significant bits (MSbs); the other
12 bits are literal data, usually a data memory address.
The use of1111’ in the 4 MSbs of an instruction
specifies a special form of NOP. If the instruction is
executed in proper sequence immediately after the first
word, the data in the second word is accessed and
used by the instruction sequence. If the first word is
skipped for some reason and the second word is
executed by itself, a NOP is executed instead. This is
necessary for cases when the two-word instruction is
preceded by a conditional instruction that changes the
PC. Example 6-4 illustrates how this works.
EXAMPLE 6-4: TWO-WORD INSTRUCTIONS
Word Address
LSB = 1LSB = 0
Program Memory
Byte Locations
000000h
000002h
000004h
000006h
Instruction 1: MOVLW 055h 0Fh 55h 000008h
Instruction 2: GOTO 0006h EFh 03h 00000Ah
F0h 00h 00000Ch
Instruction 3: MOVFF 123h, 456h C1h 23h 00000Eh
F4h 56h 000010h
000012h
000014h
Note: See Section 6.5 “Program Memory and
the Extended Instruction Set” for infor-
mation on two-word instructions in the
extended instruction set.
CASE 1:
Object Code Source Code
0110 01 10 000 0 00 00 TS TFS Z REG1 ; is RA M lo ca ti on 0?
1100 0001 0010 0011 MOVFF REG1, REG2 ; No, skip this word
1111 0100 0101 0110 ; Execute this word as a NOP
0010 0100 0000 0000 ADDWF REG3 ; continue code
CASE 2:
Object Code Source Code
0110 01 10 000 0 00 00 TS TF SZ REG1 ; is RA M lo ca ti on 0?
1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes, ex ec ut e th is wor d
1111 0100 0101 0110 ; 2nd word of instruction
0010 01 00 000 0 00 00 AD DW F REG 3 ; con ti nu e co de
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DS39931D-page 84 2011 Microchip Technology Inc.
6.3 Data Memory Organization
The data memory in PIC18 devices is implemented as
static RAM. Each register in the data memory has a
12-bit address, allowing up to 4096 bytes of data
memory. The memory space is divided into as many as
16 banks that contain 256 bytes each. The
PIC18F46J50 family implements all available banks
and provides 3.8 Kbytes of data memory available to
the user. Figure 6-6 provides the data memory
organization for the devices.
The data memory contains Special Function Registers
(SFRs) and General Purpose Registers (GPRs). The
SFRs are used for control and status of the controller
and peripheral functions, while GPRs are used for data
storage and scratchpad operations in the user’s
application. Any read of an unimplemented location will
read as ‘0’s.
The instruction set and architecture allow operations
across all banks. The entire data memory may be
accessed by Direct, Indirect or Indexed Addressing
modes. Addressing modes are discussed later in this
section.
To ensure that commonly used registers (select SFRs
and select GPRs) can be accessed in a single cycle,
PIC18 devices implement an Access Bank. This is a
256-byte memory space that provides fast access to
select SFRs and the lower portion of GPR Bank 0 with-
out using the BSR. Section 6.3.3 “Access Bank”
provides a detailed description of the Access RAM.
6.3.1 USB RAM
All 3.8 Kbytes of the GPRs implemented on the
PIC18F46J50 family devices can be accessed simulta-
neously by both the microcontroller core and the Serial
Interface Engine (SIE) of the USB module. The SIE
uses a dedicated USB DMA engine to store any
incoming data packets (OUT/SETUP) directly into main
system data memory.
For IN data packets, the SIE can directly read the
contents of general purpose SRAM and use it to create
USB data packets that are sent to the host.
SRAM Bank 4 (400h-4FFh) is unique. In addition to
being accessible by both the microcontroller core and
the USB module, the SIE uses a portion of Bank 4 as
Special Function Registers (SFRs). These SFRs
compose the Buffer Descriptor Table (BDT).
When the USB module is enabled, the BDT registers
are used to control the behavior of the USB DMA oper-
ation for each of the enabled endpoints. The exact
number of SRAM locations that are used for the BDT
depends on how many endpoints are enabled and what
USB Ping-Pong mode is used. For more details, see
Section 22.3 “USB RAM”.
When the USB module is disabled, these SRAM loca-
tions behave like any other GPR location. When the
USB module is disabled, these locations may be used
for any general purpose.
6.3.2 BANK SELECT REGISTER
Large areas of data memory require an efficient
addressing scheme to make rapid access to any
address possible. Ideally, this means that an entire
address does not need to be provided for each read or
write operation. For PIC18 devices, this is accom-
plished with a RAM banking scheme. This divides the
memory space into 16 contiguous banks of 256 bytes.
Depending on the instruction, each location can be
addressed directly by its full 12-bit address, or an 8-bit
low-order address and a 4-bit Bank Pointer.
Most instructions in the PIC18 instruction set make use
of the Bank Pointer, known as the Bank Select Register
(BSR). This SFR holds the 4 MSbs of a location’s
address; the instruction itself includes the 8 LSbs. Only
the four lower bits of the BSR are implemented
(BSR<3:0>). The upper four bits are unused; they will
always read ‘0’ and cannot be written to. The BSR can
be loaded directly by using the MOVLB instruction.
The value of the BSR indicates the bank in data
memory. The 8 bits in the instruction show the location
in the bank and can be thought of as an offset from the
bank’s lower boundary. The relationship between the
BSR’s value and the bank division in data memory is
illustrated in Figure 6-7.
Since, up to 16 registers may share the same low-order
address, the user must always be careful to ensure that
the proper bank is selected before performing a data
read or write. For example, writing what should be
program data to an 8-bit address of F9h while the BSR
is 0Fh, will end up resetting the PC.
While any bank can be selected, only those banks that
are actually implemented can be read or written to.
Writes to unimplemented banks are ignored, while
reads from unimplemented banks will return0’s. Even
so, the STATUS register will still be affected as if the
operation was successful. The data memory map in
Figure 6-6 indicates which banks are implemented.
In the core PIC18 instruction set, only the MOVFF
instruction fully specifies the 12-bit address of the
source and target registers. This instruction ignores the
BSR completely when it executes. All other instructions
include only the low-order address as an operand and
must use either the BSR or the Access Bank to locate
their target registers.
Note: The operation of some aspects of data
memory are changed when the PIC18
extended instruction set is enabled. See
Section 6.6 “Data Memory and the
Extended Instruction Set” for more
information.
Note: IN and OUT are always from the USB
host’s perspective.
2011 Microchip Technology Inc. DS39931D-page 85
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FIGURE 6- 6 : DAT A M EMORY MA P FOR PI C1 8F 46 J50 FAM ILY DEVI CE S
Bank 0
Bank 1
Bank 14
Bank 15
Data Memory Map
BSR3:BSR0
= 0000
= 0001
= 1111
060h
05Fh
F5Fh
FFFh
00h
5Fh
60h
FFh
Access Bank
When a = 0:
The BSR is ignored and the
Access Bank is used.
The first 96 bytes are general
purpose RAM (from Bank 0).
The remaining 160 bytes are
Special Function Registers
(from Bank 15).
When a = 1:
The BSR specifies the bank
used by the instruction.
EBFh
F00h
EFFh
1FFh
100h
0FFh
000h
Access RAM(1)
FFh
00h
FFh
00h
FFh
00h
GPR(1)
GPR(1)
Access RAM High
Access RAM Low
Bank 2
= 0010
(SFRs)
2FFh
200h
Bank 3
FFh
00h
GPR(1)
FFh
= 0011
= 1101
GPR, BDT(1)
GPR(1)
GPR(1)
GPR(1)
GPR(1)
GPR(1)
GPR(1)
GPR(1)
GPR(1)
GPR(1)
4FFh
400h
5FFh
500h
3FFh
300h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
00h
GPR(1)
GPR(1)
= 0110
= 0111
= 1010
= 1100
= 1000
= 0101
= 1001
= 1011
= 0100 Bank 4
Bank 5
Bank 6
Bank 7
Bank 8
Bank 9
Bank 10
Bank 11
Bank 12
Bank 13
= 1110
6FFh
600h
7FFh
700h
8FFh
800h
9FFh
900h
AFFh
A00h
BFFh
B00h
CFFh
C00h
DFFh
D00h
E00h
Note 1: These banks also serve as RAM buffers for USB operation. See Sect ion 6.3.1 “USB RAM” for more information.
2: Addresses, EC0h through F5Fh, are not part of the Access Bank. Either the BANKED or the MOVFF instruction should
be used to access these SFRs.
C0h
60h
Access SFRs
Non-Access
SFR
(2)
Non-Access
SFR
(2)
EC0h
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FIGURE 6-7: USE OF THE BANK SELEC T REGISTER (DIR ECT ADDRESSI NG)
6.3.3 ACCESS BANK
While the use of the BSR with an embedded 8-bit
address allows users to address the entire range of
data memory, it also means that the user must always
ensure that the correct bank is selected. Otherwise,
data may be read from or written to the wrong location.
This can be disastrous if a GPR is the intended target
of an operation, but an SFR is written to instead.
Verifying and/or changing the BSR for each read or
write to data memory can become very inefficient.
To streamline access for the most commonly used data
memory locations, the data memory is configured with
an Access Bank, which allows users to access a
mapped block of memory without specifying a BSR.
The Access Bank consists of the first 96 bytes of
memory (00h-5Fh) in Bank 0 and the last 160 bytes of
memory (60h-FFh) in Bank 15. The lower half is known
as the Access RAM and is composed of GPRs. The
upper half is where the device’s SFRs are mapped.
These two areas are mapped contiguously in the
Access Bank and can be addressed in a linear fashion
by an 8-bit address (Figure 6-6).
The Access Bank is used by core PIC18 instructions
that include the Access RAM bit (the ‘a’ parameter in
the instruction). When ‘a’ is equal to ‘1’, the instruction
uses the BSR and the 8-bit address included in the
opcode for the data memory address. When ‘a’ is ‘0’,
however, the instruction is forced to use the Access
Bank address map; the current value of the BSR is
ignored entirely.
Using this “forced” addressing allows the instruction to
operate on a data address in a single cycle without
updating the BSR first. For 8-bit addresses of 60h and
above, this means that users can evaluate and operate
on SFRs more efficiently. The Access RAM below 60h
is a good place for data values that the user might need
to access rapidly, such as immediate computational
results or common program variables. Access RAM
also allows for faster and more code efficient context
saving and switching of variables.
The mapping of the Access Bank is slightly different
when the extended instruction set is enabled (XINST
Configuration bit = 1). This is discussed in more detail
in Section 6.6.3 “Mapping the Access Bank in
Indexed Literal Offset Mode”.
6.3.4 GENERAL PURPOSE
REGISTER FILE
PIC18 devices may have banked memory in the GPR
area. This is data RAM, which is available for use by all
instructions. GPRs start at the bottom of Bank 0
(address 000h) and grow upward toward the bottom of
the SFR area. GPRs are not initialized by a POR and
are unchanged on all other Resets.
Note 1: The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to
the registers of the Access Bank.
2: The MOVFF instruction embeds the entire 12-bit address in the instruction.
Data Memory
Bank Select(2)
70
From Opcode(2)
0000
000h
100h
200h
300h
F00h
E00h
FFFh
Bank 0
Bank 1
Bank 2
Bank 14
Bank 15
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
00h
FFh
Bank 3
through
Bank 13
0010 11111111
70
BSR(1)
11111111
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6.3.5 SPECIAL FUNCTION REGISTERS
The SFRs are registers used by the CPU and periph-
eral modules for controlling the desired operation of the
device. These registers are implemented as static
RAM. SFRs start at the top of data memory (FFFh) and
extend downward to occupy more than the top half of
Bank 15 (F40h to FFFh). Table 6-2, Table 6-3 and
Table 6-4 provide a list of these registers.
The SFRs can be classified into two sets: those
associated with the “core” device functionality (ALU,
Resets and interrupts) and those related to the
peripheral functions. The Reset and Interrupt registers
are described in their corresponding chapters, while the
ALU’s STATUS register is described later in this section.
Registers related to the operation of the peripheral
features are described in the chapter for that peripheral.
The SFRs are typically distributed among the
peripherals whose functions they control. Unused SFR
locations are unimplemented and read as ‘0’s
Note: The SFRs, located between EC0h and F5Fh,
are not part of the Access Bank. Either
BANKED instructions (using BSR) or the
MOVFF instruction should be used to access
these locations. When programming in
MPLAB® C18, the compiler will automatically
use the appropriate addressing mode.
TABLE 6-2: ACCESS BANK SPECIAL FUNCTION REGISTER MAP
Address Name Address Name Address Name Address Name Address Name
FFFh
TOSU
FDFh
INDF2
(1)
FBFh
PSTR1CON
F9Fh
IPR1
F7Fh
SPBRGH1
FFEh
TOSH
FDEh
POSTINC2
(1)
FBEh
ECCP1AS
F9Eh
PIR1
F7Eh
BAUDCON1
FFDh
TOSL
FDDh
POSTDEC2
(1)
FBDh
ECCP1DEL
F9Dh
PIE1
F7Dh
SPBRGH2
FFCh
STKPTR
FDCh
PREINC2
(1)
FBCh
CCPR1H
F9Ch
RCSTA2
F7Ch
BAUDCON2
FFBh
PCLATU
FDBh
PLUSW2
(1)
FBBh
CCPR1L
F9Bh
OSCTUNE
F7Bh
TMR3H
FFAh
PCLATH
FDAh
FSR2H
FBAh
CCP1CON
F9Ah
T1GCON
F7Ah
TMR3L
FF9h
PCL
FD9h
FSR2L
FB9h
PSTR2CON
F99h
RTCVALH
F79h
T3CON
FF8h
TBLPTRU
FD8h
STATUS
FB8h
ECCP2AS
F98h
RTCVALL
F78h
TMR4
FF7h
TBLPTRH
FD7h
TMR0H
FB7h
ECCP2DEL
F97h
T3GCON
F77h
PR4
FF6h
TBLPTRL
FD6h
TMR0L
FB6h
CCPR2H
F96h
TRISE
F76h
T4CON
FF5h
TABLAT
FD5h
T0CON
FB5h
CCPR2L
F95h
TRISD
F75h SSP2BUF
FF4h
PRODH
FD4h
(5)
FB4h
CCP2CON
F94h
TRISC
F74h SSP2ADD
(3)
FF3h
PRODL
FD3h
OSCCON
FB3h
CTMUCONH
F93h
TRISB
F73h SSP2STAT
FF2h
INTCON
FD2h
CM1CON
FB2h
CTMUCONL
F92h
TRISA
F72h SSP2CON1
FF1h
INTCON2
FD1h
CM2CON
FB1h
CTMUICON
F91h
ALRMCFG
F71h SSP2CON2
FF0h
INTCON3
FD0h
RCON
FB0h
SPBRG1
F90h
ALRMRPT
F70h
CMSTAT
FEFh
INDF0
(1)
FCFh
TMR1H
FAFh
RCREG1
F8Fh
ALRMVALH
F6Fh PMADDRH
(2,4)
FEEh
POSTINC0
(1)
FCEh
TMR1L
FAEh
TXREG1
F8Eh
ALRMVALL
F6Eh PMADDRL
(2,4)
FEDh
POSTDEC0
(1)
FCDh
T1CON
FADh
TXSTA1
F8Dh
LATE
(2)
F6Dh
PMDIN1H
(2)
FECh
PREINC0
(1)
FCCh
TMR2
FACh
RCSTA1
F8Ch
LATD
(2)
F6Ch
PMDIN1L
(2)
FEBh
PLUSW0
(1)
FCBh
PR2
FABh
SPBRG2
F8Bh
LATC
F6Bh
TXADDRL
FEAh
FSR0H
FCAh
T2CON
FAAh
RCREG2
F8Ah
LATB
F6Ah
TXADDRH
FE9h
FSR0L
FC9h
SSP1BUF
FA9h
TXREG2
F89h
LATA
F69h
RXADDRL
FE8h
WREG
FC8h
SSP1ADD
(3)
FA8h
TXSTA2
F88h
DMACON1
F68h
RXADDRH
FE7h
INDF1
(1)
FC7h
SSP1STAT
FA7h
EECON2
F87h
(5)
F67h
DMABCL
FE6h
POSTINC1
(1)
FC6h
SSP1CON1
FA6h
EECON1
F86h
DMACON2
F66h
DMABCH
FE5h
POSTDEC1
(1)
FC5h
SSP1CON2
FA5h
IPR3
F85h
HLVDCON
F65h
UCON
FE4h
PREINC1
(1)
FC4h
ADRESH
FA4h
PIR3
F84h
PORTE
(2)
F64h
USTAT
FE3h
PLUSW1
(1)
FC3h
ADRESL
FA3h
PIE3
F83h
PORTD
(2)
F63h
UEIR
FE2h
FSR1H
FC2h
ADCON0
FA2h
IPR2
F82h
PORTC
F62h
UIR
FE1h
FSR1L
FC1h
ADCON1
FA1h
PIR2
F81h
PORTB
F61h
UFRMH
FE0h
BSR
FC0h
WDTCON
FA0h
PIE2
F80h
PORTA
F60h
UFRML
Note 1: This is not a physical register.
2: This register is not available on 28-pin devices.
3: SSPxADD and SSPxMSK share the same address.
4: PMADDRH and PMDOUTH share the same address, and PMADDRL and PMDOUTL share the same address.
PMADDRx is used in Master modes and PMDOUTx is used in Slave modes.
5: Reserved; do not write to this location.
PIC18F46J50 FAMILY
DS39931D-page 88 2011 Microchip Technology Inc.
TABLE 6-3: NON-ACCESS BANK SPECIAL FUNCTION REGISTER MAP
Address Name Address Name Address Name Address Name Address Name
F5Fh PMCONH F3Fh RTCCFG F1Fh EFFh PPSCON EDFh
F5Eh PMCONL F3Eh RTCCAL F1Eh EFEh RPINR24 EDEh RPOR24(1)
F5Dh PMMODEH F3Dh REFOCON F1Dh EFDh RPINR23 EDDh RPOR23(1)
F5Ch PMMODEL F3Ch PADCFG1 F1Ch EFCh RPINR22 EDCh RPOR22(1)
F5Bh PMDOUT2H F3Bh —F1Bh EFBh RPINR21 EDBh RPOR21(1)
F5Ah PMDOUT2L F3Ah —F1Ah—EFAh EDAh RPOR20(1)
F59h PMDIN2H F39h UCFG F19h —EF9h ED9h RPOR19(1)
F58h PMDIN2L F38h UADDR F18h —EF8h ED8h RPOR18
F57h PMEH F37h UEIE F17h EF7h RPINR17 ED7h RPOR17
F56h PMEL F36h UIE F16h EF6h RPINR16 ED6h
F55h PMSTATH F35h UEP15 F15h —EF5h—ED5h
F54h PMSTATL F34h UEP14 F14h —EF4h—ED4h
F53h CVRCON F33h UEP13 F13h EF3h RPINR13 ED3h RPOR13
F52h TCLKCON F32h UEP12 F12h EF2h RPINR12 ED2h RPOR12
F51h —F31hUEP11F11h—EF1h ED1h RPOR11
F50h F30h UEP10 F10h —EF0h ED0h RPOR10
F4Fh DSGPR1 F2Fh UEP9 F0Fh EEFh ECFh RPOR9
F4Eh DSGPR0 F2Eh UEP8 F0Eh EEEh RPINR8 ECEh RPOR8
F4Dh DSCONH F2Dh UEP7 F0Dh EEDh RPINR7 ECDh RPOR7
F4Ch DSCONL F2Ch UEP6 F0Ch EECh RPINR6 ECCh RPOR6
F4Bh
DSWAKEH F2Bh UEP5 F0Bh EEBh ECBh RPOR5
F4Ah
DSWAKEL F2Ah UEP4 F0Ah EEAh RPINR4 ECAh RPOR4
F49h
ANCON1 F29h UEP3 F09h EE9h RPINR3 EC9h RPOR3
F48h
ANCON0 F28h UEP2 F08h EE8h RPINR2 EC8h RPOR2
F47h
F27h UEP1 F07h EE7h RPINR1 EC7h RPOR1
F46h
F26h UEP0 F06h EE6h EC6h RPOR0
F45h
—F25h F05h EE5h —EC5h
F44h
—F24h F04h EE4h —EC4h
F43h
—F23h F03h EE3h —EC3h
F42h
ODCON1 F22h F02h EE2h —EC2h
F41h
ODCON2 F21h F01h EE1h —EC1h
F40h
ODCON3 F20h F00h EE0h
EC0h
Note 1: This register is not available on 28-pin devices.
2011 Microchip Technology Inc. DS39931D-page 89
PIC18F46J50 FAMILY
6.3.5.1 Context Defined SFRs
There are several registers that share the same
address in the SFR space. The register’s definition and
usage depends on the operating mode of its associated
peripheral. These registers are:
SSPxADD and SSPxMSK: These are two
separate hardware registers, accessed through a
single SFR address. The operating mode of the
MSSP modules determines which register is
being accessed. See Section 19.5.3.4 “7-Bit
Address Masking Mode for additional details.
PMADDRH/L and PMDOUT2H/L: In this case,
these named buffer pairs are actually the same
physical registers. The Parallel Master Port (PMP)
module’s operating mode determines what func-
tion the registers take on. See Section 11.1.2
“Data Registers” for additional details.
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
TOSU Top-of-Stack Upper Byte (TOS<20:16>) ---0 0000 69, 81
TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 69, 79
TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 69, 79
STKPTR STKFUL STKUNF SP4 SP3 SP2 SP1 SP0 00-0 0000 69, 79
PCLATU —bit 21
(1) Holding Register for PC<20:16> ---0 0000 69, 79
PCLATH Holding Register for PC<15:8> 0000 0000 69, 79
PCL PC Low Byte (PC<7:0>) 0000 0000 69, 79
TBLPTRU bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) --00 0000 69, 112
TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 69, 112
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 69, 112
TABLAT Program Memory Table Latch 0000 0000 69, 112
PRODH Product Register High Byte xxxx xxxx 69, 113
PRODL Product Register Low Byte xxxx xxxx 69, 113
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 69, 117
INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 1111 1111 69, 117
INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 1100 0000 69, 117
INDF0 Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register) N/A 69, 98
POSTINC0 Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register) N/A 69, 99
POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register) N/A 69, 99
PREINC0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) N/A 69, 99
PLUSW0 Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) –
value of FSR0 offset by W
N/A 69, 99
FSR0H —— Indirect Data Memory Address Pointer 0 High Byte ---- 0000 69, 98
FSR0L Indirect Data Memory Address Pointer 0 Low Byte xxxx xxxx 69, 98
WREG Working Register xxxx xxxx 69, 81
INDF1 Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register) N/A 69, 98
POSTINC1 Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register) N/A 69, 99
POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register) N/A 69, 99
PREINC1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) N/A 70, 99
PLUSW1 Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) –
value of FSR1 offset by W
N/A 69, 99
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Mas kin g Mo de s” for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
PIC18F46J50 FAMILY
DS39931D-page 90 2011 Microchip Technology Inc.
FSR1H Indirect Data Memory Address Pointer 1 High Byte ---- 0000 69, 98
FSR1L Indirect Data Memory Address Pointer 1 Low Byte xxxx xxxx 69, 98
BSR Bank Select Register ---- 0000 69, 84
INDF2 Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register) N/A 69, 98
POSTINC2 Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register) N/A 70, 99
POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register) N/A 70, 99
PREINC2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) N/A 70, 99
PLUSW2 Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) –
value of FSR2 offset by W
N/A 70, 99
FSR2H Indirect Data Memory Address Pointer 2 High Byte ---- 0000 70, 98
FSR2L Indirect Data Memory Address Pointer 2 Low Byte xxxx xxxx 70, 98
STATUS —N OV Z DCC---x xxxx 70, 96
TMR0H Timer0 Register High Byte 0000 0000 70, 203
TMR0L Timer0 Register Low Byte xxxx xxxx 70, 203
T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 70, 196
OSCCON IDLEN IRCF2 IRCF1 IRCF0 OSTS(2) SCS1 SCS0 0110 q-00 70, 43
CM1CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 0001 1111 70, 391
CM2CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 0001 1111 70, 391
RCON IPEN —CMRI TO PD POR BOR 0-11 1100 68, 70,
129
TMR1H Timer1 Register High Byte xxxx xxxx 70, 203
TMR1L Timer1 Register Low Byte xxxx xxxx 70, 203
T1CON TMR1CS1 TMR1CS0 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC RD16 TMR1ON 0000 0000 70, 203
TMR2 Timer2 Register 0000 0000 70, 211
PR2 Timer2 Period Register 1111 1111 70, 211
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 70, 211
SSP1BUF MSSP1 Receive Buffer/Transmit Register xxxx xxxx 70, 288,
322
SSP1ADD MSSP1 Address Register (I2C™ Slave mode), MSSP1 Baud Rate Reload Register (I2C Master mode) 0000 0000 70, 293
SSP1MSK(4) MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 1111 1111 70, 295
SSP1STAT SMP CKE D/A PSR/WUA BF 0000 0000 70, 270,
289
SSP1CON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 70, 270,
290
SSP1CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 70, 270,
291
GCEN ACKSTAT ADMSK5(4) ADMSK4(4) ADMSK3(4) ADMSK2(4) ADMSK1(4) SEN
ADRESH A/D Result Register High Byte xxxx xxxx 70, 356
ADRESL A/D Result Register Low Byte xxxx xxxx 70, 356
ADCON0 VCFG1 VCFG0 CHS3 CHS2 CHS1 CHS0 GO/DONE ADON 0000 0000 69, 347
ADCON1 ADFM ADCAL ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0000 0000 70, 347
WDTCON REGSLP LVDSTAT ULPLVL DS ULPEN ULPSINK SWDTEN 1qx- q000 70, 427
PSTR1CON CMPL1 CMPL0 STRSYNC STRD STRC STRB STRA 00-0 0001 70, 265
ECCP1AS ECCP1ASE ECCP1AS2 ECCP1AS1 ECCP1AS0 PSS1AC1 PSS1AC0 PSS1BD1 PSS1BD0 0000 0000 70
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Masking Modes for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
2011 Microchip Technology Inc. DS39931D-page 91
PIC18F46J50 FAMILY
ECCP1DEL P1RSEN P1DC6 P1DC5 P1DC4 P1DC3 P1DC2 P1DC1 P1DC0 0000 0000 71
CCPR1H Capture/Compare/PWM Register 1 HIgh Byte xxxx xxxx 71
CCPR1L Capture/Compare/PWM Register 1 Low Byte xxxx xxxx 71
CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 0000 0000 71
PSTR2CON CMPL1 CMPL0 STRSYNC STRD STRC STRB STRA 00-0 0001 71, 265
ECCP2AS ECCP2ASE ECCP2AS2 ECCP2AS1 ECCP2AS0 PSS2AC1 PSS2AC0 PSS2BD1 PSS2BD0 0000 0000 71
ECCP2DEL P2RSEN P2DC6 P2DC5 P2DC4 P2DC3 P2DC2 P2DC1 P2DC0 0000 0000 71
CCPR2H Capture/Compare/PWM Register 2 High Byte xxxx xxxx 71
CCPR2L Capture/Compare/PWM Register 2 Low Byte xxxx xxxx 71
CCP2CON P2M1 P2M0 DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 0000 0000 71
CTMUCONH CTMUEN CTMUSIDL TGEN EDGEN EDGSEQEN IDISSEN 0-00 000- 71
CTMUCONL EDG2POL EDG2SEL1 EDG2SEL0 EDG1POL EDG1SEL1 EDG1SEL0 EDG2STAT EDG1STAT 0000 00xx 71
CTMUICON ITRIM5 ITRIM4 ITRIM3 ITRIM2 ITRIM1 ITRIM0 IRNG1 IRNG0 0000 0000 71
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte 0000 0000 71, 327
RCREG1 EUSART1 Receive Register 0000 0000 71, 336,
328
TXREG1 EUSART1 Transmit Register xxxx xxxx 71, 336,
335
TXSTA1 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 71, 333
RCSTA1 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 71, 336
SPBRG2 EUSART2 Baud Rate Generator Register Low Byte 0000 0000 71, 327
RCREG2 EUSART2 Receive Register 0000 0000 71, 336,
338
TXREG2 EUSART2 Transmit Register 0000 0000 71, 333,
335
TXSTA2 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 71, 333
EECON2 Program Memory Control Register 2 (not a physical register) ---- ---- 71, 104
EECON1 WPROG FREE WRERR WREN WR --00 x00- 71, 104
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 1111 1111 71, 126
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 0000 0000 71, 120
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 0000 0000 71, 123
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 1111 1111 71, 126
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 0000 0000 71, 120
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 0000 0000 71, 123
IPR1 PMPIP(5) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 1111 1111 71, 126
PIR1 PMPIF(5) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 0000 0000 71, 120
PIE1 PMPIE(5) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 0000 0000 71, 123
RCSTA2 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 72, 336
OSCTUNE INTSRC PLLEN TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 0000 0000 72, 39
T1GCON TMR1GE T1GPOL T1GTM T1GSPM T1GGO/
T1DONE
T1GVAL T1GSS1 T1GSS0 0000 0x00 201
RTCVALH RTCC Value Register Window High Byte, Based on RTCPTR<1:0> 0xxx xxxx 72, 231
RTCVALL RTCC Value Register Window Low Byte, Based on RTCPTR<1:0> 0xxx xxxx 72, 231
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Mas kin g Mo de s” for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
PIC18F46J50 FAMILY
DS39931D-page 92 2011 Microchip Technology Inc.
T3GCON TMR3GE T3GPOL T3GTM T3GSPM T3GGO/
T3DONE
T3GVAL T3GSS1 T3GSS0 0000 0x00 72, 214
TRISE TRISE2 TRISE1 TRISE0 ---- -111 72
TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 1111 1111 72, 146
TRISC TRISC7 TRISC6 TRISC2 TRISC1 TRISC0 11-- -111 72, 143
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 1111 1111 72, 139
TRISA TRISA7(7) TRISA6(7) TRISA5 TRISA3 TRISA2 TRISA1 TRISA0 qq1- 1111 72, 136
ALRMCFG ALRMEN CHIME AMASK3 AMASK2 AMASK1 AMASK0 ALRMPTR1 ALRMPTR0 0000 0000 72, 229
ALRMRPT ARPT7 ARPT6 ARPT5 ARPT4 ARPT3 ARPT2 ARPT1 ARPT0 0000 0000 72, 230
ALRMVALH Alarm Value Register Window High Byte, Based on ALRMPTR<1:0> xxxx xxxx 72, 234
ALRMVALL Alarm Value Register Window Low Byte, Based on ALRMPTR<1:0> xxxx xxxx 72, 234
LATE LATE2 LATE1 LATE0 ---- -xxx 72, 149
LATD LATD7 LATD6 LATD5 LATD4 LATD3 LATD2 LATD1 LATD0 xxxx xxxx 72, 147
LATC LATC7 LATC6 LATC2 LATC1 LATC0 xxxx -xxx 72, 142
LATB LATB7 LATB6 LATB5 LATB4 LATB3 LATB2 LATB1 LATB0 xxxx xxxx 72, 142
LATA LATA7 L ATA 6 L ATA5 LATA3 LATA2 LATA1 LATA0 xxx- xxxx 72, 142
DMACON1 SSCON1 SSCON0 TXINC RXINC DUPLEX1 DUPLEX0 DLYINTEN DMAEN 0000 0000 72, 282
DMATXBUF SPI DMA Transmit Buffer xxxx xxxx 72
DMACON2 DLYCYC3 DLYCYC2 DLYCYC1 DLYCYC0 INTLVL3 INTLVL2 INTLVL1 INTLVL0 0000 0000 72, 283
HLVDCON VDIRMAG BGVST IRVST HLVDEN HLVDL3 HLVDL2 HLVDL1 HLVDL0 0000 0000 72
PORTE RDPU REPU RE2 RE1 RE0 00-- -xxx 72, 132
PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx 72, 132
PORTC RC7 RC6 RC5 RC4 RC2 RC1 RC0 xxxx -xxx 72, 132
PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx 72, 132
PORTA RA7 RA6 RA5 RA3 RA2 RA1 RA0 xxx- xxxx 72, 356
SPBRGH1 EUSART1 Baud Rate Generator Register High Byte 0000 0000 72, 327
BAUDCON1 ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 0100 0-00 72, 327
SPBRGH2 EUSART2 Baud Rate Generator Register High Byte 0000 0000 72, 327
BAUDCON2 ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 0100 0-00 72, 327
TMR3H Timer3 Register High Byte xxxx xxxx 73, 197
TMR3L Timer3 Register Low Byte xxxx xxxx 73, 197
T3CON TMR3CS1 TMR3CS0 T3CKPS1 T3CKPS0 T3OSCEN T3SYNC RD16 TMR3ON 0000 0000 73, 197
TMR4 Timer4 Register 0000 0000 73, 223
PR4 Timer4 Period Register 1111 1111 73, 197
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 -000 0000 73, 223
SSP2BUF MSSP2 Receive Buffer/Transmit Register xxxx xxxx 73, 288,
322
SSP2ADD/ MSSP2 Address Register (I2C™ Slave mode), MSSP2 Baud Rate Reload Register (I2C Master mode) 0000 0000 73, 288
SSP2MSK(4)MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 1111 1111 73, 295
SSP2STAT SMP CKE D/A PSR/WUA BF 0000 0000 73, 270,
310
SSP2CON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 73, 270,
322
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Masking Modes for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
2011 Microchip Technology Inc. DS39931D-page 93
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SSP2CON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 73, 270,
322
GCEN ACKSTAT ADMSK5(4) ADMSK4(4) ADMSK3(4) ADMSK2(4) ADMSK1(4) SEN
CMSTAT COUT2 COUT1 ---- --11 73, 389
PMADDRH/ CS1 Parallel Master Port Address High Byte -000 0000 73, 177
PMDOUT1H(5,6) Parallel Port Out Data High Byte (Buffer 1) 0000 0000 73, 180
PMADDRL/ Parallel Master Port Address Low Byte 0000 0000 73, 176
PMDOUT1L(5,6) Parallel Port Out Data Low Byte (Buffer 0) 0000 0000 73, 177
PMDIN1H(5) Parallel Port In Data High Byte (Buffer 1) 0000 0000 73, 177
PMDIN1L(5) Parallel Port In Data Low Byte (Buffer 0) 0000 0000 73, 177
TXADDRL SPI DMA Transit Data Pointer Low Byte xxxx xxxx 73, 284
TXADDRH —— SPI DMA Transit Data Pointer High Byte ---- xxxx 73, 284
RXADDRL SPI DMA Receive Data Pointer Low Byte xxxx xxxx 73, 284
RXADDRH —— SPI DMA Receive Data Pointer High Byte ---- xxxx 73, 284
DMABCL SPI DMA Byte Count Low Byte xxxx xxxx 73, 284
DMABCH SPI DMA Byte Count High
Byte
---- --xx 73, 284
UCON PPBRST SE0 PKTDIS USBEN RESUME SUSPND -0x0 000- 73, 359
USTAT ENDP3 ENDP2 ENDP1 ENDP0 DIR PPBI -xxx xxx- 73, 363
UEIR BTSEF BTOEF DFN8EF CRC16EF CRC5EF PIDEF 0--0 0000 73, 376
UIR SOFIF STALLIF IDLEIF TRNIF ACTVIF UERRIF URSTIF -000 0000 73, 373
UFRMH —FRM10FRM9FRM8---- -xxx 73, 365
UFRML FRM7 FRM6 FRM5 FRM4 FRM3 FRM2 FRM1 FRM0 xxxx xxxx 73, 365
PMCONH(5) PMPEN ADRMUX1 ADRMUX0 PTBEEN PTWREN PTRDEN 0--0 0000 73, 170
PMCONL(5) CSF1 CSF0 ALP CS1P BEP WRSP RDSP 000- 0000 73, 171
PMMODEH(5) BUSY IRQM1 IRQM0 INCM1 INCM0 MODE16 MODE1 MODE0 0000 0000 74, 172
PMMODEL(5) WAITB1 WAITB0 WAITM3 WAITM2 WAITM1 WAITM0 WAITE1 WAITE0 0000 0000 74, 173
PMDOUT2H(5) Parallel Port Out Data High Byte (Buffer 3) 0000 0000 74, 176
PMDOUT2L(5) Parallel Port Out Data Low Byte (Buffer 2) 0000 0000 74, 176
PMDIN2H(5) Parallel Port In Data High Byte (Buffer 3) 0000 0000 74, 176
PMDIN2L(5) Parallel Port In Data Low Byte (Buffer 2) 0000 0000 74, 176
PMEH(5) PTEN15 PTEN14 PTEN13 PTEN12 PTEN11 PTEN10 PTEN9 PTEN8 0000 0000 74, 174
PMEL(5) PTEN7 PTEN6 PTEN5 PTEN4 PTEN3 PTEN2 PTEN1 PTEN0 0000 0000 74, 174
PMSTATH(5) IBF IBOV IB3F IB2F IB1F IB0F 00-- 0000 74, 175
PMSTATL(5) OBE OBUF OB3E OB2E OB1E OB0E 10-- 1111 74, 175
CVRCON CVREN CVROE CVRR r CVR3 CVR2 CVR1 CVR0 0000 0000 74, 392
TCLKCON —T1RUN T3CCP2 T3CCP1 ---0 --00 202
DSGPR1 Deep Sleep Persistent General Purpose Register (contents retained even in Deep Sleep) uuuu uuuu 58
DSGPR0 Deep Sleep Persistent General Purpose Register (contents retained even in Deep Sleep) uuuu uuuu 58
DSCONH DSEN r DSULPEN RTCWDIS 0--- -000 57
DSCONL ULPWDIS DSBOR RELEASE ---- -000 57
DSWAKEH —DSINT0---- ---0 59
DSWAKEL DSFLT DSULP DSWDT DSRTC DSMCLR DSPOR 0-00 00-1 59
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Mas kin g Mo de s” for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
PIC18F46J50 FAMILY
DS39931D-page 94 2011 Microchip Technology Inc.
ANCON1 VBGEN r PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 00-0 0000 74, 348
ANCON0 PCFG7(5) PCFG6(5) PCFG5(5) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 0000 0000 74, 347
ODCON1 ECCP20D ECCP10D ---- --00 74, 134
ODCON2 U2OD U1OD ---- --00 74, 134
ODCON3 SPI2OD SPI1OD ---- --00 74, 135
RTCCFG RTCEN RTCWREN RTCSYNC HALFSEC RTCOE RTCPTR1 RTCPTR0 0-00 0000 74, 227
RTCCAL CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0 0000 0000 74, 228
REFOCON ROON ROSSLP ROSEL RODIV3 RODIV2 RODIV1 RODIV0 0-00 0000 74, 44
PADCFG1 RTSECSEL1 RTSECSEL0 PMPTTL ---- -000 74, 135
UCFG UTEYE UOEMON UPUEN UTRDIS FSEN PPB1 PPB0 00-0 0000 74, 360
UADDR ADDR6 ADDR5 ADDR4 ADDR3 ADDR2 ADDR1 ADDR0 -000 0000 74, 365
UEIE BTSEE BTOEE DFN8EE CRC16EE CRC5EE PIDEE 0--0 0000 74, 377
UIE SOFIE STALLIE IDLEIE TRNIE ACTVIE UERRIE URSTIE -000 0000 74, 375
UEP15 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP14 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP13 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP12 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP11 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP10 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP9 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP8 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP7 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 74, 364
UEP6 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
UEP5 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
UEP4 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
UEP3 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
UEP2 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
UEP1 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
UEP0 EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL ---0 0000 75, 364
PPSCON —IOLOCK---- ---0 155
RPINR24 Input Function FLT0 to Input Pin Mapping Bits ---1 1111 75, 160
RPINR23 Input Function SS2 to Input Pin Mapping Bits ---1 1111 75, 160
RPINR22 Input Function SCK2 to Input Pin Mapping Bits ---1 1111 75, 160
RPINR21 Input Function SDI2 to Input Pin Mapping Bits ---1 1111 75, 159
RPINR17 Input Function CK2 to Input Pin Mapping Bits ---1 1111 75, 159
RPINR16 Input Function RX2DT2 to Input Pin Mapping Bits ---1 1111 75
RPINR13 Input Function T3G to Input Pin Mapping Bits ---1 1111 75
RPINR12 Input Function T1G to Input Pin Mapping Bits ---1 1111 75, 158
RPINR8 Input Function IC2 to Input Pin Mapping Bits ---1 1111 75, 158
RPINR7 Input Function IC1 to Input Pin Mapping Bits ---1 1111 75, 157
RPINR6 Input Function T3CKI to Input Pin Mapping Bits ---1 1111 75, 157
RPINR4 Input Function T0CKI to Input Pin Mapping Bits ---1 1111 75, 157
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Masking Modes for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
2011 Microchip Technology Inc. DS39931D-page 95
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RPINR3 Input Function INT3 to Input Pin Mapping Bits ---1 1111 76, 156
RPINR2 Input Function INT2 to Input Pin Mapping Bits ---1 1111 76
RPINR1 Input Function INT1 to Input Pin Mapping Bits ---1 1111 76, 156
RPOR24(5) Remappable Pin RP24 Output Signal Select Bits ---0 0000 76, 168
RPOR23(5) Remappable Pin RP23 Output Signal Select Bits ---0 0000 76, 167
RPOR22(5) Remappable Pin RP22 Output Signal Select Bits ---0 0000 76, 167
RPOR21(5) Remappable Pin RP21 Output Signal Select Bits ---0 0000 76, 167
RPOR20(5) Remappable Pin RP20 Output Signal Select Bits ---0 0000 76, 166
RPOR19(5) Remappable Pin RP19 Output Signal Select Bits ---0 0000 76, 166
RPOR18 Remappable Pin RP18 Output Signal Select Bits ---0 0000 76, 166
RPOR17 Remappable Pin RP17 Output Signal Select Bits ---0 0000 76, 165
RPOR13 Remappable Pin RP13 Output Signal Select Bits ---0 0000 76, 165
RPOR12 Remappable Pin RP12 Output Signal Select Bits ---0 0000 76, 165
RPOR11 Remappable Pin RP11 Output Signal Select Bits ---0 0000 76, 164
RPOR10 Remappable Pin RP10 Output Signal Select Bits ---0 0000 76, 164
RPOR9 Remappable Pin RP9 Output Signal Select Bits ---0 0000 76, 164
RPOR8 Remappable Pin RP8 Output Signal Select Bits ---0 0000 76, 163
RPOR7 Remappable Pin RP7 Output Signal Select Bits ---0 0000 76, 163
RPOR6 Remappable Pin RP6 Output Signal Select Bits ---0 0000 76, 163
RPOR5 Remappable Pin RP5 Output Signal Select Bits ---0 0000 76, 162
RPOR4 Remappable Pin RP4 Output Signal Select Bits ---0 0000 76, 162
RPOR3 Remappable Pin RP3 Output Signal Select Bits ---0 0000 76, 162
RPOR2 Remappable Pin RP2 Output Signal Select Bits ---0 0000 76, 161
RPOR1 Remappable Pin RP1 Output Signal Select Bits ---0 0000 76, 161
RPOR0 Remappable Pin RP0 Output Signal Select Bits ---0 0000 76, 161
TABLE 6-4: REGISTER FILE SUMMARY (PIC18F46J50 FAMILY) (CONTINUED)
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on
POR, BOR Details
on Page :
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved. Bold indicates shared access SFRs.
Note 1: Bit 21 of the PC is only available in Serial Programming (SP) modes.
2: Reset value is ‘0 when Two-Speed Start-up is enabled and ‘1’ if disabled.
3: The SSPxMSK registers are only accessible when SSPxCON2<3:0> = 1001.
4: Alternate names and definitions for these bits when the MSSP module is operating in I2C™ Slave mode. See Section 19.5.3.2 “Address
Mas kin g Mo de s” for details.
5: These bits and/or registers are only available on 44-pin devices; otherwise, they are unimplemented and read as 0’. Reset values are
shown for 44-pin devices.
6: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the same physical registers and addresses, but have
different functions determined by the module’s operating mode. See Section 11.1.2 “Data Registers” for more information.
7: The TRISA6 and TRISA7 bits are only implemented when the pins are not configured for primary oscillator functions.
PIC18F46J50 FAMILY
DS39931D-page 96 2011 Microchip Technology Inc.
6.3.6 STATUS REGISTER
The STATUS register in Register 6-2, contains the
arithmetic status of the ALU. The STATUS register can
be the operand for any instruction, as with any other
register. If the STATUS register is the destination for an
instruction that affects the Z, DC, C, OV or N bits, then
the write to these five bits is disabled.
These bits are set or cleared according to the device
logic. Therefore, the result of an instruction with the
STATUS register as destination may be different than
intended. For example, CLRF STATUS will set the Z bit
but leave the other bits unchanged. The STATUS
register then reads back as ‘000u u1uu’. It is recom-
mended, therefore, that only BCF, BSF, SWAPF, MOVFF
and MOVWF instructions are used to alter the STATUS
register because these instructions do not affect the Z,
C, DC, OV or N bits in the STATUS register.
For other instructions not affecting any Status bits, see
the instruction set summary in Table 2 8-2 and
Table 28-3.
Note: The C and DC bits operate as a borrow
and digit borrow bits respectively, in
subtraction.
REGISTER 6-2: STATUS REGISTER (ACCESS FD8h)
U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x
—NOVZDC
(1) C(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as0
bit 4 N: Negative bit
This bit is used for signed arithmetic (2’s complement). It indicates whether the result was negative
(ALU MSB = 1).
1 = Result was negative
0 = Result was positive
bit 3 OV: Overflow bit
This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit magnitude,
which causes the sign bit (bit 7) to change state.
1 = Overflow occurred for signed arithmetic (in this arithmetic operation)
0 = No overflow occurred
bit 2 Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
bit 1 DC: Digit carry/borrow bit(1)
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the 4th low-order bit of the result occurred
0 = No carry-out from the 4th low-order bit of the result
bit 0 C: Carry/borrow bit(2)
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the MSb of the result occurred
0 = No carry-out from the MSb of the result occurred
Note 1: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register.
2: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the
source register.
2011 Microchip Technology Inc. DS39931D-page 97
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6.4 Data Addressing Modes
While the program memory can be addressed in only
one way, through the PC, information in the data mem-
ory space can be addressed in several ways. For most
instructions, the addressing mode is fixed. Other
instructions may use up to three modes, depending on
which operands are used and whether or not the
extended instruction set is enabled.
The addressing modes are:
Inherent
Literal
•Direct
•Indirect
An additional addressing mode, Indexed Literal Offset,
is available when the extended instruction set is
enabled (XINST Configuration bit = 1). Its operation is
discussed in more detail in Section 6.6.1 “Indexed
Addressing with Literal Offset”.
6.4.1 INHERENT AND LITERAL
ADDRESSING
Many PIC18 control instructions do not need any
argument at all; they either perform an operation that
globally affects the device, or they operate implicitly on
one register. This addressing mode is known as
Inherent Addressing. Examples include SLEEP, RESET
and DAW.
Other instructions work in a similar way, but require an
additional explicit argument in the opcode. This is
known as Literal Addressing mode, because they
require some literal value as an argument. Examples
include ADDLW and MOVLW, which respectively, add or
move a literal value to the W register. Other examples
include CALL and GOTO, which include a 20-bit
program memory address.
6.4.2 DIRECT ADDRESSING
Direct Addressing specifies all or part of the source
and/or destination address of the operation within the
opcode itself. The options are specified by the
arguments accompanying the instruction.
In the core PIC18 instruction set, bit-oriented and
byte-oriented instructions use some version of Direct
Addressing by default. All of these instructions include
some 8-bit Literal Address as their LSB. This address
specifies either a register address in one of the banks
of data RAM (Section 6.3.4 “General Purpose
Register File”), or a location in the Access Bank
(Section 6.3.3 “Access Bank ) as the data source for
the instruction.
The Access RAM bit, ‘a’, determines how the address
is interpreted. When ‘a’ is ‘1’, the contents of the BSR
(Section 6.3.2 “Bank Sel ect Register”) are used with
the address to determine the complete 12-bit address
of the register. When ‘a’ is ‘0’, the address is interpreted
as being a register in the Access Bank. Addressing that
uses the Access RAM is sometimes also known as
Direct Forced Addressing mode.
A few instructions, such as MOVFF, include the entire
12-bit address (either source or destination) in their
opcodes. In these cases, the BSR is ignored entirely.
The destination of the operation’s results is determined
by the destination bit, ‘d’. When ‘d’ is ‘1’, the results are
stored back in the source register, overwriting its
original contents. When ‘d’ is ‘0’, the results are stored
in the W register. Instructions without the ‘d’ argument
have a destination that is implicit in the instruction; their
destination is either the target register being operated
on or the W register.
6.4.3 INDIRECT ADDRESSING
Indirect Addressing allows the user to access a location
in data memory without giving a fixed address in the
instruction. This is done by using File Select Registers
(FSRs) as pointers to the locations to be read or written
to. Since the FSRs are themselves located in RAM as
SFRs, they can also be directly manipulated under
program control. This makes FSRs very useful in
implementing data structures such as tables and arrays
in data memory.
The registers for Indirect Addressing are also
implemented with Indirect File Operands (INDFs) that
permit automatic manipulation of the pointer value with
auto-incrementing, auto-decrementing or offsetting
with another value. This allows for efficient code using
loops, such as the example of clearing an entire RAM
bank in Example 6-5. It also enables users to perform
Indexed Addressing and other Stack Pointer
operations for program memory in data memory.
EXAMPLE 6-5: HOW TO CLEAR RAM
(BANK 1) USING INDIRECT
ADDRESSING
Note: The execution of some instructions in the
core PIC18 instruction set are changed
when the PIC18 extended instruction set is
enabled. See Section 6.6 “Data Memory
and the Extended Instruction Set” for
more information.
LFSR FSR0, 0x100;
NEXT CLRF POSTINC0 ; Clear INDF
; register then
; inc pointer
BTFSS FSR0H, 1 ; All done with
; Bank1?
BRA NEXT ; NO, clear next
CONTINUE ; YES, continue
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DS39931D-page 98 2011 Microchip Technology Inc.
6.4.3.1 FSR Registers and the INDF
Operand (INDF)
At the core of Indirect Addressing are three sets of
registers: FSR0, FSR1 and FSR2. Each represents a
pair of 8-bit registers, FSRnH and FSRnL. The four
upper bits of the FSRnH register are not used, so each
FSR pair holds a 12-bit value. This represents a value
that can address the entire range of the data memory
in a linear fashion. The FSR register pairs then serve as
pointers to data memory locations.
Indirect Addressing is accomplished with a set of INDF
operands, INDF0 through INDF2. These can be pre-
sumed as “virtual” registers: they are mapped in the
SFR space but are not physically implemented. Read-
ing or writing to a particular INDF register actually
accesses its corresponding FSR register pair. A read
from INDF1, for example, reads the data at the address
indicated by FSR1H:FSR1L. Instructions that use the
INDF registers as operands actually use the contents
of their corresponding FSR as a pointer to the instruc-
tion’s target. The INDF operand is just a convenient
way of using the pointer.
Because Indirect Addressing uses a full 12-bit address,
data RAM banking is not necessary. Thus, the current
contents of the BSR and the Access RAM bit have no
effect on determining the target address.
FIGURE 6-8: INDIRECT ADDRESSING
FSR1H:FSR1L
0
7
Data Memory
000h
100h
200h
300h
F00h
E00h
FFFh
Bank 0
Bank 1
Bank 2
Bank 14
Bank 15
Bank 3
through
Bank 13
ADDWF, INDF1, 1
07
Using an instruction with one of the
Indirect Addressing registers as the
operand....
...uses the 12-bit address stored in
the FSR pair associated with that
register....
...to determine the data memory
location to be used in that operation.
In this case, the FSR1 pair contains
FCCh. This means the contents of
location FCCh will be added to that
of the W register and stored back in
FCCh.
xxxx1111 11001100
2011 Microchip Technology Inc. DS39931D-page 99
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6.4.3.2 FSR Registers and POSTINC,
POSTDEC, PREINC and PLUSW
In addition to the INDF operand, each FSR register pair
also has four additional indirect operands. Like INDF,
these are “virtual” registers that cannot be indirectly
read or written to. Accessing these registers actually
accesses the associated FSR register pair, but also
performs a specific action on its stored value. They are:
POSTDEC: accesses the FSR value, then
automatically decrements it by ‘1’ thereafter
POSTINC: accesses the FSR value, then
automatically increments it by ‘1’ thereafter
PREINC: increments the FSR value by ‘1’, then
uses it in the operation
PLUSW: adds the signed value of the W register
(range of -128 to +127) to that of the FSR and
uses the new value in the operation
In this context, accessing an INDF register uses the
value in the FSR registers without changing them.
Similarly, accessing a PLUSW register gives the FSR
value offset by the value in the W register; neither value
is actually changed in the operation. Accessing the
other virtual registers changes the value of the FSR
registers.
Operations on the FSRs with POSTDEC, POSTINC
and PREINC affect the entire register pair; that is, roll-
overs of the FSRnL register from FFh to 00h carry over
to the FSRnH register. On the other hand, results of
these operations do not change the value of any flags
in the STATUS register (e.g., Z, N, OV, etc.).
The PLUSW register can be used to implement a form
of Indexed Addressing in the data memory space. By
manipulating the value in the W register, users can
reach addresses that are fixed offsets from pointer
addresses. In some applications, this can be used to
implement some powerful program control structure,
such as software stacks, inside of data memory.
6.4.3.3 Operations by FSRs on FSRs
Indirect Addressing operations that target other FSRs
or virtual registers represent special cases. For
example, using an FSR to point to one of the virtual
registers will not result in successful operations. As a
specific case, assume that FSR0H:FSR0L contains
FE7h, the address of INDF1. Attempts to read the
value of the INDF1, using INDF0 as an operand, will
return 00h. Attempts to write to INDF1, using INDF0 as
the operand, will result in a NOP.
On the other hand, using the virtual registers to write to
an FSR pair may not occur as planned. In these cases,
the value will be written to the FSR pair but without any
incrementing or decrementing. Thus, writing to INDF2
or POSTDEC2 will write the same value to the
FSR2H:FSR2L.
Since the FSRs are physical registers mapped in the
SFR space, they can be manipulated through all direct
operations. Users should proceed cautiously when
working on these registers, particularly if their code
uses Indirect Addressing.
Similarly, operations by Indirect Addressing are gener-
ally permitted on all other SFRs. Users should exercise
appropriate caution that they do not inadvertently
change settings that might affect the operation of the
device.
6.5 Program Memory and the
Extended Instruct ion Set
The operation of program memory is unaffected by the
use of the extended instruction set.
Enabling the extended instruction set adds five
additional two-word commands to the existing PIC18
instruction set: ADDFSR, CALLW, MOVSF, MOVSS and
SUBFSR. These instructions are executed as described
in Section 6.2.4 “Two-Word Instructions”.
6.6 Data Memory and the Extended
Instruction Set
Enabling the PIC18 extended instruction set (XINST
Configuration bit = 1) significantly changes certain
aspects of data memory and its addressing. Specifically,
the use of the Access Bank for many of the core PIC18
instructions is different. This is due to the introduction of
a new addressing mode for the data memory space.
This mode also alters the behavior of Indirect
Addressing using FSR2 and its associated operands.
What does not change is just as important. The size of
the data memory space is unchanged, as well as its
linear addressing. The SFR map remains the same.
Core PIC18 instructions can still operate in both Direct
and Indirect Addressing mode; inherent and literal
instructions do not change at all. Indirect Addressing
with FSR0 and FSR1 also remains unchanged.
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6.6.1 INDEXED ADDRESSING WITH
LITERAL OFFSET
Enabling the PIC18 extended instruction set changes
the behavior of Indirect Addressing using the FSR2
register pair and its associated file operands. Under
proper conditions, instructions that use the Access
Bank, that is, most bit and byte-oriented instructions,
can invoke a form of Indexed Addressing using an
offset specified in the instruction. This special address-
ing mode is known as Indexed Addressing with Literal
Offset, or Indexed Literal Offset mode.
When using the extended instruction set, this
addressing mode requires the following:
The use of the Access Bank is forced (‘a’ = 0)
The file address argument is less than or equal to
5Fh
Under these conditions, the file address of the
instruction is not interpreted as the lower byte of an
address (used with the BSR in Direct Addressing) or as
an 8-bit address in the Access Bank. Instead, the value
is interpreted as an offset value to an Address Pointer
specified by FSR2. The offset and the contents of
FSR2 are added to obtain the target address of the
operation.
6.6.2 INSTRUCTIONS AFFECTED BY
INDEXED LITERAL OFFSET MODE
Any of the core PIC18 instructions that can use Direct
Addressing are potentially affected by the Indexed
Literal Offset Addressing mode. This includes all byte
and bit-oriented instructions, or almost one-half of the
standard PIC18 instruction set. Instructions that only
use Inherent or Literal Addressing modes are
unaffected.
Additionally, byte and bit-oriented instructions are not
affected if they do not use the Access Bank (Access RAM
bit is ‘1’), or include a file address of 60h or above.
Instructions meeting these criteria will continue to
execute as before. A comparison of the different possible
addressing modes, when the extended instruction set is
enabled, is provided in Figure 6-9.
Those who desire to use byte or bit-oriented instruc-
tions, in the Indexed Literal Offset mode, should note
the changes to assembler syntax for this mode. This is
described in more detail in Sect i on 2 8 . 2.1 E xt en d ed
Instruction Syntax”.
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FIGURE 6-9: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND BYTE-ORIENTED
INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED)
EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff)
When a = 0 and f 60h:
The instruction executes in
Direct Forced mode. ‘f’ is
interpreted as a location in the
Access RAM between 060h
and FFFh. This is the same as
locations F60h to FFFh
(Bank 15) of data memory.
Locations below 060h are not
available in this addressing
mode.
When a = 0 and f5Fh:
The instruction executes in
Indexed Literal Offset mode. ‘f’
is interpreted as an offset to the
address value in FSR2. The
two are added together to
obtain the address of the target
register for the instruction. The
address can be anywhere in
the data memory space.
Note that in this mode, the
correct syntax is:
ADDWF [k], d
where ‘k’ is same as ‘f’.
When a = 1 (all values of f):
The instruction executes in
Direct mode (also known as
Direct Long mode). ‘f’ is
interpreted as a location in
one of the 16 banks of the data
memory space. The bank is
designated by the Bank Select
Register (BSR). The address
can be in any implemented
bank in the data memory
space.
000h
060h
100h
F00h
F60h
FFFh
Valid range
00h
60h
FFh
Data Memory
Access RAM
Bank 0
Bank 1
through
Bank 14
Bank 15
SFRs
000h
060h
100h
F00h
F60h
FFFh Data Memory
Bank 0
Bank 1
through
Bank 14
Bank 15
SFRs
FSR2H FSR2L
ffffffff001001da
ffffffff001001da
000h
060h
100h
F00h
F60h
FFFh Data Memory
Bank 0
Bank 1
through
Bank 14
Bank 15
SFRs
for ‘f’
BSR
00000000
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6.6.3 MAPPING THE ACCESS BANK IN
INDEXED LITERAL OFFSET MODE
The use of Indexed Literal Offset Addressing mode
effectively changes how the lower part of Access RAM
(00h to 5Fh) is mapped. Rather than containing just the
contents of the bottom part of Bank 0, this mode maps
the contents from Bank 0 and a user-defined “window
that can be located anywhere in the data memory
space. The value of FSR2 establishes the lower
boundary of the addresses mapped to the window,
while the upper boundary is defined by FSR2, plus 95
(5Fh). Addresses in the Access RAM above 5Fh are
mapped as previously described (see Section 6.3.3
“Access Bank”). Figure 6-10 provides an example of
Access Bank remapping in this addressing mode.
Remapping of the Access Bank applies only to opera-
tions using the Indexed Literal Offset mode. Operations
that use the BSR (Access RAM bit is ‘1’) will continue
to use Direct Addressing as before. Any Indirect or
Indexed Addressing operation that explicitly uses any
of the indirect file operands (including FSR2) will con-
tinue to operate as standard Indirect Addressing. Any
instruction that uses the Access Bank, but includes a
register address of greater than 05Fh, will use Direct
Addressing and the normal Access Bank map.
6.6.4 BSR IN INDEXED LITERAL OFFSET
MODE
Although the Access Bank is remapped when the
extended instruction set is enabled, the operation of the
BSR remains unchanged. Direct Addressing, using the
BSR to select the data memory bank, operates in the
same manner as previously described.
FIGURE 6-10: REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET ADDRESSING
Data Memory
000h
100h
200h
F60h
F00h
FFFh
Bank 1
Bank 15
Bank 2
through
Bank 14
SFRs
05Fh
ADDWF f, d, a
FSR2H:FSR2L = 120h
Locations in the region
from the FSR2 Pointer
(120h) to the pointer plus
05Fh (17Fh) are mapped
to the bottom of the
Access RAM (000h-05Fh).
Special Function Registers
at F60h through FFFh are
mapped to 60h through
FFh, as usual.
Bank 0 addresses below
5Fh are not available in
this mode. They can still
be addressed by using the
BSR.
Access Bank
00h
FFh
Bank 0
SFRs
Bank 1 “Window”
Not Accessible
Window
Example Situation:
120h
17Fh
5Fh
60h
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7.0 FLASH PROGRAM MEMORY
The Flash program memory is fully readable, writable
and erasable during normal operation.
A read from program memory is executed on 1 byte at
a time. A write to program memory is executed on
blocks of 64 bytes at a time or 2 bytes at a time.
Program memory is erased in blocks of 1024 bytes at
a time. A bulk erase operation may not be issued from
user code.
Writing or erasing program memory will cease
instruction fetches until the operation is complete. The
program memory cannot be accessed during the write
or erase, therefore, code cannot execute. An internal
programming timer terminates program memory writes
and erases.
A value written to program memory does not need to be
a valid instruction. Executing a program memory
location that forms an invalid instruction results in a
NOP.
7.1 Table Reads and Table Writes
In order to read and write program memory, there are
two operations that allow the processor to move bytes
between the program memory space and the data RAM:
Table Read (TBLRD)
Table Write (TBLWT)
The program memory space is 16 bits wide, while the
data RAM space is 8 bits wide. Table reads and table
writes move data between these two memory spaces
through an 8-bit register (TABLAT).
Table read operations retrieve data from program
memory and place it into the data RAM space.
Figure 7-1 illustrates the operation of a table read with
program memory and data RAM.
Table write operations store data from the data memory
space into holding registers in program memory. The
procedure to write the contents of the holding registers
into program memory is detailed in Section 7.5 “Writin g
to Flash Program Memory”. Figure 7-2 illustrates the
operation of a table write with program memory and data
RAM.
Table operations work with byte entities. A table block
containing data, rather than program instructions, is not
required to be word-aligned. Therefore, a table block can
start and end at any byte address. If a table write is being
used to write executable code into program memory,
program instructions will need to be word-aligned.
FIGU RE 7-1: TABLE REA D OPERA TION
Table Pointer(1)
Table Latch (8-bit)
Program Memory
TBLPTRH TBLPTRL
TABLAT
TBLPTRU
Instruction: TBLRD*
Note 1: The Table Pointer register points to a byte in program memory.
Program Memory
(TBLPTR)
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FIGURE 7-2: TABLE WRITE OPERATION
7.2 Control Registers
Several control registers are used in conjunction with
the TBLRD and TBLWT instructions. Those are:
EECON1 register
EECON2 register
TABLAT register
TBLPTR registers
7.2.1 EECON1 AND EECON2 REGISTERS
The EECON1 register (Register 7-1) is the control
register for memory accesses. The EECON2 register is
not a physical register; it is used exclusively in the
memory write and erase sequences. Reading
EECON2 will read all ‘0’s.
The WPROG bit, when set, will allow programming
two bytes per word on the execution of the WR
command. If this bit is cleared, the WR command will
result in programming on a block of 64 bytes.
The FREE bit, when set, will allow a program memory
erase operation. When FREE is set, the erase
operation is initiated on the next WR command. When
FREE is clear, only writes are enabled.
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear. The WRERR bit is
set in hardware when the WR bit is set and cleared
when the internal programming timer expires and the
write operation is complete.
The WR control bit initiates write operations. The bit
cannot be cleared, only set, in software. It is cleared in
hardware at the completion of the write operation.
Ta bl e P oi nt e r(1) Table Latch (8-bit)
TBLPTRH TBLPTRL TABLAT
Program Memory
(TBLPTR)
TBLPTRU
Instruction: TBLWT*
Note 1: The Table Pointer actually points to one of 64 holding registers, the address of which is determined by
TBLPTRL<5:0>. The process for physically writing data to the program memory array is discussed in
Section 7.5 “Writing to Flash Program Memory”.
Holding Registers
Program Memory
Note: During normal operation, the WRERR is
read as ‘1’. This can indicate that a write
operation was prematurely terminated by
a Reset, or a write operation was
attempted improperly.
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REGISTER 7-1: EECON1: EEPROM CONTROL REGISTER 1 (ACCESS FA6h)
U-0 U-0 R/W-0 R/W-0 R/W-x R/W-0 R/S-0 U-0
WPROG FREE WRERR WREN WR
bit 7 bit 0
Legend: S = Settable bit (cannot be cleared in software)
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as ‘0
bit 5 WPROG: One Word-Wide Program bit
1 = Program 2 bytes on the next WR command
0 = Program 64 bytes on the next WR command
bit 4 FREE: Flash Erase Enable bit
1 = Perform an erase operation on the next WR command (cleared by hardware after completion of erase)
0 = Perform write only
bit 3 WRERR: Flash Program Error Flag bit
1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal
operation or an improper write attempt)
0 = The write operation is complete
bit 2 WREN: Flash Program Write Enable bit
1 = Allows write cycles to Flash program memory
0 = Inhibits write cycles to Flash program memory
bit 1 WR: Write Control bit
1 = Initiates a program memory erase cycle or write cycle
(The operation is self-timed and the bit is cleared by hardware once the write is complete. The WR
bit can only be set (not cleared) in software.)
0 = Write cycle is complete
bit 0 Unimplemented: Read as ‘0
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7.2.2 TABLE LATCH REGISTER (TABLAT)
The Table Latch (TABLAT) is an 8-bit register mapped
into the Special Function Register (SFR) space. The
Table Latch register is used to hold 8-bit data during
data transfers between program memory and data
RAM.
7.2.3 TABLE POINTER REGISTER
(TBLPTR)
The Table Pointer (TBLPTR) register addresses a byte
within the program memory. The TBLPTR comprises
three SFR registers: Table Pointer Upper Byte, Table
Pointer High Byte and Table Pointer Low Byte
(TBLPTRU:TBLPTRH:TBLPTRL). These three registers
join to form a 22-bit wide pointer. The low-order 21 bits
allow the device to address up to 2 Mbytes of program
memory space. The 22nd bit allows access to the device
ID, the user ID and the Configuration bits.
The Table Pointer register, TBLPTR, is used by the
TBLRD and TBLWT instructions. These instructions can
update the TBLPTR in one of four ways based on the
table operation.
Table 7-1 provides these operations. These operations
on the TBLPTR only affect the low-order 21 bits.
7.2.4 TABLE POINTER BOUNDARIES
TBLPTR is used in reads, writes and erases of the
Flash program memory.
When a TBLRD is executed, all 22 bits of the TBLPTR
determine which byte is read from program memory
into TABLAT.
When a TBLWT is executed, the seven Least Significant
bits (LSbs) of the Table Pointer register (TBLPTR<6:0>)
determine which of the 64 program memory holding
registers is written to. When the timed write to program
memory begins (via the WR bit), the 12 Most Significant
bits (MSbs) of the TBLPTR (TBLPTR<21:10>)
determine which program memory block of 1024 bytes
is written to. For more information, see Section 7.5
“Writing to Flash Program Memory”.
When an erase of program memory is executed, the
12 MSbs of the Table Pointer register point to the
1024-byte block that will be erased. The LSbs are
ignored.
Figure 7-3 illustrates the relevant boundaries of
TBLPTR based on Flash program memory operations.
TABLE 7-1: TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
FIGURE 7-3: TABLE POINTER BOUNDARIES BASED ON OPERATION
Example Operation on Table Pointer
TBLRD*
TBLWT* TBLPTR is not modified
TBLRD*+
TBLWT*+ TBLPTR is incremented after the read/write
TBLRD*-
TBLWT*- TBLPTR is decremented after the read/write
TBLRD+*
TBLWT+* TBLPTR is incremented before the read/write
21 16 15 87 0
ERASE: TB LPTR<20:10>
TABLE WRITE: TBLPTR<20:6>
TABLE READ: TBLPTR<21:0>
TBLPTRL
TBLPTRH
TBLPTRU
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7.3 Reading the Flash Program
Memory
The TBLRD instruction is used to retrieve data from
program memory and places it into data RAM. Table
reads from program memory are performed one byte at
a time.
TBLPTR points to a byte address in program space.
Executing TBLRD places the byte pointed to into
TABLAT. In addition, TBLPTR can be modified
automatically for the next table read operation.
The internal program memory is typically organized by
words. The LSb of the address selects between the high
and low bytes of the word.
Figure 7-4 illustrates the interface between the internal
program memory and the TABLAT.
FIGURE 7-4: READS FROM FLASH PROGRAM MEMORY
EXAMPLE 7-1: READING A FLASH PROGRAM MEMORY WORD
(Even Byte Address)
Program Memory
(Odd Byte Address)
TBLRD TABLAT
TBLPTR = xxxxx1
FETCH
Instruction Register
(IR) Read Register
TBLPTR = xxxxx0
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base
MOVWF TBLPTRU ; address of the word
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
READ_WORD TBLRD*+ ; read into TABLAT and increment
MOVF TABLAT, W ; get data
MOVWF WORD_EVEN
TBLRD*+ ; read into TABLAT and increment
MOVF TABLAT, W ; get data
MOVWF WORD_ODD
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7.4 Erasing Flash Program Memory
The minimum erase block is 512 words or 1024 bytes.
Only through the use of an external programmer, or
through ICSP control, can larger blocks of program
memory be bulk erased. Word erase in the Flash array
is not supported.
When initiating an erase sequence from the micro-
controller itself, a block of 1024 bytes of program
memory is erased. The Most Significant 12 bits of the
TBLPTR<21:10> point to the block being erased;
TBLPTR<9:0> are ignored.
The EECON1 register commands the erase operation.
The WREN bit must be set to enable write operations.
The FREE bit is set to select an erase operation. For
protection, the write initiate sequence for EECON2
must be used.
A long write is necessary for erasing the internal Flash.
Instruction execution is halted while in a long write
cycle. The long write will be terminated by the internal
programming timer.
7.4.1 FLASH PROGRAM MEMORY
ERASE SEQUENCE
The sequence of events for erasing a block of internal
program memory location is:
1. Load Table Pointer register with the address of
the row being erased.
2. Set the WREN and FREE bits (EECON1<2,4>)
to enable the erase operation.
3. Disable interrupts.
4. Write 0x55 to EECON2.
5. Write 0xAA to EECON2.
6. Set the WR bit; this will begin the erase cycle.
7. The CPU will stall for the duration of the erase
for TIE (see Parameter D133B).
8. Re-enable interrupts.
EXAMPLE 7-2: ERASING FLASH PROGRAM MEMORY
MOVLW CODE_ADDR_UPPER ; load TBLPTR with the base
MOVWF TBLPTRU ; address of the memory block
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
ERASE_ROW BSF EECON1, WREN ; enable write to memory
BSF EECON1, FREE ; enable Erase operation
BCF INTCON, GIE ; disable interrupts
Required MOVLW 0x55
Sequence MOVWF EECON2 ; write 0x55
MOVLW 0xAA
MOVWF EECON2 ; write 0xAA
BSF EECON1, WR ; start erase (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
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7.5 Writing to Flash Program Memory
The programming block is 32 words or 64 bytes.
Programming one word or 2 bytes at a time is also
supported.
Table writes are used internally to load the holding reg-
isters needed to program the Flash memory. There are
64 holding registers used by the table writes for
programming.
Since the Table Latch (TABLAT) is only a single byte, the
TBLWT instruction may need to be executed 64 times for
each programming operation (if WPROG = 0). All of the
table write operations will essentially be short writes
because only the holding registers are written. At the
end of updating the 64 holding registers, the EECON1
register must be written to in order to start the
programming operation with a long write.
The long write is necessary for programming the
internal Flash. Instruction execution is halted while in a
long write cycle. The long write will be terminated by
the internal programming timer.
The on-chip timer controls the write time. The
write/erase voltages are generated by an on-chip
charge pump, rated to operate over the voltage range
of the device.
FIGURE 7-5: TABLE WRITES TO FLASH PROGRAM MEMORY
7.5.1 FLASH PROGRAM MEMORY WRITE
SEQUENCE
The sequence of events for programming an internal
program memory location should be:
1. Read 1024 bytes into RAM.
2. Update data values in RAM as necessary.
3. Load the Table Pointer register with the address
being erased.
4. Execute the erase procedure.
5. Load the Table Pointer register with the address
of the first byte being written, minus 1.
6. Write the 64 bytes into the holding registers with
auto-increment.
7. Set the WREN bit (EECON1<2>) to enable byte
writes.
8. Disable interrupts.
9. Write 0x55 to EECON2.
10. Write 0xAA to EECON2.
11. Set the WR bit. This will begin the write cycle.
12. The CPU will stall for the duration of the write for
TIW (see Parameter D133A).
13. Re-enable interrupts.
14. Repeat Steps 6 through 13 until all 1024 bytes
are written to program memory.
15. Verify the memory (table read).
An example of the required code is provided in
Example 7-3 on the following page.
Note 1: Unlike previous PIC® devices, devices of
the PIC18F46J50 family do not reset the
holding registers after a write occurs. The
holding registers must be cleared or
overwritten before a programming
sequence.
2: To maintain the endurance of the pro-
gram memory cells, each Flash byte
should not be programmed more than
once between erase operations. Before
attempting to modify the contents of the
target cell a second time, an erase of the
target page, or a bulk erase of the entire
memory, must be performed.
TABLAT
TBLPTR = xxxx3FTBLPTR = xxxxx1TBLPTR = xxxxx0
Write Register
TBLPTR = xxxxx2
Program Memory
Holding Register Holding Register Holding Register Holding Register
88 8 8
Note: Before setting the WR bit, the Table
Pointer address needs to be within the
intended address range of the 64 bytes in
the holding register.
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EXAMPLE 7-3: W RITING TO FLASH PROGRAM MEMORY
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base address
MOVWF TBLPTRU ; of the memory block, minus 1
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW
MOVWF TBLPTRL
ERASE_BLOCK BSF EECON1, WREN ; enable write to memory
BSF EECON1, FREE ; enable Erase operation
BCF INTCON, GIE ; disable interrupts
MOVLW 0x55
MOVWF EECON2 ; write 0x55
MOVLW 0xAA
MOVWF EECON2 ; write 0xAA
BSF EECON1, WR ; start erase (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
MOVLW D'16'
MOVWF WRITE_COUNTER ; Need to write 16 blocks of 64 to write
; one erase block of 1024
RESTART_BUFFER MOVLW D'64'
MOVWF COUNTER
MOVLW BUFFER_ADDR_HIGH ; point to buffer
MOVWF FSR0H
MOVLW BUFFER_ADDR_LOW
MOVWF FSR0L
FILL_BUFFER ... ; read the new data from I2C, SPI,
; PSP, USART, etc.
WRITE_BUFFER MOVLW D’64’ ; number of bytes in holding register
MOVWF COUNTER
WRITE_BYTE_TO_HREGSMOVFF POSTINC0, WREG ; get low byte of buffer data
MOVWF TABLAT ; present data to table latch
TBLWT+* ; write data, perform a short write
; to internal TBLWT holding register.
DECFSZ COUNTER ; loop until buffers are full
BRA WRITE_BYTE_TO_HREGS
PROGRAM_MEMORY BSF EECON1, WREN ; enable write to memory
BCF INTCON, GIE ; disable interrupts
MOVLW 0x55
Required MOVWF EECON2 ; write 0xAA
Sequence MOVLW 0xAA
MOVWF EECON2 ; write 0xAA
BSF EECON1, WR ; start program (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
BCF EECON1, WREN ; disable write to memory
DECFSZ WRITE_COUNTER ; done with one write cycle
BRA RESTART_BUFFER ; if not done replacing the erase block
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7.5.2 FLASH PROGRAM MEMORY WRITE
SEQUENCE (WORD
PROGRAMMING)
The PIC18F46J50 family of devices has a feature that
allows programming a single word (two bytes). This
feature is enabled when the WPROG bit is set. If the
memory location is already erased, the following
sequence is required to enable this feature:
1. Load the Table Pointer register with the address
of the data to be written. (It must be an even
address.)
2. Write the 2 bytes into the holding registers by
performing table writes. (Do not post-increment
on the second table write.)
3. Set the WREN bit (EECON1<2>) to enable
writes and the WPROG bit (EECON1<5>) to
select Word Write mode.
4. Disable interrupts.
5. Write 0x55 to EECON2.
6. Write 0xAA to EECON2.
7. Set the WR bit; this will begin the write cycle.
8. The CPU will stall for the duration of the write for
TIW (see Parameter D133A).
9. Re-enable interrupts.
EXAMPLE 7-4: SINGLE-WORD WRITE TO FLASH PROGRAM MEMORY
MOVLW CODE_ADDR_UPPER ; Load TBLPTR with the base address
MOVWF TBLPTRU
MOVLW CODE_ADDR_HIGH
MOVWF TBLPTRH
MOVLW CODE_ADDR_LOW ; The table pointer must be loaded with an even
address
MOVWF TBLPTRL
MOVLW DATA0 ; LSB of word to be written
MOVWF TABLAT
TBLWT*+
MOVLW DATA1 ; MSB of word to be written
MOVWF TABLAT
TBLWT* ; The last table write must not increment the table
pointer! The table pointer needs to point to the
MSB before starting the write operation.
PROGRAM_MEMORY BSF EECON1, WPROG ; enable single word write
BSF EECON1, WREN ; enable write to memory
BCF INTCON, GIE ; disable interrupts
MOVLW 0x55
Required MOVWF EECON2 ; write 0x55
Sequence MOVLW 0xAA
MOVWF EECON2 ; write 0xAA
BSF EECON1, WR ; start program (CPU stall)
BSF INTCON, GIE ; re-enable interrupts
BCF EECON1, WPROG ; disable single word write
BCF EECON1, WREN ; disable write to memory
PIC18F46J50 FAMILY
DS39931D-page 112 2011 Microchip Technology Inc.
7.5.3 WRITE VERIFY
Depending on the application, good programming
practice may dictate that the value written to the
memory should be verified against the original value.
This should be used in applications where excessive
writes can stress bits near the specification limit.
7.5.4 UNEXPECTED TERMINATION OF
WRITE OPERATION
If a write is terminated by an unplanned event, such as
loss of power or an unexpected Reset, the memory
location just programmed should be verified and repro-
grammed if needed. If the write operation is interrupted
by a MCLR Reset or a WDT time-out Reset during
normal operation, the user can check the WRERR bit
and rewrite the location(s) as needed.
7.6 Flash Program Operation Duri ng
Code Protection
See Section 27.6 “Program Verification and Code
Protection” for details on code protection of Flash
program memory.
TABLE 7-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values on
Page:
TBLPTRU bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) 69
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 69
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 69
TABLAT Program Memory Table Latch 69
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
EECON2 Program Memory Control Register 2 (not a physical register) 71
EECON1 WPROG FREE WRERR WREN WR 71
Legend: = unimplemented, read as ‘0’. Shaded cells are not used during Flash program memory access.
2011 Microchip Technology Inc. DS39931D-page 113
PIC18F46J50 FAMILY
8.0 8 x 8 HARDWARE MULTIPLIER
8.1 Introduction
All PIC18 devices include an 8 x 8 hardware multiplier
as part of the ALU. The multiplier performs an unsigned
operation and yields a 16-bit result that is stored in the
product register pair, PRODH:PRODL. The multiplier’s
operation does not affect any flags in the STATUS
register.
Making multiplication a hardware operation allows it to
be completed in a single instruction cycle. This has the
advantages of higher computational throughput and
reduced code size for multiplication algorithms and
allows the PIC18 devices to be used in many applica-
tions previously reserved for digital signal processors.
Table 8-1 provides a comparison of various hardware
and software multiply operations, along with the
savings in memory and execution time.
8.2 Operation
Example 8-1 provides the instruction sequence for an
8 x 8 unsigned multiplication. Only one instruction is
required when one of the arguments is already loaded
in the WREG register.
Example 8-2 provides the instruction sequence for an
8 x 8 signed multiplication. To account for the sign bits
of the arguments, each argument’s Most Significant bit
(MSb) is tested and the appropriate subtractions are
done.
EXAMPLE 8-1: 8 x 8 UNSIGNED MULTIPLY
ROUTIN E
EXAMPLE 8-2: 8 x 8 SIGNED MULTIPL Y
ROUTINE
TABLE 8-1: PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
MOVF ARG1, W ;
MULWF ARG2 ; ARG1 * ARG2 ->
; PRODH:PRODL
MOVF ARG1, W
MULWF ARG2 ; ARG1 * ARG2 ->
; PRODH:PRODL
BTFSC ARG2, SB ; Test Sign Bit
SUBWF PRODH, F ; PRODH = PRODH
; - ARG1
MOVF ARG2, W
BTFSC ARG1, SB ; Test Sign Bit
SUBWF PRODH, F ; PRODH = PRODH
; - ARG2
Routine Multiply Method Program
Memory
(Words)
Cycles
(Max)
Time
@ 48 MHz @ 10 MHz @ 4 MHz
8 x 8 unsigned Without hardware multiply 13 69 5.7 s27.6 s69 s
Hardware multiply 1 1 83.3 ns 400 ns 1 s
8 x 8 signed Without hardware multiply 33 91 7.5 s36.4 s91 s
Hardware multiply 6 6 500 ns 2.4 s6 s
16 x 16 unsigned Without hardware multiply 21 242 20.1 s96.8 s242 s
Hardware multiply 28 28 2.3 s 11.2 s28 s
16 x 16 signed Without hardware multiply 52 254 21.6 s 102.6 s254 s
Hardware multiply 35 40 3.3 s16.0 s40 s
PIC18F46J50 FAMILY
DS39931D-page 114 2011 Microchip Technology Inc.
Example 8-3 provides the instruction sequence for a
16 x 16 unsigned multiplication. Equation 8-1 provides
the algorithm that is used. The 32-bit result is stored in
four registers (RES<3:0>).
EQUATION 8-1: 16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
EXAMPLE 8-3: 16 x 16 UNSIGN ED
MULTIPLY ROUTINE
Example 8-4 provides the sequence to do a 16 x 16
signed multiply. Equation 8-2 provides the algorithm
used. The 32-bit result is stored in four registers
(RES<3:0>). To account for the sign bits of the
arguments, the MSb for each argument pair is tested
and the appropriate subtractions are done.
EQUATION 8-2: 16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
EXAMPLE 8-4: 16 x 1 6 S IGNE D MUL TIP LY
ROUTINE
RES3:RES0 = ARG1H:ARG1L · ARG2H:ARG2L
= (ARG1H · ARG2H · 216) +
(ARG1H · ARG2L · 28) +
(ARG1L · ARG2H · 28) +
(ARG1L · ARG2L)
MOVF ARG1L, W
MULWF ARG2L ; ARG1L * ARG2L->
; PRODH:PRODL
MOVFF PRODH, RES1 ;
MOVFF PRODL, RES0 ;
MOVF ARG1H, W
MULWF ARG2H ; ARG1H * ARG2H->
; PRODH:PRODL
MOVFF PRODH, RES3 ;
MOVFF PRODL, RES2 ;
MOVF ARG1L, W
MULWF ARG2H ; ARG1L * ARG2H->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES3, F ;
MOVF ARG1H, W ;
MULWF ARG2L ; ARG1H * ARG2L->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES3, F ;
RES3:RES0 = ARG1H:ARG1L · ARG2H:ARG2L
= (ARG1H · ARG2H · 216) +
(ARG1H · ARG2L · 28) +
(ARG1L · ARG2H · 28) +
(ARG1L · ARG2L) +
(-1 · ARG2H<7> · ARG1H:ARG1L · 216) +
(-1 · ARG1H<7> · ARG2H:ARG2L · 216)
MOVF ARG1L, W
MULWF ARG2L ; ARG1L * ARG2L ->
; PRODH:PRODL
MOVFF PRODH, RES1 ;
MOVFF PRODL, RES0 ;
MOVF ARG1H, W
MULWF ARG2H ; ARG1H * ARG2H ->
; PRODH:PRODL
MOVFF PRODH, RES3 ;
MOVFF PRODL, RES2 ;
MOVF ARG1L, W
MULWF ARG2H ; ARG1L * ARG2H ->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES 2, F ;
CLRF WREG ;
ADDWFC RES 3, F ;
MOVF ARG1H, W ;
MULWF ARG2L ; ARG1H * ARG2L ->
; PRODH:PRODL
MOVF PRODL, W ;
ADDWF RES1, F ; Add cross
MOVF PRODH, W ; products
ADDWFC RES2, F ;
CLRF WREG ;
ADDWFC RES 3, F ;
BTFSS ARG2H, 7 ; ARG2H:ARG2L neg?
BRA SIGN_ARG1 ; no, check ARG1
MOVF ARG1L, W ;
SUBWF RES2 ;
MOVF ARG1H, W ;
SUBWFB RES 3
SIGN_ARG1
BTFSS ARG1H, 7 ; ARG1H:ARG1L neg?
BRA CONT_CODE ; no, don e
MOVF ARG2L, W ;
SUBWF RES2 ;
MOVF ARG2H, W ;
SUBWFB RES 3
CONT_CODE
:
2011 Microchip Technology Inc. DS39931D-page 115
PIC18F46J50 FAMILY
9.0 INTERRUPTS
Devices of the PIC18F46J50 family have multiple inter-
rupt sources and an interrupt priority feature that allows
most interrupt sources to be assigned a high-priority
level or a low-priority level. The high-priority interrupt
vector is at 0008h and the low-priority interrupt vector
is at 0018h. High-priority interrupt events will interrupt
any low-priority interrupts that may be in progress.
There are 13 registers, which are used to control
interrupt operation. These registers are:
RCON
•INTCON
INTCON2
INTCON3
PIR1, PIR2, PIR3
PIE1, PIE2, PIE3
IPR1, IPR2, IPR3
It is recommended that the Microchip header files
supplied with MPLAB® IDE be used for the symbolic
bit names in these registers. This allows the
assembler/compiler to automatically take care of the
placement of these bits within the specified register.
In general, interrupt sources have three bits to control
their operation. They are:
Flag bit to indicate that an interrupt event
occurred
Enable bit that allows program execution to
branch to the interrupt vector address when the
flag bit is set
Priority bit to select high priority or low priority
The interrupt priority feature is enabled by setting the
IPEN bit (RCON<7>). When interrupt priority is
enabled, there are two bits which enable interrupts
globally. Setting the GIEH bit (INTCON<7>) enables all
interrupts that have the priority bit set (high priority).
Setting the GIEH and GIEL bits (INTCON<7:6>)
enables interrupts that have the priority bit cleared (low
priority). When the interrupt flag, enable bit and
appropriate Global Interrupt Enable bits are set, the
interrupt will vector immediately to address, 0008h or
0018h, depending on the priority bit setting. Individual
interrupts can be disabled through their corresponding
enable bits.
When the IPEN bit is cleared (default state), the
interrupt priority feature is disabled and interrupts are
compatible with PIC® mid-range devices. In
Compatibility mode, the interrupt priority bits for each
source have no effect. INTCON<6> is the PEIE bit,
which enables/disables all peripheral interrupt sources.
INTCON<7> is the GIE bit, which enables/disables all
interrupt sources. All interrupts branch to address,
0008h, in Compatibility mode.
When an interrupt is responded to, the Global Interrupt
Enable bit is automatically cleared by hardware to dis-
able further interrupts. If the IPEN bit is cleared, this is
the GIE bit. If interrupt priority levels are used, this will be
either the GIEH bit, if the interrupt was configured for
high-priority, or the GIEL bit, if the interrupt was config-
ured for low-priority. When executing in the interrupt
context, application firmware should not attempt to
manually re-enable the respective GIEH or GIEL bit that
was cleared in hardware. High-priority interrupt sources
can interrupt a low-priority interrupt. Low-priority inter-
rupts are not processed while high-priority interrupts are
in progress.
When an interrupt occurs, the return address is pushed
onto the stack and the PC is loaded with the interrupt
vector address (0008h or 0018h). Once in the Interrupt
Service Routine (ISR), the source(s) of the interrupt
can be determined by polling the interrupt flag bits. The
interrupt flag bit, or individual PIEx enable bit, must be
cleared in software before returning from the interrupt
handler to avoid recursive interrupts.
The “return from interrupt” instruction, RETFIE, exits
the interrupt routine and sets the GIE bit (GIEH or GIEL
if priority levels are used), which re-enables interrupts.
For external interrupt events, such as the INTx pins or
the PORTB input change interrupt, the interrupt latency
will be three to four instruction cycles. The exact
latency is the same for one or two-cycle instructions.
Individual interrupt flag bits are set regardless of the
status of their corresponding enable bit or the GIE bit.
Note: Do not use the MOVFF instruction to modify
any of the interrupt control registers while
any interrupt is enabled. Doing so may
cause erratic microcontroller behavior.
PIC18F46J50 FAMILY
DS39931D-page 116 2011 Microchip Technology Inc.
FIGU RE 9-1 : PIC18F 46J50 FAMIL Y INTE RR UPT LOG IC
TMR0IE
GIE/GIEH
PEIE/GIEL
Wake-up if in
Interrupt to CPU
Vector to Location
0008h
INT2IF
INT2IE
INT2IP
INT1IF
INT1IE
INT1IP
TMR0IF
TMR0IE
TMR0IP
RBIF
RBIE
RBIP
IPEN
TMR0IF
TMR0IP
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
RBIF
RBIE
RBIP
INT0IF
INT0IE
PEIE/GIEL
Interrupt to CPU
Vector to Location
IPEN
IPEN
0018h
PIR1<7:0>
PIE1<7:0>
IPR1<7:0>
High-Priority Interrupt Generation
Low-Priority Interrupt Generation
Idle or Sleep modes
GIE/GIEH
INT3IF
INT3IE
INT3IP
INT3IF
INT3IE
INT3IP
PIR2<7:0>
PIE2<7:0>
IPR2<7:0>
PIR3<7:0>
PIE3<7:0>
IPR3<7:0>
PIR1<7:0>
PIE1<7:0>
IPR1<7:0>
PIR2<7:0>
PIE2<7:0>
IPR2<7:0>
PIR3<7:0>
PIE3<7:0>
IPR3<7:0>
IPEN
2011 Microchip Technology Inc. DS39931D-page 117
PIC18F46J50 FAMILY
9.1 INTCON Registers
The INTCON registers are readable and writable
registers, which contain various enable, priority and
flag bits.
Note: Interrupt flag bits are set when an interrupt
condition occurs regardless of the state of
its corresponding enable bit or the Global
Interrupt Enable bit. User software should
ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt.
This feature allows for software polling.
REGISTER 9-1: INTCON: INTERRUPT CONTROL REGISTER (ACCESS FF2h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x
GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 GIE/GIEH: Global Interrupt Enable bit
When IPEN = 0:
1 = Enables all unmasked interrupts
0 = Disables all interrupts
When IPEN = 1:
1 = Enables all high-priority interrupts (also enables low-priority interrupts when GIEL is also set)
0 = Disables all interrupts
bit 6 PEIE/GIEL: Peripheral/Low-Priority Interrupt Enable bit
When IPEN = 0:
1 = Enables all unmasked peripheral interrupts (when GIE is also set)
0 = Disables all peripheral interrupts
When IPEN = 1:
1 = Enables all interrupts configured for low priority (when GIEH is also set)
0 = Disables all interrupts configured for low priority
bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit
1 = Enables the TMR0 overflow interrupt
0 = Disables the TMR0 overflow interrupt
bit 4 INT0IE: INT0 External Interrupt Enable bit
1 = Enables the INT0 external interrupt
0 = Disables the INT0 external interrupt
bit 3 RBIE: RB Port Change Interrupt Enable bit
1 = Enables the RB port change interrupt
0 = Disables the RB port change interrupt
bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit
1 = TMR0 register has overflowed (must be cleared in software)
0 = TMR0 register did not overflow
bit 1 INT0IF: INT0 External Interrupt Flag bit
1 = The INT0 external interrupt occurred (must be cleared in software)
0 = The INT0 external interrupt did not occur
bit 0 RBIF: RB Port Change Interrupt Flag bit(1)
1 = At least one of the RB<7:4> pins changed state (must be cleared in software)
0 = None of the RB<7:4> pins have changed state
Note 1: A mismatch condition will continue to set this bit. Reading PORTB and waiting 1 TCY will end the mismatch
condition and allow the bit to be cleared.
PIC18F46J50 FAMILY
DS39931D-page 118 2011 Microchip Technology Inc.
REGISTER 9-2: INTCON2: INTERRUPT CONTROL REGISTER 2 (ACCESS FF1h)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RBPU: PORTB Pull-up Enable bit
1 = All PORTB pull-ups are disabled
0 = PORTB pull-ups are enabled by individual PORT TRIS values
bit 6 INTEDG0: External Interrupt 0 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 5 INTEDG1: External Interrupt 1 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 4 INTEDG2: External Interrupt 2 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 3 INTEDG3: External Interrupt 3 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 INT3IP: INT3 External Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 RBIP: RB Port Change Interrupt Priority bit
1 =High priority
0 = Low priority
Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding
enable bit or the Global Interrupt Enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
2011 Microchip Technology Inc. DS39931D-page 119
PIC18F46J50 FAMILY
REGISTER 9-3: INTCON3: INTERRUPT CONTROL REGISTER 3 (ACCESS FF0h)
R/W-1 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 INT2IP: INT2 External Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 INT1IP: INT1 External Interrupt Priority bit
1 =High priority
0 = Low priority
bit 5 INT3IE: INT3 External Interrupt Enable bit
1 = Enables the INT3 external interrupt
0 = Disables the INT3 external interrupt
bit 4 INT2IE: INT2 External Interrupt Enable bit
1 = Enables the INT2 external interrupt
0 = Disables the INT2 external interrupt
bit 3 INT1IE: INT1 External Interrupt Enable bit
1 = Enables the INT1 external interrupt
0 = Disables the INT1 external interrupt
bit 2 INT3IF: INT3 External Interrupt Flag bit
1 = The INT3 external interrupt occurred (must be cleared in software)
0 = The INT3 external interrupt did not occur
bit 1 INT2IF: INT2 External Interrupt Flag bit
1 = The INT2 external interrupt occurred (must be cleared in software)
0 = The INT2 external interrupt did not occur
bit 0 INT1IF: INT1 External Interrupt Flag bit
1 = The INT1 external interrupt occurred (must be cleared in software)
0 = The INT1 external interrupt did not occur
Note: Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding
enable bit or the Global Interrupt Enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
PIC18F46J50 FAMILY
DS39931D-page 120 2011 Microchip Technology Inc.
9.2 PIR Registers
The PIR registers contain the individual flag bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are three Peripheral Interrupt
Request (Flag) registers (PIR1, PIR2, PIR3).
Note 1: Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the Global
Interrupt Enable bit, GIE (INTCON<7>).
2: User software should ensure the
appropriate interrupt flag bits are cleared
prior to enabling an interrupt and after
servicing that interrupt.
REGISTER 9-4: PIR1: PE RIPH ERA L INTER RUPT REQU EST (FLAG ) REGI STER 1 (A CCE SS F9Eh)
R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0
PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPIF: Parallel Master Port Read/Write Interrupt Flag bit(1)
1 = A read or a write operation has taken place (must be cleared in software)
0 = No read or write has occurred
bit 6 ADIF: A/D Converter Interrupt Flag bit
1 = An A/D conversion completed (must be cleared in software)
0 = The A/D conversion is not complete
bit 5 RC1IF: EUSART1 Receive Interrupt Flag bit
1 = The EUSART1 receive buffer, RCREG1, is full (cleared when RCREG1 is read)
0 = The EUSART1 receive buffer is empty
bit 4 TX1IF: EUSART1 Transmit Interrupt Flag bit
1 = The EUSART1 transmit buffer, TXREG1, is empty (cleared when TXREG1 is written)
0 = The EUSART1 transmit buffer is full
bit 3 SSP1IF: Master Synchronous Serial Port 1 Interrupt Flag bit
1 = The transmission/reception is complete (must be cleared in software)
0 = Waiting to transmit/receive
bit 2 CCP1IF: ECCP1 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1 = TMR2 to PR2 match occurred (must be cleared in software)
0 = No TMR2 to PR2 match occurred
bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared in software)
0 = TMR1 register did not overflow
Note 1: These bits are unimplemented on 28-pin devices.
2011 Microchip Technology Inc. DS39931D-page 121
PIC18F46J50 FAMILY
REGISTER 9-5: PIR2: PE RIPH ERA L INTER RUPT REQU EST (FLAG ) REGI STER 2 (A CCE SS FA1h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit
1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software)
0 = Device clock is operating
bit 6 CM2IF: Comparator 2 Interrupt Flag bit
1 = Comparator input has changed (must be cleared in software)
0 = Comparator input has not changed
bit 5 CM1IF: Comparator 1 Interrupt Flag bit
1 = Comparator input has changed (must be cleared in software)
0 = Comparator input has not changed
bit 4 USBIF: USB Interrupt Flag bit
1 = USB has requested an interrupt (must be cleared in software)
0 = No USB interrupt request
bit 3 BCL1IF: Bus Collision Interrupt Flag bit (MSSP1 module)
1 = A bus collision occurred (must be cleared in software)
0 = No bus collision occurred
bit 2 HLVDIF/LVDIF: High/Low-Voltage Detect (HLVD) Interrupt Flag bit
1 = A High/Low-Voltage Detect condition occurred (must be cleared in software)
0 = An HLVD event has not occurred
bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit
1 = TMR3 register overflowed (must be cleared in software)
0 = TMR3 register did not overflow
bit 0 CCP2IF: ECCP2 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
PIC18F46J50 FAMILY
DS39931D-page 122 2011 Microchip Technology Inc.
REGISTER 9-6: PIR3: PE RIPH ERA L INTER RUPT REQU EST (FLAG ) REGI STER 3 (A CCE SS FA4h)
R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0
SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SSP2IF: Master Synchronous Serial Port 2 Interrupt Flag bit
1 = The transmission/reception is complete (must be cleared in software)
0 = Waiting to transmit/receive
bit 6 BCL2IF: Bus Collision Interrupt Flag bit (MSSP2 module)
1 = A bus collision occurred (must be cleared in software)
0 = No bus collision occurred
bit 5 RC2IF: EUSART2 Receive Interrupt Flag bit
1 = The EUSART2 receive buffer, RCREG2, is full (cleared when RCREG2 is read)
0 = The EUSART2 receive buffer is empty
bit 4 TX2IF: EUSART2 Transmit Interrupt Flag bit
1 = The EUSART2 transmit buffer, TXREG2, is empty (cleared when TXREG2 is written)
0 = The EUSART2 transmit buffer is full
bit 3 TMR4IF: TMR4 to PR4 Match Interrupt Flag bit
1 = TMR4 to PR4 match occurred (must be cleared in software)
0 = No TMR4 to PR4 match occurred
bit 2 CTMUIF: Charge Time Measurement Unit Interrupt Flag bit
1 = A CTMU event has occurred (must be cleared in software)
0 = CTMU event has not occurred
bit 1 TMR3GIF: Timer3 Gate Event Interrupt Flag bit
1 = A Timer3 gate event completed (must be cleared in software)
0 = No Timer3 gate event completed
bit 0 RTCCIF: RTCC Interrupt Flag bit
1 = RTCC interrupt occurred (must be cleared in software)
0 = No RTCC interrupt occurred
2011 Microchip Technology Inc. DS39931D-page 123
PIC18F46J50 FAMILY
9.3 PIE Registers
The PIE registers contain the individual enable bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are three Peripheral
Interrupt Enable registers (PIE1, PIE2, PIE3). When
IPEN = 0, the PEIE bit must be set to enable any of
these peripheral interrupts.
REGISTER 9-7: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1 (ACCESS F9Dh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPIE: Parallel Master Port Read/Write Interrupt Enable bit(1)
1 = Enables the PMP read/write interrupt
0 = Disables the PMP read/write interrupt
bit 6 ADIE: A/D Converter Interrupt Enable bit
1 = Enables the A/D interrupt
0 = Disables the A/D interrupt
bit 5 RC1IE: EUSART1 Receive Interrupt Enable bit
1 = Enables the EUSART1 receive interrupt
0 = Disables the EUSART1 receive interrupt
bit 4 TX1IE: EUSART1 Transmit Interrupt Enable bit
1 = Enables the EUSART1 transmit interrupt
0 = Disables the EUSART1 transmit interrupt
bit 3 SSP1IE: Master Synchronous Serial Port 1 Interrupt Enable bit
1 = Enables the MSSP1 interrupt
0 = Disables the MSSP1 interrupt
bit 2 CCP1IE: ECCP1 Interrupt Enable bit
1 = Enables the ECCP1 interrupt
0 = Disables the ECCP1 interrupt
bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1 = Enables the TMR2 to PR2 match interrupt
0 = Disables the TMR2 to PR2 match interrupt
bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit
1 = Enables the TMR1 overflow interrupt
0 = Disables the TMR1 overflow interrupt
Note 1: These bits are unimplemented on 28-pin devices.
PIC18F46J50 FAMILY
DS39931D-page 124 2011 Microchip Technology Inc.
REGISTER 9-8: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2 (ACCESS FA0h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 6 CM2IE: Comparator 2 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 5 CM1IE: Comparator 1 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 4 USBIE: USB Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 3 BCL1IE: Bus Collision Interrupt Enable bit (MSSP1 module)
1 = Enabled
0 = Disabled
bit 2 HLVDIE: High/Low-Voltage Detect Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 0 CCP2IE: ECCP2 Interrupt Enable bit
1 = Enabled
0 = Disabled
2011 Microchip Technology Inc. DS39931D-page 125
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REGISTER 9-9: PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3 (ACCESS FA3h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SSP2IE: Master Synchronous Serial Port 2 Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 6 BCL2IE: Bus Collision Interrupt Enable bit (MSSP2 module)
1 = Enabled
0 = Disabled
bit 5 RC2IE: EUSART2 Receive Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 4 TX2IE: EUSART2 Transmit Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 3 TMR4IE: TMR4 to PR4 Match Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 2 CTMUIE: Charge Time Measurement Unit (CTMU) Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 1 TMR3GIE: Timer3 Gate Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 0 RTCCIE: RTCC Interrupt Enable bit
1 = Enabled
0 = Disabled
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9.4 IPR Registers
The IPR registers contain the individual priority bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are three Peripheral
Interrupt Priority registers (IPR1, IPR2, IPR3). Using
the priority bits requires that the Interrupt Priority
Enable (IPEN) bit be set.
REGISTER 9-10: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1 (ACCESS F9Fh)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPIP: Parallel Master Port Read/Write Interrupt Priority bit(1)
1 =High priority
0 = Low priority
bit 6 ADIP: A/D Converter Interrupt Priority bit
1 =High priority
0 = Low priority
bit 5 RC1IP: EUSART1 Receive Interrupt Priority bit
1 =High priority
0 = Low priority
bit 4 TX1IP: EUSART1 Transmit Interrupt Priority bit
1 =High priority
0 = Low priority
bit 3 SSP1IP: Master Synchronous Serial Port Interrupt Priority bit (MSSP1 module)
1 =High priority
0 = Low priority
bit 2 CCP1IP: ECCP1 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit
1 =High priority
0 = Low priority
Note 1: These bits are unimplemented on 28-pin devices.
2011 Microchip Technology Inc. DS39931D-page 127
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REGISTER 9-11: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2 (ACCESS FA2h)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 CM2IP: Comparator 2 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 5 C12IP: Comparator 1 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 4 USBIP: USB Interrupt Priority bit
1 =High priority
0 = Low priority
bit 3 BCL1IP: Bus Collision Interrupt Priority bit (MSSP1 module)
1 =High priority
0 = Low priority
bit 2 HLVDIP: High/Low-Voltage Detect Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 CCP2IP: ECCP2 Interrupt Priority bit
1 =High priority
0 = Low priority
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DS39931D-page 128 2011 Microchip Technology Inc.
REGISTER 9-12: IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3 (ACCESS FA5h)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SSP2IP: Master Synchronous Serial Port 2 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 6 BCL2IP: Bus Collision Interrupt Priority bit (MSSP2 module)
1 =High priority
0 = Low priority
bit 5 RC2IP: EUSART2 Receive Interrupt Priority bit
1 =High priority
0 = Low priority
bit 4 TX2IP: EUSART2 Transmit Interrupt Priority bit
1 =High priority
0 = Low priority
bit 3 TMR4IE: TMR4 to PR4 Interrupt Priority bit
1 =High priority
0 = Low priority
bit 2 CTMUIP: Charge Time Measurement Unit (CTMU) Interrupt Priority bit
1 =High priority
0 = Low priority
bit 1 TMR3GIP: Timer3 Gate Interrupt Priority bit
1 =High priority
0 = Low priority
bit 0 RTCCIP: RTCC Interrupt Priority bit
1 =High priority
0 = Low priority
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9.5 RCON Register
The RCON register contains bits used to determine the
cause of the last Reset or wake-up from Idle or Sleep
mode. RCON also contains the bit that enables
interrupt priorities (IPEN).
REGISTER 9-13: RCON: RESET CONTROL REGISTER (ACCES S FD0h)
R/W-0 U-0 R/W-1 R/W-1 R-1 R-1 R/W-0 R/W-0
IPEN —CMRI TO PD POR BOR
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6 Unimplemented: Read as ‘0
bit 5 CM: Configuration Mismatch Flag bit
For details on bit operation, see Register 5-1.
bit 4 RI: RESET Instruction Flag bit
For details on bit operation, see Register 5-1.
bit 3 TO: Watchdog Timer Time-out Flag bit
For details on bit operation, see Register 5-1.
bit 2 PD: Power-Down Detection Flag bit
For details on bit operation, see Register 5-1.
bit 1 POR: Power-on Reset Status bit
For details on bit operation, see Register 5-1.
bit 0 BOR: Brown-out Reset Status bit
For details on bit operation, see Register 5-1.
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9.6 INTx Pin Interrupts
External interrupts on the INT0, INT1, INT2 and INT3
pins are edge-triggered. If the corresponding INTEDGx
bit in the INTCON2 register is set (= 1), the interrupt is
triggered by a rising edge; if the bit is clear, the trigger
is on the falling edge. When a valid edge appears on
the INTx pin, the corresponding flag bit and INTxIF are
set. This interrupt can be disabled by clearing the
corresponding enable bit, INTxIE. Flag bit, INTxIF,
must be cleared in software in the Interrupt Service
Routine before re-enabling the interrupt.
All external interrupts (INT0, INT1, INT2 and INT3) can
wake-up the processor from Sleep and Idle modes if
bit, INTxIE, was set prior to going into the
power-managed modes. After waking from Sleep or
Idle mode, the processor will branch to the interrupt
vector if the GIEH (and GIEL if configured for low prior-
ity) bit(s) are set. Deep Sleep mode can wake-up from
INT0, but the processor will start execution from the
Power-on Reset vector rather than branch to the
interrupt vector.
Interrupt priority for INT1, INT2 and INT3 is determined
by the value contained in the Interrupt Priority bits,
INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and
INT3IP (INTCON2<1>). There is no priority bit
associated with INT0; it is always a high-priority
interrupt source.
9.7 TMR0 Interrupt
In 8-bit mode (which is the default), an overflow in the
TMR0 register (FFh 00h) will set flag bit, TMR0IF. In
16-bit mode, an overflow in the TMR0H:TMR0L
register pair (FFFFh 0000h) will set TMR0IF. The
interrupt can be enabled/disabled by setting/clearing
enable bit, TMR0IE (INTCON<5>). Interrupt priority for
Timer0 is determined by the value contained in the
interrupt priority bit, TMR0IP (INTCON2<2>). See
Section 12.0 “Timer0 Module” for further details on
the Timer0 module.
9.8 PORTB Interrupt-on-Change
An input change on PORTB<7:4> sets flag bit, RBIF
(INTCON<0>). The interrupt can be enabled/disabled
by setting/clearing enable bit, RBIE (INTCON<3>).
Interrupt priority for PORTB interrupt-on-change is
determined by the value contained in the interrupt
priority bit, RBIP (INTCON2<0>).
9.9 Context Saving During Interrupt s
During interrupts, the return PC address is saved on
the stack. Additionally, the WREG, STATUS and BSR
registers are saved on the Fast Return Stack. If a fast
return from interrupt is not used (see Section 6.3
“Data Memory Organization”), the user may need to
save the WREG, STATUS and BSR registers on entry
to the Interrupt Service Routine. Depending on the
user’s application, other registers may also need to be
saved. Example 9-1 saves and restores the WREG,
STATUS and BSR registers during an Interrupt Service
Routine.
EXAMPLE 9-1: SAVING STATUS, WREG AND BSR REGISTERS IN RAM
MOVWF W_TEMP ; W_TEMP is in access bank
MOVFF STATUS, STATUS_TEMP ; STATUS_TEMP located anywhere
MOVFF BSR, BSR_TEMP ; BSR_TEMP located anywhere
;
; USER ISR CODE
;
MOVFF BSR_TEMP, BSR ; Restore BSR
MOVF W_TEMP, W ; Restore WREG
MOVFF STATUS_TEMP, STATUS ; Restore STATUS
2011 Microchip Technology Inc. DS39931D-page 131
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10.0 I/O PORTS
Depending on the device selected and features
enabled, there are up to five ports available. Some pins
of the I/O ports are multiplexed with an alternate
function from the peripheral features on the device. In
general, when a peripheral is enabled, that pin may not
be used as a general purpose I/O pin.
Each port has three registers for its operation. These
registers are:
TRIS register (Data Direction register)
PORT register (reads the levels on the pins of the
device)
LAT register (Data Latch)
Pins that are multiplexed with analog functionality (ANx
pins) also have ANCON register bits associated with
them.
The TRISx registers control which pins should be con-
figured as digital outputs (output buffer enabled) and
which pins should be left high-impedance. Writing ‘0’ to
a TRIS bit configures the specified pin as a digital out-
put. Writing a ‘1’ to a TRIS bit disables the output driver,
so the pin can be used as a digital or analog input. This
can be easily remembered by observing that ‘0’ is sim-
ilar to the letter, O (as in Output), and that ‘1 is similar
to the letter, I (as in Input).
The PORTx registers can be used to read the logic level
externally presented on pins that have been configured
as digital inputs. If a pin is configured as a digital input,
the corresponding port bit will be read as ‘1 if the exter-
nally applied voltage is greater than the VIH level for that
pin. If the externally applied voltage is below VIL, then
the PORTx bit will read as ‘0’. If the I/O pin is multiplexed
with analog functionality (an ANx pin), then the corre-
sponding PCFG bit, in the appropriate ANCONx register,
must also be set, in order to correctly read the externally
applied voltage on the pin. See the following information
regarding the ANCONx registers.
If the application firmware writes to a PORTx register,
this will cause the corresponding LATx register to be
updated. It is usually not recommended to perform
read-modify-write instructions (ex: BTG, BSF, BCF) on a
PORTx register. If the application firmware wishes to
change the output state of a pin that has been
configured as a digital output (TRIS bit = 0), it is
recommended that the firmware use the corresponding
LATx register instead.
The LATx registers hold the digital value that is output
onto a pin when the pin has been configured as a digital
output (TRIS bit = 0). Writing a ‘1’ to the LATx bit will
drive the output pin to the logic high output state.
Similarly, writing a ‘0’ to the LAT bit will drive the output
pin to a logic low output state. It is safe to perform all
types of read, write and read-modify-write instructions
on the LATx registers.
The ANCONx registers are used to configure pins with
ANx analog functionality for either Digital Input or Analog
Input mode. Setting a PCFG bit in an ANCONx register
enables the digital input buffer, allowing reads from the
PORTx register to correctly reflect the externally applied
voltage on the digital input pin. If the PCFG bit is clear,
the digital input buffer is disabled, to eliminate CMOS
input buffer cross conduction currents, when a mid-VDD
scale analog voltage is applied to the pin. This allows
analog input voltages (between VDD and VSS) to be
applied to the pin without increasing the current con-
sumption of the device. If the appropriate PCFG bit in the
ANCONx register is not set, this will cause the PORTx
register bit for that pin to read as ‘0’, regardless of the
actually applied external voltage.
At power-up, the default state of the ANCONx registers
is to configure the ANx pins for Analog mode (digital
input buffer off). Therefore, to use ANx pins as digital
inputs, the application firmware must first update the
ANCONx register(s). See Section 21.0 “10-bit Ana-
log-to-Digital Converter (A/D) Module” for more
details regarding the ANCONx registers.
Figure 10-1 displays a simplified model of a generic I/O
port, without the interfaces to other peripherals.
FIGURE 10-1: GENERIC I/O PORT
OPERATION
Data
Bus
WR LAT
WR TRIS
RD PORT
Data Latch
TRIS Latch
RD TRIS
Input
Buffer
I/O Pin(1)
QD
CK
QD
CK
EN
QD
EN
RD LAT
or PORT
Note 1: I/O pins without 5.5V tolerance have diode
protection to VDD and VSS. I/O pins with
5.5V tolerance have diode protection from
Vss.
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DS39931D-page 132 2011 Microchip Technology Inc.
10.1 I/ O P o r t P in C a pabilit ie s
When developing an application, the capabilities of the
port pins must be considered. Outputs on some pins
have higher output drive strength than others. Similarly,
some pins can tolerate higher than VDD input levels.
10.1.1 PIN OUTPUT DRIVE
General purpose output buffers are implemented with
CMOS transistors, for rail to rail output capability, when
lightly loaded. The output pin drive strengths vary for
groups of pins intended to meet the needs for a variety
of applications. PORTB and PORTC are designed to
drive higher loads, such as LEDs. All other ports are
designed for small loads; typically, indication only.
Table 10-1 summarizes the output capabilities. Refer to
Section 30.0 “Electrical Characteristics” for more
details.
TABLE 10-1: OUTPUT DRIVE LEVELS
10.1.2 INPUT PINS AND VOLTAGE
CONSIDERATIONS
The voltage tolerance of pins used as device inputs is
dependent on the pin’s input function. Pins that are used
as digital only inputs are able to handle DC voltages up to
5.5V; a level typical for digital logic circuits. In contrast,
pins that also have analog input functions of any kind can
only tolerate voltages up to VDD. Voltage excursions
beyond VDD on these pins should be avoided. Table 10-2
summarizes the input capabilities. Refer to Section 30.0
“Electrical Characteristics” for more details.
TABLE 10-2: INPUT VOLTAGE LEVELS
Port Drive Description
PORTA
(except RA6)
Minimum Intended for indication.
PORTD
PORTE
PORTB
High Suitable for strong LED
drive levels.
PORTC
PORTA<6>
Port or Pin Tolerated
Input Description
PORTA<7:0>
VDD Only VDD input levels
are tolerated.
PORTB<3:0>
PORTC<2:0>
PORTE<2:0>
PORTB<7:4>
5.5V
Tolerates input levels
above VDD, useful for
most standard logic.
PORTC<7:6>
PORTD<7:0>
PORTC<5:4> (USB) Designed for USB
specifications.
2011 Microchip Technology Inc. DS39931D-page 133
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10.1.3 INTERFACING TO A 5V SYSTEM
Though the VDDMAX of the PIC18F46J50 family is 3.6V,
these devices are still capable of interfacing with 5V
systems, even if the VIH of the target system is above
3.6V. This is accomplished by adding a pull-up resistor
to the port pin (Figure 10-2), clearing the LAT bit for that
pin and manipulating the corresponding TRIS bit
(Figure 10-1) to either allow the line to be pulled high,
or to drive the pin low. Only port pins that are tolerant of
voltages up to 5.5V can be used for this type of
interface (refer to Section 10.1.2 “Input Pins and
Voltage Co nsid erations”).
FIGURE 10-2: +5V SYSTEM HARDWARE
INTERFACE
EXAMPLE 10-1 : COMMUNICAT ING WITH
THE +5V SYSTEM
10.1.4 OPEN-DRAIN OUTPUTS
The output pins for several peripherals are also
equipped with a configurable open-drain output option.
This allows the peripherals to communicate with
external digital logic, operating at a higher voltage
level, without the use of level translators.
The open-drain option is implemented on port pins
specifically associated with the data and clock outputs
of the EUSARTs, the MSSP modules (in SPI mode) and
the ECCP modules. It is selectively enabled by setting
the open-drain control bit for the corresponding module
in the ODCON registers (Register 10-1, Register 10-2
and Register 10-3). Their configuration is discussed in
more detail with the individual port where these
peripherals are multiplexed. Output functions that are
routed through the PPS module may also use the
open-drain option. The open-drain functionality will
follow the I/O pin assignment in the PPS module.
When the open-drain option is required, the output pin
must also be tied through an external pull-up resistor,
provided by the user, to a higher voltage level, up to
5.5V (Figure 10-3). When a digital logic high signal is
output, it is pulled up to the higher voltage level.
FIGURE 10-3: USIN G THE OPEN -DRAIN
OUTPUT (USART SHOWN
AS EXAMPLE)
10.1.5 TTL INPUT BUFFER OPTION
Many of the digital I/O ports use Schmitt Trigger (ST)
input buffers. While this form of buffering works well
with many types of input, some applications may
require TTL level signals to interface with external logic
devices. This is particularly true for the Parallel Master
Port (PMP), which is likely to be interfaced to TTL level
logic or memory devices.
The inputs for the PMP can be optionally configured for
TTL buffers with the PMPTTL bit in the PADCFG1 reg-
ister (Register 10-4). Setting this bit configures all data
and control input pins for the PMP to use TTL buffers.
By default, these PMP inputs use the port’s ST buffers.
RD7
+5V Device
+5V
PIC18F46J50
BCF LATD, 7 ; set up LAT register so
; changing TRIS bit will
; drive line low
BCF TRISD, 7 ; send a 0 to the 5V system
BSF TRISD, 7 ; send a 1 to the 5V system
TXX
+5V
(at logic ‘1’)
3.3V
VDD 5V
PIC18F46J50
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DS39931D-page 134 2011 Microchip Technology Inc.
REGISTER 10-1: ODCON1: PERIPHERAL OPEN-DRAIN CONTROL REGISTER 1 (BANKED F42h)
U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0
ECCP2OD ECCP1OD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1 ECCP2OD: ECCP2 Open-Drain Output Enable bit
1 = Open-drain capability is enabled
0 = Open-drain capability is disabled
bit 0 ECCP1OD: ECCP1 Open-Drain Output Enable bit
1 = Open-drain capability is enabled
0 = Open-drain capability is disabled
REGISTER 10-2: ODCON2: PERIPHERAL OPEN-DRAIN CONTROL REGISTER 2 (BANKED F41h)
U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0
U2OD U1OD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1 U2OD: USART2 Open-Drain Output Enable bit
1 = Open-drain capability is enabled
0 = Open-drain capability is disabled
bit 0 U1OD: USART1 Open-Drain Output Enable bit
1 = Open-drain capability is enabled
0 = Open-drain capability is disabled
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REGISTER 10-3: ODCON3: PERIPHERAL OPEN-DRAIN CONTROL REGISTER 3 (BANKED F40h)
U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0
SPI2OD SPI1OD
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1 SPI2OD: SPI2 Open-Drain Output Enable bit
1 = Open-drain capability is enabled
0 = Open-drain capability is disabled
bit 0 SPI1OD: SPI1 Open-Drain Output Enable bit
1 = Open-drain capability is enabled
0 = Open-drain capability is disabled
REGISTER 10-4: PADCFG1: PAD CONFIGURATION CONTROL REGISTER 1 (BANKED F3Ch)
U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0
RTSECSEL1(1) RTSECSEL0(1) PMPTTL
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-3 Unimplemented: Read as ‘0
bit 2-1 RTSECSEL<1:0>: RTCC Seconds Clock Output Select bits(1)
11 = Reserved; do not use
10 = RTCC source clock is selected for the RTCC pin (can be INTRC, T1OSC or T1CKI, depending
upon the RTCOSC (CONFIG3L<1>) and T1OSCEN (T1CON<3>) bit settings)
01 = RTCC seconds clock is selected for the RTCC pin
00 = RTCC alarm pulse is selected for the RTCC pin
bit 0 PMPTTL: PMP Module TTL Input Buffer Select bit
1 = PMP module uses TTL input buffers
0 = PMP module uses Schmitt Trigger input buffers
Note 1: To enable the actual RTCC output, the RTCOE (RTCCFG<2>) bit needs to be set.
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DS39931D-page 136 2011 Microchip Technology Inc.
10.2 PORTA, TRISA and LATA Registers
PORTA is a 7-bit wide, bidirectional port. It may also
function as a 5-bit or 6-bit port, depending on the oscil-
lator mode selected. Setting a TRISA bit (= 1) will make
the corresponding PORTA pin an input (i.e., put the
corresponding output driver in a High-Impedance
mode). Clearing a TRISA bit (= 0) will make the
corresponding PORTA pin an output (i.e., put the
contents of the output latch on the selected pin).
Reading the PORTA register reads the status of the
pins, whereas writing to it, will write to the port latch.
The Data Latch (LATA) register is also memory mapped.
Read-modify-write operations on the LATA register read
and write the latched output value for PORTA.
Most PORTA pins are multiplexed with analog (ANx)
functionality. In order to use the analog capable pins as
digital inputs, the corresponding PCFG bits in the
ANCON0 register must be set.
Pins, RA0 through RA3, may also be used as compara-
tor inputs by setting the appropriate bits in the CMxCON
registers and configuring the pins as analog inputs.
All PORTA pins have full CMOS output drivers.
The TRISA register controls the direction of the PORTA
pins, even when they are being used as analog inputs.
EXAMPLE 10-2: INITIALIZING PORT A
Note: On a Power-on Reset (POR), RA5 and
RA<3:0> are configured as analog inputs
and read as ‘0’.
CLRF LATA ;Clearing the PORTA latches
;will cause the pins to drive
;low if configured as outputs
MOVLW 0x1F ;Configure AN0-AN4 pins
MOVFF WREG,ANCON0 ;for digital input mode
MOVLW 0xCF ;Example value used to
;initialize data direction
MOVWF TRISA ;Set RA<3:0> as inputs
;RA4 is unimplemented
;RA5 as output
;RA6 and RA7 as inputs
;(unless overridden by osc settings)
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TABLE 10-3: PORTA I/O SUMMARY
Pin Function TRIS
Setting I/O I/O
Type Description
RA0/AN0/C1INA/
ULPWU/PMA6/
RP0
RA0 1I TTL PORTA<0> data input; disabled when analog input is
enabled.
0O DIG LATA<0> data output; not affected by analog input.
AN0 1I ANA A/D Input Channel 0 and Comparator C1- input. Default input
configuration on POR; does not affect digital output.
C1INA 1I ANA Comparator 1 Input A.
ULPWU 1I ANA Ultra Low-Power Wake-up input.
PMA6(1) 0O DIG Parallel Master Port address.
RP0 1I ST Remappable Peripheral Pin 0 input.
0O DIG Remappable Peripheral Pin 0 output.
RA1/AN1/C2INA/
PMA7/RP1
RA1 1I TTL PORTA<1> data input; disabled when analog input is
enabled.
0O DIG LATA<1> data output; not affected by analog input.
AN1 1I ANA A/D Input Channel 1 and Comparator C2- input. Default input
configuration on POR; does not affect digital output.
C2INA 1I ANA Comparator 1 Input A.
PMA7(1) 0O DIG Parallel Master Port address.
RP1 1I ST Remappable Peripheral Pin 1 input.
0O DIG Remappable Peripheral Pin 1 output
RA2/AN2/
VREF-/CVREF/
C2INB
RA2 0O DIG LATA<2> data output; not affected by analog input. Disabled
when CVREF output is enabled.
1I TTL PORTA<2> data input. Disabled when analog functions are
enabled; disabled when CVREF output is enabled.
AN2 1I ANA A/D Input Channel 2 and Comparator C2+ input. Default
input configuration on POR; not affected by analog output.
VREF-1I ANA A/D and comparator voltage reference low input.
CVREF xO ANA Comparator voltage reference output. Enabling this feature
disables digital I/O.
C2INB II ANA Comparator 2 Input B.
0O ANA CTMU pulse generator charger for the C2INB comparator
input.
RA3/AN3/VREF+/
C1INB
RA3 0O DIG LATA<3> data output; not affected by analog input.
1I TTL PORTA<3> data input; disabled when analog input is
enabled.
AN3 1I ANA A/D Input Channel 3 and Comparator C1+ input. Default
input configuration on POR.
VREF+1I ANA A/D and comparator voltage reference high input.
C1INB 1I ANA Comparator 1 Input B
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option)
Note 1: This bit is only available on 44-pin devices.
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TABLE 10-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
RA5/AN4/SS1/
HLVDIN/RCV/
RP2
RA5 0O DIG LATA<5> data output; not affected by analog input.
1I TTL PORTA<5> data input; disabled when analog input is
enabled.
AN4 1I ANA A/D Input Channel 4. Default configuration on POR.
SS1 1I TTL Slave select input for MSSP1.
HLVDIN 1I ANA High/Low-Voltage Detect external trip point reference input.
RCV 1I TTL External USB transceiver RCV input.
RP2 1I ST Remappable Peripheral Pin 2 input.
0O DIG Remappable Peripheral Pin 2 output.
OSC2/CLKO/
RA6
OSC2 xO ANA Main oscillator feedback output connection (HS mode).
CLKO xO DIG System cycle clock output (FOSC/4) in RC and EC Oscillator
modes.
RA6 1I TTL PORTA<6> data input.
0O DIG LATA<6> data output.
OSC1/CLKI/RA7 OSC1 1I ANA Main oscillator input connection.
CLKI 1I ANA Main clock input connection.
RA7 1I TTL PORTA<6> data input.
0O DIG LATA<6> data output.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page
PORTA RA7 RA6 RA5 RA3 RA2 RA1 RA0 87
LATA LAT7 LAT6 LAT5 LAT3LAT2LAT1LAT0 92
TRISA TRIS7 TRIS6 TRISA5 TRISA3 TRISA2 TRISA1 TRISA0 92
ANCON0 PCFG7(1) PCFG6(1) PCFG5(1) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 90
CMxCON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 90
CVRCON CVREN CVROE CVRR r CVR3 CVR2 CVR1 CVR0 93
Legend: = unimplemented, read as ‘0’, r = reserved. Shaded cells are not used by PORTA.
Note 1: These bits are only available on 44-pin devices.
TABLE 10-3: PORTA I/O SUMMARY (CONTINUED)
Pin Function TRIS
Setting I/O I/O
Type Description
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option)
Note 1: This bit is only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 139
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10.3 PORTB, TRISB and LATB
Registers
PORTB is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISB. Setting a
TRISB bit (= 1) will make the corresponding PORTB
pin an input (i.e., put the corresponding output driver in
a High-Impedance mode). Clearing a TRISB bit (= 0)
will make the corresponding PORTB pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATB) is also memory
mapped. Read-modify-write operations on the LATB
register read and write the latched output value for
PORTB.
Each of the PORTB pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is
performed by clearing bit, RBPU (INTCON2<7>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on a POR. The integrated weak pull-ups
consist of a semiconductor structure similar to, but
somewhat different, from a discrete resistor. On an
unloaded I/O pin, the weak pull-ups are intended to
provide logic high indication, but will not necessarily
pull the pin all the way to VDD levels.
Four of the PORTB pins (RB<7:4>) have an interrupt-
on-change feature. Only pins configured as inputs can
cause this interrupt to occur (i.e., any RB<7:4> pin
configured as an output is excluded from the interrupt-
on-change comparison). The input pins (of RB<7:4>)
are compared with the old value latched on the last
read of PORTB. The “mismatch” outputs of RB<7:4>
are ORed together to generate the RB Port Change
Interrupt with Flag bit, RBIF (INTCON<0>).
This interrupt can wake the device from Sleep mode or
any of the Idle modes. Application software can clear
the interrupt flag by following these steps:
1. Any read or write of PORTB (except with the
MOVFF (ANY), PORTB instruction).
2. Wait one instruction cycle (such as executing a
NOP instruction).
3. Clear flag bit, RBIF.
A mismatch condition continues to set flag bit, RBIF.
Reading PORTB will end the mismatch condition and
allow flag bit, RBIF, to be cleared after one instruction
cycle of delay.
The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt-on-change
feature. Polling of PORTB is not recommended while
using the interrupt-on-change feature.
The RB5 pin is multiplexed with the Timer0 module
clock input and one of the comparator outputs to
become the RB5/PMA0/KBI1/SDI1/SDA1/RP8 pin.
EXAMPLE 10-3: INITIALIZING PORTB
Note: On a POR, the RB<3:0> bits are
configured as analog inputs by default and
read as ‘0’; RB<7:4> bits are configured
as digital inputs.
MOVLW 0x08 ; In itialize out put data
MOVWF LATB ; la tch values f or digital
; output pins.
MOVLB 0x0F ; AN CONx registe rs are
; not in access bank
BSF ANCON1, PCFG12, BANKED ; Con figure R B0/AN 12 for digit al input mode
BCF ANCON1, PCFG10, BANKED ; Configure RB1/AN10 for analog input mode
MOVLW 0xC3 ; RB 0 configured as digital input
MOVWF TRISB ; RB1 configured as anal og input
; RB2 configured as output low
; RB3 configured as output high
; RB4 configured as output low
; RB5 configured as output low
; RB6 configured as digital input
; RB7 configured as digital input
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DS39931D-page 140 2011 Microchip Technology Inc.
TABLE 10-5: PORTB I/O SUMMARY
Pin Function TRIS
Setting I/O I/O
Type Description
RB0/AN12/
INT0/RP3
RB0 1I TTL PORTB<0> data input; weak pull-up when RBPU bit is
cleared. Disabled when analog input is enabled.(1)
0O DIG LATB<0> data output; not affected by analog input.
AN12 1I ANA A/D Input Channel 12.(1)
INT0 1I ST External Interrupt 0 input.
RP3 1I ST Remappable Peripheral Pin 3 input.
0O DIG Remappable Peripheral Pin 3 output.
RB1/AN10/
PMBE/RTCC/
RP4
RB1 1I TTL PORTB<1> data input; weak pull-up when RBPU bit is
cleared. Disabled when analog input is enabled.(1)
0O DIG LATB<1> data output; not affected by analog input.
AN10 1I ANA A/D Input Channel 10.(1)
PMBE(3) 0O DIG Parallel Master Port byte enable output.
RTCC 0O DIG Real-Time Clock Calender output.
RP4 1I ST Remappable Peripheral Pin 4 input.
0O DIG Remappable Peripheral Pin 4 output.
RB2/AN8/
CTED1/PMA3/
VMO/REFO/
RP5
RB2 1I TTL PORTB<2> data input; weak pull-up when RBPU bit is
cleared. Disabled when analog input is enabled.(1)
0O DIG LATB<2> data output; not affected by analog input.
AN8 1I ANA A/D Input Channel 8.(1)
CTED1 1I ST CTMU Edge 1 input.
PMA3(3) 0O DIG Parallel Master Port address.
VMO 0O DIG External USB transceiver D – data output.
REFO 0O DIG Reference output clock.
RP5 1I ST Remappable Peripheral Pin 5 input.
0O DIG Remappable Peripheral Pin 5 output.
RB3/AN9/
CTED2/PMA2/
VPO/RP6
RB3 0O DIG LATB<3> data output; not affected by analog input.
1I TTL PORTB<3> data input; weak pull-up when RBPU bit is
cleared. Disabled when analog input is enabled.(1)
AN9 1I ANA A/D Input Channel 9.(1)
CTED2 1I ST CTMU Edge 2 input.
PMA2(3) 0O DIG Parallel Master Port address.
VPO 0I DIG External USB transceiver D+ data output.
RP6 1I ST Remappable Peripheral Pin 6 input.
0O DIG Remappable Peripheral Pin 6 output.
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option)
Note 1: Pins are configured as analog inputs by default on POR. Using these pins for digital inputs requires setting
the appropriate bits in the ANCONx register first.
2: All other pin functions are disabled when ICSP™ or MPLAB® ICD are enabled.
3: This functionality is only available on 44-pin devices.
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RB4/PMA1/
KBI0/SCK1/
SCL1/RP7
RB4 0O DIG LATB<4> data output; not affected by analog input.
1I TTL PORTB<4> data input; weak pull-up when RBPU bit is
cleared. Disabled when analog input is enabled.(1)
PMA1(3) 1I ST/TTL Parallel Slave Port Address input.
0O DIG Parallel Master Port Address output.
KBI0 1I TTL Interrupt-on-change pin.
SCK1 1I ST SPI clock input (MSSP1 module).
0O DIG SPI clock output (MSSP1 module).
SCL1 1II
2C/
SMBus
I2C™ clock input (MSSP1 module).
0OI
2CI
2C clock output (MSSP1 module).
RP7 1I ST Remappable Peripheral Pin 7 input.
0O DIG Remappable Peripheral Pin 7 output.
RB5/PMA0/
KBI1/SDI1/
SDA1/RP8
RB5 0O DIG LATB<5> data output.
1I TTL PORTB<5> data input; weak pull-up when RBPU bit is
cleared.
KBI1 1I TTL Interrupt-on-change pin.
PMA0(3) 1I ST/TTL Parallel Slave Port Address input
0O DIG Parallel Master Port Address output
SDI1 1I ST SPI data input (MSSP1 module).
SDA1 1II
2C/
SMBus
I2C data input (MSSP1 module).
0OI
2CI
2C™/SMBus.
RP8 1I ST Remappable Peripheral Pin 8 input.
0O DIG Remappable Peripheral Pin 8 output.
RB6/KBI2/
PGC/RP9
RB6 0O DIG LATB<6> data output.
1I TTL PORTB<6> data input; weak pull-up when RBPU bit is
cleared.
KBI2 1I TTL Interrupt-on-change pin.
PGC xI ST Serial execution (ICSP™) clock input for ICSP and ICD
operation.(2)
RP9 1I ST Remappable Peripheral Pin 9 input.
0O DIG Remappable Peripheral Pin 9 output.
TABLE 10-5: PORTB I/O SUMMARY (CONTINUED)
Pin Function TRIS
Setting I/O I/O
Type Description
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option)
Note 1: Pins are configured as analog inputs by default on POR. Using these pins for digital inputs requires setting
the appropriate bits in the ANCONx register first.
2: All other pin functions are disabled when ICSP™ or MPLAB® ICD are enabled.
3: This functionality is only available on 44-pin devices.
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DS39931D-page 142 2011 Microchip Technology Inc.
TABLE 10-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
RB7/KBI3/
PGD/RP10
RB7 0O DIG LATB<7> data output.
1I TTL PORTB<7> data input; weak pull-up when RBPU bit is
cleared.
KBI3 1I TTL Interrupt-on-change pin.
PGD xO DIG Serial execution data output for ICSP and ICD operation.(2)
xI ST Serial execution data input for ICSP and ICD operation.(2)
RP10 1I ST Remappable Peripheral Pin 10 input.
0O ST Remappable Peripheral Pin 10 output.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page
PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 92
LATB LATB7 LATB6 LATB5 LATB4 LATB3 LATB2 LATB1 LATB0 92
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 92
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 89
INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 89
INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 89
ADCON0 PCFG7 PCFG6 PCFG5 PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 90
Legend: = unimplemented, read as ‘0’. Shaded cells are not used by PORTB.
TABLE 10-5: PORTB I/O SUMMARY (CONTINUED)
Pin Function TRIS
Setting I/O I/O
Type Description
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option)
Note 1: Pins are configured as analog inputs by default on POR. Using these pins for digital inputs requires setting
the appropriate bits in the ANCONx register first.
2: All other pin functions are disabled when ICSP™ or MPLAB® ICD are enabled.
3: This functionality is only available on 44-pin devices.
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10.4 PORTC, TRISC and LATC
Registers
PORTC is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISC. Setting a
TRISC bit (= 1) will make the corresponding PORTC
pin an input (i.e., put the corresponding output driver in
a High-Impedance mode). Clearing a TRISC bit (= 0)
will make the corresponding PORTC pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATC) is also memory
mapped. Read-modify-write operations on the LATC
register read and write the latched output value for
PORTC.
PORTC is multiplexed with several peripheral functions
(see Ta b l e 1 0 - 7 ). The pins have Schmitt Trigger input
buffers.
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTC pin. Some
peripherals override the TRIS bit to make a pin an output,
while other peripherals override the TRIS bit to make a
pin an input. The user should refer to the corresponding
peripheral section for additional information.
Pins, RC4 and RC5, are multiplexed with the USB
module. Depending on the configuration of the module,
they can serve as the differential data lines for the on-
chip USB transceiver, or the data inputs from an external
USB transceiver. When used as general purpose inputs,
both RC4 and RC5 input buffers depend on the level of
the voltage applied to the VUSB pin, instead of VDD, like
all other general purpose I/O pins. Therefore, if the RC4
or RC5 general purpose input capability will be used, the
VUSB pin should not be left floating.
Unlike other PORTC pins, RC4 and RC5 do not have
TRISC bits associated with them. As digital ports, they
can only function as digital inputs. When configured for
USB operation, the data direction is determined by the
configuration and status of the USB module at a given
time. If an external transceiver is used, RC4 and RC5
always function as inputs from the transceiver. If the on-
chip transceiver is used, the data direction is determined
by the operation being performed by the module at that
time.
The contents of the TRISC register are affected by
peripheral overrides. Reading TRISC always returns
the current contents, even though a peripheral device
may be overriding one or more of the pins.
EXAMPLE 10-4: INITIALIZING PORTC
Note: On a Power-on Reset, PORTC pins
(except RC2, RC4 and RC5) are config-
ured as digital inputs. RC2 will default as
an analog input (controlled by the
ANCON1 register). To use pins, RC4 and
RC5, as digital inputs, the USB module
must be disabled (UCON<3> = 0) and the
on-chip USB transceiver must be dis-
abled (UCFG<3> = 1). The internal USB
transceiver has a POR value of enabled.
CLRF LATC ; Initialize output data
; latch values for logic
; output low value.
MOVLB 0x0F ; ANCONx registers are
; not in access bank
;Configure RC2/AN11 for digital input mode
BSF ANCON1, PCFG11, BANKED
;Disable USB transceiver to use RC4/RC5 as
;general purpose inputs
BCF UCON, USBEN ;Disable USB module
BSF UCFG, UTRDIS ;Disable USB transceiver
MOVLW 0x3F ; RC0 configured as digital input
MOVWF TRISC ; RC1 configured as digital input
; RC2 configured as digital input
; RC4 configured as digital input
; RC5 configured as digital input
; RC6 configured as digital output
; RC7 configured as digital output
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DS39931D-page 144 2011 Microchip Technology Inc.
TABLE 10-7: PORTC I/O SUMMARY
Pin Function TRIS
Setting I/O I/O
Type Description
RC0/T1OSO/
T1CKI/RP11
RC0 1I ST PORTC<0> data input.
0O DIG LATC<0> data output.
T1OSO xO ANA Timer1 oscillator output; enabled when Timer1 oscillator is
enabled. Disables digital I/O.
T1CKI 1I ST Timer1 digital clock input.
RP11 1I ST Remappable Peripheral Pin 11 input.
0O DIG Remappable Peripheral Pin 11 output.
RC1/T1OSI/
UOE/RP12
RC1 1I ST PORTC<1> data input.
0O DIG LATC<1> data output.
T1OSI xI ANA Timer1 oscillator input; enabled when Timer1 oscillator is
enabled. Disables digital I/O.
UOE 0O DIG External USB transceiver NOE output.
RP12 1I ST Remappable Peripheral Pin 12 input.
0O DIG Remappable Peripheral Pin 12 output.
RC2/AN11/
CTPLS/RP13
RC2 1I ST PORTC<2> data input.
0O DIG PORTC<2> data output.
AN11 1I ANA A/D Input Channel 11.
CTPLS 0O DIG CTMU pulse generator output.
RP13 1I ST Remappable Peripheral Pin 13 input.
0O DIG Remappable Peripheral Pin 13 output.
RC4/D-/VM RC4 xI TTL PORTC<4> data input.
D- xI XCVR USB bus minus line output.
xO XCVR USB bus minus line input.
VM 1I TTL External USB transceiver VP input.
RC5/D+/VP RC5 xI TTL PORTC<5> data input.
D+ xI XCVR USB bus plus line input.
xO XCVR USB bus plus line output.
VP 1I TTL External USB transceiver VP input.
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; I2C/SMB = I2C/SMBus input buffer; x = Don’t care (TRIS bit does not affect port direction or is
overridden for this option)
Note 1: This functionality is only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 145
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TABLE 10-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
RC6/PMA5/
TX1/CK1/RP17
RC6 1I ST PORTC<6> data input.
0O DIG LATC<6> data output.
PMA5(1) 0O DIG Parallel Master Port address.
TX1 0O DIG Asynchronous serial transmit data output (EUSART
module); takes priority over port data. User must configure
as an output.
CK1 1I ST Synchronous serial clock input (EUSART module).
0O DIG Synchronous serial clock output (EUSART module); takes
priority over port data.
RP17 1I ST Remappable Peripheral Pin 17 input.
0O DIG Remappable Peripheral Pin 17 output.
RC7/PMA4/
RX1/DT1/
SDO1/RP18
RC7 1I ST PORTC<7> data input.
0O DIG LATC<7> data output.
PMA4(1) 0O DIG Parallel Master Port address.
RX1 1I ST Asynchronous serial receive data input (EUSART module).
DT1 11 ST Synchronous serial data input (EUSART module). User
must configure as an input.
0O DIG Synchronous serial data output (EUSART module); takes
priority over port data.
SDO1 0O DIG SPI data output (MSSP1 module).
RP18 1I ST Remappable Peripheral Pin 18 input.
0O DIG Remappable Peripheral Pin 18 output.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
PORTC RC7 RC6 RC5 RC4 RC2 RC1 RC0 92
LATC LATC7 LATC6 —— LATC2 LATC1 LATC0 92
TRISC TRISC7 TRISC6 —— TRISC2 TRISC1 TRISC0 92
TABLE 10-7: PORTC I/O SUMMARY (CONTINUED)
Pin Function TRIS
Setting I/O I/O
Type Description
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level
input/output; I2C/SMB = I2C/SMBus input buffer; x = Don’t care (TRIS bit does not affect port direction or is
overridden for this option)
Note 1: This functionality is only available on 44-pin devices.
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10.5 PORTD, TRISD and LATD
Registers
PORTD is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISD. Setting a
TRISD bit (= 1) will make the corresponding PORTD
pin an input (i.e., put the corresponding output driver in
a High-Impedance mode). Clearing a TRISD bit (= 0)
will make the corresponding PORTD pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATD) is also memory
mapped. Read-modify-write operations on the LATD
register read and write the latched output value for
PORTD.
All pins on PORTD are implemented with Schmitt Trigger
input buffers. Each pin is individually configurable as an
input or an output.
EXAMPLE 10-5: INITIALIZING PORTD
Each of the PORTD pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is per-
formed by setting bit, RDPU (PORTE<7>). The weak
pull-up is automatically turned off when the port pin is
configured as an output. The pull-ups are disabled on a
POR. The integrated weak pull-ups consist of a semi-
conductor structure similar to, but somewhat different,
from a discrete resistor. On an unloaded I/O pin, the
weak pull-ups are intended to provide logic high indica-
tion, but will not necessarily pull the pin all the way to
VDD levels.
Note that the pull-ups can be used for any set of
features, similar to the pull-ups found on PORTB.
Note: PORTD is available only on 44-pin devices.
Note: On a POR, these pins are configured as
digital inputs.
CLRF LATD ;Initialize output data
;levels for output pins
MOVLW 0x7F ;Example value used to
;initial ize da ta direc tion
MOVWF TRISD ;RD0-RD6 as inputs
;RD7 as output
TABLE 10-9: PORTD I/O SUMMARY
Pin Function TRIS
Setting I/O I/O
Type Description
RD0/PMD0/
SCL2
RD0 1I ST PORTD<0> data input.
0O DIG LATD<0> data output.
PMD0 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
SCL2 1II
2C/
SMB
I2C™ clock input (MSSP2 module); input type depends on
module setting.
0OI
2CI
2C clock output (MSSP2 module); takes priority over port data.
RD1/PMD1/
SDA2
RD1 1I ST PORTD<1> data input.
0O DIG LATD<1> data output.
PMD1 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
SDA2 1II
2C/
SMB
I2C data input (MSSP2 module); input type depends on
module setting.
0OI
2CI
2C data output (MSSP2 module); takes priority over port data.
RD2/PMD2/
RP19
RD2 1I ST PORTD<2> data input.
0O DIG LATD<2> data output.
PMD2 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
RP19 1I ST Remappable Peripheral Pin 19 input.
0O DIG Remappable Peripheral Pin 19 output.
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; I2C/SMB = I2C/SMBus
input buffer; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
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TABLE 10-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
RD3/PMD3/
RP20
RD3 1I DIG PORTD<3> data input.
0O DIG LATD<3> data output.
PMD3 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
RP20 1I ST Remappable Peripheral Pin 20 input.
0O DIG Remappable Peripheral Pin 20 output.
RD4/PMD4/
RP21
RD4 1I ST PORTD<4> data input.
0O DIG LATD<4> data output.
PMD4 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
RP21 1I ST Remappable Peripheral Pin 21 input.
0O DIG Remappable Peripheral Pin 21 output.
RD5/PMD5/
RP22
RD5 1I ST PORTD<5> data input.
0O DIG LATD<5> data output.
PMD5 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
RP22 1I ST Remappable Peripheral Pin 22 input.
0O DIG Remappable Peripheral Pin 22 output.
RD6/PMD6/
RP23
RD6 1I ST PORTD<6> data input.
0O DIG LATD<6> data output.
PMD6 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
RP23 1I ST Remappable Peripheral Pin 23 input.
0O DIG Remappable Peripheral Pin 23 output.
RD7/PMD7/
RP24
RD7 1I ST PORTD<7> data input.
0O DIG LATD<7> data output.
PMD7 1I ST/TTL Parallel Master Port data in.
0O DIG Parallel Master Port data out.
RP24 1I ST Remappable Peripheral Pin 24 input.
0O DIG Remappable Peripheral Pin 24 output.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page
PORTD(1) RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 92
LATD(1) LATD7 LATD6 LATD5 LATD4 LATD3 LATD2 LATD1 LATD0 92
TRISD(1) TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 92
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTD.
Note 1: These registers are not available on 28-pin devices.
TABLE 10-9: PORTD I/O SUMMARY (CONTINUED)
Pin Function TRIS
Setting I/O I/O
Type Description
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; I2C/SMB = I2C/SMBus
input buffer; x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
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10.6 PORTE, TRISE and LATE
Registers
Depending on the particular PIC18F46J50 family
device selected, PORTE is implemented in two
different ways.
For 44-pin devices, PORTE is a 3-bit wide port. Three
pins (RE0/AN5/PMRD, RE1/AN6/PMWR and RE2/
AN7/PMCS) are individually configurable as inputs or
outputs. These pins have Schmitt Trigger input buffers.
When selected as analog inputs, these pins will read as
0’s.
The corresponding Data Direction register is TRISE.
Setting a TRISE bit (= 1) will make the corresponding
PORTE pin an input (i.e., put the corresponding output
driver in a High-Impedance mode). Clearing a TRISE
bit (= 0) will make the corresponding PORTE pin an
output (i.e., put the contents of the output latch on the
selected pin).
TRISE controls the direction of the RE pins, even when
they are being used as analog inputs. The user must
make sure to keep the pins configured as inputs when
using them as analog inputs.
The Data Latch register (LATE) is also memory
mapped. Read-modify-write operations on the LATE
register read and write the latched output value for
PORTE.
EXAMPLE 10-6: INITIALIZING PORTE
Each of the PORTE pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is per-
formed by setting bit, REPU (PORTE<6>). The weak
pull-up is automatically turned off when the port pin is
configured as an output. The pull-ups are disabled on a
POR. The integrated weak pull-ups consist of a semi-
conductor structure similar to, but somewhat different,
from a discrete resistor. On an unloaded I/O pin, the
weak pull-ups are intended to provide logic high indica-
tion, but will not necessarily pull the pin all the way to
VDD levels.
Note that the pull-ups can be used for any set of
features, similar to the pull-ups found on PORTB
Note: PORTE is available only on 44-pin devices.
Note: On a POR, RE<2:0> are configured as
analog inputs.
CLRF LATE ;Initialize LATE output
;latch values
MOVLB 0x0F ;ANCON registers not
;in access bank
BSF ANCON0,PCFG5 ;RE0/AN5 as digital
BSF ANCON0,PCFG6 ;RE1/AN6 as digital
MOVLW 0x03 ;Example value used to
;initiali ze data direction
MOVWF TRISE ;RE0, RE1 as inputs
;RE2 as output
REGISTER 10-5: PORTE REGISTER
R/W-0 R/W-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0
RDPU REPU RE2 RE1 RE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RDPU: PORTD Pull-up Enable bit
1 = PORTD pull-ups are enabled by individual TRIS values
0 = All PORTD pull-ups are disabled
bit 6 REPU: PORTE Pull-up Enable bit
1 = PORTE pull-ups are enabled by individual TRIS values
0 = All PORTE pull-ups are disabled
bit 5-3 Unimplemented: Read as ‘0
bit 2-0 RE<2:0>: PORTE Data Input bits
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TABLE 10-11: PORTE I/O SUMMARY
TABLE 10-12: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Pin Function TRIS
Setting I/O I/O
Type Description
RE0/AN5/
PMRD
RE0 1I ST PORTE<0> data input; disabled when analog input is
enabled.
0O DIG LATE<0> data output; not affected by analog input.
AN5 1I ANA A/D Input Channel 5; default input configuration on POR.
PMRD 1I ST/TTL Parallel Master Port io_rd_in.
0O DIG Parallel Master Port read strobe.
RE1/AN6/
PMWR
RE1 1I ST PORTE<1> data input; disabled when analog input is
enabled.
0O DIG LATE<1> data output; not affected by analog input.
AN6 1I ANA A/D Input Channel 6; default input configuration on POR.
PMWR 1I ST/TTL Parallel Master Port io_wr_in.
0O DIG Parallel Master Port write strobe.
RE2/AN7/
PMCS
RE2 1I ST PORTE<2> data input; disabled when analog input is
enabled.
0O DIG LATE<2> data output; not affected by analog input.
AN7 1I ANA A/D Input Channel 7; default input configuration on POR.
PMCS 0O DIG Parallel Master Port byte enable.
Legend: DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level;
I = Input; O = Output; P = Power
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page
PORTE(1) RDPU REPU —— RE2 RE1 RE0 92
LATE(1) LATE2 LATE1 LATE0 92
TRISE(1) TRISE2 TRISE1 TRISE0 92
ANCON0 PCFG7(2) PCFG6(2) PCFG5(2) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 94
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTE.
Note 1: These registers are not available on 28-pin devices.
2: These bits are only available on 44-pin devices.
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10.7 Peripheral Pin Select (PPS)
A major challenge in general purpose devices is provid-
ing the largest possible set of peripheral features while
minimizing the conflict of features on I/O pins. The
challenge is even greater on low pin count devices
similar to the PIC18F46J50 family. In an application
that needs to use more than one peripheral multiplexed
on a single pin, inconvenient work arounds in applica-
tion code, or a complete redesign, may be the only
option.
The Peripheral Pin Select (PPS) feature provides an
alternative to these choices by enabling the user’s
peripheral set selections and their placement on a wide
range of I/O pins. By increasing the pinout options
available on a particular device, users can better tailor
the microcontroller to their entire application, rather than
trimming the application to fit the device.
The PPS feature operates over a fixed subset of digital
I/O pins. Users may independently map the input and/
or output of any one of the many digital peripherals to
any one of these I/O pins. PPS is performed in software
and generally does not require the device to be
reprogrammed. Hardware safeguards are included that
prevent accidental or spurious changes to the
peripheral mapping once it has been established.
10.7.1 AVAILABLE PINS
The PPS feature is used with a range of up to 22 pins.
The number of available pins is dependent on the
particular device and its pin count. Pins that support the
PPS feature include the designation “RPn” in their full
pin designation, where “RP” designates a remappable
peripheral and “n” is the remappable pin number. See
Table 1-2 for pinout options in each package offering.
10.7.2 AVAILABLE PERIPHERALS
The peripherals managed by the PPS are all digital
only peripherals. These include general serial commu-
nications (UART and SPI), general purpose timer clock
inputs, timer-related peripherals (input capture and
output compare) and external interrupt inputs. Also
included are the outputs of the comparator module,
since these are discrete digital signals.
The PPS module is not applied to I2C, change notifica-
tion inputs, RTCC alarm outputs or peripherals with
analog inputs. Additionally, the MSSP1 and EUSART1
modules are not routed through the PPS module.
A key difference between pin select and non-pin select
peripherals is that pin select peripherals are not asso-
ciated with a default I/O pin. The peripheral must
always be assigned to a specific I/O pin before it can be
used. In contrast, non-pin select peripherals are always
available on a default pin, assuming that the peripheral
is active and not conflicting with another peripheral.
10.7.2.1 Peripheral Pin Select Function
Priority
When a pin-selectable peripheral is active on a given
I/O pin, it takes priority over all other digital I/O and digital
communication peripherals associated with the pin.
Priority is given, regardless of the type of peripheral that
is mapped. Pin select peripherals never take priority
over any analog functions associated with the pin.
10.7.3 CONTROLLING PERIPHERAL PIN
SELECT
PPS features are controlled through two sets of Special
Function Registers (SFRs): one to map peripheral
inputs and the other to map outputs. Because they are
separately controlled, a particular peripheral’s input
and output (if the peripheral has both) can be placed on
any selectable function pin without constraint.
The association of a peripheral to a peripheral-
selectable pin is handled in two different ways,
depending on whether an input or an output is being
mapped.
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10.7.3.1 Input Mapping
The inputs of the PPS options are mapped on the basis
of the peripheral; that is, a control register associated
with a peripheral dictates the pin it will be mapped to. The
RPINRx registers are used to configure peripheral input
mapping (see Register 10-7 through Register 10-21).
Each register contains a 5-bit field which is associated
with one of the pin-selectable peripherals. Programming
a given peripheral’s bit field with an appropriate 5-bit
value maps the RPn pin with that value to that peripheral.
For any given device, the valid range of values for any of
the bit fields corresponds to the maximum number of
peripheral pin selections supported by the device.
TABLE 10-13:
SELECT ABLE
INPUT SOURCES
(M A P S I N P UT TO FUNCTION)(1)
Input Name Function Name Register Configuration
Bits
External Interrupt 1 INT1 RPINR1 INTR1R<4:0>
External Interrupt 2 INT2 RPINR2 INTR2R<4:0>
External Interrupt 3 INT3 RPINR3 INTR3R<4:0>
Timer0 External Clock Input T0CKI RPINR4 T0CKR<4:0>
Timer3 External Clock Input T3CKI RPINR6 T3CKR<4:0>
Input Capture 1 CCP1 RPINR7 IC1R<4:0>
Input Capture 2 CCP2 RPINR8 IC2R<4:0>
Timer1 Gate Input T1G RPINR12 T1GR<4:0>
Timer3 Gate Input T3G RPINR13 T3GR<4:0>
EUSART2 Asynchronous Receive/Synchronous
Receive
RX2/DT2 RPINR16 RX2DT2R<4:0>
EUSART2 Asynchronous Clock Input CK2 RPINR17 CK2R<4:0>
SPI2 Data Input SDI2 RPINR21 SDI2R<4:0>
SPI2 Clock Input SCK2IN RPINR22 SCK2R<4:0>
SPI2 Slave Select Input SS2IN RPINR23 SS2R<4:0>
PWM Fault Input FLT0 RPINR24 OCFAR<4:0>
Note 1: Unless otherwise noted, all inputs use the Schmitt Trigger input buffers.
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DS39931D-page 152 2011 Microchip Technology Inc.
10.7.3.2 Output Mapping
In contrast to inputs, the outputs of the PPS options
are mapped on the basis of the pin. In this case, a
control register associated with a particular pin
dictates the peripheral output to be mapped. The
RPORx registers are used to control output mapping.
The value of the bit field corresponds to one of the
peripherals and that peripheral’s output is mapped to
the pin (see Table 10-14).
Because of the mapping technique, the list of
peripherals for output mapping also includes a null value
of ‘00000’. This permits any given pin to remain discon-
nected from the output of any of the pin-selectable
peripherals.
TABLE 10-14: SELECTABLE OUTPUT SOURCES (MAPS FUNCTION TO OUTPUT)
Function Output Function
Number(1) Output Name
NULL 0 NULL(2)
C1OUT 1 Comparator 1 Output
C2OUT 2 Comparator 2 Output
TX2/CK2 5 EUSART2 Asynchronous Transmit/Asynchronous Clock Output
DT2 6 EUSART2 Synchronous Transmit
SDO2 9 SPI2 Data Output
SCK2 10 SPI2 Clock Output
SSDMA 12 SPI DMA Slave Select
ULPOUT 13 Ultra Low-Power Wake-up Event
CCP1/P1A 14 ECCP1 Compare or PWM Output Channel A
P1B 15 ECCP1 Enhanced PWM Output, Channel B
P1C 16 ECCP1 Enhanced PWM Output, Channel C
P1D 17 ECCP1 Enhanced PWM Output, Channel D
CCP2/P2A 18 ECCP2 Compare or PWM Output
P2B 19 ECCP2 Enhanced PWM Output, Channel B
P2C 20 ECCP2 Enhanced PWM Output, Channel C
P2D 21 ECCP2 Enhanced PWM Output, Channel D
Note 1: Value assigned to the RP<4:0> pins corresponds to the peripheral output function number.
2: The NULL function is assigned to all RPn outputs at device Reset and disables the RPn output function.
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10.7.3.3 Mapping Limitations
The control schema of the PPS is extremely flexible.
Other than systematic blocks that prevent signal con-
tention caused by two physical pins being configured
as the same functional input, or two functional outputs
configured as the same pin, there are no hardware
enforced lock outs. The flexibility extends to the point of
allowing a single input to drive multiple peripherals or a
single functional output to drive multiple output pins.
10.7.4 CONTROLLING CONFIGURATION
CHANGES
Because peripheral remapping can be changed during
run time, some restrictions on peripheral remapping
are needed to prevent accidental configuration
changes. PIC18F devices include three features to
prevent alterations to the peripheral map:
Control register lock sequence
Continuous state monitoring
Configuration bit remapping lock
10.7.4.1 Control Register Lock
Under normal operation, writes to the RPINRx and
RPORx registers are not allowed. Attempted writes will
appear to execute normally, but the contents of the
registers will remain unchanged. To change these reg-
isters, they must be unlocked in hardware. The register
lock is controlled by the IOLOCK bit (PPSCON<0>).
Setting IOLOCK prevents writes to the control
registers; clearing IOLOCK allows writes.
To set or clear IOLOCK, a specific command sequence
must be executed:
1. Write 55h to EECON2<7:0>.
2. Write AAh to EECON2<7:0>.
3. Clear (or set) IOLOCK as a single operation.
IOLOCK remains in one state until changed. This
allows all of the PPS registers to be configured with a
single unlock sequence, followed by an update to all
control registers, then locked with a second lock
sequence.
10.7.4.2 Continuous State Monitoring
In addition to being protected from direct writes, the
contents of the RPINRx and RPORx registers are
constantly monitored in hardware by shadow registers.
If an unexpected change in any of the registers occurs
(such as cell disturbances caused by ESD or other
external events), a Configuration Mismatch Reset will
be triggered.
10.7.4.3 Configuration Bit Pin Select Lock
As an additional level of safety, the device can be
configured to prevent more than one write session to
the RPINRx and RPORx registers. The IOL1WAY
(CONFIG3H<0>) Configuration bit blocks the IOLOCK
bit from being cleared after it has been set once. If
IOLOCK remains set, the register unlock procedure will
not execute and the PPS Control registers cannot be
written to. The only way to clear the bit and re-enable
peripheral remapping is to perform a device Reset.
In the default (unprogrammed) state, IOL1WAY is set,
restricting users to one write session. Programming
IOL1WAY allows users unlimited access (with the
proper use of the unlock sequence) to the PPS
registers.
10.7.5 CONSIDERATIONS FOR
PERIPHERAL PIN SELECTION
The ability to control Peripheral Pin Selection intro-
duces several considerations into application design
that could be overlooked. This is particularly true for
several common peripherals that are available only as
remappable peripherals.
The main consideration is that the PPS is not available
on default pins in the device’s default (Reset) state.
Since all RPINRx registers reset to ‘11111’ and all
RPORx registers reset to ‘00000’, all PPS inputs are
tied to RP31 and all PPS outputs are disconnected.
This situation requires the user to initialize the device
with the proper peripheral configuration before any
other application code is executed. Since the IOLOCK
bit resets in the unlocked state, it is not necessary to
execute the unlock sequence after the device has
come out of Reset.
For application safety, however, it is best to set
IOLOCK and lock the configuration after writing to the
control registers.
The unlock sequence is timing-critical. Therefore, it is
recommended that the unlock sequence be executed
as an assembly language routine with interrupts
temporarily disabled. If the bulk of the application is
written in ‘C’ or another high-level language, the unlock
sequence should be performed by writing in-line
assembly.
Note: In tying PPS inputs to RP31, RP31 does
not have to exist on a device for the
registers to be reset to it.
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Choosing the configuration requires the review of all
PPSs and their pin assignments, especially those that
will not be used in the application. In all cases, unused
pin-selectable peripherals should be disabled com-
pletely. Unused peripherals should have their inputs
assigned to an unused RPn pin function. I/O pins with
unused RPn functions should be configured with the
NULL peripheral output.
The assignment of a peripheral to a particular pin does
not automatically perform any other configuration of the
pin’s I/O circuitry. In theory, this means adding a pin-
selectable output to a pin may mean inadvertently
driving an existing peripheral input when the output is
driven. Users must be familiar with the behavior of
other fixed peripherals that share a remappable pin and
know when to enable or disable them. To be safe, fixed
digital peripherals that share the same pin should be
disabled when not in use.
Along these lines, configuring a remappable pin for a
specific peripheral does not automatically turn that
feature on. The peripheral must be specifically config-
ured for operation and enabled, as if it were tied to a
fixed pin. Where this happens in the application code
(immediately following device Reset and peripheral
configuration or inside the main application routine)
depends on the peripheral and its use in the
application.
A final consideration is that the PPS functions neither
override analog inputs nor reconfigure pins with analog
functions for digital I/O. If a pin is configured as an
analog input on a device Reset, it must be explicitly
reconfigured as a digital I/O when used with a PPS.
Example 10-7 provides a configuration for bidirectional
communication with flow control using EUSART2. The
following input and output functions are used:
Input Function RX2
Output Function TX2
EXAMPLE 10-7: CONFIGURING EUSART2
INPUT AND OUTPUT
FUNCTIONS
Note: If the Configuration bit, IOL1WAY = 1,
once the IOLOCK bit is set, it cannot be
cleared, preventing any future RP register
changes. The IOLOCK bit is cleared back
to ‘0’ on any device Reset.
;*************************************
; Unlock Registers
;*************************************
; PPS registers are in
BANK 14
MOVLB 0x0E
BCF INTCON, GIE ; Disable interrupts
; for unlock sequence
MOVLW 0x55
MOVWF EECON2, 0
MOVLW 0xAA
MOVWF EECON2, 0 ; Turn off PPS Write Protect
BCF PPSCON, IOLOCK, BANKED
;***************************
; Configure Input Functions
; (See Table 9-13)
;***************************
;***************************
; Assign RX2 To Pin RP0
;***************************
MOVLW 0x00
MOVWF RPINR16, BANKED
;***************************
; Configure Output Functions
; (See Table 9-14)
;***************************
;***************************
; Assign TX2 To Pin RP1
;***************************
MOVLW 0x05
MOVWF RPOR1, BANKED
;*************************************
; Lock Registers
;*************************************
MOVLW 0x55
MOVWF EECON2, 0
MOVLW 0xAA
MOVWF EECON2, 0
; Write Protect PPS (if desired)
BSF PPSCON, IOLOCK, BANKED
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10.7.6 PERIPHERAL PIN SELECT
REGISTERS
The PIC18F46J50 family of devices implements a total
of 37 registers for remappable peripheral configuration
of 44-pin devices. The 28-pin devices have 31 registers
for remappable peripheral configuration.
Note: Input and output register values can only
be changed if IOLOCK (PPSCON<0>) = 0.
See Example 10-7 for a specific command
sequence.
REGISTER 10-6: PPSCON: PERI PHERAL PIN SELECT INPUT REGISTER 0 (BANKED EFFh)(1)
U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/W-0
—IOLOCK
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-1 Unimplemented: Read as ‘0
bit 0 IOLOCK: I/O Lock Enable bit
1 = I/O lock is active, RPORx and RPINRx registers are write-protected
0 = I/O lock is not active, pin configurations can be changed
Note 1: Register values can only be changed if IOLOCK (PPSCON<0>) = 0.
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REGISTER 10-7: RPINR1: PERIPHERAL PIN SELECT INPUT REGISTER 1 (BANKED EE7h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
INTR1R4 INTR1R3 INTR1R2 INTR1R1 INTR1R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 INTR1R<4:0>: Assign External Interrupt 1 (INT1) to the Corresponding RPn Pin bits
REGISTER 10-8: RPINR2: PERIPHERAL PIN SELECT INPUT REGISTER 2 (BANKED EE8h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
INTR2R4 INTR2R3 INTR2R2 INTR2R1 INTR2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 INTR2R<4:0>: Assign External Interrupt 2 (INT2) to the Corresponding RPn Pin bits
REGISTER 10-9: RPINR3: PERIPHERAL PIN SELECT INPUT REGISTER 3 (BANKED EE9h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
INTR3R4 INTR3R3 INTR3R2 INTR3R1 INTR3R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 INTR3R<4:0>: Assign External Interrupt 3 (INT3) to the Corresponding RPn Pin bits
2011 Microchip Technology Inc. DS39931D-page 157
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REGISTER 10-10: RPINR4: PERIPHERAL PIN SELECT INPUT REGISTER 4 (BANKED EEAh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
T0CKR4 T0CKR3 T0CKR2 T0CKR1 T0CKR0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 T0CKR<4:0>: Timer0 External Clock Input (T0CKI) to the Corresponding RPn Pin bits
REGISTER 10-11: RPINR6: PERIPHERAL PIN SELECT INPUT REGISTER 6 (BANKED EECh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
T3CKR4 T3CKR3 T3CKR2 T3CKR1 T3CKR0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 T3CKR<4:0>: Timer 3 External Clock Input (T3CKI) to the Corresponding RPn Pin bits
REGISTER 10-12: RPINR7: PERIPHERAL PIN SELECT INPUT REGISTER 7 (BANKED EEDh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
IC1R4 IC1R3 IC1R2 IC1R1 IC1R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 IC1R<4:0>: Assign Input Capture 1 (ECCP1) to the Corresponding RPn Pin bits
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REGISTER 10-13: RPINR8: PERIPHERAL PIN SELECT INPUT REGISTER 8 (BANKED EEEh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
IC2R4 IC2R3 IC2R2 IC2R1 IC2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 IC2R<4:0>: Assign Input Capture 2 (ECCP2) to the Corresponding RPn Pin bits
REGISTER 10-14: RPINR12: PERIPHERAL PIN SELECT INPUT REGISTER 12 (BANKED EF2h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
T1GR4 T1GR3 T1GR2 T1GR1 T1GR0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 T1GR<4:0>: Timer1 Gate Input (T1G) to the Corresponding RPn Pin bits
REGISTER 10-15: RPINR13: PERIPHERAL PIN SELECT INPUT REGISTER 13 (BANKED EF3h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
T3GR4 T3GR3 T3GR2 T3GR1 T3GR0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 T3GR<4:0>: Timer3 Gate Input (T3G) to the Corresponding RPn Pin bits
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REGISTER 10-16: RPINR16: PERIPHERAL PIN SELECT INPUT REGISTER 16 (BANKED EF6h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
RX2DT2R4 RX2DT2R3 RX2DT2R2 RX2DT2R1 RX2DT2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RX2DT2R<4:0>: EUSART2 Synchronous/Asynchronous Receive (RX2/DT2) to the Corresponding
RPn Pin bits
REGISTER 10-17: RPINR17: PERIPHERAL PIN SELECT INPUT REGISTER 17 (BANKED EF7h)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
CK2R4 CK2R3 CK2R2 CK2R1 CK2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 CK2R<4:0>: EUSART2 Clock Input (CK2) to the Corresponding RPn Pin bits
REGISTER 10-18: RPINR21: PERIPHERAL PIN SELECT INPUT REGISTER 21 (BANKED EFBh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
SDI2R4 SDI2R3 SDI2R2 SDI2R1 SDI2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 SD I2R<4:0>: Assign SPI2 Data Input (SDI2) to the Corresponding RPn Pin bits
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REGISTER 10-19: RPINR22: PERIPHERAL PIN SELECT INPUT REGISTER 22 (BANKED EFCh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
SCK2R4 SCK2R3 SCK2R2 SCK2R1 SCK2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 SCK2R<4:0>: Assign SPI2 Clock Input (SCK2) to the Corresponding RPn Pin bits
REGISTER 10-20: RPINR23: PERIPHERAL PIN SELECT INPUT REGISTER 23 (BANKED EFDh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
SS2R4 SS2R3 SS2R2 SS2R1 SS2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 SS2R<4:0>: Assign SPI2 Slave Select Input (SS2IN) to the Corresponding RPn Pin bits
REGISTER 10-21: RPINR24: PERIPHERAL PIN SELECT INPUT REGISTER 24 (BANKED EFEh)
U-0 U-0 U-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
OCFAR4 OCFAR3 OCFAR2 OCFAR1 OCFAR0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 OCFAR<4:0>: Assign PWM Fault Input (FLT0) to the Corresponding RPn Pin bits
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REGISTER 10-22: RPOR0: PERIP HERAL PIN SELECT OUTPUT REGISTER 0 (BANKED EC6h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP0R4 RP0R3 RP0R2 RP0R1 RP0R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP0R<4:0>: Peripheral Output Function is Assigned to RP0 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-23: RPOR1: PERIP HERAL PIN SELECT OUTPUT REGISTER 1 (BANKED EC7h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP1R4 RP1R3 RP1R2 RP1R1 RP1R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP1R<4:0>: Peripheral Output Function is Assigned to RP1 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-24: RPOR2: PERIP HERAL PIN SELECT OUTPUT REGISTER 2 (BANKED EC8h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP2R4 RP2R3 RP2R2 RP2R1 RP2R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP2R<4:0>: Peripheral Output Function is Assigned to RP2 Output Pin bits
(see Table 10-14 for peripheral function numbers)
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REGISTER 10-25: RPOR3: PERIP HERAL PIN SELECT OUTPUT REGISTER 3 (BANKED EC9h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP3R4 RP3R3 RP3R2 RP3R1 RP3R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP3R<4:0>: Peripheral Output Function is Assigned to RP3 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-26: RPOR4: PERIP HERAL PIN SELECT OUTPUT REGISTER 4 (BANKED ECAh)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP4R4 RP4R3 RP4R2 RP4R1 RP4R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP4R<4:0>: Peripheral Output Function is Assigned to RP4 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-27: RPOR5: PERIP HERAL PIN SELECT OUTPUT REGISTER 5 (BANKED ECBh)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP5R4 RP5R3 RP5R2 RP5R1 RP5R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP5R<4:0>: Peripheral Output Function is Assigned to RP5 Output Pin bits
(see Table 10-14 for peripheral function numbers)
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REGISTER 10-28: RPOR6: PERIP HERAL PIN SELECT OUTPUT REGISTER 6 (BANKED ECCh)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP6R4 RP6R3 RP6R2 RP6R1 RP6R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP6R<4:0>: Peripheral Output Function is Assigned to RP6 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-29: RPOR7: PERIP HERAL PIN SELECT OUTPUT REGISTER 7 (BANKED ECDh)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP7R4 RP7R3 RP7R2 RP7R1 RP7R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP7R<4:0>: Peripheral Output Function is Assigned to RP7 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-30: RPOR8: PERIP HERAL PIN SELECT OUTPUT REGISTER 8 (BANKED ECEh)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP8R4 RP8R3 RP8R2 RP8R1 RP8R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP8R<4:0>: Peripheral Output Function is Assigned to RP8 Output Pin bits
(see Table 10-14 for peripheral function numbers)
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REGISTER 10-31: RPOR9: PERIP HERAL PIN SELECT OUTPUT REGISTER 9 (BANKED ECFh)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP9R4 RP9R3 RP9R2 RP9R1 RP9R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP9R<4:0>: Peripheral Output Function is Assigned to RP9 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-32: RPOR10: PERIPHERAL PIN SELECT OUTPUT REGISTER 10 (BANKED ED0h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP10R4 RP10R3 RP10R2 RP10R1 RP10R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP10R<4:0>: Peripheral Output Function is Assigned to RP10 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-33: RPOR11: PERIPHERAL PIN SELECT OUTPUT REGISTER 11 (BANKED ED1h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP11R4 RP11R3 RP11R2 RP11R1 RP11R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP11R<4:0>: Peripheral Output Function is Assigned to RP11 Output Pin bits
(see Table 10-14 for peripheral function numbers)
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REGISTER 10-34: RPOR12: PERIPHERAL PIN SELECT OUTPUT REGISTER 12 (BANKED ED2h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP12R4 RP12R3 RP12R2 RP12R1 RP12R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP12R<4:0>: Peripheral Output Function is Assigned to RP12 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-35: RPOR13: PERIPHERAL PIN SELECT OUTPUT REGISTER 13 (BANKED ED3h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP13R4 RP13R3 RP13R2 RP13R1 RP13R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP13R<4:0>: Peripheral Output Function is Assigned to RP13 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-36: RPOR17: PERIPHERAL PIN SELECT OUTPUT REGISTER 17 (BANKED ED7h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP17R4 RP17R3 RP17R2 RP17R1 RP17R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP17R<4:0>: Peripheral Output Function is Assigned to RP17 Output Pin bits
(see Table 10-14 for peripheral function numbers)
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REGISTER 10-37: RPOR18: PERIPHERAL PIN SELECT OUTPUT REGISTER 18 (BANKED ED8h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP18R4 RP18R3 RP18R2 RP18R1 RP18R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP18R<4:0>: Peripheral Output Function is Assigned to RP18 Output Pin bits
(see Table 10-14 for peripheral function numbers)
REGISTER 10-38: RPOR19: PERIPHERAL PIN SELECT OUTPUT REGISTER 19 (BANKED ED9h)(1)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP19R4 RP19R3 RP19R2 RP19R1 RP19R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP19R<4:0>: Peripheral Output Function is Assigned to RP19 Output Pin bits
(see Table 10-14 for peripheral function numbers)
Note 1: RP19 pins are not available on 28-pin devices.
REGISTER 10-39: RPOR20: PERIPHERAL PIN SELECT OUTPUT REGISTER 20 (BANKED EDAh)(1)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP20R4 RP20R3 RP20R2 RP20R1 RP20R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP20R<4:0>: Peripheral Output Function is Assigned to RP20 Output Pin bits
(see Table 10-14 for peripheral function numbers)
Note 1: RP20 pins are not available on 28-pin devices.
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REGISTER 10-40: RPOR21: PERIPHERAL PIN SELECT OUTPUT REGISTER 21 (BANKED EDBh)(1)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP21R4 RP21R3 RP21R2 RP21R1 RP21R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP21R<4:0>: Peripheral Output Function is Assigned to RP21 Output Pin bits
(see Table 10-14 for peripheral function numbers)
Note 1: RP21 pins are not available on 28-pin devices.
REGISTER 10-41: RPOR22: PERIPHERAL PIN SELECT OUTPUT REGISTER 22 (BANKED EDCh)(1)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP22R4 RP22R3 RP22R2 RP22R1 RP22R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP22R<4:0>: Peripheral Output Function is Assigned to RP22 Output Pin bits
(see Table 10-14 for peripheral function numbers)
Note 1: RP22 pins are not available on 28-pin devices.
REGISTER 10-42: RPOR23: PERIPHERAL PIN SELECT OUTPUT REGISTER 23 (BANKED EDDh)(1)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP23R4 RP23R3 RP23R2 RP23R1 RP23R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP23R<4:0>: Peripheral Output Function is Assigned to RP23 Output Pin bits
(see Table 10-14 for peripheral function numbers)
Note 1: RP23 pins are not available on 28-pin devices.
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REGISTER 10-43: RPOR24: PERIPHERAL PIN SELECT OUTPUT REGISTER 24 (BANKED EDEh)(1)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
RP24R4 RP24R3 RP24R2 RP24R1 RP24R0
bit 7 bit 0
Legend: R/W = Readable, Writable bit if IOLOCK = 0
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4-0 RP24R<4:0>: Peripheral Output Function is Assigned to RP24 Output Pin bits
(see Table 10-14 for peripheral function numbers)
Note 1: RP24 pins are not available on 28-pin devices.
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11.0 PARALLEL MASTER PORT
(PMP)
The Parallel Master Port module (PMP) is an 8-bit
parallel I/O module, specifically designed to communi-
cate with a wide variety of parallel devices, such as
communication peripherals, LCDs, external memory
devices and microcontrollers. Because the interface to
parallel peripherals varies significantly, the PMP is
highly configurable. The PMP module can be
configured to serve as either a PMP or as a Parallel
Slave Port (PSP).
Key features of the PMP module are:
Up to 16 bits of Addressing when Using
Data/Address Multiplexing
Up to 8 Programmable Address Lines
One Chip Select Line
Programmable Strobe Options:
- Individual Read and Write Strobes or;
- Read/Write Strobe with Enable Strobe
Address Auto-Increment/Auto-Decrement
Programmable Address/Data Multiplexing
Programmable Polarity on Control Signals
Legacy Parallel Slave Port Support
Enhanced Parallel Slave Support:
- Address Support
- 4-Byte Deep, Auto-Incrementing Buffer
Programmable Wait States
Selectable Input Voltage Levels
FIGURE 11-1: PMP MODULE OVERVIEW
PMA<0>
PMBE
PMRD
PMWR
PMD<7:0>
PMENB
PMRD/PMWR
PMCS
PMA<1>
PMA<7:2>
PMALL
PMALH
PMA<7:0>
EEPROM
Address Bus
Data Bus
Control Lines
PIC18
LCD FIFO
Microcontroller
8-Bit Data
Up to 8-Bit Address
Parallel Master Port
Buffer
PMA<15:8>
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11.1 Module Registers
The PMP module has a total of 14 Special Function
Registers (SFRs) for its operation, plus one additional
register to set configuration options. Of these, eight
registers are used for control and six are used for PMP
data transfer.
11.1.1 CONTROL REGISTERS
The eight PMP Control registers are:
• PMCONH and PMCONL
• PMMODEH and PMMODEL
• PMSTATL and PMSTATH
• PMEH and PMEL
The PMCON registers (Register 11-1 and
Register 11-2) control basic module operations, includ-
ing turning the module on or off. They also configure
address multiplexing and control strobe configuration.
The PMMODE registers (Register 11-3 and
Register 11-4) configure the various Master and Slave
modes, the data width and interrupt generation.
The PMEH and PMEL registers (Register 11-5 and
Register 11-6) configure the module’s operation at the
hardware (I/O pin) level.
The PMSTAT registers (Register 11-5 and
Register 11-6) provide status flags for the module’s
input and output buffers, depending on the operating
mode.
REGISTER 1 1-1: PMCONH: PARALLEL PORT CONTROL REGI STER HIGH BYT E (BANKED F5Fh) (1)
R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PMPEN
ADRMUX1 ADRMUX0
PTBEEN PTWREN PTRDEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PMPEN: Parallel Master Port Enable bit
1 = PMP is enabled
0 = PMP is disabled, no off-chip access is performed
bit 6-5 Unimplemented: Read as0
bit 4-3 ADRMUX<1:0>: Address/Data Multiplexing Selection bits
11 = Reserved
10 = All 16 bits of the address are multiplexed on PMD<7:0> pins
01 = Lower 8 bits of the address are multiplexed on PMD<7:0> pins (only eight bits of address are
available in this mode)
00 = Address and data appear on separate pins (only eight bits of address are available in this mode)
bit 2 PTBEEN: Byte Enable Port Enable bit (16-Bit Master mode)
1 = PMBE port is enabled
0 = PMBE port is disabled
bit 1 PTWREN: Write Enable Strobe Port Enable bit
1 = PMWR/PMENB port is enabled
0 = PMWR/PMENB port is disabled
bit 0 PTRDEN: Read/Write Strobe Port Enable bit
1 = PMRD/PMWR port is enabled
0 = PMRD/PMWR port is disabled
Note 1: This register is only available on 44-pin devices.
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REGISTER 1 1-2: PMCONL: PARALLEL PORT CONTROL REGISTER LOW BYTE (BANKED F5Eh)(1)
R/W-0 R/W-0 R/W-0(2) R/W-0 R/W-0(2) R/W-0 R/W-0 R/W-0
CSF1 CSF0 ALP CS1P BEP WRSP RDSP
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 CSF<1:0>: Chip Select Function bits
11 = Reserved
10 = Chip select function is enabled and PMCS acts as chip select (in Master mode). Up to
13 address bits only can be generated.
01 = Reserved
00 = Chip select function is disabled (in Master mode). All 16 address bits can be generated.
bit 5 ALP: Address Latch Polarity bit(2)
1 = Active-high (PMALL and PMALH)
0 = Active-low (PMALL and PMALH)
bit 4 Unimplemented: Maintain as0
bit 3 CS1P: Chip Select Polarity bit(2)
1 = Active-high (PMCS)
0 =Active-low (PMCS
)
bit 2 BEP: Byte Enable Polarity bit
1 = Byte enable is active-high (PMBE)
0 = Byte enable is active-low (PMBE)
bit 1 WRSP: Write Strobe Polarity bit
For Slave modes and Master Mode 2 (PMMODEH<1:0> = 00,01,10):
1 = Write strobe is active-high (PMWR)
0 = Write strobe is active-low (PMWR)
For Master Mode 1 (PMMODEH<1:0> = 11):
1 = Enable strobe is active-high (PMENB)
0 = Enable strobe is active-low (PMENB)
bit 0 RDSP: Read Strobe Polarity bit
For Slave modes and Master Mode 2 (PMMODEH<1:0> = 00,01,10):
1 = Read strobe is active-high (PMRD)
0 = Read strobe is active-low (PMRD)
For Master Mode 1 (PMMODEH<1:0> = 11):
1 = Read/write strobe is active-high (PMRD/PMWR)
0 = Read/write strobe is active-low (PMRD/PMWR)
Note 1: This register is only available on 44-pin devices.
2: These bits have no effect when their corresponding pins are used as address lines.
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REGISTER 11-3: PMMODEH: PARALLEL PORT MODE REGISTER HIGH BYTE (BANKED F5Dh)(1)
R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
BUSY IRQM1 IRQM0 INCM1 INCM0 MODE16 MODE1 MODE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 BUSY: Busy bit (Master mode only)
1 = Port is busy
0 = Port is not busy
bit 6-5 IRQM<1:0>: Interrupt Request Mode bits
11 = Interrupt is generated when Read Buffer 3 is read or Write Buffer 3 is written (Buffered PSP
mode), or on a read or write operation when PMA<1:0> = 11 (Addressable PSP mode only)
10 = No interrupt is generated, processor stall is activated
01 = Interrupt is generated at the end of the read/write cycle
00 = No interrupt is generated
bit 4-3 INCM<1:0>: Increment Mode bits
11 = PSP read and write buffers auto-increment (Legacy PSP mode only)
10 = Decrement ADDR<15,13:0> by 1 every read/write cycle
01 = Increment ADDR<15,13:0> by 1 every read/write cycle
00 = No increment or decrement of the address
bit 2 MODE16: 8/16-Bit Mode bit
1 = 16-bit mode: Data register is 16 bits, a read or write to the Data register invokes two 8-bit transfers
0 = 8-bit mode: Data register is 8 bits, a read or write to the Data register invokes one 8-bit transfer
bit 1-0 MODE<1:0>: Parallel Port Mode Select bits
11 = Master Mode 1 (PMCS, PMRD/PMWR, PMENB, PMBE, PMA<x:0> and PMD<7:0>)
10 = Master Mode 2 (PMCS, PMRD, PMWR, PMBE, PMA<x:0> and PMD<7:0>)
01 = Enhanced PSP, control signals (PMRD, PMWR, PMCS, PMD<7:0> and PMA<1:0>)
00 = Legacy Parallel Slave Port, control signals (PMRD, PMWR, PMCS and PMD<7:0>)
Note 1: This register is only available on 44-pin devices.
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REGISTER 11-4: PMMODEL: PARALLEL PORT MODE REGISTER LOW BYTE (BANKED F5Ch)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WAITB1(2) WAITB0(2) WAITM3 WAITM2 WAITM1 WAITM0 WAITE1(2) WAITE0(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 WAITB<1:0>: Data Setup to Read/Write Wait State Configuration bits(2)
11 = Data wait of 4 TCY; multiplexed address phase of 4 TCY
10 = Data wait of 3 TCY; multiplexed address phase of 3 TCY
01 = Data wait of 2 TCY; multiplexed address phase of 2 TCY
00 = Data wait of 1 TCY; multiplexed address phase of 1 TCY
bit 5-2 WAITM<3:0>: Read to Byte Enable Strobe Wait State Configuration bits
1111 = Wait of additional 15 TCY
.
.
.
0001 = Wait of additional 1 T
CY
0000 = No additional Wait cycles (operation forced into one TCY)
bit 1-0 WAITE<1:0>: Data Hold After Strobe Wait State Configuration bits(2)
11 = Wait of 4 TCY
10 = Wait of 3 TCY
01 = Wait of 2 TCY
00 = Wait of 1 TCY
Note 1: This register is only available on 44-pin devices.
2: WAITBx and WAITEx bits are ignored whenever WAITM<3:0> = 0000.
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REGISTER 11-5: PMEH: PARALLEL PORT ENABLE REGISTER HIGH BYTE (BANKED F57h)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
—PTEN14
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Maintain as ‘0
bit 6 PTEN14: PMCS Port Enable bit
1 = PMCS chip select line
0 = PMCS functions as port I/O
bit 5-0 Unimplemented: Maintain as ‘0
Note 1: This register is only available on 44-pin devices.
REGISTER 11-6: PMEL: PARALLEL PORT ENABLE REGISTER LOW BYTE (BANKED F56h)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PTEN7 PTEN6 PTEN5 PTEN4 PTEN3 PTEN2 PTEN1 PTEN0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 PTEN<7:2>: PMP Address Port Enable bits
1 = PMA<7:2> function as PMP address lines
0 = PMA<7:2> function as port I/O
bit 1-0 PTEN<1:0>: PMALH/PMALL Strobe Enable bits
1 = PMA<1:0> function as either PMA<1:0> or PMALH and PMALL
0 = PMA<1:0> pads function as port I/O
Note 1: This register is only available on 44-pin devices.
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REGISTER 11-7: PMSTATH: PARALLEL PORT STATUS REGISTER HIGH BYTE (BANKED F55h)(1)
R-0 R/W-0 U-0 U-0 R-0 R-0 R-0 R-0
IBF IBOV IB3F IB2F IB1F IB0F
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IBF: Input Buffer Full Status bit
1 = All writable Input Buffer registers are full
0 = Some or all of the writable Input Buffer registers are empty
bit 6 IBOV: Input Buffer Overflow Status bit
1 = A write attempt to a full Input Byte register occurred (must be cleared in software)
0 = No overflow occurred
bit 5-4 Unimplemented: Read as0
bit 3-0 IB3F:IB0F: Input Buffer x Status Full bits
1 = Input buffer contains data that has not been read (reading the buffer will clear this bit)
0 = Input buffer does not contain any unread data
Note 1: This register is only available on 44-pin devices.
REGISTER 11-8: PMSTATL: PARALLEL PORT STATUS REGISTER LOW BYTE (BANKED F54h)(1)
R-1 R/W-0 U-0 U-0 R-1 R-1 R-1 R-1
OBE OBUF OB3E OB2E OB1E OB0E
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 OBE: Output Buffer Empty Status bit
1 = All readable Output Buffer registers are empty
0 = Some or all of the readable Output Buffer registers are full
bit 6 OBUF: Output Buffer Underflow Status bit
1 = A read occurred from an empty Output Byte register (must be cleared in software)
0 = No underflow occurred
bit 5-4 Unimplemented: Read as0
bit 3-0 OB3E:OB0E: Output Buffer x Status Empty bits
1 = Output buffer is empty (writing data to the buffer will clear this bit)
0 = Output buffer contains data that has not been transmitted
Note 1: This register is only available on 44-pin devices.
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11.1.2 DATA REGISTERS
The PMP module uses eight registers for transferring
data into and out of the microcontroller. They are
arranged as four pairs to allow the option of 16-bit data
operations:
PMDIN1H and PMDIN1L
PMDIN2H and PMDIN2L
PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L
PMDOUT2H and PMDOUT2L
The PMDIN1 register is used for incoming data in Slave
modes, and both input and output data in Master
modes. The PMDIN2 register is used for buffering input
data in select Slave modes.
The PMADDR/PMDOUT1 registers are actually a
single register pair. The name and function are dictated
by the module’s operating mode. In Master modes, the
registers function as the PMADDRH and PMADDRL
registers and contain the address of any incoming or
outgoing data. In Slave modes, the registers function
as PMDOUT1H and PMDOUT1L and are used for
outgoing data.
PMADDRH differs from PMADDRL in that it can also
have limited PMP control functions. When the module is
operating in select Master mode configurations, the
upper two bits of the register can be used to determine
the operation of chip select signals. If these are not
used, PMADDR simply functions to hold the upper 8 bits
of the address. Register 11-9 provides the function of
the individual bits in PMADDRH.
The PMDOUT2H and PMDOUT2L registers are only
used in Buffered Slave modes and serve as a buffer for
outgoing data.
11.1.3 PAD CONFIGURATION CONTROL
REGISTER
In addition to the module level configuration options,
the PMP module can also be configured at the I/O pin
for electrical operation. This option allows users to
select either the normal Schmitt Trigger input buffer on
digital I/O pins shared with the PMP, or use TTL level
compatible buffers instead. Buffer configuration is
controlled by the PMPTTL bit in the PADCFG1 register.
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REGISTER 11-9: PMADDRH: PARALLEL PORT ADDRESS REGISTER HIGH BYTE
(MASTER MODES ONLY) (ACCESS F6Fh)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CS1 Parallel Master Port Address High Byte<13:8>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Maintain as ‘0
bit 6 CS1: Chip Select bit
If PMCON<7:6> = 10:
1 = Chip select is active
0 = Chip select is inactive
If PMCON<7:6> = 11 or 00:
Bit functions as ADDR<14>.
bit 5-0 Parallel Master Port Address: High Byte<13:8> bits
Note 1: In Enhanced Slave mode, PMADDRH functions as PMDOUT1H, one of the Output Data Buffer registers.
REGISTER 11-10: PMADDRL: PARALLEL PORT ADDRESS REGISTER LOW BYTE
(MASTER MODES ONLY) (ACCESS F6Eh)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
Parallel Master Port Address Low Byte<7:0>
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 Parallel Master Port Address: Low Byte<7:0> bits
Note 1: In Enhanced Slave mode, PMADDRL functions as PMDOUT1L, one of the Output Data Buffer registers.
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11.2 Slave Port Modes
The primary mode of operation for the module is
configured using the MODE<1:0> bits in the
PMMODEH register. The setting affects whether the
module acts as a slave or a master and it determines
the usage of the control pins.
11.2.1 LEGACY MODE (PSP)
In Legacy mode (PMMODEH<1:0> = 00 and
PMPEN = 1), the module is configured as a Parallel
Slave Port (PSP) with the associated enabled module
pins dedicated to the module. In this mode, an external
device, such as another microcontroller or micro-
processor, can asynchronously read and write data
using the 8-bit data bus (PMD<7:0>), the read (PMRD),
write (PMWR) and chip select (PMCS1) inputs. It acts
as a slave on the bus and responds to the read/write
control signals.
Figure 11-2 displays the connection of the PSP.
When chip select is active and a write strobe occurs
(PMCS = 1 and PMWR = 1), the data from
PMD<7:0> is captured into the PMDIN1L register.
FIGURE 11-2: LEGACY PARALLEL SLAVE PORT EXAMPLE
PMD<7:0>
PMRD
PMWR
PIC18F Master Address Bus
Data Bus
Control Lines
PMCS1
PMD<7:0>
PMRD
PMWR
PIC18F Slave
PMCS
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11.2.2 WRITE TO SLAVE PORT
When chip select is active and a write strobe occurs
(PMCS = 1 and PMWR = 1), the data from PMD<7:0>
is captured into the lower PMDIN1L register. The
PMPIF and IBF flag bits are set when the write
ends.The timing for the control signals in Write mode is
displayed in Figure 11-3. The polarity of the control
signals are configurable.
11.2.3 READ FROM SLAVE PORT
When chip select is active and a read strobe occurs
(PMCS = 1 and PMRD = 1), the data from the
PMDOUT1L register (PMDOUT1L<7:0>) is presented
onto PMD<7:0>. Figure 11-4 provides the timing for the
control signals in Read mode.
FIGURE 11-3: PARALLE L SLAVE PORT WRITE W AVEFORMS
FIGURE 11-4: PARALLEL SLAVE PORT READ WA VEFORMS
PMCS
| Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
IBF
OBE
PMPIF
PMCS
| Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
IBF
OBE
PMPIF
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11.2.4 BUFFERED PARALLEL SLAVE
PORT MODE
Buffered Parallel Slave Port mode is functionally
identical to the legacy PSP mode with one exception,
the implementation of 4-level read and write buffers.
Buffered PSP mode is enabled by setting the INCM bits
in the PMMODEH register. If the INCM<1:0> bits are
set to ‘11’, the PMP module will act as the Buffered
PSP mode.
When the Buffered PSP mode is active, the PMDIN1L,
PMDIN1H, PMDIN2L and PMDIN2H registers become
the write buffers and the PMDOUT1L, PMDOUT1H,
PMDOUT2L and PMDOUT2H registers become the
read buffers. Buffers are numbered, 0 through 3, start-
ing with the lower byte of PMDIN1L to PMDIN2H as the
read buffers and PMDOUT1L to PMDOUT2H as the
write buffers.
11.2.4.1 READ FROM SLAVE PORT
For read operations, the bytes will be sent out
sequentially, starting with Buffer 0 (PMDOUT1L<7:0>)
and ending with Buffer 3 (PMDOUT2H<7:0>) for every
read strobe. The module maintains an internal pointer
to keep track of which buffer is to be read. Each buffer
has a corresponding read status bit, OBxE, in the
PMSTATL register. This bit is cleared when a buffer
contains data that has not been written to the bus and
is set when data is written to the bus. If the current buf-
fer location being read from is empty, a buffer underflow
is generated, and the Buffer Overflow flag bit (OBUF) is
set. If all four OBxE status bits are set, then the Output
Buffer Empty flag (OBE) will also be set.
11.2.4.2 WRITE TO SLAVE PORT
For write operations, the data has to be stored
sequentially, starting with Buffer 0 (PMDIN1L<7:0>)
and ending with Buffer 3 (PMDIN2H<7:0>). As with
read operations, the module maintains an internal
pointer to the buffer that is to be written next.
The input buffers have their own write status bits, IBxF
in the PMSTATH register. The bit is set when the buffer
contains unread incoming data, and cleared when the
data has been read. The flag bit is set on the write
strobe. If a write occurs on a buffer when its associated
IBxF bit is set, the Buffer Overflow flag, IBOV, is set;
any incoming data in the buffer will be lost. If all four
IBxF flags are set, the Input Buffer Full Flag (IBF) is set.
In Buffered Slave mode, the module can be configured
to generate an interrupt on every read or write strobe
(IRQM<1:0> = 01). It can be configured to generate an
interrupt on a read from Read Buffer 3 or a write to
Write Buffer 3, which is essentially an interrupt every
fourth read or write strobe (RQM<1:0> = 11). When
interrupting every fourth byte for input data, all input
buffer registers should be read to clear the IBxF flags.
If these flags are not cleared, then there is a risk of
hitting an overflow condition.
FIGURE 11-5: PARALLEL MASTER/SLAVE CONNECTION BUFFERED EXAMPLE
PMD<7:0>
PMRD
PMWR
PMCS
Data Bus
Control Lines
PMRD
PMWR
PIC18F Slave
PMCS
PMDOUT1L (0)
PMDOUT1H (1)
PMDOUT2L (2)
PMDOUT2H (3)
PMDIN1L (0)
PMDIN1H (1)
PMDIN2L (2)
PMDIN2H (3)
PMD<7:0> Write
Address
Pointer
Read
Address
Pointer
PIC18F Master
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11.2.5 ADDRESSABLE PARALLEL SLAVE
PORT MODE
In the Addressable Parallel Slave Port mode
(PMMODEH<1:0> = 01), the module is configured with
two extra inputs, PMA<1:0>, which are the Address
Lines 1 and 0. This makes the 4-byte buffer space
directly addressable as fixed pairs of read and write
buffers. As with Legacy Buffered mode, data is output
from PMDOUT1L, PMDOUT1H, PMDOUT2L and
PMDOUT2H, and is read in PMDIN1L, PMDIN1H,
PMDIN2L and PMDIN2H. Table 11-1 provides the
buffer addressing for the incoming address to the input
and output registers.
TABLE 11-1: SLAVE MODE BUFFER
ADDRESSING
FIGURE 11-6: PARALLE L MASTER/SLAVE CONNECTION ADDRESSED BUFFER EXAMPLE
11.2.5.1 READ FROM SLAVE PORT
When chip select is active and a read strobe occurs
(PMCS = 1 and PMRD = 1), the data from one of the
four output bytes is presented onto PMD<7:0>. Which
byte is read depends on the 2-bit address placed on
ADDR<1:0>. Table 11-1 provides the corresponding
output registers and their associated address. When an
output buffer is read, the corresponding OBxE bit is set.
The OBxE flag bit is set when all the buffers are empty.
If any buffer is already empty, OBxE = 1, the next read
to that buffer will generate an OBUF event.
FIGURE 11-7: PARALLEL SLAVE PORT READ WA VEFORMS
PMA<1:0> Output
Register
(Buffer)
Input Register
(Buffer)
00 PMDOUT1L (0) PMDIN1L (0)
01 PMDOUT1H (1) PMDIN1H (1)
10 PMDOUT2L (2) PMDIN2L (2)
11 PMDOUT2H((3) PMDIN2H (3)
PMD<7:0>
PMRD
PMWR
PIC18F Master
PMCS
PMA<1:0>
Address Bus
Data Bus
Control Lines
PMRD
PMWR
PIC18F Slave
PMCS
PMDOUT1L (0)
PMDOUT1H (1)
PMDOUT2L (2)
PMDOUT2H (3)
PMDIN1L (0)
PMDIN1H (1)
PMDIN2L (2)
PMDIN2H (3)
PMD<7:0> Write
Address
Decode
Read
Address
Decode
PMA<1:0>
| Q4 | Q1 | Q2 | Q3 | Q4
PMCS
PMWR
PMRD
PMD<7:0>
PMA<1:0>
OBE
PMPIF
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11.2.5.2 WRITE TO SLAVE PORT
When chip select is active and a write strobe occurs
(PMCS = 1 and PMWR = 1), the data from PMD<7:0>
is captured into one of the four input buffer bytes.
Which byte is written depends on the 2-bit address
placed on ADDRL<1:0>.
Table 11-1 provides the corresponding input registers
and their associated address.
When an input buffer is written, the corresponding IBxF
bit is set. The IBF flag bit is set when all the buffers are
written. If any buffer is already written (IBxF = 1), the
next write strobe to that buffer will generate an OBUF
event and the byte will be discarded.
FIGURE 11-8: PARALLE L SLAVE PORT WRITE W AVEFORMS
PMCS
| Q4 | Q1 | Q2 | Q3 | Q4
PMWR
PMRD
PMD<7:0>
IBF
PMPIF
PMA<1:0>
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11.3 MASTER PORT MODES
In its Master modes, the PMP module provides an 8-bit
data bus, up to 16 bits of address, and all the necessary
control signals to operate a variety of external parallel
devices, such as memory devices, peripherals and
slave microcontrollers. To use the PMP as a master,
the module must be enabled (PMPEN = 1) and the
mode must be set to one of the two possible Master
modes (PMMODEH<1:0> = 10 or 11).
Because there are a number of parallel devices with a
variety of control methods, the PMP module is designed
to be extremely flexible to accommodate a range of
configurations. Some of these features include:
8-Bit and 16-Bit Data modes on an 8-bit data bus
Configurable address/data multiplexing
Up to two chip select lines
Up to 16 selectable address lines
Address auto-increment and auto-decrement
Selectable polarity on all control lines
Configurable Wait states at different stages of the
read/write cycle
11.3.1 PMP AND I/O PIN CONTROL
Multiple control bits are used to configure the presence
or absence of control and address signals in the
module. These bits are PTBEEN, PTWREN, PTRDEN
and PTEN<15:0>. They give the user the ability to con-
serve pins for other functions and allow flexibility to
control the external address. When any one of these
bits is set, the associated function is present on its
associated pin; when clear, the associated pin reverts
to its defined I/O port function.
Setting a PTENx bit will enable the associated pin as
an address pin and drive the corresponding data
contained in the PMADDR register. Clearing a PTENx
bit will force the pin to revert to its original I/O function.
For the pin configured as chip select (PMCS) with the
corresponding PTENx bit set, the PTEN0 and PTEN1
bits will also control the PMALL and PMALH signals.
When multiplexing is used, the associated address
latch signals should be enabled.
11.3.2 READ/WRITE CONTROL
The PMP module supports two distinct read/write
signaling methods. In Master Mode 1, read and write
strobes are combined into a single control line,
PMRD/PMWR. A second control line, PMENB, deter-
mines when a read or write action is to be taken. In
Master Mode 2, separate read and write strobes
(PMRD and PMWR) are supplied on separate pins.
All control signals (PMRD, PMWR, PMBE, PMENB,
PMAL and PMCS) can be individually configured as
either positive or negative polarity. Configuration is
controlled by separate bits in the PMCONL register.
Note that the polarity of control signals that share the
same output pin (for example, PMWR and PMENB) are
controlled by the same bit; the configuration depends
on which Master Port mode is being used.
11.3.3 DATA WIDTH
The PMP supports data widths of both 8 bits and
16 bits. The data width is selected by the MODE16 bit
(PMMODEH<2>). Because the data path into and out
of the module is only 8 bits wide, 16-bit operations are
always handled in a multiplexed fashion, with the Least
Significant Byte (LSB) of data being presented first. To
differentiate data bytes, the byte enable control strobe,
PMBE, is used to signal when the Most Significant Byte
(MSB) of data is being presented on the data lines.
11.3.4 ADDRESS MULTIPLEXING
In either of the Master modes (PMMODEH<1:0> = 1x),
the user can configure the address bus to be multiplexed
together with the data bus. This is accomplished by
using the ADRMUX<1:0> bits (PMCONH<4:3>). There
are three Address Multiplexing modes available. Typical
pinout configurations for these modes are displayed in
Figure 11-9, Figure 11-10 and Figure 11-11.
In Demultiplexed mode (PMCONH<4:3> = 00), data and
address information are completely separated. Data bits
are presented on PMD<7:0>, and address bits are
presented on PMADDRH<6:0> and PMADDRL<7:0>.
In Partially Multiplexed mode (PMCONH<4:3> = 01), the
lower eight bits of the address are multiplexed with the
data pins on PMD<7:0>. The upper eight bits of address
are unaffected and are presented on PMADDRH<6:0>.
The PMA0 pin is used as an address latch and presents
the Address Latch Low (PMALL) enable strobe. The
read and write sequences are extended by a complete
CPU cycle, during which, the address is presented on
the PMD<7:0> pins.
In Fully Multiplexed mode (PMCONH<4:3> = 10), the
entire 16 bits of the address are multiplexed with the
data pins on PMD<7:0>. The PMA0 and PMA1 pins are
used to present Address Latch Low (PMALL) enable
strobes and Address Latch High (PMALH) enable
strobes, respectively. The read and write sequences
are extended by two complete CPU cycles. During the
first cycle, the lower eight bits of the address are
presented on the PMD<7:0> pins with the PMALL
strobe active. During the second cycle, the upper eight
bits of the address are presented on the PMD<7:0>
pins with the PMALH strobe active. In the event the
upper address bits are configured as chip select pins,
the corresponding address bits are automatically
forced to 0’.
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FIGURE 11-9: DEMULTIPLEXED ADDRESSING MODE (SEP ARATE READ AND WR ITE STRO BES
WITH CHIP SELECT)
FIGURE 11-10: PARTI ALLY MULTIPLEXED A DDRESSIN G M ODE (SEPARATE READ AND W R ITE
STROBE S WITH CHIP SELECT)
FIGURE 11-1 1: FULLY MULTIPLEXED ADDRESSING MODE (SEPARATE READ AND WRITE
STROBE S WITH CHIP SELECT)
PMRD
PMWR
PMD<7:0>
PMCS
PMA<7:0>
PIC18F
Address Bus
Data Bus
Control Lines
PMRD
PMWR
PMD<7:0>
PMCS
PMALL
PMA<7:0>
PIC18F
Address Bus
Multiplexed
Data and
Address Bus
Control Lines
PMRD
PMWR
PMD<7:0>
PMCS
PMALH
PMA<13:8>
PIC18F
Multiplexed
Data and
Address Bus
Control Lines
PMALL
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11.3.5 CHIP SELECT FEATURES
One chip select line, PMCS, is available for the Master
modes of the PMP. The chip select line is controlled by
the second Most Significant bit (MSb) of the address
bus (PMADDRH<6>). When configured for chip select,
the PMADDRH<7:6> bits are not included in any
address auto-increment/decrement. The function of the
chip select signal is configured using the chip select
function bits (PMCONL<7:6>).
11.3.6 AUTO-INCREMENT/DECREMENT
While the module is operating in one of the Master
modes, the INCMx bits (PMMODEH<4:3>) control the
behavior of the address value. The address can be
made to automatically increment or decrement after
each read and write operation. The address increments
once each operation is completed and the BUSY bit
goes to ‘0. If the chip select signals are disabled and
configured as address bits, the bits will participate in
the increment and decrement operations; otherwise,
the CS1 bit values will be unaffected.
11.3.7 WAIT STATES
In Master mode, the user has control over the duration
of the read, write and address cycles by configuring the
module Wait states. Three portions of the cycle, the
beginning, middle and end, are configured using the
corresponding WAITBx, WAITMx and WAITEx bits in
the PMMODEL register.
The WAITBx bits (PMMODEL<7:6>) set the number of
Wait cycles for the data setup prior to the
PMRD/PMWT strobe in Mode 10, or prior to the
PMENB strobe in Mode 11. The WAITMx bits
(PMMODEL<5:2>) set the number of Wait cycles for
the PMRD/PMWT strobe in Mode 10, or for the PMENB
strobe in Mode 11. When this Wait state setting is ‘0’,
then WAITB and WAITE have no effect. The WAITE
bits (PMMODEL<1:0>) define the number of Wait
cycles for the data hold time after the PMRD/PMWT
strobe in Mode 10, or after the PMENB strobe in
Mode 11.
11.3.8 READ OPERATION
To perform a read on the PMP, the user reads the
PMDIN1L register. This causes the PMP to output the
desired values on the chip select lines and the address
bus. Then the read line (PMRD) is strobed. The read
data is placed into the PMDIN1L register.
If the 16-bit mode is enabled (MODE16 = 1), the read
of the low byte of the PMDIN1L register will initiate two
bus reads. The first read data byte is placed into the
PMDIN1L register and the second read data is placed
into the PMDIN1H.
Note that the read data obtained from the PMDIN1L
register is actually the read value from the previous
read operation. Hence, the first user read will be a
dummy read to initiate the first bus read and fill the
Read register. Also, the requested read value will not
be ready until after the BUSY bit is observed low. Thus,
in a back-to-back read operation, the data read from
the register will be the same for both reads. The next
read of the register will yield the new value.
11.3.9 WRITE OPERATION
To perform a write onto the parallel bus, the user writes
to the PMDIN1L register. This causes the module to
first output the desired values on the chip select lines
and the address bus. The write data from the PMDIN1L
register is placed onto the PMD<7:0> data bus. Then,
the write line (PMWR) is strobed. If the 16-bit mode is
enabled (MODE16 = 1), the write to the PMDIN1L
register will initiate two bus writes. The first write will
consist of the data contained in PMDIN1L and the
second write will contain the PMDIN1H.
11.3.10 PARALLEL MASTER PORT STATUS
11.3.10.1 The BUSY Bit
In addition to the PMP interrupt, a BUSY bit is provided
to indicate the status of the module. This bit is used
only in Master mode. While any read or write operation
is in progress, the BUSY bit is set for all but the very last
CPU cycle of the operation. In effect, if a single-cycle
read or write operation is requested, the BUSY bit will
never be active. This allows back-to-back transfers.
While the bit is set, any request by the user to initiate a
new operation will be ignored (i.e., writing or reading
the lower byte of the PMDIN1L register will neither
initiate a read nor a write).
11.3.10.2 Interrupts
When the PMP module interrupt is enabled for Master
mode, the module will interrupt on every completed
read or write cycle; otherwise, the BUSY bit is available
to query the status of the module.
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11.3.11 MASTER MODE TIMING
This section contains a number of timing examples that
represent the common Master mode configuration
options. These options vary from 8-bit to 16-bit data,
fully demultiplexed to fully multiplexed address and
Wait states.
FIGU RE 11-12: READ AND W R IT E TIMING, 8 - BI T D ATA, DEM ULT IPL E XE D AD DR ES S
FIGURE 11-13: READ TIMIN G, 8 -BIT D ATA, PARTIALLY MU LTIPLEXED ADDRESS
FIGU RE 11-14: RE AD TIMING, 8 -BI T D ATA, WAIT S TATES ENA B LED , PA RT IA LL Y
MULTIPLEXED ADDRE SS
PMWR
PMRD
PMPIF
PMD<7:0>
PMCS
PMA<7:0>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
BUSY
Q2 Q3 Q4Q1
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
BUSY
Address<7:0> Data
PMRD
PMWR
PMALL
PMD<7:0>
PMCS
Q1- - -
PMPIF
Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - -
WAITM<3:0> = 0010
WAITE<1:0> = 00
WAITB<1:0> = 01
BUSY
Address<7:0> Data
2011 Microchip Technology Inc. DS39931D-page 187
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FIGURE 11-15: WRITE TIMING, 8-BIT DAT A, PARTIALLY MULTIPLEXED ADDRESS
FIGURE 11-16: WRIT E T I MING, 8-BIT DATA, WAIT STATES ENABLED, PARTIALLY
MULTIPLEXED ADDRE SS
FIGURE 11-17: READ TIMIN G, 8 -BIT D ATA, PARTIALLY MU LTIPLEXED ADDRESS,
ENAB LE STROBE
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
Data
BUSY
Address<7:0>
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q1- - -
PMPIF
Data
Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - - Q1- - -
WAITM<3:0> = 0010
WAITB<1:0> = 01
BUSY
Address<7:0>
WAITE<1:0> = 00
PMRD/PMWR
PMENB
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
BUSY
Address<7:0> Data
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FIGURE 11-18: WRITE TIMI NG, 8-BIT DATA, PARTIALLY MULTIPLEXED ADDRESS,
ENAB LE STROBE
FIGURE 11-19: READ T IMI NG, 8 -BIT D AT A , FULLY MULTIPLEXED 1 6-BIT A DDRE SS
FIGURE 11-20: WRIT E T IMI NG, 8 -BIT DA TA, FULLY MULTIPLEXED 16-BI T ADDRESS
PMRD/PMWR
PMENB
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
Data
BUSY
Address<7:0>
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALH
Data
PMPIF
BUSY
Address<7:0> Address<13:8>
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALH
Data
PMPIF
BUSY
Address<7:0> Address<13:8>
2011 Microchip Technology Inc. DS39931D-page 189
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FIGURE 11-21: READ TIMING, 16-BIT DATA, DEMULTIPLEXED ADDRESS
FIGU RE 11-22: WRITE T I MI NG, 1 6 -BI T D ATA, DEM ULT IPL E XE D AD DR ES S
FIGURE 11-23: READ TIMING, 16-BIT MULTIPLEXED DAT A , PARTIALLY MULTIPLEXED ADD RESS
PMWR
PMRD
PMD<7:0>
PMCS
PMA<7:0>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
PMBE
BUSY
MSBLSB
PMWR
PMRD
PMD<7:0>
PMCS
PMA<7:0>
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
LSB MSB
PMBE
BUSY
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
PMBE
BUSY
Address<7:0> LSB MSB
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FIGURE 11-24: WRITE TI MI NG, 1 6-BIT MU LTIPLEXED DATA, PARTIALLY
MULTIPLEXED ADDRE SS
FIGURE 11-25: READ T IMI NG, 1 6-BIT M ULTIPLEXED DATA, FULLY MU LTIPLEXED
16-BIT ADDRESS
FIGURE 11-26: WRI TE T I MING, 16-BIT MULTIPLEXED DATA, FULLY MULTIPLEXED
16-BIT ADDRESS
PMWR
PMRD
PMALL
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMPIF
LSB MSB
PMBE
BUSY
Address<7:0>
PMWR
PMRD
PMBE
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALL
PMPIF
PMALH
BUSY
Q2 Q3 Q4Q1
Address<7:0> LSBAddress<13:8> MSB
PMWR
PMRD
PMBE
PMD<7:0>
PMCS
Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1Q2 Q3 Q4Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4Q1
PMALL
PMALH
MSBLSB
PMPIF
BUSY
Q2 Q3 Q4Q1
Address<7:0> Address<13:8>
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11.4 Application Examples
This section introduces some potential applications for
the PMP module.
11.4.1 MULTIPLEXED MEMORY OR
PERIPHERAL
Figure 11-27 demonstrates the hookup of a memory or
another addressable peripheral in Full Multiplex mode.
Consequently, this mode achieves the best pin saving
from the microcontroller perspective. However, for this
configuration, there needs to be some external latches
to maintain the address.
FIGURE 11-27: MULTIPLEXED ADDRESSING APPLIC ATI ON EXAM PLE
11.4.2 PARTIALLY MULTIPLEXED
MEMORY OR PERIPHERAL
Partial multiplexing implies using more pins; however,
for a few extra pins, some extra performance can be
achieved. Figure 11-28 provides an example of a
memory or peripheral that is partially multiplexed with
an external latch. If the peripheral has internal latches,
as displayed in Figure 11-29, then no extra circuitry is
required except for the peripheral itself.
FIGURE 11-28: EXAMPLE OF A PARTIALLY MU LTIPLEXED A DDRESSIN G A PPLICATION
FIGURE 11-29: EXAMPLE OF AN 8 -BIT MU LTIPLEXED A DDRESS A ND DATA APPLICATION
PMD<7:0>
PMALH
D<7:0>
373 A<13:0>
D<7:0>
A<7:0>
373
PMRD
PMWR
OE WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMALL
A<15:8>
D<7:0>
373 A<7:0>
D<7:0>
A<7:0>
PMRD
PMWR
OE WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMALL
PMD<7:0>
ALE
PMRD
PMWR
RD
WR
CS
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMALL
AD<7:0>
Parallel Peripheral
PMD<7:0>
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DS39931D-page 192 2011 Microchip Technology Inc.
11.4.3 PARALLEL EEPROM EXAMPLE
Figure 11-30 provides an example connecting parallel
EEPROM to the PMP. Figure 11-31 demonstrates a
slight variation to this, configuring the connection for
16-bit data from a single EEPROM.
FIGURE 11-30: PARALLEL EEPROM EX AMPLE (UP TO 15 -BIT A DDRESS, 8-BIT D ATA)
FIGURE 11-31: PARALLEL EEPROM EXAMPLE (UP TO 15-BIT ADDRESS, 16-BIT DAT A)
11.4.4 LCD CONTROLLER EXAMPLE
The PMP module can be configured to connect to a
typical LCD controller interface, as displayed in
Figure 11-32. In this case the PMP module is config-
ured for active-high control signals, since common LCD
displays require active-high control.
FIGU RE 11-32: LCD CONT RO L EX A MPL E ( B YT E M O DE O PE RA TIO N )
PMA<n:0> A<n:0>
D<7:0>
PMRD
PMWR
OE
WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMD<7:0>
Para ll el EEPROM
PMA<n:0> A<n:1>
D<7:0>
PMRD
PMWR
OE
WR
CE
PIC18F
Address Bus
Data Bus
Control Lines
PMCS
PMD<7:0>
Para ll el EEPROM
PMBE A0
PMRD/PMWR
D<7:0>
PIC18F
Address Bus
Data Bus
Control Lines
PMA0
R/W
RS
E
LCD Controller
PMCS
PM<7:0>
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TABLE 11-2: REGISTERS ASSOCIATED WITH PMP MODULE
Na me Bi t 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(2) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(2) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(2) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PMCONH(2) PMPEN ADRMUX1 ADRMUX0 PTBEEN PTWREN PTRDEN 74
PMCONL(2) CSF1 CSF0 ALP CS1P BEP WRSP RDSP 74
PMADDRH(1,2)/ CS1 Parallel Master Port Address High Byte 73
PMDOUT1H(1,2) Parallel Port Out Data High Byte (Buffer 1) 73
PMADDRL(1,2)/ Parallel Master Port Address Low Byte 73
PMDOUT1L(1,2) Parallel Port Out Data Low Byte (Buffer 0) 73
PMDOUT2H(2) Parallel Port Out Data High Byte (Buffer 3) 74
PMDOUT2L(2) Parallel Port Out Data Low Byte (Buffer 2) 74
PMDIN1H(2) Parallel Port In Data High Byte (Buffer 1) 73
PMDIN1L(2) Parallel Port In Data Low Byte (Buffer 0) 73
PMDIN2H(2) Parallel Port In Data High Byte (Buffer 3) 74
PMDIN2L(2) Parallel Port In Data Low Byte (Buffer 2) 74
PMMODEH(2) BUSY IRQM1 IRQM0 INCM1 INCM0 MODE16 MODE1 MODE0 74
PMMODEL(2) WAITB1 WAITB0 WAITM3 WAITM2 WAITM1 WAITM0 WAITE1 WAITE0 74
PMEH(2) —PTEN14 74
PMEL(2) PTEN7 PTEN6 PTEN5 PTEN4 PTEN3 PTEN2 PTEN1 PTEN0 74
PMSTATH(2) IBF IBOV IB3F IB2F IB1F IB0F 74
PMSTATL(2) OBE OBUF OB3E OB2E OB1E OB0E 74
PADCFG1 RTSECSEL1 RTSECSEL0 PMPTTL 74
Legend: = unimplemented, read as0. Shaded cells are not used during PMP operation.
Note 1: The PMADDRH/PMDOUT1H and PMADDRL/PMDOUT1L register pairs share the physical registers and
addresses, but have different functions, determined by the module’s operating mode.
2: These bits and/or registers are only available on 44-pin devices.
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NOTES:
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12.0 TIMER0 MODULE
The Timer0 module incorporates the following features:
Software-selectable operation as a timer or
counter in both 8-bit or 16-bit modes
Readable and writable registers
Dedicated 8-bit, software-programmable
prescaler
Selectable clock source (internal or external)
Edge select for external clock
Interrupt-on-overflow
The T0CON register (Register 12-1) controls all
aspects of the module’s operation, including the
prescale selection. It is both readable and writable.
Figure 12-1 provides a simplified block diagram of the
Timer0 module in 8-bit mode. Figure 12-2 provides a
simplified block diagram of the Timer0 module in 16-bit
mode.
REGISTER 12-1: T0CON: TIMER0 CONTROL REGISTER (ACCESS FD5h)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 TMR0ON: Timer0 On/Off Control bit
1 = Enables Timer0
0 = Stops Timer0
bit 6 T08BIT: Timer0 8-Bit/16-Bit Control bit
1 = Timer0 is configured as an 8-bit timer/counter
0 = Timer0 is configured as a 16-bit timer/counter
bit 5 T0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin input edge (set by T0SE)
0 = Internal clock (FOSC/4)
bit 4 T0SE: Timer0 Source Edge Select bit
1 = Increment on high-to-low transition on T0CKI pin
0 = Increment on low-to-high transition on T0CKI pin
bit 3 PSA: Timer0 Prescaler Assignment bit
1 = Timer0 prescaler is not assigned. Timer0 clock input bypasses prescaler.
0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.
bit 2-0 T0PS<2:0>: Timer0 Prescaler Select bits
111 = 1:256 Prescale value
110 = 1:128 Prescale value
101 = 1:64 Prescale value
100 = 1:32 Prescale value
011 = 1:16 Prescale value
010 = 1:8 Prescale value
001 = 1:4 Prescale value
000 = 1:2 Prescale value
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12.1 Timer0 Operation
Timer0 can operate as either a timer or a counter. The
mode is selected with the T0CS bit (T0CON<5>). In
Timer mode (T0CS = 0), the module increments on
every clock by default unless a different prescaler value
is selected (see Section 12.3 “Prescaler”). If the
TMR0 register is written to, the increment is inhibited
for the following two instruction cycles. The user can
work around this by writing an adjusted value to the
TMR0 register.
The Counter mode is selected by setting the T0CS bit
(= 1). In this mode, Timer0 increments either on every
rising edge or falling edge of pin, T0CKI. The
incrementing edge is determined by the Timer0 Source
Edge Select bit, T0SE (T0CON<4>); clearing this bit
selects the rising edge. Restrictions on the external
clock input are discussed below.
An external clock source can be used to drive Timer0;
however, it must meet certain requirements to ensure
that the external clock can be synchronized with the
internal phase clock (T
OSC). There is a delay between
synchronization and the onset of incrementing the
timer/counter.
12.2 Timer0 Reads and Writes in 16-Bit
Mode
TMR0H is not the actual high byte of Timer0 in 16-bit
mode. It is actually a buffered version of the real high
byte of Timer0, which is not directly readable nor
writable (refer to Figure 12-2). TMR0H is updated with
the contents of the high byte of Timer0 during a read of
TMR0L. This provides the ability to read all 16 bits of
Timer0 without having to verify that the read of the high
and low byte were valid, due to a rollover between
successive reads of the high and low byte.
Similarly, a write to the high byte of Timer0 must also
take place through the TMR0H Buffer register. The high
byte is updated with the contents of TMR0H when a
write occurs to TMR0L. This allows all 16 bits of Timer0
to be updated at once.
FIGU RE 12 -1: T IME R0 BLO CK DI AGRAM ( 8-B IT MODE)
FIGU RE 12 -2: T IMER 0 BLO CK DIAG RAM ( 16-BIT MODE)
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
T0CKI pin
T0SE
0
1
1
0
T0CS
FOSC/4
Programmable
Prescaler
Sync with
Internal
Clocks
TMR0L
(2 TCY Delay)
Internal Data Bus
PSA
T0PS<2:0>
Set
TMR0IF
on Overflow
38
8
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
T0CKI pin
T0SE
0
1
1
0
T0CS
FOSC/4
Sync with
Internal
Clocks
TMR0L
(2 TCY Delay)
Internal Data Bus
8
PSA
T0PS<2:0>
Set
TMR0IF
on Overflow
3
TMR0
TMR0H
High Byte
88
8
Read TMR0L
Write TMR0L
8
Programmable
Prescaler
2011 Microchip Technology Inc. DS39931D-page 197
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12.3 Prescaler
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not directly readable or writable.
Its value is set by the PSA and T0PS<2:0> bits
(T0CON<3:0>), which determine the prescaler
assignment and prescale ratio.
Clearing the PSA bit assigns the prescaler to the
Timer0 module. When it is assigned, prescale values
from 1:2 through 1:256, in power-of-2 increments, are
selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0, MOVWF
TMR0, BSF TMR0, etc.) clear the prescaler count.
12.3.1 SWITCHING PRESCALER
ASSIGNMENT
The prescaler assignment is fully under software
control and can be changed “on-the-fly” during program
execution.
12.4 Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0
register overflows from FFh to 00h in 8-bit mode, or
from FFFFh to 0000h in 16-bit mode. This overflow sets
the TMR0IF flag bit. The interrupt can be masked by
clearing the TMR0IE bit (INTCON<5>). Before
re-enabling the interrupt, the TMR0IF bit must be
cleared in software by the Interrupt Service Routine
(ISR).
Since Timer0 is shutdown in Sleep mode, the TMR0
interrupt cannot awaken the processor from Sleep.
TABLE 12-1: REGISTERS ASSOCIATED WITH TIMER0
Note: Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count but will not change the prescaler
assignment.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 B it 1 Bit 0 Reset
Values
on Page:
TMR0L Timer0 Register Low Byte 90
TMR0H Timer0 Register High Byte 90
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 90
T0CON TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 90
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by Timer0.
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NOTES:
2011 Microchip Technology Inc. DS39931D-page 199
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13.0 TIMER1 MODULE
The Timer1 timer/counter module incorporates these
features:
Software-selectable operation as a 16-bit timer or
counter
Readable and writable 8-bit registers (TMR1H
and TMR1L)
Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
Interrupt-on-overflow
Reset on ECCP Special Event Trigger
Device clock status flag (T1RUN)
Timer with gated control
Figure 13-1 displays a simplified block diagram of the
Timer1 module.
The module incorporates its own low-power oscillator
to provide an additional clocking option. The Timer1
oscillator can also be used as a low-power clock source
for the microcontroller in power-managed operation.
Timer1 is controlled through the T1CON Control
register (Register 13-1). It also contains the Timer1
Oscillator Enable bit (T1OSCEN). Timer1 can be
enabled or disabled by setting or clearing control bit,
TMR1ON (T1CON<0>).
The FOSC clock source (TMR1CS<1:0> = 01) should not
be used with the ECCP capture/compare features. If the
timer will be used with the capture or compare features,
always select one of the other timer clocking options.
REGISTER 13-1: T1CON: TIMER1 CONTROL REGISTER (ACCESS FCDh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
TMR1CS1 TMR1CS0 T1CKPS1 T1CKPS0
T1OSCEN
T1SYNC RD16 TMR1ON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 TMR1CS<1:0>: Timer1 Clock Source Select bits
10 = Timer1 clock source is the T1OSC or T1CKI pin
01 = Timer1 clock source is the system clock (FOSC)(1)
00 = Timer1 clock source is the instruction clock (FOSC/4)
bit 5-4 T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 3 T1OSCEN: Timer1 Oscillator Source Select bit
When TMR1CS<1:0> = 10:
1 = Power up the Timer1 crystal driver and supply the Timer1 clock from the crystal output
0 = Timer1 crystal driver is off, Timer1 clock is from the T1CKI input pin(2)
When TMR1CS<1:0> = 0x:
1 = Power up the Timer1 crystal driver
0 = Timer1 crystal driver is off(2)
bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit
TMR1CS<1:0> = 10:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
TMR1CS<1:0> = 0x:
This bit is ignored. Timer1 uses the internal clock when TMR1CS<1:0> = 0x.
Note 1: The FOSC clock source should not be selected if the timer will be used with the ECCP capture/compare
features.
2: The Timer1 oscillator crystal driver is powered whenever T1OSCEN (T1CON) or T3OSCEN (T3CON) = 1.
The circuit is enabled by the logical OR of these two bits. When disabled, the inverter and feedback resistor
are disabled to eliminate power drain. The TMR1ON and TMR3ON bits do not have to be enabled to power
up the crystal driver.
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DS39931D-page 200 2011 Microchip Technology Inc.
bit 1 RD16: 16-Bit Read/Write Mode Enable bit
1 = Enables register read/write of Timer1 in one 16-bit operation
0 = Enables register read/write of Timer1 in two 8-bit operations
bit 0 TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
REGISTER 13-1: T1CON: TIMER1 CONTROL REGISTER (ACCESS FCDh) (CONTINUED)
Note 1: The FOSC clock source should not be selected if the timer will be used with the ECCP capture/compare
features.
2: The Timer1 oscillator crystal driver is powered whenever T1OSCEN (T1CON) or T3OSCEN (T3CON) = 1.
The circuit is enabled by the logical OR of these two bits. When disabled, the inverter and feedback resistor
are disabled to eliminate power drain. The TMR1ON and TMR3ON bits do not have to be enabled to power
up the crystal driver.
2011 Microchip Technology Inc. DS39931D-page 201
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13.1 Timer1 Gate Control Register
The Timer1 Gate Control register (T1GCON),
displayed in Register 13-2, is used to control the
Timer1 gate.
REGISTER 13-2: T1GCON: TIMER1 GATE CONTROL REGISTER (ACCESS F9Ah)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-x R/W-0 R/W-0
TMR1GE T1GPOL T1GTM T1GSPM T1GGO/T1DONE T1GVAL T1GSS1 T1GSS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 TMR1GE: Timer1 Gate Enable bit
If TMR1ON = 0:
This bit is ignored.
If TMR1ON = 1:
1 = Timer1 counting is controlled by the Timer1 gate function
0 = Timer1 counts regardless of the Timer1 gate function
bit 6 T1GPOL: Timer1 Gate Polarity bit
1 = Timer1 gate is active-high (Timer1 counts when gate is high)
0 = Timer1 gate is active-low (Timer1 counts when gate is low)
bit 5 T1GTM: Timer1 Gate Toggle Mode bit
1 = Timer1 Gate Toggle mode is enabled
0 = Timer1 Gate Toggle mode is disabled and toggle flip-flop is cleared
Timer1 gate flip-flop toggles on every rising edge.
bit 4 T1GSPM: Timer1 Gate Single Pulse Mode bit
1 = Timer1 Gate Single Pulse mode is enabled and is controlling Timer1 gate
0 = Timer1 Gate Single Pulse mode is disabled
bit 3 T1GGO/T1DONE: Timer1 Gate Single Pulse Acquisition Status bit
1 = Timer1 gate single pulse acquisition is ready, waiting for an edge
0 = Timer1 gate single pulse acquisition has completed or has not been started
This bit is automatically cleared when T1GSPM is cleared.
bit 2 T1GVAL: Timer1 Gate Current State bit
Indicates the current state of the Timer1 gate that could be provided to TMR1H:TMR1L; unaffected by
Timer1 Gate Enable (TMR1GE) bit.
bit 1-0 T1GSS<1:0>: Timer1 Gate Source Select bits
00 = Timer1 gate pin
01 = Timer0 overflow output
10 = TMR2 to match PR2 output
Note 1: Programming the T1GCON prior to T1CON is recommended.
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DS39931D-page 202 2011 Microchip Technology Inc.
REGISTER 13-3: TCLKCON: TIMER CLOCK CONTROL REGISTER (BANKED F52h)
U-0 U-0 U-0 R-0 U-0 U-0 R/W-0 R/W-0
T1RUN —T3CCP2T3CCP1
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4 T1RUN: Timer1 Run Status bit
1 = Device is currently clocked by T1OSC/T1CKI
0 = System clock comes from an oscillator other than T1OSC/T1CKI
bit 3-2 Unimplemented: Read as ‘0
bit 1-0 T3CCP<2:1>: ECCP Timer Assignment bits
10 = ECCP1 and ECCP2 both use Timer3 (capture/compare) and Timer4 (PWM)
01 = ECCP1 uses Timer1 (compare/capture) and Timer2 (PWM); ECCP2 uses Timer3 (capture/compare)
and Timer4 (PWM)
00 = ECCP1 and ECCP2 both use Timer1 (capture/compare) and Timer2 (PWM)
2011 Microchip Technology Inc. DS39931D-page 203
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13.2 Timer1 Operation
The Timer1 module is an 8-bit or 16-bit incrementing
counter, which is accessed through the
TMR1H:TMR1L register pair.
When used with an internal clock source, the module is
a timer and increments on every instruction cycle.
When used with an external clock source, the module
can be used as either a timer or counter and
increments on every selected edge of the external
source.
Timer1 is enabled by configuring the TMR1ON and
TMR1GE bits in the T1CON and T1GCON registers,
respectively.
When Timer1 is enabled, the RC1/T1OSI/UOE/RP12
and RC0/T1OSO/T1CKI/RP11 pins become inputs.
This means the values of TRISC<1:0> are ignored and
the pins are read as ‘0’.
13.3 Clock Source Selection
The TMR1CS<1:0> and T1OSCEN bits of the T1CON
register are used to select the clock source for Timer1.
Register 13-1 displays the clock source selections.
13.3.1 INTERNAL CLOCK SOURCE
When the internal clock source is selected, the
TMR1H:TMR1L register pair will increment on multiples
of FOSC as determined by the Timer1 prescaler.
13.3.2 EXTERNAL CLOCK SOURCE
When the external clock source is selected, the Timer1
module may work as a timer or a counter.
When enabled to count, Timer1 is incremented on the
rising edge of the external clock input, T1CKI, or the
capacitive sensing oscillator signal. Either of these
external clock sources can be synchronized to the
microcontroller system clock or they can run
asynchronously.
When used as a timer with a clock oscillator, an
external 32.768 kHz crystal can be used in conjunction
with the dedicated internal oscillator circuit.
TABLE 13-1: TIMER1 CLOCK SOURCE SELECTION
Note: In Counter mode, a falling edge must be
registered by the counter prior to the first
incrementing rising edge after any one or
more of the following conditions:
• Timer1 is enabled after a POR
• Write to TMR1H or TMR1L
• Timer1 is disabled
• Timer1 is disabled (TMR1ON = 0)
when T1CKI is high, then Timer1 is
enabled (TMR1ON = 1) when T1CKI is
low.
TMR1CS1 TMR1CS0 T1OSCEN Clock Source
01xClock Source (FOSC)
00xInstruction Clock (FOSC/4)
100External Clock on T1CKI Pin
101Oscillator Circuit on T1OSI/T1OSO Pin
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DS39931D-page 204 2011 Microchip Technology Inc.
FIGU RE 13-1: T IM ER1 BL OCK DI AGRA M
TMR1H TMR1L
T1SYNC
T1CKPS<1:0>
Prescaler
1, 2, 4, 8
0
1
Synchronized
Clock Input
2
Set Flag bit
TMR1IF on
Overflow TMR1(2)
TMR1ON
Note 1: ST buffer is a high-speed type when using T1CKI.
2: Timer1 register increments on the rising edge.
3: Synchronization does not operate while in Sleep.
T1G
T1OSC
FOSC/4
Internal
Clock
T1OSO/T1CKI
T1OSI
T1OSCEN
1
0
T1CKI
TMR1CS<1:0>
(1)
Synchronize(3)
det
Sleep Input
TMR1GE
0
1
00
01
10
From Timer0
From Timer2
T1GPOL
D
Q
CK
Q
0
1
T1GVAL
T1GTM
Single Pulse
Acq. Control
T1GSPM
T1GGO/T1DONE
T1GSS<1:0>
EN
OUT
10
00
01
FOSC
Internal
Clock
Match PR2
Overflow
R
D
EN
Q
Q1
RD
T1GCON
Data Bus
det
Interrupt
TMR1GIF
Set
T1CLK
FOSC/2
Internal
Clock
D
EN
Q
T1G_IN
TMR1ON
2011 Microchip Technology Inc. DS39931D-page 205
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13.4 Timer1 16-Bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes.
When the RD16 control bit (T1CON<1>) is set, the
address for TMR1H is mapped to a buffer register for
the high byte of Timer1. A read from TMR1L loads the
contents of the high byte of Timer1 into the Timer1 High
Byte Buffer register. This provides the user with the
ability to accurately read all 16 bits of Timer1 without
having to determine whether a read of the high byte,
followed by a read of the low byte, has become invalid
due to a rollover between reads.
A write to the high byte of Timer1 must also take place
through the TMR1H Buffer register. The Timer1 high
byte is updated with the contents of TMR1H when a
write occurs to TMR1L. This allows a user to write all
16 bits to both the high and low bytes of Timer1 at once.
The high byte of Timer1 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer1 High Byte Buffer register.
Writes to TMR1H do not clear the Timer1 prescaler.
The prescaler is only cleared on writes to TMR1L.
13.5 Timer1 Oscillator
An on-chip crystal oscillator circuit is incorporated
between pins, T1OSI (input) and T1OSO (amplifier
output). It is enabled by setting the Timer1 Oscillator
Enable bit, T1OSCEN (T1CON<3>). The oscillator is a
low-power circuit rated for 32 kHz crystals. It will
continue to run during all power-managed modes. The
circuit for a typical LP oscillator is depicted in
Figure 13-2. Table 13-2 provides the capacitor selection
for the Timer1 oscillator.
The user must provide a software time delay to ensure
proper start-up of the Timer1 oscillator.
FIGURE 13-2: EXTERNAL COMPONENTS
FOR THE TIMER1 LP
OSCILLATOR
T ABLE 13-2: CAPACITOR SELECTION FOR
THE TIMER
OSCILLATOR(2,3,4,5)
The Timer1 crystal oscillator drive level is determined
based on the LPT1OSC (CONFIG2L<4>) Configura-
tion bit. The Higher Drive Level mode, LPT1OSC = 1,
is intended to drive a wide variety of 32.768 kHz
crystals with a variety of load capacitance (CL) ratings.
The Lower Drive Level mode is highly optimized for
extremely low-power consumption. It is not intended to
drive all types of 32.768 kHz crystals. In the Low Drive
Level mode, the crystal oscillator circuit may not work
correctly if excessively large discrete capacitors are
placed on the T1OSI and T1OSO pins. This mode is
only designed to work with discrete capacitances of
approximately 3 pF-10 pF on each pin.
Crystal manufacturers usually specify a CL (load
capacitance) rating for their crystals. This value is
related to, but not necessarily the same as, the values
that should be used for C1 and C2 in Figure 13-2. See
the crystal manufacturer’s applications information for
more details on how to select the optimum C1 and C2
for a given crystal. The optimum value depends in part
on the amount of parasitic capacitance in the circuit,
which is often unknown. Therefore, after values have
been selected, it is highly recommended that thorough
testing and validation of the oscillator be performed.
Note: See the Notes with Table 13-2 for additional
information about capacitor selection.
C1
C2
XTAL
PIC18F46J50
T1OSI
T1OSO
32.768 kHz
12 pF
12 pF
Oscillator
Type Freq. C1 C2
LP 32 kHz 12 pF(1) 12 pF(1)
Note 1: Microchip suggests these values as a
starting point in validating the oscillator
circuit.
2: Higher capacitance increases the stabil-
ity of the oscillator but also increases the
start-up time.
3: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external
components.
4: Capacitor values are for design guidance
only. Values listed would be typical of a
CL= 10 pF rated crystal when
LPT1OSC = 1.
5: Incorrect capacitance value may result in
a frequency not meeting the crystal
manufacturer’s tolerance specification.
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13.5.1 USING TIMER1 AS A
CLOCK SOURCE
The Timer1 oscillator is also available as a clock source
in power-managed modes. By setting the clock select
bits, SCS<1:0> (OSCCON<1:0>), to ‘01’, the device
switches to SEC_RUN mode; both the CPU and
peripherals are clocked from the Timer1 oscillator. If the
IDLEN bit (OSCCON<7>) is cleared and a SLEEP
instruction is executed, the device enters SEC_IDLE
mode. Additional details are available in Section 4.0
“Low-Power Modes”.
Whenever the Timer1 oscillator is providing the clock
source, the Timer1 system clock status flag, T1RUN
(TCLKCON<4>), is set. This can be used to determine
the controller’s current clocking mode. It can also
indicate the clock source currently being used by the
Fail-Safe Clock Monitor. If the Clock Monitor is enabled
and the Timer1 oscillator fails while providing the clock,
polling the T1RUN bit will indicate whether the clock is
being provided by the Timer1 oscillator or another
source.
13.5.2 TIMER1 OSCILLATOR LAYOUT
CONSIDERATIONS
The Timer1 oscillator circuit draws very little power
during operation. Due to the low-power nature of the
oscillator, it may also be sensitive to rapidly changing
signals in close proximity. This is especially true when
the oscillator is configured for extremely Low-Power
mode (LPT1OSC = 0).
The oscillator circuit, displayed in Figure 13-2, should
be located as close as possible to the microcontroller.
There should be no circuits passing within the oscillator
circuit boundaries other than VSS or VDD.
If a high-speed circuit must be located near the
oscillator (such as the ECCP1 pin in Output Compare
or PWM mode, or the primary oscillator using the
OSC2 pin), a grounded guard ring around the oscillator
circuit, as displayed in Figure 13-3, may be helpful
when used on a single-sided PCB or in addition to a
ground plane.
FIGURE 13-3: OSCILLATOR CIRCUIT
WITH GROUNDED
GUAR D RING
In the Low Drive Level mode, LPT1OSC = 0, it is critical
that the RC2 I/O pin signals be kept away from the
oscillator circuit. Configuring RC2 as a digital output,
and toggling it, can potentially disturb the oscillator
circuit, even with relatively good PCB layout. If
possible, it is recommended to either leave RC2
unused, or use it as an input pin with a slew rate limited
signal source. If RC2 must be used as a digital output,
it may be necessary to use the Higher Drive Level
Oscillator mode (LPT1OSC = 1) with many PCB lay-
outs. Even in the High Drive Level mode, careful layout
procedures should still be followed when designing the
oscillator circuit.
In addition to dV/dt induced noise considerations, it is
also important to ensure that the circuit board is clean.
Even a very small amount of conductive soldering flux
residue can cause PCB leakage currents which can
overwhelm the oscillator circuit.
13.6 Timer1 Interrupt
The TMR1 register pair (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
Timer1 interrupt, if enabled, is generated on overflow
which is latched in interrupt flag bit, TMR1IF
(PIR1<0>). This interrupt can be enabled or disabled
by setting or clearing the Timer1 Interrupt Enable bit,
TMR1IE (PIE1<0>).
VDD
OSC1
VSS
OSC2
RC0
RC1
RC2
Note: Not drawn to scale.
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13.7 Resetting Timer1 Using the ECCP
S pecial Event Trigger
If ECCP1 or ECCP2 is configured to use Timer1 and to
generate a Special Event Trigger in Compare mode
(CCPxM<3:0> = 1011), this signal will reset Timer3.
The trigger from ECCP2 will also start an A/D conver-
sion if the A/D module is enabled (see Section 18.3.4
“Special Event Trigger” for more information).
The module must be configured as either a timer or a
synchronous counter to take advantage of this feature.
When used this way, the CCPRxH:CCPRxL register
pair effectively becomes a Period register for Timer1.
If Timer1 is running in Asynchronous Counter mode,
this Reset operation may not work.
In the event that a write to Timer1 coincides with a
Special Event Trigger, the write operation will take
precedence.
13.8 Timer1 Gate
The Timer1 can be configured to count freely or the count
can be enabled and disabled using the Timer1 gate
circuitry. This is also referred to as Timer1 gate count
enable.
Timer1 gate can also be driven by multiple selectable
sources.
13.8.1 TIMER1 GATE COUNT ENABLE
The Timer1 Gate Enable mode is enabled by setting
the TMR1GE bit of the T1GCON register. The polarity
of the Timer1 Gate Enable mode is configured using
the T1GPOL bit of the T1GCON register.
When Timer1 Gate Enable mode is enabled, Timer1
will increment on the rising edge of the Timer1 clock
source. When Timer1 Gate Enable mode is disabled,
no incrementing will occur and Timer1 will hold the
current count. See Figure 13-4 for timing details.
TABLE 13-3: TIMER1 GATE ENABLE
SELECTIONS
FIGU RE 13-4: T I ME R 1 GAT E CO UN T E N AB LE M ODE
Note: The Special Event Trigger from the
ECCPx module will not set the TMR1IF
interrupt flag bit (PIR1<0>).
T1CLK T1GPOL T1G Timer 1 Operation
00Counts
01Holds Count
10Holds Count
11Counts
TMR1GE
T1GPOL
T1G_IN
T1CKI
T1GVAL
Timer1 NN + 1 N + 2 N + 3 N + 4
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13.8.2 TIMER1 GATE SOURCE
SELECTION
The Timer1 gate source can be selected from one of
four different sources. Source selection is controlled by
the T1GSSx bits of the T1GCON register. The polarity
for each available source is also selectable. Polarity
selection is controlled by the T1GPOL bit of the
T1GCON register.
TABLE 13-4: TIMER1 GATE SOURCES
13.8.2.1 T1G Pin Gate Operation
The T1G pin is one source for Timer1 gate control. It
can be used to supply an external source to the Timer1
gate circuitry.
13.8.2.2 Timer0 Overflow Gate Operation
When Timer0 increments from FFh to 00h, a
low-to-high pulse will automatically be generated and
internally supplied to the Timer1 gate circuitry.
13.8.2.3 Timer2 Match Gate Operation
The TMR2 register will increment until it matches the
value in the PR2 register. On the very next increment
cycle, TMR2 will be reset to 00h. When this Reset occurs,
a low-to-high pulse will automatically be generated and
internally supplied to the Timer1 gate circuitry.
The pulse remains high for one instruction cycle and
returns to low until the next match.
When T1GPOL = 1, Timer1 increments for a single
instruction cycle, following TMR2 matching PR2.
With T1GPOL = 0, Timer1 increments, except during
the cycle following the match.
13.8.3 TIMER1 GATE TOGGLE MODE
When Timer1 Gate Toggle mode is enabled, it is
possible to measure the full cycle length of a Timer1 gate
signal, as opposed to the duration of a single level pulse.
The Timer1 gate source is routed through a flip-flop that
changes state on every incrementing edge of the
signal. See Figure 13-5 for timing details.
The T1GVAL bit will indicate when the Toggled mode is
active and the timer is counting.
The Timer1 Gate Toggle mode is enabled by setting the
T1GTM bit of the T1GCON register. When the T1GTM
bit is cleared, the flip-flop is cleared and held clear. This
is necessary in order to control which edge is
measured.
FIGURE 13-5: TIMER1 GATE TOGGLE MODE
T1GSS<1:0> Timer1 Gate Source
00 Timer1 Gate Pin
01 Overflow of Timer0
(TMR0 increments from FFh to 00h)
10 TMR2 to Match PR2
(TMR2 increments to match PR2)
TMR1GE
T1GPOL
T1GTM
T1G_IN
T1CKI
T1GVAL
Timer1 N N + 1 N + 2 N + 3 N + 4 N + 5 N + 6 N + 7 N + 8
2011 Microchip Technology Inc. DS39931D-page 209
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13.8.4 TIMER1 GATE SINGLE PULSE
MODE
When Timer1 Gate Single Pulse mode is enabled, it is
possible to capture a single pulse gate event. Timer1
Gate Single Pulse mode is first enabled by setting the
T1GSPM bit in the T1GCON register. Next, the
T1GGO/T1DONE bit in the T1GCON register must be
set. The Timer1 will be fully enabled on the next incre-
menting edge. On the next trailing edge of the pulse,
the T1GGO/T1DONE bit will automatically be cleared.
No other gate events will be allowed to increment
Timer1 until the T1GGO/T1DONE bit is once again set
in software.
Clearing the T1GSPM bit of the T1GCON register will
also clear the T1GGO/T1DONE bit. See Figure 13-6
for timing details.
Enabling the Toggle mode and the Single Pulse mode,
simultaneously, will permit both sections to work together.
This allows the cycle times on the Timer1 gate source to
be measured. See Figure 13-7 for timing details.
13.8.5 TIMER1 GATE VALUE STATUS
When the Timer1 gate value status is utilized, it is
possible to read the most current level of the gate
control value. The value is stored in the T1GVAL bit in
the T1GCON register. The T1GVAL bit is valid even
when the Timer1 gate is not enabled (TMR1GE bit is
cleared).
FIGURE 13-6: TI MER1 GATE SINGLE PULSE MODE
TMR1GE
T1GPOL
T1G_IN
T1CKI
T1GVAL
Timer1 N N + 1 N + 2
T1GSPM
T1GGO/
T1DONE
Set by Software
Cleared by Hardware on
Falling Edge of T1GVAL
Set by Hardware on
Falling Edge of T1GVAL
Cleared by Software
Cleared by
Software
TMR1GIF
Counting Enabled on
Rising Edge of T1G
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DS39931D-page 210 2011 Microchip Technology Inc.
FIGURE 13-7: TIMER1 GATE SINGLE PULSE AND TOGGLE COMBINED MODE
TABLE 13-5: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Name Bit 7 Bit 6 Bit 5 B it 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 89
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 91
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 91
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 91
TMR1L Timer1 Register Low Byte 90
TMR1H Timer1 Register High Byte 90
T1CON TMR1CS1 TMR1CS0 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC RD16 TMR1ON 90
T1GCON TMR1GE T1GPOL T1GTM T1GSPM T1GGO/
T1DONE
T1GVAL T1GSS1 T1GSS0 91
TCLKCON T1RUN T3CCP2 T3CCP1 93
Legend: Shaded cells are not used by the Timer1 module.
Note 1: These bits are only available on 44-pin devices.
TMR1GE
T1GPOL
T1G_IN
T1CKI
T1GVAL
Timer1 NN + 1 N + 2
T1GSPM
T1GGO/
T1DONE
Set by Software
Cleared by Hardware on
Falling Edge of T1GVAL
Set by Hardware on
Falling Edge of T1GVAL
Cleared by Software
Cleared by
Software
TMR1GIF
T1GTM
Counting Enabled on
Rising Edge of T1G
N + 4
N + 3
2011 Microchip Technology Inc. DS39931D-page 211
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14.0 TIMER2 MODULE
The Timer2 module incorporates the following features:
8-bit Timer and Period registers (TMR2 and PR2,
respectively)
Readable and writable (both registers)
Software-programmable prescaler
(1:1, 1:4 and 1:16)
Software-programmable postscaler
(1:1 through 1:16)
Interrupt on TMR2 to PR2 match
Optional use as the shift clock for the
MSSP modules
The module is controlled through the T2CON register
(Register 14-1) which enables or disables the timer and
configures the prescaler and postscaler. Timer2 can be
shut off by clearing control bit, TMR2ON (T2CON<2>),
to minimize power consumption.
A simplified block diagram of the module is shown in
Figure 14-1.
14.1 Timer2 Operation
In normal operation, TMR2 is incremented from 00h on
each clock (FOSC/4). A 4-bit counter/prescaler on the
clock input gives direct input, divide-by-4 and
divide-by-16 prescale options. These are selected by
the prescaler control bits, T2CKPS<1:0>
(T2CON<1:0>). The value of TMR2 is compared to that
of the Period register, PR2, on each clock cycle. When
the two values match, the comparator generates a
match signal as the timer output. This signal also resets
the value of TMR2 to 00h on the next cycle and drives
the output counter/postscaler (see Section 14.2
“T imer2 Interrupt”).
The TMR2 and PR2 registers are both directly readable
and writable. The TMR2 register is cleared on any
device Reset, while the PR2 register initializes at FFh.
Both the prescaler and postscaler counters are cleared
on the following events:
A write to the TMR2 register
A write to the T2CON register
Any device Reset (Power-on Reset (POR), MCLR
Reset, Watchdog Timer Reset (WDTR) or
Brown-out Reset (BOR))
TMR2 is not cleared when T2CON is written.
REGISTER 14-1: T2CON: TIMER2 CONTROL REGISTER (ACCESS FCAh)
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-3 T2OUTPS<3:0>: Timer2 Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
1111 = 1:16 Postscale
bit 2 TMR2ON: Timer2 On bit
1 = Timer2 is on
0 = Timer2 is off
bit 1-0 T2CKPS<1:0>: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
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14.2 Timer2 Interrupt
Timer2 can also generate an optional device interrupt.
The Timer2 output signal (TMR2 to PR2 match) pro-
vides the input for the 4-bit output counter/postscaler.
This counter generates the TMR2 Match Interrupt Flag,
which is latched in TMR2IF (PIR1<1>). The interrupt is
enabled by setting the TMR2 Match Interrupt Enable
bit, TMR2IE (PIE1<1>).
A range of 16 postscaler options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS<3:0> (T2CON<6:3>).
14.3 Timer2 Output
The unscaled output of TMR2 is available primarily to
the ECCP modules, where it is used as a time base for
operations in PWM mode.
Timer2 can be optionally used as the shift clock source
for the MSSP modules operating in SPI mode.
Additional information is provided in Section 19.0
“Master Synchronous Serial Port (MSSP) Module”.
FIGU RE 14 -1: T IME R2 BLO CK DI AGRAM
TABLE 14-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 89
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 91
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 91
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 91
TMR2 Timer2 Register 90
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 90
PR2 Timer2 Period Register 90
Legend: = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
Note 1: These bits are only available on 44-pin devices.
Comparator
TMR2 Output
TMR2
Postscaler
Prescaler PR2
2
FOSC/4
1:1 to 1:16
1:1, 1:4, 1:16
4
T2OUTPS<3:0>
T2CKPS<1:0>
Set TMR2IF
Internal Data Bus
8
Reset
TMR2/PR2
8
8
(to PWM or MSSPx)
Match
2011 Microchip Technology Inc. DS39931D-page 213
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15.0 TIMER3 MODULE
The Timer3 timer/counter module incorporates these
features:
Software-selectable operation as a 16-bit timer or
counter
Readable and writable 8-bit registers (TMR3H
and TMR3L)
Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
Interrupt-on-overflow
Module Reset on ECCP Special Event Trigger
A simplified block diagram of the Timer3 module is
shown in Figure 15-1.
The Timer3 module is controlled through the T3CON
register (Register 15-1). It also selects the clock source
options for the ECCP modules; see Section 18.1.1
“ECCP Module and Timer Resources” for more
information.
The FOSC clock source (TMR3CS<1:0> = 01) should not
be used with the ECCP capture/compare features. If the
timer will be used with the capture or compare features,
always select one of the other timer clocking options.
REGISTER 15-1: T3CON: TIMER3 CONTROL REGISTER (ACCESS F79h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
TMR3CS1 TMR3CS0 T3CKPS1 T3CKPS0 T3OSCEN T3SYNC RD16 TMR3ON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 TMR3CS<1:0>: Timer3 Clock Source Select bits
10 = Timer3 clock source is the Timer1 oscillator or the T3CKI digital input pin (assigned in PPS module)
01 = Timer3 clock source is the system clock (FOSC)(1)
00 = Timer3 clock source is the instruction clock (FOSC/4)
bit 5-4 T3CKPS<1:0>: Timer3 Input Clock Prescale Select bits
11 = 1:8 Prescale value
10 = 1:4 Prescale value
01 = 1:2 Prescale value
00 = 1:1 Prescale value
bit 3 T3OSCEN: Timer3 Oscillator Source Select bit
When TMR3CS<1:0> = 10:
1 = Power up the Timer1 crystal driver (T1OSC) and supply the Timer3 clock from the crystal output
0 = Timer1 crystal driver is off, Timer3 clock is from the T3CKI digital input pin assigned in PPS module(2)
When TMR3CS<1:0> = 0x:
1 = Power up the Timer1 crystal driver (T1OSC)
0 = Timer1 crystal driver is off(2)
bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit
When TMR3CS<1:0> = 10:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR3CS<1:0> = 0x:
This bit is ignored; Timer3 uses the internal clock.
bit 1 RD16: 16-Bit Read/Write Mode Enable bit
1 = Enables register read/write of Timer3 in one 16-bit operation
0 = Enables register read/write of Timer3 in two 8-bit operations
bit 0 TMR3ON: Timer3 On bit
1 = Enables Timer3
0 = Stops Timer3
Note 1: The FOSC clock source should not be selected if the timer will be used with the ECCP capture/compare features.
2: The Timer1 oscillator crystal driver is powered whenever T1OSCEN (T1CON) or T3OSCEN (T3CON) = 1.
The circuit is enabled by the logical OR of these two bits. When disabled, the inverter and feedback resistor
are disabled to eliminate power drain. The TMR1ON and TMR3ON bits do not have to be enabled to power
up the crystal driver.
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DS39931D-page 214 2011 Microchip Technology Inc.
15.1 Timer3 Gate Control Register
The Timer3 Gate Control register (T3GCON), provided
in Register 14-2, is used to control the Timer3 gate.
REGISTER 15-2: T3GCON: TIMER3 GATE CONTROL REGISTER (ACCESS F97h)(1)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-x R/W-0 R/W-0
TMR3GE T3GPOL T3GTM T3GSPM T3GGO/T3DONE T3GVAL T3GSS1 T3GSS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 TMR3GE: Timer3 Gate Enable bit
If TMR3ON = 0:
This bit is ignored.
If TMR3ON = 1:
1 = Timer3 counting is controlled by the Timer3 gate function
0 = Timer3 counts regardless of Timer3 gate function
bit 6 T3GPOL: Timer3 Gate Polarity bit
1 = Timer3 gate is active-high (Timer3 counts when gate is high)
0 = Timer3 gate is active-low (Timer3 counts when gate is low)
bit 5 T3GTM: Timer3 Gate Toggle Mode bit
1 = Timer3 Gate Toggle mode is enabled.
0 = Timer3 Gate Toggle mode is disabled and toggle flip-flop is cleared
Timer3 gate flip-flop toggles on every rising edge.
bit 4 T3GSPM: Timer3 Gate Single Pulse Mode bit
1 = Timer3 Gate Single Pulse mode is enabled and is controlling Timer3 gate
0 = Timer3 Gate Single Pulse mode is disabled
bit 3 T3GGO/T3DONE: Timer3 Gate Single Pulse Acquisition Status bit
1 = Timer3 gate single pulse acquisition is ready, waiting for an edge
0 = Timer3 gate single pulse acquisition has completed or has not been started
This bit is automatically cleared when T3GSPM is cleared.
bit 2 T3GVAL: Timer3 Gate Current State bit
Indicates the current state of the Timer3 gate that could be provided to TMR3H:TMR3L. Unaffected by
Timer3 Gate Enable bit (TMR3GE).
bit 1-0 T3GSS<1:0>: Timer3 Gate Source Select bits
10 = TMR2 to match PR2 output
01 = Timer0 overflow output
00 = Timer3 gate pin (T3G)
Note 1: Programming the T3GCON prior to T3CON is recommended.
2011 Microchip Technology Inc. DS39931D-page 215
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REGISTER 15-3: TCLKCON: TIMER CLOCK CONTROL REGISTER (BANKED F52h)
U-0 U-0 U-0 R-0 U-0 U-0 R/W-0 R/W-0
T1RUN —T3CCP2T3CCP1
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4 T1RUN: Timer1 Run Status bit
1 = Device is currently clocked by T1OSC/T1CKI
0 = System clock comes from an oscillator other than T1OSC/T1CKI
bit 3-2 Unimplemented: Read as ‘0
bit 1-0 T3CCP<2:1>: ECCP Timer Assignment bits
10 = ECCP1 and ECCP2 both use Timer3 (capture/compare) and Timer4 (PWM)
01 = ECCP1 uses Timer1 (compare/capture) and Timer2 (PWM); ECCP2 uses Timer3 (capture/compare)
and Timer4 (PWM)
00 = ECCP1 and ECCP2 both use Timer1 (capture/compare) and Timer2 (PWM)
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DS39931D-page 216 2011 Microchip Technology Inc.
15.2 Timer3 Operation
Timer3 can operate in one of three modes:
•Timer
Synchronous Counter
Asynchronous Counter
Timer with Gated Control
The operating mode is determined by the clock select
bits, TMR3CSx (T3CON<7:6>). When the TMR3CSx bits
are cleared (= 00), Timer3 increments on every internal
instruction cycle (FOSC/4). When TMR3CSx = 01, the
Timer3 clock source is the system clock (FOSC), and
when it is ‘10’, Timer3 works as a counter from the
external clock from the T3CKI pin (on the rising edge
after the first falling edge) or the Timer1 oscillator.
FIGU RE 15-1: T IME R3 BL OCK DI AGRA M
TMR3H TMR3L
T3SYNC
T3CKPS<1:0>
Prescaler
1, 2, 4, 8
0
1
Synchronized
Clock Input
2
Set flag bit
TMR1IF on
Overflow TMR3(2)
TMR3ON
Note 1: ST buffer is a high-speed type when using T3CKI.
2: Timer3 register increments on the rising edge.
3: Synchronization does not operate while in Sleep.
4: If T3OSCEN = 1, the clock is from the Timer1 crystal output. If T3OSCEN = 0, the clock is from the
T3CKI digital input pin assigned in the PPS module.
T3G
FOSC/4
Internal
Clock
TMR3CS<1:0>
Synchronize(3)
det
Sleep Input
TMR3GE
0
1
00
01
10
From Timer0
From Timer2
T3GPOL
D
Q
CK
Q
0
1
T3GVAL
T3GTM
Single Pulse
Acq. Control
T3GSPM
T3GGO/T3DONE
T3GSS<1:0>
10
00
01
FOSC
Internal
Clock
Match PR2
Overflow
R
D
EN
Q
Q1
RD
T3GCON
Data Bus
det
Interrupt
TMR3GIF
Set
T3CLK
FOSC/2
Internal
Clock
D
EN
Q
T3G_IN
TMR3ON
T3CKI(1) or
T1OSC(4)
2011 Microchip Technology Inc. DS39931D-page 217
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15.3 Timer3 16-Bit Read/Write Mode
Timer3 can be configured for 16-bit reads and writes
(see Section 15.3 “Timer3 16-Bit Read/Write
Mode”). When the RD16 control bit (T3CON<1>) is
set, the address for TMR3H is mapped to a buffer reg-
ister for the high byte of Timer3. A read from TMR3L
will load the contents of the high byte of Timer3 into the
Timer3 High Byte Buffer register. This provides the user
with the ability to accurately read all 16 bits of Timer3
without having to determine whether a read of the high
byte, followed by a read of the low byte, has become
invalid due to a rollover between reads.
A write to the high byte of Timer3 must also take place
through the TMR3H Buffer register. The Timer3 high
byte is updated with the contents of TMR3H when a
write occurs to TMR3L. This allows a user to write all
16 bits to both the high and low bytes of Timer3 at once.
The high byte of Timer3 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer3 High Byte Buffer register.
Writes to TMR3H do not clear the Timer3 prescaler.
The prescaler is only cleared on writes to TMR3L.
15.4 Using the Timer1 Oscillator as the
Timer3 Clock Source
The Timer1 internal oscillator may be used as the clock
source for Timer3. The Timer1 oscillator is enabled by
setting the T1OSCEN (T1CON<3>) bit. To use it as the
Timer3 clock source, the TMR3CS bit must also be set.
As previously noted, this also configures Timer3 to
increment on every rising edge of the oscillator source.
The Timer1 oscillator is described in Section 13.0
“Tim er 1 Mod ule” .
15.5 Timer3 Gate
Timer3 can be configured to count freely or the count
can be enabled and disabled using Timer3 gate
circuitry. This is also referred to as Timer3 gate count
enable.
Timer3 gate can also be driven by multiple selectable
sources.
15.5.1 TIMER3 GATE COUNT ENABLE
The Timer3 Gate Enable mode is enabled by setting
the TMR3GE bit of the T3GCON register. The polarity
of the Timer3 Gate Enable mode is configured using
the T3GPOL bit of the T3GCON register.
When Timer3 Gate Enable mode is enabled, Timer3
will increment on the rising edge of the Timer3 clock
source. When Timer3 Gate Enable mode is disabled,
no incrementing will occur and Timer3 will hold the
current count. See Figure 15-2 for timing details.
TABLE 15-1: TIMER3 GATE ENABLE
SELECTIONS
FIGU RE 15-2: T I ME R 3 GAT E CO UN T E N AB LE M ODE
T3CLK T3GPOL T3G Timer 3 Operation
00Counts
01Holds Count
10Holds Count
11Counts
TMR3GE
T3GPOL
T3G_IN
T1CKI
T3GVAL
Timer3 NN + 1 N + 2 N + 3 N + 4
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15.5.2 TIMER3 GATE SOURCE
SELECTION
The Timer3 gate source can be selected from one of
four different sources. Source selection is controlled by
the T3GSSx bits of the T3GCON register. The polarity
for each available source is also selectable. Polarity
selection is controlled by the T3GPOL bit of the
T3GCON register.
TABLE 15-2: TIMER3 GATE SOURCES
15.5.2.1 T3G Pin Gate Operation
The T3G pin is one source for Timer3 gate control. It
can be used to supply an external source to the Timer3
gate circuitry.
15.5.2.2 Timer0 Overflow Gate Operation
When Timer0 increments from FFh to 00h, a
low-to-high pulse will automatically be generated and
internally supplied to the Timer3 gate circuitry.
15.5.2.3 Timer2 Match Gate Operation
The TMR2 register will increment until it matches the
value in the PR2 register. On the very next increment
cycle, TMR2 will be reset to 00h. When this Reset
occurs, a low-to-high pulse will automatically be
generated and internally supplied to the Timer3 gate
circuitry.
15.5.3 TIMER3 GATE TOGGLE MODE
When Timer3 Gate Toggle mode is enabled, it is
possible to measure the full cycle length of a Timer3
gate signal, as opposed to the duration of a single level
pulse.
The Timer1 gate source is routed through a flip-flop that
changes state on every incrementing edge of the
signal. See Figure 15-3 for timing details.
The T3GVAL bit will indicate when the Toggled mode is
active and the timer is counting.
Timer3 Gate Toggle mode is enabled by setting the
T3GTM bit of the T3GCON register. When the T3GTM
bit is cleared, the flip-flop is cleared and held clear. This
is necessary in order to control which edge is
measured.
FIGURE 15-3: TIMER3 GATE TOGGLE MODE
T3GSS<1:0> Timer3 Gate Source
00 Timer3 Gate Pin
01 Overflow of Timer0
(TMR0 increments from FFh to 00h)
10 TMR2 to Match PR2
(TMR2 increments to match PR2)
11 Reserved
TMR3GE
T3GPOL
T3GTM
T3G_IN
T1CKI
T3GVAL
Timer3 N N + 1 N + 2 N + 3 N + 4 N + 5 N + 6 N + 7 N + 8
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15.5.4 TIMER3 GATE SINGLE PULSE
MODE
When Timer3 Gate Single Pulse mode is enabled, it is
possible to capture a single pulse gate event. Timer3
Gate Single Pulse mode is first enabled by setting the
T3GSPM bit in the T3GCON register. Next, the
T3GGO/T3DONE bit in the T3GCON register must be
set.
The Timer3 will be fully enabled on the next increment-
ing edge. On the next trailing edge of the pulse, the
T3GGO/T3DONE bit will automatically be cleared. No
other gate events will be allowed to increment Timer3
until the T3GGO/T3DONE bit is once again set in
software.
Clearing the T3GSPM bit of the T3GCON register will
also clear the T3GGO/T3DONE bit. See Figure 15-4
for timing details.
Enabling the Toggle mode and the Single Pulse mode,
simultaneously, will permit both sections to work
together. This allows the cycle times on the Timer3 gate
source to be measured. See Figure 15-5 for timing
details.
FIGURE 15-4: TI MER3 GATE SINGLE PULSE MODE
TMR3GE
T3GPOL
T3G_IN
T1CKI
T3GVAL
Timer3 N N + 1 N + 2
T3GSPM
T3GGO/
T3DONE
Set by Software
Cleared by Hardware on
Falling Edge of T3GVAL
Set by Hardware on
Falling Edge of T3GVAL
Cleared by Software
Cleared by
Software
TMR3GIF
Counting Enabled on
Rising Edge of T3G
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FIGURE 15-5: TIMER3 GATE SINGLE PULSE AND TOGGLE COMBINED MODE
15.5.5 TIMER3 GATE VALUE STATUS
When Timer3 gate value status is utilized, it is possible
to read the most current level of the gate control value.
The value is stored in the T3GVAL bit in the T3GCON
register. The T3GVAL bit is valid even when the Timer3
gate is not enabled (TMR3GE bit is cleared).
15.5.6 TIMER3 GATE EVENT INTERRUPT
When the Timer3 gate event interrupt is enabled, it is
possible to generate an interrupt upon the completion
of a gate event. When the falling edge of T3GVAL
occurs, the TMR3GIF flag bit in the PIR3 register will be
set. If the TMR3GIE bit in the PIE3 register is set, then
an interrupt will be recognized.
The TMR3GIF flag bit operates even when the Timer3
gate is not enabled (TMR3GE bit is cleared).
TMR3GE
T3GPOL
T3G_IN
T1CKI
T3GVAL
Timer3 NN + 1 N + 2
T3GSPM
T3GGO/
T3DONE
Set by Software
Cleared by Hardware on
Falling Edge of T3GVAL
Set by Hardware on
Falling Edge of T3GVAL
Cleared by Software
Cleared by
Software
TMR3GIF
T3GTM
Counting Enabled on
Rising Edge of T3G
N + 4
N + 3
2011 Microchip Technology Inc. DS39931D-page 221
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15.6 Timer3 Interrupt
The TMR3 register pair (TMR3H:TMR3L) increments
from 0000h to FFFFh and overflows to 0000h. The
Timer3 interrupt, if enabled, is generated on overflow
and is latched in interrupt flag bit, TMR3IF (PIR2<1>).
This interrupt can be enabled or disabled by setting or
clearing the Timer3 Interrupt Enable bit, TMR3IE
(PIE2<1>).
15.7 Resetting Timer3 Using the ECCP
S pecial Event Trigger
If ECCP1 or ECCP2 is configured to use Timer3 and to
generate a Special Event Trigger in Compare mode
(CCPxM<3:0> = 1011), this signal will reset Timer3.
The trigger from ECCP2 will also start an A/D conver-
sion if the A/D module is enabled (see Section 18.3.4
“Special Event Trigger” for more information).
The module must be configured as either a timer or
synchronous counter to take advantage of this feature.
When used this way, the CCPRxH:CCPRxL register
pair effectively becomes a Period register for Timer3.
If Timer3 is running in Asynchronous Counter mode,
the Reset operation may not work.
In the event that a write to Timer3 coincides with a
Special Event Trigger from an ECCP module, the write
will take precedence.
TABLE 15-3: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Note: The Special Event Triggers from the
ECCPx module will not set the TMR3IF
interrupt flag bit (PIR1<0>).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 89
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 91
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 91
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 91
TMR3L Timer3 Register Low Byte 92
TMR3H Timer3 Register High Byte 92
T1CON TMR1CS1 TMR1CS0 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC RD16 TMR1ON 90
T3CON TMR3CS1 TMR3CS0 T3CKPS1 T3CKPS0 T3OSCEN T3SYNC RD16 TMR3ON 92
T3GCON TMR3GE T3GPOL T3GTM T3GSPM T3GGO/
T3DONE
T3GVAL T3GSS1 T3GSS0 92
TCLKCON T1RUN T3CCP2 T3CCP1 93
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 91
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 91
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 91
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.
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DS39931D-page 222 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 223
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16.0 TIMER4 MODULE
The Timer4 timer module has the following features:
8-Bit Timer register (TMR4)
8-Bit Period register (PR4)
Readable and writable (both registers)
Software-programmable prescaler (1:1, 1:4, 1:16)
Software-programmable postscaler (1:1 to 1:16)
Interrupt on TMR4 match of PR4
Timer4 has a control register shown in Register 16-1.
Timer4 can be shut off by clearing control bit, TMR4ON
(T4CON<2>), to minimize power consumption. The
prescaler and postscaler selection of Timer4 is also
controlled by this register. Figure 16-1 is a simplified
block diagram of the Timer4 module.
16.1 Timer4 Operation
Timer4 can be used as the PWM time base for the
PWM mode of the ECCP modules. The TMR4 register
is readable and writable and is cleared on any device
Reset. The input clock (FOSC/4) has a prescale option
of 1:1, 1:4 or 1:16, selected by control bits,
T4CKPS<1:0> (T4CON<1:0>). The match output of
TMR4 goes through a 4-bit postscaler (which gives a
1:1 to 1:16 scaling inclusive) to generate a TMR4
interrupt, latched in flag bit, TMR4IF (PIR3<3>).
The prescaler and postscaler counters are cleared
when any of the following occurs:
A write to the TMR4 register
A write to the T4CON register
Any device Reset (Power-on Reset (POR), MCLR
Reset, Watchdog Timer Reset (WDTR) or
Brown-out Reset (BOR))
TMR4 is not cleared when T4CON is written.
REGISTER 16-1: T4CON: TIMER4 CONTROL REGISTER (ACCESS F76h)
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-3 T4OUTPS<3:0>: Timer4 Output Postscale Select bits
0000 = 1:1 Postscale
0001 = 1:2 Postscale
1111 = 1:16 Postscale
bit 2 TMR4ON: Timer4 On bit
1 = Timer4 is on
0 = Timer4 is off
bit 1-0 T4CKPS<1:0>: Timer4 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
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DS39931D-page 224 2011 Microchip Technology Inc.
16.2 Timer4 Interrupt
The Timer4 module has an 8-bit Period register, PR4,
which is both readable and writable. Timer4 increments
from 00h until it matches PR4 and then resets to 00h on
the next increment cycle. The PR4 register is initialized
to FFh upon Reset.
16.3 Output of TMR4
The output of TMR4 (before the postscaler) is used
only as a PWM time base for the ECCP modules. It is
not used as a baud rate clock for the MSSP modules as
is the Timer2 output.
FIGU RE 16 -1: T IME R4 BLO CK DI AGRAM
TABLE 16-1: REGISTERS ASSOCIATED WITH TIMER4 AS A TIMER/COUNTER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 89
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 91
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 91
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 91
TMR4 Timer4 Register 92
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 92
PR4 Timer4 Period Register 92
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer4 module.
Comparator
TMR4 Output
TMR4
Postscaler
Prescaler PR4
2
FOSC/4
1:1 to 1:16
1:1, 1:4, 1:16
4
T4OUTPS<3:0>
T4CKPS<1:0>
Set TMR4IF
Internal Data Bus
8
Reset
TMR4/PR4
8
8
(to PWM)
Match
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17.0 REAL-TIME CLOCK AND
CALENDAR (RTCC)
The key features of the Real-Time Clock and Calendar
(RTCC) module are:
Time: hours, minutes and seconds
24-hour format (military time)
Calendar: weekday, date, month and year
Alarm configurable
Year range: 2000 to 2099
Leap year correction
BCD format for compact firmware
Optimized for low-power operation
User calibration with auto-adjust
Calibration range: 2.64 seconds error per month
Requirements: external 32.768 kHz clock crystal
Alarm pulse or seconds clock output on RTCC pin
The RTCC module is intended for applications where
accurate time must be maintained for an extended
period with minimum to no intervention from the CPU.
The module is optimized for low-power usage in order
to provide extended battery life while keeping track of
time.
The module is a 100-year clock and calendar with auto-
matic leap year detection. The range of the clock is
from 00:00:00 (midnight) on January 1, 2000 to
23:59:59 on December 31, 2099. Hours are measured
in 24-hour (military time) format. The clock provides a
granularity of one second with half-second visibility to
the user.
FIGU RE 17-1: RTC C B LOC K DI AG R AM
RTCC Prescalers
RTCC Timer
Comparator
Compare Registers
Repeat Counter
YEAR
MTHDY
WKDYHR
MINSEC
ALMTHDY
ALWDHR
ALMINSEC
with Masks
RTCC Interrupt Logic
RTCCFG
ALRMRPT
Alarm
Event
0.5s
RTCC Clock Domain
Alarm Pulse
RTCC Interrupt
CPU Clock Domain
RTCVAL
ALRMVAL
RTCC Pin
RTCOE
Internal RC
32.768 kHz Input
from Timer1 Oscillator
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DS39931D-page 226 2011 Microchip Technology Inc.
17.1 RTCC MODULE REGISTE RS
The RTCC module registers are divided into following
categories:
RTCC Control Registers
RTCCFG
RTCCAL
PADCFG1
•ALRMCFG
•ALRMRPT
RTCC Value Registers
RTCVALH and RTCVALL – Can access the
following registers
- YEAR
-MONTH
-DAY
- WEEKDAY
-HOUR
- MINUTE
- SECOND
Alarm Value Registers
ALRMVALH and ALRMVALL – Can access the
following registers:
- ALRMMNTH
-ALRMDAY
-ALRMWD
-ALRMHR
- ALRMMIN
- ALRMSEC
Note: The RTCVALH and RTCVALL registers
can be accessed through RTCRPT<1:0>.
ALRMVALH and ALRMVALL can be
accessed through ALRMPTR<1:0>.
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17.1.1 RTCC CONTROL REGISTERS
REGISTER 17-1: RTCCFG: RTCC CONFIGURATION REGISTER (BANKED F3Fh)(1)
R/W-0 U-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0
RTCEN(2) RTCWREN RTCSYNC HALFSEC(3) RTCOE RTCPTR1 RTCPTR0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 RTCEN: RTCC Enable bit(2)
1 = RTCC module is enabled
0 = RTCC module is disabled
bit 6 Unimplemented: Read as ‘0
bit 5 RTCWREN: RTCC Value Registers Write Enable bit
1 = RTCVALH and RTCVALL registers can be written to by the user
0 = RTCVALH and RTCVALL registers are locked out from being written to by the user
bit 4 RTCSYNC: RTCC Value Registers Read Synchronization bit
1 = RTCVALH, RTCVALL and ALCFGRPT registers can change while reading due to a rollover ripple
resulting in an invalid data read
If the register is read twice and results in the same data, the data can be assumed to be valid.
0 = RTCVALH, RTCVALL or ALCFGRPT registers can be read without concern over a rollover ripple
bit 3 HALFSEC: Half-Second Status bit(3)
1 = Second half period of a second
0 = First half period of a second
bit 2 RTCOE: RTCC Output Enable bit
1 = RTCC clock output is enabled
0 = RTCC clock output is disabled
bit 1-0 RTCPTR<1:0>: RTCC Value Register Window Pointer bits
Points to the corresponding RTCC Value registers when reading the RTCVALH and RTCVALL registers;
the RTCPTR<1:0> value decrements on every read or write of RTCVALH until it reaches ‘00’.
RTCVAL<15:8>:
00 = Minutes
01 = Weekday
10 = Month
11 = Reserved
RTCVAL<7:0>:
00 = Seconds
01 = Hours
10 = Day
11 = Year
Note 1: The RTCCFG register is only affected by a POR.
2: A write to the RTCEN bit is only allowed when RTCWREN = 1.
3: This bit is read-only. It is cleared to ‘0 on a write to the lower half of the MINSEC register.
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REGISTER 17-2: RTCCA L: RTCC CALIBRATION REGISTER (BANKED F3Eh)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 CAL<7:0>: RTC Drift Calibration bits
01111111 = Maximum positive adjustment; adds 508 RTC clock pulses every minute
.
.
.
00000001 = Minimum positive adjustment; adds four RTC clock pulses every minute
00000000 = No adjustment
11111111 = Minimum negative adjustment; subtracts four RTC clock pulses every minute
.
.
.
10000000 = Maximum negative adjustment; subtracts 512 RTC clock pulses every minute
REGISTER 17-3: PADCFG1: PAD CONFIGURATION REGISTER (BANKED F3Ch)
U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0 R/W-0
RTSECSEL1(1) RTSECSEL0(1) PMPTTL
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-3 Unimplemented: Read as ‘0
bit 2-1 RTSECSEL<1:0>: RTCC Seconds Clock Output Select bits(1)
11 = Reserved; do not use
10 = RTCC source clock is selected for the RTCC pin (pin can be INTRC or T1OSC, depending on the
RTCOSC (CONFIG3L<1>) setting)
01 = RTCC seconds clock is selected for the RTCC pin
00 = RTCC alarm pulse is selected for the RTCC pin
bit 0 PMPTTL: PMP Module TTL Input Buffer Select bit
1 = PMP module uses TTL input buffers
0 = PMP module uses Schmitt input buffers
Note 1: To enable the actual RTCC output, the RTCOE (RTCCFG<2>) bit must be set.
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REGISTER 17-4: ALRMCFG: ALARM CONFIGURATION REGISTER (ACCESS F91h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ALRMEN CHIME AMASK3 AMASK2 AMASK1 AMASK0 ALRMPTR1 ALRMPTR0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ALRMEN: Alarm Enable bit
1 = Alarm is enabled (cleared automatically after an alarm event whenever ARPT<7:0> = 0000 0000
and CHIME = 0)
0 = Alarm is disabled
bit 6 CHIME: Chime Enable bit
1 = Chime is enabled; ARPT<7:0> bits are allowed to roll over from 00h to FFh
0 = Chime is disabled; ARPT<7:0> bits stop once they reach 00h
bit 5-2 AMASK<3:0>: Alarm Mask Configuration bits
0000 = Every half second
0001 = Every second
0010 = Every 10 seconds
0011 = Every minute
0100 = Every 10 minutes
0101 = Every hour
0110 = Once a day
0111 = Once a week
1000 = Once a month
1001 = Once a year (except when configured for February 29th, once every four years)
101x = Reserved – do not use
11xx = Reserved – do not use
bit 1-0 ALRMPTR<1:0>: Alarm Value Register Window Pointer bits
Points to the corresponding Alarm Value registers when reading the ALRMVALH and ALRMVALL
registers. The ALRMPTR<1:0> value decrements on every read or write of ALRMVALH until it reaches
00’.
ALRMVAL<15:8>:
00 = ALRMMIN
01 =ALRMWD
10 =ALRMMNTH
11 = Unimplemented
ALRMVAL<7:0>:
00 = ALRMSEC
01 =ALRMHR
10 =ALRMDAY
11 = Unimplemented
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REGISTER 17-5: ALRMRPT: ALARM REPEAT COUNTER REGISTER (ACCESS F90h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ARPT7 ARPT6 ARPT5 ARPT4 ARPT3 ARPT2 ARPT1 ARPT0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 ARPT<7:0>: Alarm Repeat Counter Value bits
11111111 = Alarm will repeat 255 more times
.
.
.
00000000 = Alarm will not repeat
The counter decrements on any alarm event. The counter is prevented from rolling over from 00h to
FFh unless CHIME = 1.
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17.1.2 RTCVALH AND RTCVALL
REGISTER MAPPINGS
REGISTER 17-6: RESERVED REGISTER (ACCESS F99h, PTR 11b)
U-0 U-0 U-0 U-0 U-0 U-0 U-0 U-0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 Unimplemented: Read as ‘0
REGISTER 17-7: YEAR: YEAR VALUE REGISTER (ACCESS F98h, PTR 11b)(1)
R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
YRTEN3 YRTEN2 YRTEN1 YRTEN0 YRONE3 YRONE2 YRONE1 YRONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 YRTEN<3:0>: Binary Coded Decimal Value of Year’s Tens Digit bits
Contains a value from 0 to 9.
bit 3-0 YRONE<3:0>: Binary Coded Decimal Value of Year’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to the YEAR register is only allowed when RTCWREN = 1.
REGISTER 17-8: MONTH: MONTH VALUE REGISTER (ACCESS F99h, PTR 10b)(1)
U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x
MTHTEN0 MTHONE3 MTHONE2 MTHONE1 MTHONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4 MTHTEN0: Binary Coded Decimal Value of Month’s Tens Digit bit
Contains a value of 0 or 1.
bit 3-0 MTHONE<3:0>: Binary Coded Decimal Value of Month’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to this register is only allowed when RTCWREN = 1.
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REGISTER 17-9: DAY: DAY VALUE REGISTER (ACCESS F98h, PTR 10b)(1)
U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
DAYTEN1 DAYTEN0 DAYONE3 DAYONE2 DAYONE1 DAYONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as ‘0
bit 5-4 DAYTEN<1:0>: Binary Coded Decimal value of Day’s Tens Digit bits
Contains a value from 0 to 3.
bit 3-0 DAYONE<3:0>: Binary Coded Decimal Value of Day’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to this register is only allowed when RTCWREN = 1.
REGISTER 17-10: WKDY: WEEKDAY VALUE REGISTER (ACCESS F99h, PTR 01b)(1)
U-0 U-0 U-0 U-0 U-0 R/W-x R/W-x R/W-x
WDAY2 WDAY1 WDAY0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-3 Unimplemented: Read as ‘0
bit 2-0 WDAY<2:0>: Binary Coded Decimal Value of Weekday Digit bits
Contains a value from 0 to 6.
Note 1: A write to this register is only allowed when RTCWREN = 1.
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REGISTER 17-11: HOURS: HOURS VALUE REGISTER (ACCESS F98h, PTR 01b)(1)
U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
HRTEN1 HRTEN0 HRONE3 HRONE2 HRONE1 HRONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as ‘0
bit 5-4 HRTEN<1:0>: Binary Coded Decimal Value of Hour’s Tens Digit bits
Contains a value from 0 to 2.
bit 3-0 HRONE<3:0>: Binary Coded Decimal Value of Hour’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to this register is only allowed when RTCWREN = 1.
REGISTER 17-12: MIN UTES: MINUTES VALUE REGISTER (ACCESS F99h, PTR 00b)
U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
MINTEN2 MINTEN1 MINTEN0 MINONE3 MINONE2 MINONE1 MINONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-4 MINTEN<2:0>: Binary Coded Decimal Value of Minute’s Tens Digit bits
Contains a value from 0 to 5.
bit 3-0 MINONE<3:0>: Binary Coded Decimal Value of Minute’s Ones Digit bits
Contains a value from 0 to 9.
REGISTER 17-13: SECONDS: SECONDS VALUE REGISTER (ACCESS F98h, PTR 00b)
U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
SECTEN2 SECTEN1 SECTEN0 SECONE3 SECONE2 SECONE1 SECONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-4 SECTEN<2:0>: Binary Coded Decimal Value of Second’s Tens Digit bits
Contains a value from 0 to 5.
bit 3-0 SECONE<3:0>: Binary Coded Decimal Value of Second’s Ones Digit bits
Contains a value from 0 to 9.
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17.1.3 ALRMVALH AND ALRMVALL
REGISTER MAPPINGS
REGISTER 17-14: ALRMMNTH: ALARM MONTH VALUE REGISTER (ACCESS F8Fh, PTR 10b)(1)
U-0 U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x
MTHTEN0 MTHONE3 MTHONE2 MTHONE1 MTHONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4 MTHTEN0: Binary Coded Decimal Value of Month’s Tens Digit bit
Contains a value of 0 or 1.
bit 3-0 MTHONE<3:0>: Binary Coded Decimal Value of Month’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to this register is only allowed when RTCWREN = 1.
REGISTER 17-15: ALRMDAY: ALARM DAY VALUE REGISTER (ACCESS F8Eh, PTR 10b)(1)
U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
DAYTEN1 DAYTEN0 DAYONE3 DAYONE2 DAYONE1 DAYONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as ‘0
bit 5-4 DAYTEN<1:0>: Binary Coded Decimal Value of Day’s Tens Digit bits
Contains a value from 0 to 3.
bit 3-0 DAYONE<3:0>: Binary Coded Decimal Value of Day’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to this register is only allowed when RTCWREN = 1.
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REGISTER 17-16: ALRMWD: ALARM WEEKDAY VALUE REGISTER (ACCESS F8Fh, PTR 01b)(1)
U-0 U-0 U-0 U-0 U-0 R/W-x R/W-x R/W-x
WDAY2 WDAY1 WDAY0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-3 Unimplemented: Read as ‘0
bit 2-0 WDAY<2:0>: Binary Coded Decimal Value of Weekday Digit bits
Contains a value from 0 to 6.
Note 1: A write to this register is only allowed when RTCWREN = 1.
REGISTER 17-17: ALRMHR: ALARM HOURS VALUE REGISTER (ACCESS F8Eh, PTR 01b)(1)
U-0 U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
HRTEN1 HRTEN0 HRONE3 HRONE2 HRONE1 HRONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 Unimplemented: Read as ‘0
bit 5-4 HRTEN<1:0>: Binary Coded Decimal Value of Hour’s Tens Digit bits
Contains a value from 0 to 2.
bit 3-0 HRONE3:HRONE0: Binary Coded Decimal Value of Hour’s Ones Digit bits
Contains a value from 0 to 9.
Note 1: A write to this register is only allowed when RTCWREN = 1.
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REGISTER 17-18: ALRMMIN: ALARM MINUTES VALUE REGISTER (ACCESS F8Fh, PTR 00b)
U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
MINTEN2 MINTEN1 MINTEN0 MINONE3 MINONE2 MINONE1 MINONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-4 MINTEN<2:0>: Binary Coded Decimal Value of Minute’s Tens Digit bits
Contains a value from 0 to 5.
bit 3-0 MINONE<3:0>: Binary Coded Decimal Value of Minute’s Ones Digit bits
Contains a value from 0 to 9.
REGISTER 17-19: ALRMSEC: ALARM SECONDS VALUE REGISTER (ACCESS F8Eh, PTR 00b)
U-0 R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
SECTEN2 SECTEN1 SECTEN0 SECONE3 SECONE2 SECONE1 SECONE0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-4 SECTEN<2:0>: Binary Coded Decimal Value of Second’s Tens Digit bits
Contains a value from 0 to 5.
bit 3-0 SECONE<3:0>: Binary Coded Decimal Value of Second’s Ones Digit bits
Contains a value from 0 to 9.
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17.1.4 RTCEN BIT WRITE
An attempt to write to the RTCEN bit while
RTCWREN = 0 will be ignored. RTCWREN must be
set before a write to RTCEN can take place.
Like the RTCEN bit, the RTCVALH and RTCVALL
registers can only be written to when RTCWREN = 1.
A write to these registers, while RTCWREN = 0, will be
ignored.
17.2 Operation
17.2.1 REGISTER INTERFACE
The register interface for the RTCC and alarm values is
implemented using the Binary Coded Decimal (BCD)
format. This simplifies the firmware, when using the
module, as each of the digits is contained within its own
4-bit value (see Figure 17-2 and Figure 17-3).
FIGURE 17-2: TIMER DIGIT FORMAT
FIGURE 17-3: ALARM DIGIT FORMAT
0-60-9 0-9 0-3 0-9
0-9 0-9 0-90-2 0-5 0-5 0/1
Day Of WeekYear Day
Hours
(24-hour format) Minutes Seconds 1/2 Second Bit
0-1 0-9
Month
(binary format)
0-60-3 0-9
0-9 0-9 0-90-2 0-5 0-5
Day Of WeekDay
Hours
(24-hour format) Minutes Seconds
0-1 0-9
Month
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17.2.2 CLOCK SOURCE
As mentioned earlier, the RTCC module is intended to
be clocked by an external Real-Time Clock (RTC) crystal
oscillating at 32.768 kHz, but can also be clocked by the
INTRC. The RTCC clock selection is decided by the
RTCOSC bit (CONFIG3L<1>).
Calibration of the crystal can be done through this
module to yield an error of 3 seconds or less per month.
(For further details, see Section 17.2.9 “Calibration.)
FIGURE 17-4: CLOCK SOURCE MULTIPLEXING
17.2.2.1 Real-Time Clock Enable
The RTCC module can be clocked by an external,
32.768 kHz crystal (Timer1 oscillator or T1CKI input) or
the INTRC oscillator, which can be selected in
CONFIG3L<1>.
If the Timer1 oscillator will be used as the clock source
for the RTCC, make sure to enable it by setting
T1CON<3> (T1OSCEN). The selected RTC clock can
be brought out to the RTCC pin by the
RTSECSEL<1:0> bits in the PADCFG register.
17.2.3 DIGIT CARRY RULES
This section explains which timer values are affected
when there is a rollover.
Time of Day: From 23:59:59 to 00:00:00 with a
carry to the Day field
Month: From 12/31 to 01/01 with a carry to the
Year field
Day of Week: From 6 to 0 with no carry (see
Table 17-1)
Year Carry: From 99 to 00; this also surpasses the
use of the RTCC
For the day to month rollover schedule, see Table 17-2.
Considering that the following values are in BCD
format, the carry to the upper BCD digit will occur at a
count of 10 and not at 16 (SECONDS, MINUTES,
HOURS, WEEKDAY, DAYS and MONTHS).
TABLE 17-1: DAY OF WEEK SCHEDULE
Note 1: Writing to the lower half of the MINSEC register resets all counters, allowing fraction of a second synchronization;
clock prescaler is held in Reset when RTCEN = 0.
32.768 kHz XTAL
1:16384
Half Second(1)
Half-Second
Clock One-Second Clock
Year
Month
Day
Day of Week
Second Hour:Minute
Clock Prescaler(1)
from T1OSC
Internal RC
CONFIG 3L<1>
Day of Week
Sunday 0
Monday 1
Tuesday 2
Wednesday 3
Thursday 4
Friday 5
Saturday 6
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TABLE 17-2: DAY TO MONTH ROLLOVER
SCHEDULE
17.2.4 LEAP YEAR
Since the year range on the RTCC module is 2000 to
2099, the leap year calculation is determined by any
year divisible by ‘4’ in the above range. Only February
is effected in a leap year.
February will have 29 days in a leap year and 28 days in
any other year.
17.2.5 GENERAL FUNCTIONALITY
All Timer registers containing a time value of seconds or
greater are writable. The user configures the time by
writing the required year, month, day, hour, minutes and
seconds to the Timer registers, via Register Pointers
(see Section 17.2.8 “Register Mapping”).
The timer uses the newly written values and proceeds
with the count from the required starting point.
The RTCC is enabled by setting the RTCEN bit
(RTCCFGL<7>). If enabled, while adjusting these
registers, the timer still continues to increment. However,
any time the MINSEC register is written to, both of the
timer prescalers are reset to ‘0’. This allows fraction of a
second synchronization.
The Timer registers are updated in the same cycle as
the write instruction’s execution by the CPU. The user
must ensure that when RTCEN = 1, the updated
registers will not be incremented at the same time. This
can be accomplished in several ways:
By checking the RTCSYNC bit (RTCCFG<4>)
By checking the preceding digits from which a
carry can occur
By updating the registers immediately following
the seconds pulse (or alarm interrupt)
The user has visibility to the half-second field of the
counter. This value is read-only and can be reset only
by writing to the lower half of the SECONDS register.
17.2.6 SAFETY WINDOW FOR REGISTER
READS AND WRITES
The RTCSYNC bit indicates a time window during
which the RTCC Clock Domain registers can be safely
read and written without concern about a rollover.
When RTCSYNC = 0, the registers can be safely
accessed by the CPU.
Whether RTCSYNC = 1 or 0, the user should employ a
firmware solution to ensure that the data read did not
fall on a rollover boundary, resulting in an invalid or
partial read. This firmware solution would consist of
reading each register twice and then comparing the two
values. If the two values matched, then, a rollover did
not occur.
17.2.7 WRITE LOCK
In order to perform a write to any of the RTCC Timer
registers, the RTCWREN bit (RTCCFG<5>) must be
set.
To avoid accidental writes to the RTCC Timer register, it
is recommended that the RTCWREN bit (RTCCFG<5>)
be kept clear at any time other than while writing to. For
the RTCWREN bit to be set, there is only one instruction
cycle time window allowed between the 55h/AA
sequence and the setting of RTCWREN. For that
reason, it is recommended that users follow the code
example in Example 17-1.
EX A M P L E 1 7 - 1 : SETTING THE
RTCWREN BIT
17.2.8 REGISTER MAPPING
To limit the register interface, the RTCC Timer and
Alarm Timer registers are accessed through
corresponding Register Pointers. The RTCC Value reg-
ister window (RTCVALH<15:8> and RTCVALL<7:0>)
uses the RTCPTR bits (RTCCFG<1:0>) to select the
required Timer register pair.
By reading or writing to the RTCVALH register, the
RTCC Pointer value (RTCPTR<1:0>) decrements by 1
until it reaches ‘00’. Once it reaches ‘00’, the MINUTES
and SECONDS value will be accessible through
RTCVALH and RTCVALL until the pointer value is
manually changed.
Month Maxim um D ay Field
01 (January) 31
02 (February) 28 or 29(1)
03 (March) 31
04 (April) 30
05 (May) 31
06 (June) 30
07 (July) 31
08 (August) 31
09 (September) 30
10 (October) 31
11 (November) 30
12 (December) 31
Note 1: See Section 17.2.4 “Leap Year”.
movlb 0x0F ;RTCCFG is banked
bcf INTCON, GIE ;Disable interrupts
movlw 0x55
movwf EECON2
movlw 0xAA
movwf EECON2
bsf RTCCFG,RTCWREN
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TABLE 17-3: RTCVALH AND RTCVALL
REGISTER MAPPING
The Alarm Value register window (ALRMVALH and
ALRMVALL) uses the ALRMPTR bits (ALRMCFG<1:0>)
to select the desired Alarm register pair.
By reading or writing to the ALRMVALH register, the
Alarm Pointer value, ALRMPTR<1:0>, decrements
by 1 until it reaches ‘00’. Once it reaches ‘00’, the
ALRMMIN and ALRMSEC value will be accessible
through ALRMVALH and ALRMVALL until the pointer
value is manually changed.
TABLE 17-4: ALRMVAL REGISTER
MAPPING
17.2.9 CALIBRATION
The real-time crystal input can be calibrated using the
periodic auto-adjust feature. When properly calibrated,
the RTCC can provide an error of less than three
seconds per month.
To perform this calibration, find the number of error
clock pulses and store the value in the lower half of the
RTCCAL register. The 8-bit, signed value – loaded into
RTCCAL – is multiplied by ‘4’ and will either be added
or subtracted from the RTCC timer, once every minute.
To calibrate the RTCC module:
1. Use another timer resource on the device to find
the error of the 32.768 kHz crystal.
2. Convert the number of error clock pulses per
minute (see Equation 17-1).
EQUATION 17-1: CONVERTING ERROR
CLOCK PULSES
If the oscillator is faster than ideal (negative
result from Step 2), the RCFGCALL register
value needs to be negative. This causes the
specified number of clock pulses to be
subtracted from the timer counter once every
minute.
If the oscillator is slower than ideal (positive
result from Step 2), the RCFGCALL register
value needs to be positive. This causes the
specified number of clock pulses to be added to
the timer counter once every minute.
3. Load the RTCCAL register with the correct
value.
Writes to the RTCCAL register should occur only when
the timer is turned off, or immediately after the rising
edge of the seconds pulse.
RTCPTR<1:0> RTCC Value Register Window
RTCVAL<15:8> RTCVAL<7:0>
00 MINUTES SECONDS
01 WEEKDAY HOURS
10 MONTH DAY
11 YEAR
ALRMPTR<1:0> Alarm Value Register Window
ALRMVAL<15:8> ALRMVAL<7:0>
00 ALRMMIN ALRMSEC
01 ALRMWD ALRMHR
10 ALRMMNTH ALRMDAY
11 ——
Note: In determining the crystal’s error value, it
is the user’s responsibility to include the
crystal’s initial error from drift due to
temperature or crystal aging.
(Ideal Frequency (32,768) – Measured Frequency) *
60 = Error Clocks per Minute
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17.3 Alarm
The alarm features and characteristics are:
Configurable from half a second to one year
Enabled using the ALRMEN bit (ALRMCFG<7>,
Register 17-4)
Offers one-time and repeat alarm options
17.3.1 CONFIGURING THE ALARM
The alarm feature is enabled using the ALRMEN bit.
This bit is cleared when an alarm is issued. The bit will
not be cleared if the CHIME bit = 1 or if ALRMRPT 0.
The interval selection of the alarm is configured
through the ALRMCFG bits (AMASK<3:0>). (See
Figure 17-5.) These bits determine which and how
many digits of the alarm must match the clock value for
the alarm to occur.
The alarm can also be configured to repeat based on a
preconfigured interval. The number of times this occurs
after the alarm is enabled is stored in the ALRMRPT
register.
FIGURE 17-5: A LARM M ASK SE TTINGS
Note: While the alarm is enabled (ALRMEN = 1),
changing any of the registers, other than
the RTCCAL, ALRMCFG and ALRMRPT
registers, and the CHIME bit, can result in
a false alarm event leading to a false alarm
interrupt. To avoid this, only change the
timer and alarm values while the alarm is
disabled (ALRMEN = 0). It is recom-
mended that the ALRMCFG and
ALRMRPT registers, and CHIME bit be
changed when RTCSYNC = 0.
Note 1: Annually, except when configured for February 29.
s
ss
mss
mm s s
hh mm ss
dhhmmss
dd hh mm ss
mm d d h h mm s s
Day of the
Week Month Day Hours Minutes Seconds
Alarm Mask Setting
AMASK<3:0>
0000 – Every half second
0001 – Every second
0010 – Every 10 seconds
0011 – Every minute
0100 – Every 10 minutes
0101 – Every hour
0110 – Every day
0111 – Every week
1000 – Every month
1001 – Every year(1)
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When ALRMCFG = 00 and the CHIME bit = 0
(ALRMCFG<6>), the repeat function is disabled and
only a single alarm will occur. The alarm can be
repeated up to 255 times by loading the ALRMRPT
register with FFh.
After each alarm is issued, the ALRMRPT register is
decremented by one. Once the register has reached
00’, the alarm will be issued one last time.
After the alarm is issued a last time, the ALRMEN bit is
cleared automatically and the alarm turned off. Indefinite
repetition of the alarm can occur if the CHIME bit = 1.
When CHIME = 1, the alarm is not disabled when the
ALRMRPT register reaches ‘00’, but it rolls over to FF
and continues counting indefinitely.
17.3.2 ALARM INTERRUPT
At every alarm event, an interrupt is generated. Addi-
tionally, an alarm pulse output is provided that operates
at half the frequency of the alarm.
The alarm pulse output is completely synchronous with
the RTCC clock and can be used as a trigger clock to
other peripherals. This output is available on the RTCC
pin. The output pulse is a clock with a 50% duty cycle
and a frequency half that of the alarm event (see
Figure 17-6).
The RTCC pin also can output the seconds clock. The
user can select between the alarm pulse, generated by
the RTCC module, or the seconds clock output.
The RTSECSEL (PADCFG1<2:1>) bits select between
these two outputs:
Alarm pulse – RTSECSEL<2:1> = 00
Seconds clock – RTSECSEL<2:1> = 0
FI GU RE 1 7 - 6 : TIMER PULSE GENERA TION
17.4 Low-Power Modes
The timer and alarm can optionally continue to operate
while in Sleep, Idle and even Deep Sleep mode. An
alarm event can be used to wake-up the microcontroller
from any of these Low-Power modes.
17.5 Reset
17.5.1 DEVICE RESET
When a device Reset occurs, the ALRMCFG and
ALRMRPT registers are forced to the Reset state,
causing the alarm to be disabled (if enabled prior to the
Reset). If the RTCC was enabled, it will continue to
operate when a basic device Reset occurs.
17.5.2 POWER-ON RESET (POR)
The RTCCFG and ALRMRPT registers are reset only
on a POR. Once the device exits the POR state, the
clock registers should be reloaded with the desired
values.
The timer prescaler values can be reset only by writing
to the SECONDS register. No device Reset can affect
the prescalers.
RTCEN bit
ALRMEN bit
RTCC Alarm Event
RTCC Pin
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17.6 Register Maps
Table 17-5, Table 17-6 and Table 17-7 summarize the
registers associated with the RTCC module.
TABLE 17-5: RTCC CONTROL REGISTERS
File N a m e Bit 7 Bit 6 B it 5 Bit 4 B it 3 Bit 2 Bit 1 Bit 0 All
Resets
RTCCFG RTCEN RTCWREN RTCSYNC HALFSEC RTCOE RTCPTR1 RTCPTR0 0000
RTCCAL CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0 0000
PADCFG1 RTSECSEL1 RTSECSEL0 PMPTTL 0000
ALRMCFG ALRMEN CHIME AMASK3 AMASK2 AMASK1 AMASK0 ALRMPTR1 ALRMPTR0 0000
ALRMRPT ARPT7 ARPT6 ARPT5 ARPT4 ARPT3 ARPT2 ARPT1 ARPT0 0000
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCCIF 0000
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCCIE 0000
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCCIP 0000
Legend: — = unimplemented, read as ‘0’. Reset values are shown in hexadecimal for 44-pin devices.
TABLE 17-6: RTCC VALUE REGISTERS
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 B it 1 Bit 0 All Reset s
RTCVALH RTCC Value Register Window High Byte, Based on RTCPTR<1:0> xxxx
RTCVALL RTCC Value Register Window Low Byte, Based on RTCPTR<1:0> xxxx
RTCCFG RTCEN RTCWREN RTCSYNC HALFSEC RTCOE RTCPTR1 RTCPTR0 0000
ALRMCFG ALRMEN CHIME AMASK3 AMASK2 AMASK1 AMASK0 ALRMPTR1 ALRMPTR0 0000
ALRMVALH Alarm Value Register Window High Byte, Based on ALRMPTR<1:0> xxxx
ALRMVALL Alarm Value Register Window Low Byte, Based on ALRMPTR<1:0> xxxx
Legend: — = unimplemented, read as ‘0’. Reset values are shown in hexadecimal for 44-pin devices.
TABLE 17-7: ALARM VALUE REGISTERS
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 All
Resets
ALRMRPT ARPT7 ARPT6 ARPT5 ARPT4 ARPT3 ARPT2 ARPT1 ARPT0 0000
ALRMVALH Alarm Value Register Window High Byte, Based on ALRMPTR<1:0> xxxx
ALRMVALL Alarm Value Register Window Low Byte, Based on ALRMPTR<1:0> xxxx
RTCCAL CAL7 CAL6 CAL5 CAL4 CAL3 CAL2 CAL1 CAL0 0000
RTCVALH RTCC Value Register Window High Byte, Based on RTCPTR<1:0> xxxx
RTCVALL RTCC Value Register Window Low Byte, Based on RTCPTR<1:0> xxxx
Legend: — = unimplemented, read as ‘0’. Reset values are shown in hexadecimal for 44-pin devices.
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NOTES:
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18.0 ENHANCED
CAPTURE/COMPARE/PWM
(ECCP) MODULE
PIC18F46J50 family devices have two Enhanced
Capture/Compare/PWM (ECCP) modules: ECCP1 and
ECCP2. These modules contain a 16-bit register, which
can operate as a 16-bit Capture register, a 16-bit
Compare register or a PWM Master/Slave Duty Cycle
register. These ECCP modules are upward compatible
with the standard CCP module found in many prior
PIC16 and PIC18 devices.
ECCP1 and ECCP2 are implemented as standard CCP
modules with enhanced PWM capabilities. These
include:
Provision for two or four output channels
Output Steering modes
Programmable polarity
Programmable dead-band control
Automatic shutdown and restart
The enhanced features are discussed in detail in
Section 18.5 “PWM (Enhanced Mode)”.
Note: Register and bit names referencing one of
the two ECCP modules substitute an ‘x
for the module number. For example, reg-
isters CCP1CON and CCP2CON, which
have the same definitions, are called
CCPxCON. Figures and diagrams use
ECCP1-based names, but those names
also apply to ECCP2, with a “2” replacing
the illustration name’s “1”.
When writing firmware, the “x” in register
and bit names must be replaced with the
appropriate module number.
Note: PxA, PxB, PxC and PxD are associated
with the remappable pins (RPn).
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REGISTER 18-1: CCPxCON: ENHANCED CAPTURE/COMPARE/PWM x CONTROL REGISTER
(ACCESS FBAh, FB4h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PxM1 PxM0 DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 PxM<1:0>: Enhanced PWM Output Configuration bits
If CCPxM<3:2> = 00, 01, 10:
xx = PxA is assigned as capture/compare input/output; PxB, PxC and PxD are assigned as port pins
If CCPxM<3:2> = 11:
00 = Single output: PxA, PxB, PxC and PxD are controlled by steering (see Section 18.5.7 “Pulse
Steering Mode)
01 = Full-bridge output forward: PxD is modulated; PxA is active; PxB, PxC is inactive
10 = Half-bridge output: PxA, PxB are modulated with dead-band control; PxC and PxD are
assigned as port pins
11 = Full-bridge output reverse: PxB is modulated; PxC is active; PxA and PxD are inactive
bit 5-4 DCxB<1:0>: PWM Duty Cycle bit 1 and bit 0
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found
in CCPRxL.
bit 3-0 CCPxM<3:0>: ECCPx Mode Select bits
0000 = Capture/Compare/PWM off (resets ECCPx module)
0001 = Reserved
0010 = Compare mode, toggle output on match
0011 = Capture mode
0100 = Capture mode, every falling edge
0101 = Capture mode, every rising edge
0110 = Capture mode, every 4th rising edge
0111 = Capture mode, every 16th rising edge
1000 = Compare mode, initialize ECCPx pin low, set output on compare match (set CCPxIF)
1001 = Compare mode, initialize ECCPx pin high, clear output on compare match (set CCPxIF)
1010 = Compare mode, generate software interrupt only, ECCPx pin reverts to I/O state
1011 = Compare mode, trigger special event (ECCPx resets TMR1 or TMR3, starts A/D conversion,
sets CCxIF bit)
1100 = PWM mode; PxA and PxC are active-high; PxB and PxD are active-high
1101 = PWM mode; PxA and PxC are active-high; PxB and PxD are active-low
1110 = PWM mode; PxA and PxC are active-low; PxB and PxD are active-high
1111 = PWM mode; PxA and PxC are active-low; PxB and PxD are active-low
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In addition to the expanded range of modes available
through the CCPxCON and ECCPxAS registers, the
ECCP modules have two additional registers associated
with Enhanced PWM operation and auto-shutdown
features. They are:
ECCPxDEL (Enhanced PWM Control)
PSTRxCON (Pulse Steering Control)
18.1 ECCP Outputs and Configuration
The Enhanced CCP module may have up to four PWM
outputs, depending on the selected operating mode.
These outputs, designated PxA through PxD, are
routed through the Peripheral Pin Select (PPS)
module. Therefore, individual functions may be
mapped to any of the remappable I/O pins, RPn. The
outputs that are active depend on the ECCP operating
mode selected. The pin assignments are summarized
in Table 18-4.
To configure the I/O pins as PWM outputs, the proper
PWM mode must be selected by setting the PxM<1:0>
and CCPxM<3:0> bits. The appropriate TRIS direction
bits for the port pins must also be set as outputs and the
output functions need to be assigned to I/O pins in the
PPS module. (For details on configuring the module,
see Section 10.7 “Peripheral Pin Select (PPS)”.)
18.1.1 ECCP MODULE AND TIMER
RESOURCES
The ECCP modules utilize Timers 1, 2, 3 or 4, depending
on the mode selected. Timer1 and Timer3 are available
to modules in Capture or Compare modes, while Timer2
and Timer4 are available for modules in PWM mode.
TABLE 18-1: ECCP MODE – TIMER
RESOURCE
The assignment of a particular timer to a module is
determined by the Timer-to-ECCP enable bits in the
TCLKCON register (Register 13-3). The interactions
between the two modules are depicted in Figure 18-1.
Capture operations are designed to be used when the
timer is configured for Synchronous Counter mode.
Capture operations may not work as expected if the
associated timer is configured for Asynchronous Counter
mode.
ECCP Mode Timer Resource
Capture Timer1 or Timer3
Compare Timer1 or Timer3
PWM Timer2 or Timer4
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18.2 Capture Mode
In Capture mode, the CCPRxH:CCPRxL register pair
captures the 16-bit value of the TMR1 or TMR3
registers when an event occurs on the corresponding
ECCPx pin. An event is defined as one of the following:
Every falling edge
Every rising edge
•Every 4
th rising edge
•Every 16
th rising edge
The event is selected by the mode select bits,
CCPxM<3:0>, of the CCPxCON register. When a
capture is made, the interrupt request flag bit, CCPxIF,
is set; it must be cleared by software. If another capture
occurs before the value in register CCPRx is read, the
old captured value is overwritten by the new captured
value.
18.2.1 ECCP PIN CONFIGURATION
In Capture mode, the appropriate ECCPx pin should be
configured as an input by setting the corresponding
TRIS direction bit.
Additionally, the ECCPx input function needs to be
assigned to an I/O pin through the Peripheral Pin
Select module. For details on setting up the
remappable pins, see Section 10.7 “Peripheral Pin
Select (PPS)”.
18.2.2 TIMER1/TIMER3 MODE SELECTION
The timers that are to be used with the capture feature
(Timer1 and/or Timer3) must be running in Timer mode
or Synchronized Counter mode. In Asynchronous
Counter mode, the capture operation may not work.
The timer to be used with each ECCP module is
selected in the TCLKCON register (Register 13-3).
18.2.3 SOFTWARE INTERRUPT
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep the
CCPxIE interrupt enable bit clear to avoid false interrupts.
The interrupt flag bit, CCPxIF, should also be cleared
following any such change in operating mode.
18.2.4 ECCP PRESCALER
There are four prescaler settings in Capture mode; they
are specified as part of the operating mode selected by
the mode select bits (CCPxM<3:0>). Whenever the
ECCP module is turned off, or Capture mode is dis-
abled, the prescaler counter is cleared. This means
that any Reset will clear the prescaler counter.
Switching from one capture prescaler to another may
generate an interrupt. Also, the prescaler counter will
not be cleared; therefore, the first capture may be from
a non-zero prescaler. Example 18-1 provides the
recommended method for switching between capture
prescalers. This example also clears the prescaler
counter and will not generate the “false” interrupt.
EXAMPLE 18-1: CHANGING BETWEEN
CAPTURE PRESCALERS
FIGURE 18-1: CAPTURE MODE OPERATION BLOCK DIAGRAM
Note: If the ECCPx pin is configured as an
output, a write to the port can cause a
capture condition.
CLRF CCP1CON ; Turn CCP module off
MOVLW NEW_CAPT_PS ; Load WREG with the
; new prescaler mode
; value and CCP ON
MOVWF CCP1CON ; Load CCP1CON with
; this value
CCPR1H CCPR1L
TMR1H TMR1L
Set CCP1IF
TMR3
Enable
Q1:Q4
CCP1CON<3:0>
ECCP1 Pin
Prescaler
1, 4, 16
and
Edge Detect
TMR1
Enable
TMR3H TMR3L
4
4
TCLKCON (<T3CCP<2:1>)
TCLKCON (<T3CCP<2:1>)
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18.3 Compare Mode
In Compare mode, the 16-bit CCPRx register value is
constantly compared against either the TMR1 or TMR3
register pair value. When a match occurs, the ECCPx
pin can be:
Driven high
•Driven low
Toggled (high-to-low or low-to-high)
Remain unchanged (that is, reflects the state of
the I/O latch)
The action on the pin is based on the value of the mode
select bits (CCPxM<3:0>). At the same time, the
interrupt flag bit, CCPxIF, is set.
18.3.1 ECCP PIN CONFIGURATION
Users must configure the ECCPx pin as an output by
clearing the appropriate TRIS bit.
18.3.2 TIMER1/TIMER3 MODE SELECTION
Timer1 and/or Timer3 must be running in Timer mode
or Synchronized Counter mode if the ECCP module is
using the compare feature. In Asynchronous Counter
mode, the compare operation will not work reliably.
18.3.3 SOFTWARE INTERRUPT MODE
When the Generate Software Interrupt mode is chosen
(CCPxM<3:0> = 1010), the ECCPx pin is not affected;
only the CCPxIF interrupt flag is affected.
18.3.4 SPECIAL EVENT TRIGGER
The ECCP module is equipped with a Special Event
Trigger. This is an internal hardware signal generated
in Compare mode to trigger actions by other modules.
The Special Event Trigger is enabled by selecting
the Compare Special Event Trigger mode
(CCPxM<3:0> = 1011).
The Special Event Trigger resets the Timer register pair
for whichever timer resource is currently assigned as the
module’s time base. This allows the CCPRx registers to
serve as a programmable period register for either timer.
The Special Event Trigger can also start an A/D conver-
sion. In order to do this, the A/D Converter must
already be enabled.
FIGU RE 18-2: CO MPARE MOD E O PE RAT I O N BLO CK D IA GRA M
Note: Clearing the CCPxCON register will force
the ECCPx compare output latch
(depending on device configuration) to the
default low level. This is not the PORTx
I/O data latch.
TMR1H TMR1L
TMR3H TMR3L
CCPR1H CCPR1L
Comparator
Set CCP1IF
Q
S
R
Output
Logic
Special Event Trigger
ECCP1 Pin
TRIS
CCP1CON<3:0>
Output Enable
4
(Timer1/Timer3 Reset, A/D Trigger)
Compare
Match
TCLKCON (<T3CCP<2:1>)
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18.4 PWM Mode
In Pulse-Width Modulation (PWM) mode, the CCPx pin
produces up to a 10-bit resolution PWM output.
Figure 18-3 shows a simplified block diagram of the
CCP module in PWM mode.
For a step-by-step procedure on how to set up a CCP
module for PWM operation, see Section 18.4.3
“Setup for PWM Operation”.
FIGURE 18-3: SIMPLIFIED PWM BLOCK
DIAGRAM
A PWM output (Figure 18-4) has a time base (period)
and a time that the output stays high (duty cycle).
The frequency of the PWM is the inverse of the
period (1/period).
FIGURE 18-4: PWM OUTPUT
18.4.1 PWM PERIOD
The PWM period is specified by writing to the PR2
(PR4) register. The PWM period can be calculated
using Equation 18-1:
EQUATION 18-1:
PWM frequency is defined as 1/[PWM period].
When TMR2 (TMR4) is equal to PR2 (PR4), the
following three events occur on the next increment
cycle:
TMR2 (TMR4) is cleared
The CCPx pin is set (exception: if PWM Duty
Cycle = 0%, the CCPx pin will not be set)
The PWM duty cycle is latched from CCPRxL into
CCPRxH
18.4.2 PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the
CCPRxL register and to the CCPxCON<5:4> bits. Up
to 10-bit resolution is available. The CCPRxL contains
the eight MSbs and the CCPxCON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPRxL:CCPxCON<5:4>. Equation 18-2 is used to
calculate the PWM duty cycle in time.
EQUATION 18-2:
CCPRxL and CCPxCON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPRxH until after a match between PR2 (PR4) and
TMR2 (TMR4) occurs (i.e., the period is complete). In
PWM mode, CCPRxH is a read-only register.
CCPRxL
Comparator
Comparator
PRx
CCPxCON<5:4>
QS
RCCPx
TRIS
Output Enable
CCPRxH
TMRx
2 LSbs Latched
from Q Clocks
Reset
Match
TMRx = PRx
Latch
09
(1)
Note 1: The two LSbs of the Duty Cycle register are held by a
2-bit latch that is part of the module’s hardware. It is
physically separate from the CCPRx registers.
Duty Cycle Register
Set CCPx Pin
Duty Cycle
Pin
Period
Duty Cycle
TMR2 (TMR4) = PR2 (TMR4)
TMR2 (TMR4) = Duty Cycle
TMR2 (TMR4) = PR2 (PR4)
Note: The Timer2 and Timer 4 postscalers (see
Section 15.0 “Timer3 Module” and
Section 16.0 “Timer4 Module) are not
used in the determination of the PWM
frequency. The postscaler could be used
to have a servo update rate at a different
frequency than the PWM output.
PWM Period = [(PR2) + 1] • 4 • TOSC
(TMR2 Prescale Value)
PWM Duty Cycle = (CCPRXL:CCPXCON<5:4>) •
TOSC • (TMR2 Prescale Value)
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The CCPRxH register and a 2-bit internal latch are
used to double-buffer the PWM duty cycle. This
double-buffering is essential for glitchless PWM
operation.
When the CCPRxH and 2-bit latch match TMR2
(TMR4), concatenated with an internal 2-bit Q clock or
2 bits of the TMR2 (TMR4) prescaler, the CCPx pin is
cleared.
The maximum PWM resolution (bits) for a given PWM
frequency is given by Equation 18-3:
EQUATION 18-3:
18.4.3 SETUP FOR PWM OPERATION
The following steps should be taken when configuring
the CCP module for PWM operation:
1. Set the PWM period by writing to the PR2 (PR4)
register.
2. Set the PWM duty cycle by writing to the
CCPRxL register and CCPxCON<5:4> bits.
3. Make the CCPx pin an output by clearing the
appropriate TRIS bit.
4. Set the TMR2 (TMR4) prescale value, then
enable Timer2 (Timer4) by writing to T2CON
(T4CON).
5. Configure the CCPx module for PWM operation.
TABLE 18-2: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
Note: If the PWM duty cycle value is longer than
the PWM period, the CCPx pin will not be
cleared.
log(FPWM
log(2)
FOSC )bitsPWM Resolution (max) =
PWM Frequency 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz
Timer Prescaler (1, 4, 16)1641111
PR2 Value FFh FFh FFh 3Fh 1Fh 17h
Maximum Resolution (bits) 10 10 10 8 7 6.58
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TABLE 18-3: REGISTERS ASSOCIATED WITH PWM, TIMER2 AND TIMER4
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Pag e:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
RCON IPEN CM RI TO PD POR BOR 70
PIR1 PMPIF ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP LVDIP TMR3IP CCP2IP 72
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF LVDIF TMR3IF CCP2IF 72
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE LVDIE TMR3IE CCP2IE 72
TCLKCON T1RUN T3CCP2 T3CCP1 74
TMR2 Timer2 Register 70
PR2 Timer2 Period Register 70
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 70
TMR4 Timer4 Register 73
PR4 Timer4 Period Register 73
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 73
CCPR1L Capture/Compare/PWM Register 1 Low Byte 71
CCPR1H Capture/Compare/PWM Register 1 High Byte 71
CCPRL2L Capture/Compare/PWM Register 2 Low Byte 71
CCPR2H Capture/Compare/PWM Register 2 High Byte 71
CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 73
CCP2CON P2M1 P2M0 DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 73
ODCON1 —ECCP2ODECCP1OD74
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PWM, Timer2 or Timer4.
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18.5 PWM (Enhanced Mode)
The Enhanced PWM mode can generate a PWM signal
on up to four different output pins with up to 10 bits of
resolution. It can do this through four different PWM
Output modes:
Single PWM
Half-Bridge PWM
Full-Bridge PWM, Forward mode
Full-Bridge PWM, Reverse mode
To select an Enhanced PWM mode, the PxM bits of the
CCPxCON register must be set appropriately.
The PWM outputs are multiplexed with I/O pins and are
designated: PxA, PxB, PxC and PxD. The polarity of the
PWM pins is configurable and is selected by setting the
CCPxM bits in the CCPxCON register appropriately.
Table 18-1 provides the pin assignments for each
Enhanced PWM mode.
Figure 18-5 provides an example of a simplified block
diagram of the Enhanced PWM module.
FIGURE 18- 5: EXAMPLE SIMPLIFIED B LOCK DIA GRAM O F THE E NHANC ED PWM MO DE
Note: To prevent the generation of an
incomplete waveform when the PWM is
first enabled, the ECCP module waits until
the start of a new PWM period before
generating a PWM signal.
Note 1: The TRIS register value for each PWM output must be configured appropriately.
2: Any pin not used by an Enhanced PWM mode is available for alternate pin functions.
CCPR1L
CCPR1H (Slave)
Comparator
TMR2
Comparator
PR2
(1)
RQ
S
Duty Cycle Registers DC1B<1:0>
Clear Timer2,
Toggle PWM Pin and
Latch Duty Cycle
Note 1: The 8-bit TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create
the 10-bit time base.
2: These pins are remappable.
TRIS
ECCP1/
RPn
TRIS
R
Pn
TRIS
P
Rn
TRIS
P
Rn
Output
Controller
PxM<1:0>
2
CCPxM<3:0>
4
ECCP1DEL
ECCPx/PxA(2)
PxB(2)
PxC(2)
PxD(2)
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TABLE 18-4: EXAMPLE PIN ASSIGNMENTS FOR VARIOUS PWM ENHANCED MODES
FIGU RE 18 -6: EXA MPLE PWM (ENH ANCE D MODE ) OUTP UT RELA TIO NSHI P S
(ACT IVE- HIG H STATE)
ECCP Mode PxM<1:0> PxA PxB PxC PxD
Single 00 Yes(1) Yes(1) Yes (1) Yes (1)
Half-Bridge 10 Yes Yes No No
Full-Bridge, Forward 01 Ye s Yes Yes Yes
Full-Bridge, Reverse 11 Yes Yes Ye s Yes
Note 1: Outputs are enabled by pulse steering in Single mode (see Register 18-4).
0
Period
00
10
01
11
Signal PR2 + 1
PxM<1:0>
PxA Modulated
PxA Modulated
PxB Modulated
PxA Active
PxB Inactive
PxC Inactive
PxD Modulated
PxA Inactive
PxB Modulated
PxC Active
PxD Inactive
Pulse Width
(Single Output)
(Half-Bridge)
(Full-Bridge,
Forward)
(Full-Bridge,
Reverse)
Delay(1) Delay(1)
Relationships:
Period = 4 * T
OSC * (PR2 + 1) * (TMR2 Prescale Value)
Pulse Width = TOSC * (CCPRxL<7:0>:CCPxCON<5:4>) * (TMR2 Prescale Value)
Delay = 4 * TOSC * (ECCPxDEL<6:0>)
Note 1: Dead-band delay is programmed using the ECCPxDEL register (Sec tio n 18.5.6 “ Pr og ram m ab le Dea d- Ban d
Delay Mode”).
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FIGURE 18-7: EXAMPLE ENHANCED PWM OUTPUT RELATIONSHIP S (ACTIVE-LOW S T ATE)
0
Period
00
10
01
11
Signal PR2 + 1
PxM<1:0>
PxA Modulated
PxA Modulated
PxB Modulated
PxA Active
PxB Inactive
PxC Inactive
PxD Modulated
PxA Inactive
PxB Modulated
PxC Active
PxD Inactive
Pulse
Width
(Single Output)
(Half-Bridge)
(Full-Bridge,
Forward)
(Full-Bridge,
Reverse)
Delay(1) Delay(1)
Relationships:
Period = 4 * T
OSC * (PR2 + 1) * (TMR2 Prescale Value)
Pulse Width = TOSC * (CCPRxL<7:0>:CCPxCON<5:4>) * (TMR2 Prescale Value)
Delay = 4 * TOSC * (ECCPxDEL<6:0>)
Note 1: Dead-band delay is programmed using the ECCP1DEL register (Section 18.5.6 “Programmable Dead-Band
Delay Mode”).
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18.5.1 HALF-BRIDGE MODE
In Half-Bridge mode, two pins are used as outputs to
drive push-pull loads. The PWM output signal is output
on the PxA pin, while the complementary PWM output
signal is output on the PxB pin (see Figure 18-8). This
mode can be used for half-bridge applications, as
shown in Figure 18-9, or for full-bridge applications,
where four power switches are being modulated with
two PWM signals.
In Half-Bridge mode, the programmable dead-band delay
can be used to prevent shoot-through current in
half-bridge power devices. The value of the PxDC<6:0>
bits of the ECCPxDEL register sets the number of
instruction cycles before the output is driven active. If the
value is greater than the duty cycle, the corresponding
output remains inactive during the entire cycle. See
Section 18.5.6 “Programmable Dead-Band Delay
Mode” for more details of the dead-band delay
operations.
Since the PxA and PxB outputs are multiplexed with the
port data latches, the associated TRIS bits must be
cleared to configure PxA and PxB as outputs.
FIGURE 18-8: EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
FIGURE 18-9: EXAMPLE OF HALF-BRIDGE APPLICATIONS
Period
Pulse Width
td
td
(1)
PxA(2)
PxB(2)
td = Dead-Band Delay
Period
(1) (1)
Note 1: At this time, the TMR2 register is equal to the
PR2 register.
2: Output signals are shown as active-high.
PxA
PxB
FET
Driver
FET
Driver
Load
+
-
+
-
FET
Driver
FET
Driver
V+
Load
FET
Driver
FET
Driver
PxA
PxB
Standard Half-Bridge Circuit (“Push-Pull”)
Half-Bridge Output Driving a Full-Bridge Circuit
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18.5.2 FULL-BRIDGE MODE
In Full-Bridge mode, all four pins are used as outputs.
An example of a full-bridge application is provided in
Figure 18-10.
In the Forward mode, the PxA pin is driven to its active
state, the PxD pin is modulated, while the PxB and PxC
pins will be driven to their inactive state as provided in
Figure 18-11.
In the Reverse mode, the PxC pin is driven to its active
state, the PxB pin is modulated, while the PxA and PxD
pins will be driven to their inactive state as provided
Figure 18-11.
The PxA, PxB, PxC and PxD outputs are multiplexed
with the port data latches. The associated TRIS bits
must be cleared to configure the PxA, PxB, PxC and
PxD pins as outputs.
FIGURE 18-10: EXAMPLE OF FULL-BRIDGE APPLICATION
PxA
PxC
FET
Driver
FET
Driver
V+
V-
Load
FET
Driver
FET
Driver
PxB
PxD
QA
QB QD
QC
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FIGURE 18-11: EXAMPLE OF FULL-BRIDGE PWM OUTPUT
Period
Pulse Width
PxA(2)
PxB(2)
PxC(2)
PxD(2)
Forw a r d M o de
(1)
Period
Pulse Width
PxA(2)
PxC(2)
PxD(2)
PxB(2)
Reverse Mode
(1)
(1)
(1)
Note 1: At this time, the TMR2 register is equal to the PR2 register.
2: The output signal is shown as active-high.
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18.5.2.1 Direction Change in Full-Bridge
Mode
In the Full-Bridge mode, the PxM1 bit in the CCPxCON
register allows users to control the forward/reverse
direction. When the application firmware changes this
direction control bit, the module will change to the new
direction on the next PWM cycle.
A direction change is initiated in software by changing
the PxM1 bit of the CCPxCON register. The following
sequence occurs prior to the end of the current PWM
period:
The modulated outputs (PxB and PxD) are placed
in their inactive state.
The associated unmodulated outputs (PxA and
PxC) are switched to drive in the opposite
direction.
PWM modulation resumes at the beginning of the
next period.
See Figure 18-12 for an illustration of this sequence.
The Full-Bridge mode does not provide a dead-band
delay. As one output is modulated at a time, a
dead-band delay is generally not required. There is a
situation where a dead-band delay is required. This
situation occurs when both of the following conditions
are true:
1. The direction of the PWM output changes when
the duty cycle of the output is at or near 100%.
2. The turn-off time of the power switch, including
the power device and driver circuit, is greater
than the turn-on time.
Figure 18-13 shows an example of the PWM direction
changing from forward to reverse, at a near 100% duty
cycle. In this example, at time, t1, the PxA and PxD
outputs become inactive, while the PxC output
becomes active. Since the turn-off time of the power
devices is longer than the turn-on time, a shoot-through
current will flow through power devices, QC and QD
(see Figure 18-10), for the duration of ‘t’. The same
phenomenon will occur to power devices, QA and QB,
for PWM direction change from reverse to forward.
If changing PWM direction at high duty cycle is required
for an application, two possible solutions for eliminating
the shoot-through current are:
1. Reduce PWM duty cycle for one PWM period
before changing directions.
2. Use switch drivers that can drive the switches off
faster than they can drive them on.
Other options to prevent shoot-through current may
exist.
FIGU RE 18 -12: EXAMPLE OF PWM DI RECT ION CHA NGE
Pulse Width
Period(1)
Signal
Note 1: The direction bit, PxM1 of the CCPxCON register, is written any time during the PWM cycle.
2: When changing directions, the PxA and PxC signals switch before the end of the current PWM cycle. The
modulated PxB and PxD signals are inactive at this time. The length of this time is:
(1/FOSC) TMR2 Prescale Value
Period
(2)
PxA (Active-High)
PxB (Active-High)
PxC (Active-High)
PxD (Active-High)
Pulse Width
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FIGU RE 18 -13: EXAMPLE O F PWM DIRE CTIO N CHA NGE AT NEA R 100% DUTY CYC LE
18.5.3 START-UP CONSIDERATIONS
When any PWM mode is used, the application
hardware must use the proper external pull-up and/or
pull-down resistors on the PWM output pins.
The CCPxM<1:0> bits of the CCPxCON register allow
the user to choose whether the PWM output signals are
active-high or active-low for each pair of PWM output
pins (PxA/PxC and PxB/PxD). The PWM output
polarities must be selected before the PWM pin output
drivers are enabled. Changing the polarity configura-
tion while the PWM pin output drivers are enable is not
recommended since it may result in damage to the
application circuits.
The PxA, PxB, PxC and PxD output latches may not be
in the proper states when the PWM module is
initialized. Enabling the PWM pin output drivers at the
same time as the Enhanced PWM modes may cause
damage to the application circuit. The Enhanced PWM
modes must be enabled in the proper Output mode and
complete a full PWM cycle before enabling the PWM
pin output drivers. The completion of a full PWM cycle
is indicated by the TMR2IF or TMR4IF bit of the PIR1
or PIR3 register being set as the second PWM period
begins.
Forward Period Reverse Period
PxA
TON
TOFF
T = TOFF – TON
PxB
PxC
PxD
External Switch D
Potential
Shoot-Through Current
Note 1: All signals are shown as active-high.
2: TON is the turn-on delay of power switch, QC, and its driver.
3: TOFF is the turn-off delay of power switch, QD, and its driver.
External Switch C
t1
PW
PW
Note: When the microcontroller is released from
Reset, all of the I/O pins are in the
high-impedance state. The external
circuits must keep the power switch
devices in the OFF state until the micro-
controller drives the I/O pins with the
proper signal levels or activates the PWM
output(s).
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18.5.4 ENHANCED PWM
AUTO-SHUTDOWN MODE
The PWM mode supports an Auto-Shutdown mode that
will disable the PWM outputs when an external
shutdown event occurs. Auto-Shutdown mode places
the PWM output pins into a predetermined state. This
mode is used to help prevent the PWM from damaging
the application.
The auto-shutdown sources are selected using the
ECCPxAS<2:0> bits of the ECCPxAS register. A
shutdown event may be generated by:
•A logic0’ on the pin that is assigned the FLT0
input function
Comparator C1
Comparator C2
Setting the ECCPxASE bit in firmware
A shutdown condition is indicated by the ECCPxASE
(Auto-Shutdown Event Status) bit of the ECCPxAS
register. If the bit is a ‘0’, the PWM pins are operating
normally. If the bit is a ‘1’, the PWM outputs are in the
shutdown state.
When a shutdown event occurs, two things happen:
The ECCPxASE bit is set to ‘1’. The ECCPxASE will
remain set until cleared in firmware or an auto-restart
occurs (see Section 18.5.5 “Auto-Restart Mode”).
The enabled PWM pins are asynchronously placed in
their shutdown states. The PWM output pins are
grouped into pairs, [PxA/PxC] and [PxB/PxD]. The state
of each pin pair is determined by the PSSxAC and
PSSxBD bits of the ECCPxAS register. Each pin pair
may be placed into one of three states:
Drive logic 1
Drive logic 0
Tri-state (high-impedance)
REGISTER 18-2: ECCPxAS: ECCPx AUTO-SHUTDOWN CONTROL REGISTER
(ACCESS FBEh, FB8h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ECCPxASE ECCPxAS2 ECCPxAS1 ECCPxAS0 PSSxAC1 PSSxAC0 PSSxBD1 PSSxBD0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ECCPxASE: ECCP Auto-Shutdown Event Status bit
1 = A shutdown event has occurred; ECCP outputs are in a shutdown state
0 = ECCP outputs are operating
bit 6-4 ECCPxAS<2:0>: ECCP Auto-Shutdown Source Select bits
000 = Auto-shutdown is disabled
001 = Comparator C1OUT output is high
010 = Comparator C2OUT output is high
011 = Either Comparator C1OUT or C2OUT is high
100 =V
IL on FLT0 pin
101 =V
IL on FLT0 pin or Comparator C1OUT output is high
110 =V
IL on FLT0 pin or Comparator C2OUT output is high
111 =V
IL on FLT0 pin or Comparator C1OUT or Comparator C2OUT is high
bit 3-2 PSSxAC<1:0>: Pins PxA and PxC Shutdown State Control bits
00 = Drive PxA and PxC pins to ‘0
01 = Drive PxA and PxC pins to ‘1
1x = PxA and PxC pins tri-state
bit 1-0 PSSxBD<1:0>: Pins PxB and PxD Shutdown State Control bits
00 = Drive PxB and PxD pins to ‘0
01 = Drive PxB and PxD pins to ‘1
1x = PxB and PxD pins tri-state
Note 1: The auto-shutdown condition is a level-based signal, not an edge-based signal. As long as the level is
present, the auto-shutdown will persist.
2: Writing to the ECCPxASE bit is disabled while an auto-shutdown condition persists.
3: Once the auto-shutdown condition has been removed and the PWM restarted (either through firmware or
auto-restart), the PWM signal will always restart at the beginning of the next PWM period.
PIC18F46J50 FAMILY
DS39931D-page 262 2011 Microchip Technology Inc.
FIGURE 18-14: PWM AUTO-SHUTDOWN WITH FIRMWARE RESTART (PxRSEN = 0)
18.5.5 AUTO-RESTART MODE
The Enhanced PWM can be configured to automatically
restart the PWM signal once the auto-shutdown condi-
tion has been removed. Auto-restart is enabled by
setting the PxRSEN bit in the ECCPxDEL register.
If auto-restart is enabled, the ECCPxASE bit will
remain set as long as the auto-shutdown condition is
active. When the auto-shutdown condition is removed,
the ECCPxASE bit will be cleared via hardware and
normal operation will resume.
The module will wait until the next PWM period begins,
however, before re-enabling the output pin. This behav-
ior allows the auto-shutdown with auto-restart features
to be used in applications based on current mode PWM
control.
FIGURE 18-15: PWM AUTO-SHUTD OWN WITH AUTO-RESTART ENABLED (PxRSEN = 1)
Shutdown
PWM
ECCPxASE bit
Activity
Event
Shutdown
Event Occurs
Shutdown
Event Clears
PWM
Resumes
Normal PWM
Start of
PWM Period
ECCPxASE
Cleared by
Firmware
PWM Period
Shutdown
PWM
ECCPxASE bit
Activity
Event
Shutdown
Event Occurs
Shutdown
Event Clears
PWM
Resumes
Normal PWM
Start of
PWM Period
PWM Period
2011 Microchip Technology Inc. DS39931D-page 263
PIC18F46J50 FAMILY
18.5.6 PROGRAMMABLE DEAD-BAND
DELAY MODE
In half-bridge applications, where all power switches are
modulated at the PWM frequency, the power switches
normally require more time to turn off than to turn on. If
both the upper and lower power switches are switched
at the same time (one turned on and the other turned
off), both switches may be on for a short period until one
switch completely turns off. During this brief interval, a
very high current (shoot-through current) will flow
through both power switches, shorting the bridge supply.
To avoid this potentially destructive shoot-through
current from flowing during switching, turning on either of
the power switches is normally delayed to allow the
other switch to completely turn off.
In Half-Bridge mode, a digitally, programmable
dead-band delay is available to avoid shoot-through
current from destroying the bridge power switches. The
delay occurs at the signal transition from the non-active
state to the active state. See Figure 18-16 for
illustration. The lower seven bits of the associated
ECCPxDEL register (Register 18-3) set the delay
period in terms of microcontroller instruction cycles
(T
CY or 4 TOSC).
FIGURE 18-16: EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
FIGU RE 18 -17: EXAMPLE OF HALF- BRI DGE AP PLIC ATION S
Period
Pulse Width
td
td
(1)
PxA(2)
PxB(2)
td = Dead-Band Delay
Period
(1) (1)
Note 1: At this time, the TMR2 register is equal to the
PR2 register.
2: Output signals are shown as active-high.
PxA
PxB
FET
Driver
FET
Driver
V+
V-
Load
+
V
-
+
V
-
Standard Half-Bridge Circuit (“Push-P ull ”)
PIC18F46J50 FAMILY
DS39931D-page 264 2011 Microchip Technology Inc.
18.5.7 PULSE STEERING MODE
In Single Output mode, pulse steering allows any of the
PWM pins to be the modulated signal. Additionally, the
same PWM signal can simultaneously be available on
multiple pins.
Once the Single Output mode is selected
(CCPxM<3:2> = 11 and PxM<1:0> = 00 of the
CCPxCON register), the user firmware can bring out
the same PWM signal to one, two, three or four output
pins by setting the appropriate STR<D:A> bits of the
PSTRxCON register, as provided in Table 18-4.
While the PWM Steering mode is active, the
CCPxM<1:0> bits of the CCPxCON register select the
PWM output polarity for the Px<D:A> pins.
The PWM auto-shutdown operation also applies to
PWM Steering mode, as described in Section 18.5.4
“Enhanced PWM Auto-Shutdown Mode”. An
auto-shutdown event will only affect pins that have
PWM outputs enabled.
REGISTER 18-3: ECCPxDEL: ENHANCED PWM CONTROL REGISTER (ACCES S FBDh, FB7h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PxRSEN PxDC6 PxDC5 PxDC4 PxDC3 PxDC2 PxDC1 PxDC0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 PxRSEN: PWM Restart Enable bit
1 = Upon auto-shutdown, the ECCPxASE bit clears automatically once the shutdown event goes
away; the PWM restarts automatically
0 = Upon auto-shutdown, ECCPxASE must be cleared by software to restart the PWM
bit 6-0 PxDC<6:0>: PWM Delay Count bits
PxDCn = Number of FOSC/4 (4 * TOSC) cycles between the scheduled time when a PWM signal
should transition active and the actual time it transitions active.
Note: The associated TRIS bits must be set to
output (0’) to enable the pin output driver
in order to see the PWM signal on the pin.
2011 Microchip Technology Inc. DS39931D-page 265
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REGISTER 18-4: PSTRxCON: PULSE STEERING CONTROL REGISTER (ACCESS FBFh, FB9h)(1)
R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-1
CMPL1 CMPL0 STRSYNC STRD STRC STRB STRA
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 CMPL<1:0>: Complementary Mode Output Assignment Steering Sync bits
1 = Modulated output pin toggles between PxA and PxB for each period
0 = Complementary output assignment disabled; STR<D:A> bits are used to determine Steering mode
bit 5 Unimplemented: Read as ‘0
bit 4 STRSYNC: Steering Sync bit
1 = Output steering update occurs on next PWM period
0 = Output steering update occurs at the beginning of the instruction cycle boundary
bit 3 STRD: Steering Enable bit D
1 = PxD pin has the PWM waveform with polarity control from CCPxM<1:0>
0 = PxD pin is assigned to port pin
bit 2 STRC: Steering Enable bit C
1 = PxC pin has the PWM waveform with polarity control from CCPxM<1:0>
0 = PxC pin is assigned to port pin
bit 1 STRB: Steering Enable bit B
1 = PxB pin has the PWM waveform with polarity control from CCPxM<1:0>
0 = PxB pin is assigned to port pin
bit 0 STRA: Steering Enable bit A
1 = PxA pin has the PWM waveform with polarity control from CCPxM<1:0>
0 = PxA pin is assigned to port pin
Note 1: The PWM Steering mode is available only when the CCPxCON register bits, CCPxM<3:2> = 11, and
PxM<1:0> = 00.
PIC18F46J50 FAMILY
DS39931D-page 266 2011 Microchip Technology Inc.
FIGURE 18-18: SIMPLIFIED S TEER ING
BLOCK DIAGRAM 18.5.7.1 Steering Synchronization
The STRSYNC bit of the PSTRxCON register gives the
user two selections of when the steering event will
happen. When the STRSYNC bit is ‘0’, the steering
event will happen at the end of the instruction that
writes to the PSTRxCON register. In this case, the out-
put signal at the Px<D:A> pins may be an incomplete
PWM waveform. This operation is useful when the user
firmware needs to immediately remove a PWM signal
from the pin.
When the STRSYNC bit is ‘1’, the effective steering
update will happen at the beginning of the next PWM
period. In this case, steering on/off the PWM output will
always produce a complete PWM waveform.
Figures 18-19 and 18-20 illustrate the timing diagrams
of the PWM steering depending on the STRSYNC
setting.
FIGURE 18-19: EXAMPLE OF STEERING EVENT AT END OF INSTRUCTION (STRSYNC = 0)
FIGURE 18-20: EXAMPLE OF STEERING EVENT AT BEGINNING OF INSTRUCTION (STRSYNC = 1)
1
0TRIS
RPn Pin
PORT Data
PxA Signal
STRA
1
0TRIS
RPn Pin
PORT Data
STRB
1
0
TRIS
RPn Pin
PORT Data
STRC
1
0TRIS
RPn Pin
PORT Data
STRD
Note 1: Port outputs are configured as displayed
when the CCPxCON register bits,
PxM<1:0> = 00 and CCPxM<3:2> = 11.
2: Single PWM output requires setting at least
one of the STRx bits.
CCPxM1
CCPxM0
CCPxM1
CCPxM0
PWM
P1n = PWM
STRn
P1<D:A> Port Data
PWM Period
Port Data
PWM
Port Data
P1n = PWM
STRn
P1<D:A> Port Data
2011 Microchip Technology Inc. DS39931D-page 267
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18.5.8 OPERATION IN POWER-MANAGED
MODES
In Sleep mode, all clock sources are disabled. Timer2
will not increment and the state of the module will not
change. If the ECCPx pin is driving a value, it will con-
tinue to drive that value. When the device wakes up, it
will continue from this state. If Two-Speed Start-ups are
enabled, the initial start-up frequency from HFINTOSC
and the postscaler may not be stable immediately.
In PRI_IDLE mode, the primary clock will continue to
clock the ECCPx module without change.
18.5.8.1 Operation with Fail-Safe
Clock Monitor (FSCM)
If the Fail-Safe Clock Monitor (FSCM) is enabled, a
clock failure will force the device into the
power-managed RC_RUN mode and the OSCFIF bit of
the PIR2 register will be set. The ECCPx will then be
clocked from the internal oscillator clock source, which
may have a different clock frequency than the primary
clock.
18.5.9 EFFECTS OF A RESET
Both Power-on Reset and subsequent Resets will force
all PORTS to Input mode and the ECCP registers to
their Reset states.
This forces the ECCP module to reset to a state
compatible with previous, non-enhanced ECCP
modules used on other PIC18 and PIC16 devices.
TABLE 18-5: REGISTERS ASSOCIATED WITH ECCP1 MODULE AND TIMER1 TO TIMER3
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF 87
RCON IPEN RI TO PD POR BOR 90
PIR1 PMPIF(1) ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF 87
PIE1 PMPIE(1) ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE 91
IPR1 PMPIP(1) ADIP RCIP TXIP SSPIP CCP1IP TMR2IP TMR1IP 91
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 91
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 91
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 91
TCLKCON T1RUN T3CCP2 T3CCP1 93
TMR4 Timer4 Register 93
T4CON T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0 93
PR4 Timer4 Period Register 93
TMR1L Timer1 Register Low Byte 87
TMR1H Timer1 Register High Byte 87
T1CON TMR1CS1 TMR1CS0 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC RD16 TMR1ON 87
TMR2 Timer2 Register 87
T2CON T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 87
PR2 Timer2 Period Register 87
TMR3L Timer3 Register Low Byte 87
TMR3H Timer3 Register High Byte 87
T3CON TMR3CS1 TMR3CS0 T3CKPS1 T3CKPS0 T3OSCEN T3SYNC RD16 TMR3ON 87
CCPR1L Capture/Compare/PWM Register 1 Low Byte 87
CCPR1H Capture/Compare/PWM Register 1 High Byte 87
CCP1CON P1M1 P1M0 DC1B1 DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 87
ECCP1AS ECCP1ASE ECCP1AS2 ECCP1AS1 ECCP1AS0 PSS1AC1 PSS1AC0 PSS1BD1 PSS1BD0 87
ECCP1DEL P1RSEN P1DC6 P1DC5 P1DC4 P1DC3 P1DC2 P1DC1 P1DC0 264
Legend: = unimplemented, read as0. Shaded cells are not used during ECCP operation.
Note 1: These bits are only available on 44-pin devices.
PIC18F46J50 FAMILY
DS39931D-page 268 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 269
PIC18F46J50 FAMILY
19.0 MASTER SYNCHRONOUS
SERIAL PORT (MS SP)
MODULE
The Master Synchronous Serial Port (MSSP) module is
a serial interface, useful for communicating with other
peripheral or microcontroller devices. These peripheral
devices include serial EEPROMs, shift registers,
display drivers, ADCs, DACs and many other types of
integrated circuits.
19.1 Master SSP (MSSP) Module
Overview
The MSSP module can operate in one of two modes:
Serial Peripheral Interface (SPI)
Inter-Integrated Circuit (I2C™)
- Full Master mode
- Slave mode (with general address call)
The I2C interface supports the following modes in
hardware:
•Master mode
Multi-Master mode
Slave mode with 5-bit and 7-bit address masking
(with address masking for both 10-bit and 7-bit
addressing)
All members of the PIC18F46J50 family have two
MSSP modules, designated as MSSP1 and MSSP2.
The modules operate independently:
PIC18F4XJ50 devices – Both modules can be
configured for either I2C or SPI communication
PIC18F2XJ50 devices:
- MSSP1 can be used for either I2C or SPI
communication
- MSSP2 can be used only for SPI
communication
All of the MSSP1 module-related SPI and I2C I/O
functions are hard-mapped to specific I/O pins.
For MSSP2 functions:
SPI I/O functions (SDO2, SDI2, SCK2 and SS2)
are all routed through the Peripheral Pin Select
(PPS) module.
These functions may be configured to use any of
the RPn remappable pins, as described in
Section 10.7 “Peripheral Pin Select (PPS)”.
•I
2C functions (SCL2 and SDA2) have fixed pin
locations.
On all PIC18F46J50 family devices, the SPI DMA
capability can only be used in conjunction with MSSP2.
The SPI DMA feature is described in Section 19.4
“SPI DMA Module”.
Note: Throughout this section, generic refer-
ences to an MSSP module in any of its
operating modes may be interpreted as
being equally applicable to MSSP1 or
MSSP2. Register names and module I/O
signals use the generic designator ‘x’ to
indicate the use of a numeral to distin-
guish a particular module when required.
Control bit names are not individuated.
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DS39931D-page 270 2011 Microchip Technology Inc.
19.2 Control Registers
Each MSSP module has three associated control
registers. These include a status register (SSPxSTAT)
and two control registers (SSPxCON1 and SSPxCON2).
The use of these registers and their individual Configura-
tion bits differ significantly depending on whether the
MSSP module is operated in SPI or I2C mode.
Additional details are provided under the individual
sections.
19.3 SPI Mode
The SPI mode allows 8 bits of data to be synchronously
transmitted and received simultaneously. All four
modes of SPI are supported.
When MSSP2 is used in SPI mode, it can optionally be
configured to work with the SPI DMA submodule
described in Section 19.4 “SPI DMA Module”.
To accomplish communication, typically three pins are
used:
Serial Data Out (SDOx) –
RC7/RX1/DT1/SDO1/RP18 or
SDO2/Remappable
Serial Data In (SDIx)
RB5/PMA0/KBI1/SDI1/SDA1/RP8 or
SDI2/Remappable
Serial Clock (SCKx)
RB4/PMA1/KBI0/SCK1/SCL1/RP7 or
SCK2/Remappable
Additionally, a fourth pin may be used when in a Slave
mode of operation:
Slave Select (SSx) – RA5/AN4/SS1/
HLVDIN/RCV/RP2 or SS2/Remappable
Figure 19-1 depicts the block diagram of the MSSP
module when operating in SPI mode.
FIGURE 19-1: MSSPx BLOCK DIAGRAM
(SPI MODE)
Note: In devices with more than one MSSP
module, it is very important to pay close
attention to the SSPxCON register
names. SSP1CON1 and SSP1CON2
control different operational aspects of the
same module, while SSP1CON1 and
SSP2CON1 control the same features for
two different modules.
( )
Read Write
Internal
Data Bus
SSPxSR reg
SSPM<3:0>
bit 0 Shift
Clock
SSx Control
Enable
Edge
Select
Clock Select
TMR2 Output
TOSC
Prescaler
4, 16, 64
2
Edge
Select
2
4
Data to TXx/RXx in SSPxSR
TRIS bit
2
SMP:CKE
SDOx
SSPxBUF reg
SDIx
SSx
SCKx
Note: Only port I/O names are used in this diagram for
the sake of brevity. Refer to the text for a full list of
multiplexed functions.
2011 Microchip Technology Inc. DS39931D-page 271
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19.3.1 REGISTERS
Each MSSP module has four registers for SPI mode
operation. These are:
MSSPx Control Register 1 (SSPxCON1)
MSSPx Status Register (SSPxSTAT)
Serial Receive/Transmit Buffer Register
(SSPxBUF)
MSSPx Shift Register (SSPxSR) – Not directly
accessible
SSPxCON1 and SSPxSTAT are the control and status
registers in SPI mode operation. The SSPxCON1
register is readable and writable. The lower six bits of
the SSPxSTAT are read-only. The upper two bits of the
SSPxSTAT are read/write.
SSPxSR is the shift register used for shifting data in or
out. SSPxBUF is the buffer register to which data
bytes are written to or read from.
In receive operations, SSPxSR and SSPxBUF
together create a double-buffered receiver. When
SSPxSR receives a complete byte, it is transferred to
SSPxBUF and the SSPxIF interrupt is set.
During transmission, the SSPxBUF is not
double-buffered. A write to SSPxBUF will write to both
SSPxBUF and SSPxSR.
Since the SSPxBUF register is double-buffered for
receive operations, using read-modify-write instruc-
tions that target SSPxBUF, twice per instruction, such
as BCF, COMF, etc., will not work. SSPxBUF may be
read or written using standard instructions that target
the register, once per instruction, such as MOVWF, MOVF
(dest = WREG) and MOVFF.
Similarly, when debugging under an In-Circuit Debug-
ger, performing actions that cause reads of SSPxBUF
(ex: debug watch) can consume data that the
application code was expecting to receive.
REGISTER 19-1: SSPxSTAT: MSSPx STATUS REGISTER (SPI MODE) (ACCESS FC7h, F73h)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
SMP CKE(1) D/A PSR/WUA BF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SMP: Sample bit
SPI Master mode:
1 = Input data is sampled at the end of data output time
0 = Input data is sampled at the middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
bit 6 CKE: SPI Clock Select bit(1)
1 = Transmit occurs on transition from active to Idle clock state
0 = Transmit occurs on transition from Idle to active clock state
bit 5 D/A: Data/Address bit
Used in I2C™ mode only.
bit 4 P: Stop bit
Used in I2C mode only; this bit is cleared when the MSSP module is disabled, SSPEN is cleared.
bit 3 S: Start bit
Used in I2C mode only.
bit 2 R/W: Read/Write Information bit
Used in I2C mode only.
bit 1 UA: Update Address bit
Used in I2C mode only.
bit 0 BF: Buffer Full Status bit
1 = Receive is complete, SSPxBUF is full
0 = Receive is not complete, SSPxBUF is empty
Note 1: Polarity of clock state is set by the CKP bit (SSPxCON1<4>).
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DS39931D-page 272 2011 Microchip Technology Inc.
REGISTER 19-2: SSPxCON1: MSSPx CONTROL REGISTER 1 (SPI MODE) (ACCESS FC6h, F72h)
R/W-0 R/C-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WCOL SSPOV(1) SSPEN(2) CKP SSPM3(3) SSPM2(3) SSPM1(3) SSPM0(3)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit C = Clearable bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WCOL: Write Collision Detect bit
1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in
software)
0 = No collision
bit 6 SSPOV: Receive Overflow Indicator bit(1)
SPI Slave mode:
1 = A new byte is received while the SSPxBUF register is still holding the previous data. In case of over-
flow, the data in SSPxSR is lost. Overflow can only occur in Slave mode. The user must read the
SSPxBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software).
0 = No overflow
bit 5 SSPEN: Master Synchronous Serial Port Enable bit(2)
1 = Enables serial port and configures SCKx, SDOx, SDIx and SSx as serial port pins
0 = Disables serial port and configures these pins as I/O port pins
bit 4 CKP: Clock Polarity Select bit
1 = Idle state for clock is a high level
0 = Idle state for clock is a low level
bit 3-0 SSPM<3:0>: Master Synchronous Serial Port Mode Select bits(3)
0101 = SPI Slave mode, Clock = SCKx pin, SSx pin control is disabled, SSx can be used as I/O pin
0100 = SPI Slave mode, Clock = SCKx pin, SSx pin control is enabled
0011 = SPI Master mode, Clock = TMR2 output/2
0010 = SPI Master mode, Clock = FOSC/64
0001 = SPI Master mode, Clock = FOSC/16
0000 = SPI Master mode, Clock = FOSC/4
Note 1: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by
writing to the SSPxBUF register.
2: When enabled, this pin must be properly configured as input or output.
3: Bit combinations, not specifically listed here, are either reserved or implemented in I2C™ mode only.
2011 Microchip Technology Inc. DS39931D-page 273
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19.3.2 OPERATION
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits (SSPxCON1<5:0> and SSPxSTAT<7:6>).
These control bits allow the following to be specified:
Master mode (SCKx is the clock output)
Slave mode (SCKx is the clock input)
Clock Polarity (Idle state of SCKx)
Data Input Sample Phase (middle or end of data
output time)
Clock Edge (output data on rising/falling edge of
SCKx)
Clock Rate (Master mode only)
Slave Select mode (Slave mode only)
Each MSSP module consists of a Transmit/Receive
Shift register (SSPxSR) and a Buffer register
(SSPxBUF). The SSPxSR shifts the data in and out of
the device, MSb first. The SSPxBUF holds the data that
was written to the SSPxSR until the received data is
ready. Once the 8 bits of data have been received, that
byte is moved to the SSPxBUF register. Then, the Buffer
Full (BF) detect bit (SSPxSTAT<0>) and the interrupt
flag bit, SSPxIF, are set. This double-buffering of the
received data (SSPxBUF) allows the next byte to start
reception before reading the data that was just received.
Any write to the SSPxBUF register during transmis-
sion/reception of data will be ignored and the Write
Collision Detect bit, WCOL (SSPxCON1<7>), will be set.
User software must clear the WCOL bit so that it can be
determined if the following write(s) to the SSPxBUF
register completed successfully.
The Buffer Full bit, BF (SSPxSTAT<0>), indicates when
SSPxBUF has been loaded with the received data
(transmission is complete). When the SSPxBUF is read,
the BF bit is cleared. This data may be irrelevant if the
SPI is only a transmitter. Generally, the MSSP interrupt
is used to determine when the transmission/reception
has completed. If the interrupt method is not going to be
used, then software polling can be done to ensure that a
write collision does not occur.
Example 19-1 provides the loading of the SSPxBUF
(SSPxSR) for data transmission.
The SSPxSR is not directly readable or writable and
can only be accessed by addressing the SSPxBUF
register. Additionally, the SSPxSTAT register indicates
the various status conditions.
19.3.3 OPEN-DRAIN OUTPUT OPTION
The drivers for the SDOx output and SCKx clock pins
can be optionally configured as open-drain outputs.
This feature allows the voltage level on the pin to be
pulled to a higher level through an external pull-up
resistor, provided the SDOx or SCKx pin is not multi-
plexed with an ANx analog function. This allows the
output to communicate with external circuits without the
need for additional level shifters. For more information,
see Section 10.1.4 “Open-Drain Outputs”.
The open-drain output option is controlled by the
SPI2OD and SPI1OD bits (ODCON3<1:0>). Setting an
SPIxOD bit configures both SDOx and SCKx pins for the
corresponding open-drain operation.
EXAMPLE 19-1: LOADING THE SSP1BUF (SSP1SR) REGISTER
Note: When the application software is expecting
to receive valid data, the SSPxBUF should
be read before the next byte of transfer
data is written to the SSPxBUF. Application
software should follow this process even
when the current contents of SSPxBUF
are not important.
LOOP BTFSS SSP1STAT, BF ;Has data been received (transmit complete)?
BRA LOOP ;No
MOVF SSP1BUF, W ;WREG reg = contents of SSP1BUF
MOVWF RXDATA ;Save in user RAM, if data is meaningful
MOVF TXDATA, W ;W reg = contents of TXDATA
MOVWF SSP1BUF ;New data to xmit
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19.3.4 ENABLING SPI I/O
To enable the serial port, MSSP Enable bit, SSPEN
(SSPxCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, reinitialize the
SSPxCON1 registers and then set the SSPEN bit. This
configures the SDIx, SDOx, SCKx and SSx pins as
serial port pins. For the pins to behave as the serial port
function, the appropriate TRIS bits, ANCON/PCFG bits
and Peripheral Pin Select registers (if using MSSP2)
should be correctly initialized prior to setting the
SSPEN bit.
A typical SPI serial port initialization process follows:
Initialize ODCON3 register (optional open-drain
output control)
Initialize remappable pin functions (if using
MSSP2, see Section 10.7 “Peripheral Pin
Select (PPS)”)
Initialize SCKx LAT value to desired Idle SCK
level (if master device)
Initialize SCKx ANCON/PCFG bit (if Slave mode
and multiplexed with ANx function)
Initialize SCKx TRIS bit as output (Master mode)
or input (Slave mode)
Initialize SDIx ANCON/PCFG bit (if SDIx is
multiplexed with ANx function)
Initialize SDIx TRIS bit
Initialize SSx ANCON/PCFG bit (if Slave mode
and multiplexed with ANx function)
Initialize SSx TRIS bit (Slave modes)
Initialize SDOx TRIS bit
Initialize SSPxSTAT register
Initialize SSPxCON1 register
Set SSPEN bit to enable the module
Any MSSP1 serial port function that is not desired may
be overridden by programming the corresponding Data
Direction (TRIS) register to the opposite value. If
individual MSSP2 serial port functions will not be used,
they may be left unmapped.
19.3.5 TYPICAL CONNECTION
Figure 19-2 illustrates a typical connection between two
microcontrollers. The master controller (Processor 1)
initiates the data transfer by sending the SCKx signal.
Data is shifted out of both shift registers on their pro-
grammed clock edge and latched on the opposite edge
of the clock. Both processors should be programmed to
the same Clock Polarity (CKP), then both controllers
would send and receive data at the same time. Whether
the data is meaningful (or dummy data) depends on the
application software. This leads to three scenarios for
data transmission:
Master sends valid dataSlave sends dummy
data
Master sends valid dataSlave sends valid data
Master sends dummy dataSlave sends valid data
FIGURE 19-2: SPI MASTER/SLAVE CONNECTION
Note: When MSSP2 is used in SPI Master
mode, the SCK2 function must be config-
ured as both an output and an input in the
PPS module. SCK2 must be initialized as
an output pin (by writing 0x0A to one of
the RPORx registers). Additionally,
SCK2IN must also be mapped to the
same pin by initializing the RPINR22 reg-
ister. Failure to initialize SCK2/SCK2IN as
both output and input will prevent the
module from receiving data on the SDI2
pin, as the module uses the SCK2IN
signal to latch the received data.
Serial Input Buffer
(SSPxBUF)
Shift Register
(SSPxSR)
MSb LSb
SDOx
SDIx
PROCESSOR 1
SCKx
SPI Master SSPM<3:0> = 00xxb
Serial Input Buffer
(SSPxBUF)
Shift Register
(SSPxSR)
LSb
MSb
SDIx
SDOx
PROCESSOR 2
SCKx
SPI Slave SSPM<3:0> = 010xb
Serial Clock
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19.3.6 MASTER MODE
The master can initiate the data transfer at any time
because it controls the SCKx. The master determines
when the slave (Processor 2, Figure 19-2) is to
broadcast data by the software protocol.
In Master mode, the data is transmitted/received as
soon as the SSPxBUF register is written to. If the SPI
is only going to receive, the SDOx output could be dis-
abled (programmed as an input). The SSPxSR register
will continue to shift in the signal present on the SDIx
pin at the programmed clock rate. As each byte is
received, it will be loaded into the SSPxBUF register as
if a normal received byte (interrupts and status bits
appropriately set). This could be useful in receiver
applications as a “Line Activity Monitor” mode.
The CKP is selected by appropriately programming the
CKP bit (SSPxCON1<4>). This then, would give
waveforms for SPI communication as illustrated in
Figure 19-3, Figure 19-5 and Figure 19-6, where the
Most Significant Byte (MSB) is transmitted first. In
Master mode, the SPI clock rate (bit rate) is
user-programmable to be one of the following:
•F
OSC/4 (or TCY)
•FOSC/16 (or 4 • TCY)
•F
OSC/64 (or 16 • TCY)
Timer2 output/2
When using the Timer2 output/2 option, the Period
Register 2 (PR2) can be used to determine the SPI bit
rate. However, only PR2 values of 0x01 to 0xFF are
valid in this mode.
Figure 19-3 illustrates the waveforms for Master mode.
When the CKE bit is set, the SDOx data is valid before
there is a clock edge on SCKx. The change of the input
sample is shown based on the state of the SMP bit. The
time when the SSPxBUF is loaded with the received
data is shown.
FIGURE 19-3: SPI MODE WAVEFORM (MASTER MODE)
Note: To avoid lost data in Master mode, a read
of the SSPxBUF must be performed to
clear the Buffer Full (BF) detect bit
(SSPxSTAT<0>) between each
transmission.
SCKx
(CKP = 0
SCKx
(CKP = 1
SCKx
(CKP = 0
SCKx
(CKP = 1
4 Clock
Modes
Input
Sample
Input
Sample
SDIx
bit 7 bit 0
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
bit 7
SDIx
SSPxIF
(SMP = 1)
(SMP = 0)
(SMP = 1)
CKE = 1)
CKE = 0)
CKE = 1)
CKE = 0)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
(CKE = 0)
(CKE = 1)
Next Q4 Cycle
after Q2
bit 0
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19.3.7 SLAVE MODE
In Slave mode, the data is transmitted and received as
the external clock pulses appear on SCKx. When the
last bit is latched, the SSPxIF interrupt flag bit is set.
While in Slave mode, the external clock is supplied by
the external clock source on the SCKx pin. This
external clock must meet the minimum high and low
times as specified in the electrical specifications.
While in Sleep mode, the slave can transmit/receive
data. When a byte is received, the device can be
configured to wake-up from Sleep.
19.3.8 SLAVE SELECT
SYNCHRONIZATION
The SSx pin allows a Synchronous Slave mode. The
SPI must be in Slave mode with the SSx pin control
enabled (SSPxCON1<3:0> = 04h). When the SSx pin
is low, transmission and reception are enabled and the
SDOx pin is driven. When the SSx pin goes high, the
SDOx pin is no longer driven, even if in the middle of a
transmitted byte and becomes a floating output.
External pull-up/pull-down resistors may be desirable
depending on the application.
When the SPI module resets, the bit counter is forced
to ‘0’. This can be done by either forcing the SSx pin to
a high level or clearing the SSPEN bit.
To emulate two-wire communication, the SDOx pin can
be connected to the SDIx pin. When the SPI needs to
operate as a receiver, the SDOx pin can be configured
as an input. This disables transmissions from the
SDOx. The SDIx can always be left as an input (SDIx
function) since it cannot create a bus conflict.
FIGURE 19-4: SLAVE SYNCHRONIZATION WAV EFORM
Note 1: When the SPI is in Slave mode with the
SSx pin control enabled
(SSPxCON1<3:0> = 0100), the SPI
module will reset if the SSx pin is set to
VDD.
2: If the SPI is used in Slave mode with CKE
set, then the SSx pin control must be
enabled.
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7
SDOx bit 7 bit 6 bit 7
SSPxIF
Interrupt
(SMP = 0)
CKE = 0)
CKE = 0)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
bit 0
bit 7
bit 0
Next Q4 Cycle
after Q2
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FIGURE 19-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
FIGURE 19-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
SSPxIF
Interrupt
(SMP = 0)
CKE = 0)
CKE = 0)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
Optional
Next Q4 Cycle
after Q2
bit 0
SCKx
(CKP = 1
SCKx
(CKP = 0
Input
Sample
SDIx
bit 7 bit 0
SDOx bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
SSPxIF
Interrupt
(SMP = 0)
CKE = 1)
CKE = 1)
(SMP = 0)
Write to
SSPxBUF
SSPxSR to
SSPxBUF
SSx
Flag
Not Optional
Next Q4 Cycle
after Q2
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19.3.9 OPERATION IN POWER-MANAGED
MODES
In SPI Master mode, module clocks may be operating
at a different speed than when in full-power mode. In
the case of Sleep mode, all clocks are halted.
In Idle modes, a clock is provided to the peripherals.
That clock can be from the primary clock source, the
secondary clock (Timer1 oscillator) or the INTOSC
source. See Section 3.5 “Clock Sources and
Oscillato r Switchin g” for additional information.
In most cases, the speed that the master clocks SPI
data is not important; however, this should be
evaluated for each system.
If MSSP interrupts are enabled, they can wake the
controller from Sleep mode, or one of the Idle modes,
when the master completes sending data. If an exit
from Sleep or Idle mode is not desired, MSSP
interrupts should be disabled.
If the Sleep mode is selected, all module clocks are
halted and the transmission/reception will remain in
that state until the device wakes. After the device
returns to Run mode, the module will resume
transmitting and receiving data.
In SPI Slave mode, the SPI Transmit/Receive Shift
register operates asynchronously to the device. This
allows the device to be placed in any power-managed
mode and data to be shifted into the SPI
Transmit/Receive Shift register. When all 8 bits have
been received, the MSSP interrupt flag bit will be set,
and if enabled, will wake the device.
19.3.10 EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
19.3.11 BUS MODE COMPATIBILITY
Table 19-1 provides the compatibility between the
standard SPI modes and the states of the CKP and
CKE control bits.
TABLE 19-1: SPI BUS MODES
19.3.12 SPI CLOCK SPEED AND MODULE
INTERACTIONS
Because MSSP1 and MSSP2 are independent
modules, they can operate simultaneously at different
data rates. Setting the SSPM<3:0> bits of the
SSPxCON1 register determines the rate for the
corresponding module.
An exception is when both modules use Timer2 as a
time base in Master mode. In this instance, any
changes to the Timer2 module’s operation will affect
both MSSP modules equally. If different bit rates are
required for each module, the user should select one of
the other three time base options for one of the
modules.
Standard SPI Mode
Terminology
Control Bits State
CKP CKE
0, 0 0 1
0, 1 0 0
1, 0 1 1
1, 1 1 0
Note: There is also an SMP bit, which controls
when the data is sampled.
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TABLE 19-2: REGISTERS ASSOCIATED WITH SPI OPERATION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(2) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(2) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(2) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
TRISA TRISA7 TRISA6 TRISA5 TRISA3 TRISA2 TRISA1 TRISA0 72
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 72
TRISC TRISC7 TRISC6 ———TRISC2 TRISC1 TRISC0 72
SSP1BUF MSSP1 Receive Buffer/Transmit Register 70
SSPxCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 70
SSPxSTAT SMP CKE D/A P S R/W UA BF 70
SSP2BUF MSSP2 Receive Buffer/Transmit Register 73
ODCON3(1) ————SPI2ODSPI1OD74
Legend: Shaded cells are not used by the MSSP module in SPI mode.
Note 1: Configuration SFR overlaps with default SFR at this address; available only when WDTCON<4> = 1.
2: These bits are only available on 44-pin devices.
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19.4 SPI DMA MODULE
The SPI DMA module contains control logic to allow the
MSSP2 module to perform SPI direct memory access
transfers. This enables the module to quickly transmit
or receive large amounts of data with relatively little
CPU intervention. When the SPI DMA module is used,
MSSP2 can directly read and write to general purpose
SRAM. When the SPI DMA module is not enabled,
MSSP2 functions normally, but without DMA capability.
The SPI DMA module is composed of control logic, a
Destination Receive Address Pointer, a Transmit
Source Address Pointer, an interrupt manager and a
Byte Count register for setting the size of each DMA
transfer. The DMA module may be used with all SPI
Master and Slave modes, and supports both
half-duplex and full-duplex transfers.
19.4.1 I/O PIN CONSIDERATIONS
When enabled, the SPI DMA module uses the MSSP2
module. All SPI related input and output signals,
related to MSSP2, are routed through the Peripheral
Pin Select module. The appropriate initialization proce-
dure, as described in Section 19.4.6 “Using the SPI
DMA Module”, will need to be followed prior to using
the SPI DMA module. The output pins assigned to the
SDO2 and SCK2 functions can optionally be config-
ured as open-drain outputs, such as for level shifting
operations mentioned in the same section.
19.4.2 RAM TO RAM COPY OPERATIONS
Although the SPI DMA module is primarily intended to
be used for SPI communication purposes, the module
can also be used to perform RAM to RAM copy opera-
tions. To do this, configure the module for Full-Duplex
Master mode operation, but assign the SDO2 output
and SDI2 input functions onto the same RPn pin in the
PPS module. Also assign SCK2 out and SCK2 in onto
the same RPn pin (a different pin than used for SDO2
and SDI2). This will allow the module to operate in
Loopback mode, providing RAM copy capability.
19.4.3 IDLE AND SLEEP
CONSIDERATIONS
The SPI DMA module remains fully functional when the
microcontroller is in Idle mode.
During normal Sleep, the SPI DMA module is not func-
tional and should not be used. To avoid corrupting a
transfer, user firmware should be careful to make
certain that pending DMA operations are complete by
polling the DMAEN bit in the DMACON1 register, prior
to putting the microcontroller into Sleep.
In SPI Slave modes, the MSSP2 module is capable of
transmitting and/or receiving one byte of data while in
Sleep mode. This allows the SSP2IF flag in the PIR3
register to be used as a wake-up source. When the
DMAEN bit is cleared, the SPI DMA module is
effectively disabled, and the MSSP2 module functions
normally, but without DMA capabilities. If the DMAEN
bit is clear prior to entering Sleep, it is still possible to
use the SSP2IF as a wake-up source without any data
loss.
Neither MSSP2 nor the SPI DMA module will provide
any functionality in Deep Sleep. Upon exiting from
Deep Sleep, all of the I/O pins, MSSP2 and SPI DMA
related registers will need to be fully reinitialized before
the SPI DMA module can be used again.
19.4.4 REGISTERS
The SPI DMA engine is enabled and controlled by the
following Special Function Registers:
DMACON1 DMACON2
TXADDRH TXADDRL
RXADDRH RXADDRL
DMABCH DMABCL
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19.4.4.1 DMACON1
The DMACON1 register is used to select the main oper-
ating mode of the SPI DMA module. The SSCON1 and
SSCON0 bits are used to control the slave select pin.
When MSSP2 is used in SPI Master mode with the SPI
DMA module, SSDMA can be controlled by the DMA
module as an output pin. If MSSP2 will be used to com-
municate with an SPI slave device that needs the SSx
pin to be toggled periodically, the SPI DMA hardware
can automatically be used to deassert SSx between
each byte, every two bytes or every four bytes.
Alternatively, user firmware can manually generate
slave select signals with normal general purpose I/O
pins, if required by the slave device(s).
When the TXINC bit is set, the TXADDR register will
automatically increment after each transmitted byte.
Automatic transmit address increment can be disabled
by clearing the TXINC bit. If the automatic transmit
address increment is disabled, each byte, which is out-
put on SDO2, will be the same (the contents of the
SRAM pointed to by the TXADDR register) for the
entire DMA transaction.
When the RXINC bit is set, the RXADDR register will
automatically increment after each received byte.
Automatic receive address increment can be disabled
by clearing the RXINC bit. If RXINC is disabled in
Full-Duplex or Half-Duplex Receive modes, all incom-
ing data bytes on SDI2 will overwrite the same memory
location pointed to by the RXADDR register. After the
SPI DMA transaction has completed, the last received
byte will reside in the memory location pointed to by the
RXADDR register.
The SPI DMA module can be used for either half-duplex
receive only communication, half-duplex transmit only
communication or full-duplex simultaneous transmit and
receive operations. All modes are available for both SPI
master and SPI slave configurations. The DUPLEX0
and DUPLEX1 bits can be used to select the desired
operating mode.
The behavior of the DLYINTEN bit varies greatly
depending on the SPI operating mode. For example
behavior for each of the modes, see Figure 19-3
through Figure 19-6.
SPI Slave mode, DLYINTEN = 1: In this mode, an
SSP2IF interrupt will be generated during a transfer if
the time between successful byte transmission events is
longer than the value set by the DLYCYC<3:0> bits in
the DMACON2 register. This interrupt allows slave
firmware to know that the master device is taking an
unusually large amount of time between byte transmis-
sions. For example, this information may be useful for
implementing application-defined communication proto-
cols, involving time-outs if the bus remains Idle for too
long. When DLYINTEN = 1, the DLYLVL<3:0> interrupts
occur normally according to the selected setting.
SPI Slave mode, DLYINTEN = 0: In this mode, the
time-out-based interrupt is disabled. No additional
SSP2IF interrupt events will be generated by the SPI
DMA module, other than those indicated by the
INTLVL<3:0> bits in the DMACON2 register. In this
mode, always set DLYCYC<3:0> = 0000.
SPI Master mode, DLYINTEN = 0: The DLYCYC<3:0>
bits in the DMACON2 register determine the amount of
additional inter-byte delay, which is added by the SPI
DMA module during a transfer. The Master mode SS2
output feature may be used.
SPI Master mode, DLYINTEN = 1: The amount of
hardware overhead is slightly reduced in this mode,
and the minimum inter-byte delay is 8 T
CY for FOSC/4,
9 TCY for FOSC/16 and 15 TCY for FOSC/64. This mode
can potentially be used to obtain slightly higher effec-
tive SPI bandwidth. In this mode, the SS2 control
feature cannot be used, and should always be disabled
(DMACON1<7:6> = 00). Additionally, the interrupt
generating hardware (used in Slave mode) remains
active. To avoid extraneous SSP2IF interrupt events,
set the DMACON2 delay bits, DLYCYC<3:0> = 1111,
and ensure that the SPI serial clock rate is no slower
than FOSC/64.
In SPI Master modes, the DMAEN bit is used to enable
the SPI DMA module and to initiate an SPI DMA trans-
action. After user firmware sets the DMAEN bit, the
DMA hardware will begin transmitting and/or receiving
data bytes according to the configuration used. In SPI
Slave modes, setting the DMAEN bit will finish the
initialization steps needed to prepare the SPI DMA
module for communication (which must still be initiated
by the master device).
To avoid possible data corruption, once the DMAEN bit
is set, user firmware should not attempt to modify any
of the MSSP2 or SPI DMA related registers, with the
exception of the INTLVL bits in the DMACON2 register.
If user firmware wants to halt an ongoing DMA transac-
tion, the DMAEN bit can be manually cleared by the
firmware. Clearing the DMAEN bit while a byte is
currently being transmitted will not immediately halt the
byte in progress. Instead, any byte currently in
progress will be completed before the MSSP2 and SPI
DMA modules go back to their Idle conditions. If user
firmware clears the DMAEN bit, the TXADDR,
RXADDR and DMABC registers will no longer update,
and the DMA module will no longer make any
additional read or writes to SRAM; therefore, state
information can be lost.
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REGISTER 19-3: DMACON1: DMA CONTROL REGISTER 1 (ACCESS F88h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
SSCON1 SSCON0 TXINC RXINC DUPLEX1 DUPLEX0 DLYINTEN DMAEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-6 SSCON<1:0>: SSDMA Output Control bits (Master modes only)
11 = SSDMA is asserted for the duration of 4 bytes; DLYINTEN is always reset low
01 = SSDMA is asserted for the duration of 2 bytes; DLYINTEN is always reset low
10 = SSDMA is asserted for the duration of 1 byte; DLYINTEN is always reset low
00 = SSDMA is not controlled by the DMA module; DLYINTEN bit is software-programmable
bit 5 TXINC: Transmit Address Increment Enable bit
Allows the transmit address to increment as the transfer progresses.
1 = The transmit address is to be incremented from the initial value of TXADDR<11:0>
0 = The transmit address is always set to the initial value of TXADDR<11:0>
bit 4 RXINC: Receive Address Increment Enable bit
Allows the receive address to increment as the transfer progresses.
1 = The receive address is to be incremented from the inti al value of RXADDR<11:0>
0 = The receive address is always set to the initial value of RXADDR<11:0>
bit 3-2 DUPLEX<1:0>: Transmit/Receive Operating Mode Select bits
10 = SPI DMA operates in Full-Duplex mode, data is simultaneously transmitted and received
01 = DMA operates in Half-Duplex mode, data is transmitted only
00 = DMA operates in Half-Duplex mode, data is received only
bit 1 DLYINTEN: Delay Interrupt Enable bit
Enables the interrupt to be invoked after the number of T
CY cycles specified in DLYCYC<2:0> has
elapsed from the latest completed transfer.
1 = The interrupt is enabled, SSCON<1:0> must be set to ‘00
0 = The interrupt is disabled
bit 0 DMAEN: DMA Operation Start/Stop bit
This bit is set by the users’ software to start the DMA operation. It is reset back to zero by the DMA
engine when the DMA operation is completed or aborted.
1 = DMA is in session
0 = DMA is not in session
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19.4.4.2 DMACON2
The DMACON2 register contains control bits for
controlling interrupt generation and inter-byte delay
behavior. The INTLVL<3:0> bits are used to select when
an SSP2IF interrupt should be generated.The function
of the DLYCYC<3:0> bits depends on the SPI operating
mode (Master/Slave), as well as the DLYINTEN setting.
In SPI Master mode, the DLYCYC<3:0> bits can be used
to control how much time the module will Idle between
bytes in a transfer. By default, the hardware requires a
minimum delay of: 8 TCY for FOSC/4, 9 TCY for FOSC/16
and 15 TCY for FOSC/64. Additional delay can be added
with the DLYCYC bits. In SPI Slave modes, the
DLYCYC<3:0> bits may optionally be used to trigger an
additional time-out based interrupt.
REGISTER 19-4: DMACON2: DMA CONTROL REGISTER 2 (ACCESS F86h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
DLYCYC3 DLYCYC2 DLYCYC1 DLYCYC0 INTLVL3 INTLVL2 INTLVL1 INTLVL0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 DLYCYC<3:0>: Delay Cycle Selection bits
When DLYINTEN = 0, these bits specify the additional delay (above the base overhead of the hard-
ware) in number of TCY cycles before the SSP2BUF register is written again for the next transfer. When
DLYINTEN = 1, these bits specify the delay in number of TCY cycles from the latest completed transfer
before an interrupt to the CPU is invoked. In this case, the additional delay before the SSP2BUF
register is written again is 1 T
CY + (base overhead of hardware).
1111 = Delay time in number of instruction cycles is 2,048 cycles
1110 = Delay time in number of instruction cycles is 1,024 cycles
1101 = Delay time in number of instruction cycles is 896 cycles
1100 = Delay time in number of instruction cycles is 768 cycles
1011 = Delay time in number of instruction cycles is 640 cycles
1010 = Delay time in number of instruction cycles is 512 cycles
1001 = Delay time in number of instruction cycles is 384 cycles
1000 = Delay time in number of instruction cycles is 256 cycles
0111 = Delay time in number of instruction cycles is 128 cycles
0110 = Delay time in number of instruction cycles is 64 cycles
0101 = Delay time in number of instruction cycles is 32 cycles
0100 = Delay time in number of instruction cycles is 16 cycles
0011 = Delay time in number of instruction cycles is 8 cycles
0010 = Delay time in number of instruction cycles is 4 cycles
0001 = Delay time in number of instruction cycles is 2 cycles
0000 = Delay time in number of instruction cycles is 1 cycle
bit 3-0 INTLVL<3:0>: Watermark Interrupt Enable bits
These bits specify the amount of remaining data yet to be transferred (transmitted and/or received)
upon which an interrupt is generated.
1111 = Amount of remaining data to be transferred is 576 bytes
1110 = Amount of remaining data to be transferred is 512 bytes
1101 = Amount of remaining data to be transferred is 448 bytes
1100 = Amount of remaining data to be transferred is 384 bytes
1011 = Amount of remaining data to be transferred is 320 bytes
1010 = Amount of remaining data to be transferred is 256 bytes
1001 = Amount of remaining data to be transferred is 192 bytes
1000 = Amount of remaining data to be transferred is 128 bytes
0111 = Amount of remaining data to be transferred is 67 bytes
0110 = Amount of remaining data to be transferred is 32 bytes
0101 = Amount of remaining data to be transferred is 16 bytes
0100 = Amount of remaining data to be transferred is 8 bytes
0011 = Amount of remaining data to be transferred is 4 bytes
0010 = Amount of remaining data to be transferred is 2 bytes
0001 = Amount of remaining data to be transferred is 1 byte
0000 = Transfer complete
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19.4.4.3 DMABCH and DMABCL
The DMABCH and DMABCL register pair forms a 10-bit
Byte Count register, which is used by the SPI DMA
module to send/receive up to 1,024 bytes for each DMA
transaction. When the DMA module is actively running
(DMAEN = 1), the DMA Byte Count register decrements
after each byte is transmitted/received. The DMA trans-
action will halt, and the DMAEN bit will be automatically
cleared by hardware after the last byte has completed.
After a DMA transaction is complete, the DMABC
register will read 0x000.
Prior to initiating a DMA transaction by setting the
DMAEN bit, user firmware should load the appropriate
value into the DMABCH/DMABCL registers. The
DMABC is a “base zero” counter, so the actual number
of bytes, which will be transmitted, follows in
Equation 19-1.
For example, if user firmware wants to transmit 7 bytes
in one transaction, DMABC should be loaded with
006h. Similarly, if user firmware wishes to transmit
1,024 bytes, DMABC should be loaded with 3FFh.
EQUATION 19-1: BYTES TRANSMITTED
FOR A GIVEN DMABC
19.4.4.4 TXADDRH and TXADDRL
The TXADDRH and TXADDRL registers pair together
to form a 12-bit Transmit Source Address Pointer
register. In modes that use TXADDR (Full-Duplex and
Half-Duplex Transmit), the TXADDR will be incre-
mented after each byte is transmitted. Transmitted data
bytes will be taken from the memory location pointed to
by the TXADDR register. The contents of the memory
locations pointed to by TXADDR will not be modified by
the DMA module during a transmission.
The SPI DMA module can read from and transmit data
from all general purpose memory on the device, including
memory used for USB endpoint buffers. The SPI DMA
module cannot be used to read from the Special Function
Registers (SFRs) contained in Banks 14 and 15.
19.4.4.5 RXADDRH and RXADDRL
The RXADDRH and RXADDRL register pair together
to form a 12-bit Receive Destination Address Pointer.
In modes that use RXADDR (Full-Duplex and
Half-Duplex Receive), the RXADDR register will be
incremented after each byte is received. Received data
bytes will be stored at the memory location pointed to
by the RXADDR register.
The SPI DMA module can write received data to all
general purpose memory on the device, including
memory used for USB endpoint buffers. The SPI DMA
module cannot be used to modify the Special Function
Registers contained in Banks 14 and 15.
19.4.5 INTERRUPTS
The SPI DMA module alters the behavior of the SSP2IF
interrupt flag. In normal/non-DMA modes, the SSP2IF is
set once after every single byte is transmitted/received
through the MSSP2 module. When MSSP2 is used with
the SPI DMA module, the SSP2IF interrupt flag will be
set according to the user-selected INTLVL<3:0> value
specified in the DMACON2 register. The SSP2IF inter-
rupt condition will also be generated once the SPI DMA
transaction has fully completed and the DMAEN bit has
been cleared by hardware.
The SSP2IF flag becomes set once the DMA byte count
value indicates that the specified INTLVL has been
reached. For example, if DMACON2<3:0> = 0101
(16 bytes remaining), the SSP2IF interrupt flag will
become set once DMABC reaches 00Fh. If user
firmware then clears the SSP2IF interrupt flag, the flag
will not be set again by the hardware until after all bytes
have been fully transmitted and the DMA transaction is
complete.
For example, if DMABC = 00Fh (implying 16 bytes are
remaining) and user firmware writes1111’ to
INTLVL<3:0> (interrupt when 576 bytes are remain-
ing), the SSP2IF interrupt flag will immediately become
set. If user firmware clears this interrupt flag, a new
interrupt condition will not be generated until either:
user firmware again writes INTLVL with an interrupt
level higher than the actual remaining level, or the DMA
transaction completes and the DMAEN bit is cleared.
BytesXMIT DMABC 1+
Note: User firmware may modify the INTLVL bits
while a DMA transaction is in progress
(DMAEN = 1). If an INTLVL value is
selected which is higher than the actual
remaining number of bytes (indicated by
DMABC + 1), the SSP2IF interrupt flag
will immediately become set.
Note: If the INTLVL bits are modified while a
DMA transaction is in progress, care
should be taken to avoid inadvertently
changing the DLYCYC<3:0> value.
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19.4.6 USING THE SPI DMA MODULE
The following steps would typically be taken to enable
and use the SPI DMA module:
1. Configure the I/O pins, which will be used by
MSSP2:
a) Assign SCK2, SDO2, SDI2 and SS2 to RPn
pins as appropriate for the SPI mode which
will be used. Only functions which will be
used need to be assigned to a pin.
b) Initialize the associated LATx registers for
the desired Idle SPI bus state.
c) If Open-Drain Output mode on SDO2 and
SCK2 (Master mode) is desired, set
ODCON3<1>.
d) Configure corresponding TRISx bits for
each I/O pin used.
2. Configure and enable MSSP2 for the desired
SPI operating mode:
a) Select the desired operating mode (Master
or Slave, SPI Mode 0, 1, 2 and 3) and con-
figure the module by writing to the
SSP2STAT and SSP2CON1 registers.
b) Enable MSSP2 by setting SSP2CON1<5> = 1.
3. Configure the SPI DMA engine.:
a) Select the desired operating mode by
writing the appropriate values to
DMACON2 and DMACON1.
b) Initialize the TXADDRH/TXADDRL Pointer
(Full-Duplex or Half-Duplex Transmit Only
mode).
c) Initialize the RXADDRH/RXADDRL Pointer
(Full-Duplex or Half-Duplex Receive Only
mode).
d) Initialize the DMABCH/DMABCL Byte Count
register with the number of bytes to be
transferred in the next SPI DMA operation.
e) Set the DMAEN bit (DMACON1<0>).
In SPI Master modes, this will initiate a DMA
transaction. In SPI Slave modes, this will
complete the initialization process, and the
module will now be ready to begin receiving
and/or transmitting data to the master
device once the master starts the
transaction.
4. Detect the SSP2IF interrupt condition (PIR3<7):
a) If the interrupt was configured to occur at
the completion of the SPI DMA transaction,
the DMAEN bit (DMACON1<0>) will be
clear. User firmware may prepare the
module for another transaction by repeating
Steps 3.b through 3.e.
b) If the interrupt was configured to occur prior
to the completion of the SPI DMA trans-
action, the DMAEN bit may still be set,
indicating the transaction is still in progress.
User firmware would typically use this inter-
rupt condition to begin preparing new data
for the next DMA transaction. Firmware
should not repeat Steps 3.b. through 3.e.
until the DMAEN bit is cleared by the
hardware, indicating the transaction is
complete.
Example 19-2 provides example code demonstrating
the initialization process and the steps needed to use
the SPI DMA module to perform a 512-byte
Full-Duplex, Master mode transfer.
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EXAMPLE 19-2: 512-BYTE SPI MASTER MODE Init AND TRANSFER
;For this example, let's use RP5(RB2) for SCK2,
;RP4(RB1) for SDO2, and RP3(RB0) for SDI2
;Let’s use SPI master mode, CKE = 0, CKP = 0,
;without using slave select signalling.
InitSPIPins:
movlb 0x0F ;Select bank 15, for access to ODCON3 register
bcf ODCON3, SPI2OD ;Let’s not use open drain outputs in this example
bcf LATB, RB2 ;Initialize our (to be) SCK2 pin low (idle).
bcf LATB, RB1 ;Initialize our (to be) SDO2 pin to an idle state
bcf TRISB, RB1 ;Make SDO2 output, and drive low
bcf TRISB, RB2 ;Make SCK2 output, and drive low (idle state)
bsf TRISB, RB0 ;SDI2 is an input, make sure it is tri-stated
;Now we should unlock the PPS registers, so we can
;assign the MSSP2 functions to our desired I/O pins.
movlb 0x0E ;Select bank 14 for access to PPS registers
bcf INTCON, GIE ;I/O Pin unlock sequence will not work if CPU
;services an interrupt during the sequence
movlw 0x55 ;Unlock sequence consists of writing 0x55
movwf EECON2 ;and 0xAA to the EECON2 register.
movlw 0xAA
movwf EECON2
bcf PPSCON, IOLOCK ;We may now write to RPINRx and RPORx registers
bsf INTCON, GIE ;May now turn back on interrupts if desired
movlw 0x03 ;RP3 will be SDI2
movwf RPINR21 ;Assign the SDI2 function to pin RP3
movlw 0x0A ;Let’s assign SCK2 output to pin RP4
movwf RPOR4 ;RPOR4 maps output signals to RP4 pin
movlw 0x04 ;SCK2 als o needs to be conf igured as an input on the
same pin
movwf RPINR22 ;SCK2 input function taken from RP4 pin
movlw 0x09 ;0x09 is SDO2 output
movwf RPOR5 ;Assign SDO2 output signal to the RP5 (RB2) pin
movlb 0x0F ;Done with PPS registers, bank 15 has other SFRs
InitMSSP2:
clrf SSP2STAT ;CKE = 0, SMP = 0 (sampled at middle of bit)
movlw b'00000000' ;CKP = 0, SPI Master mode, Fosc/4
movwf SSP2CON1 ;MSSP2 initialized
bsf SSP2CON1, SSPEN ;Enable the MSSP2 module
InitSPIDMA:
movlw b'00111010' ;Full duplex, RX/TXINC enabled, no SSCON
movwf DMACON1 ;DLYINTEN is set, so DLYCYC3:DLYCYC0 = 1111
movlw b'11110000' ;Minimum delay between bytes, interrupt
movwf DMACON2 ;only once when the transaction is complete
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;Somewhere else in our project, lets assume we have
;allocated some RAM for use as SPI receive and
;transmit buffers.
; udata 0x500
;DestBuf res 0x200 ;Let’s reserve 0x500-0x6FF for use as our SPI
; ;receive data buffer in this example
;SrcBuf res 0x200 ;Lets reserve 0x700-0x8FF for use as our SPI
; ;transmit data buffer in this example
PrepareTransfer:
movlw HIGH(DestBuf) ;Get high byte of DestBuf address (0x05)
movwf RXADDRH ;Load upper four bits of the RXADDR register
movlw LOW(DestBuf) ;Get low byte of the DestBuf address (0x00)
movwf RXADDRL ;Load lower eight bits of the RXADDR register
movlw HIGH(SrcBuf) ;Get high byte of SrcBuf address (0x07)
movwf TXADDRH ;Load upper four bits of the TXADDR register
movlw LOW(SrcBuf) ;Get low byte of the SrcBuf address (0x00)
movwf TXADDRL ;Load lower eight bits of the TXADDR register
movlw 0x01 ;Lets move 0x200 (512) bytes in one DMA xfer
movwf DMABCH ;Load the upper two bits of DMABC register
movlw 0xFF ;Actual bytes transferred is (DMABC + 1), so
movwf DMABCL ;we load 0x01FF into DMABC to xfer 0x200 bytes
BeginXfer:
bsf DMACON1, DMAEN ;The SPI DMA module will now begin transferring
;the data taken from SrcBuf, and will store
;received bytes into DestBuf.
;Execute whatever ;CPU is now free to do whatever it wants to
;and the DMA operation will continue without
;intervention, until it completes.
;When the transfer is complete, the SSP2IF flag in
;the PIR3 register will become set, and the DMAEN bit
;is automatically cleared by the hardware.
;The DestBuf (0x500-0x7FF) will contain the received
;data. To start another transfer, firmware wil l need
;to reinitialize RXADDR, TXADDR, DMABC and then
;set the DMAEN bit.
EXAMPLE 19-2: 512-BYTE SPI MASTER MODE Init AND TRANSFER (CONTINUED)
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19.5 I2C Mode
The MSSP module in I2C mode fully implements all
master and slave functions (including general call
support), and provides interrupts on Start and Stop bits
in hardware to determine a free bus (multi-master
function). The MSSP module implements the standard
mode specifications and 7-bit and 10-bit addressing.
Two pins are used for data transfer:
Serial Clock (SCLx) –
RB4/PMA1/KBI0/SCK1/SCL1/RP7 or
RD0/PMD0/SCL2
Serial Data (SDAx) –
RB5/PMA0/KBI1/SDI1/SDA1/RP8 or
RD1/PMD1/SDA2
The user must configure these pins as inputs by setting
the associated TRIS bits. These pins are up to 5.5V
tolerant, allowing direct use in I2C busses operating at
voltages higher than VDD.
FIGUR E 19-7: MSSPx BLOCK DIAGRAM
(I2C™ MODE)
19.5.1 REGISTERS
The MSSP module has six registers for I2C operation.
These are:
MSSPx Control Register 1 (SSPxCON1)
MSSPx Control Register 2 (SSPxCON2)
MSSPx Status Register (SSPxSTAT)
Serial Receive/Transmit Buffer Register
(SSPxBUF)
MSSPx Shift Register (SSPxSR) – Not directly
accessible
MSSPx Address Register (SSPxADD)
MSSPx 7-Bit Address Mask Register (SSPxMSK)
SSPxCON1, SSPxCON2 and SSPxSTAT are the
control and status registers in I2C mode operation. The
SSPxCON1 and SSPxCON2 registers are readable and
writable. The lower six bits of the SSPxSTAT are
read-only. The upper two bits of the SSPxSTAT are
read/write.
SSPxSR is the shift register used for shifting data in or
out. SSPxBUF is the buffer register to which data
bytes are written to or read from.
SSPxADD contains the slave device address when the
MSSP is configured in I2C Slave mode. When the
MSSP is configured in Master mode, the lower seven
bits of SSPxADD act as the Baud Rate Generator
(BRG) reload value.
SSPxMSK holds the slave address mask value when
the module is configured for 7-Bit Address Masking
mode. While it is a separate register, it shares the same
SFR address as SSPxADD; it is only accessible when
the SSPM<3:0> bits are specifically set to permit
access. Additional details are provided in
Section 19.5.3.4 “7-Bit Address Masking Mode”.
In receive operations, SSPxSR and SSPxBUF
together, create a double-buffered receiver. When
SSPxSR receives a complete byte, it is transferred to
SSPxBUF and the SSPxIF interrupt is set.
During transmission, the SSPxBUF is not
double-buffered. A write to SSPxBUF will write to both
SSPxBUF and SSPxSR.
Read Write
SSPxSR reg
Match Detect
SSPxADD reg
SSPxBUF reg
Internal
Data Bus
Addr Match
Set, Reset
S, P bits
(SSPxSTAT reg)
Shift
Clock
MSb LSb
Note: Only port I/O names are used in this diagram for
the sake of brevity. Refer to the text for a full list of
multiplexed functions.
SCLx
SDAx
Start and
Stop bit Detect
Address Mask
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REGISTER 19-5: SSPxSTAT: MSSPx STATUS REGISTER (I2C™ MODE) (ACCESS FC7h, F73h)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
SMP CKE D/A P(1) S(1) R/W(2,3) UA BF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SMP: Slew Rate Control bit
In Master or Slave mode:
1 = Slew rate control is disabled for Standard Speed mode (100 kHz and 1 MHz)
0 = Slew rate control is enabled for High-Speed mode (400 kHz)
bit 6 CKE: SMBus Select bit
In Master or Slave mode:
1 = Enable SMBus-specific inputs
0 = Disable SMBus-specific inputs
bit 5 D/A: Data/Address bit
In Master mode:
Reserved.
In Slave mode:
1 = Indicates that the last byte received or transmitted was data
0 = Indicates that the last byte received or transmitted was address
bit 4 P: Stop bit(1)
1 = Indicates that a Stop bit has been detected last
0 = Stop bit was not detected last
bit 3 S: Start bit(1)
1 = Indicates that a Start bit has been detected last
0 = Start bit was not detected last
bit 2 R/W: Read/Write Information bit(2,3)
In Slave mode:
1 = Read
0 = Write
In Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
bit 1 UA: Update Address bit (10-Bit Slave mode only)
1 = Indicates that the user needs to update the address in the SSPxADD register
0 = Address does not need to be updated
bit 0 BF: Buffer Full Status bit
In Transmit mode:
1 = SSPxBUF is full
0 = SSPxBUF is empty
In Receive mode:
1 = SSPxBUF is full (does not include the ACK and Stop bits)
0 = SSPxBUF is empty (does not include the ACK and Stop bits)
Note 1: This bit is cleared on Reset and when SSPEN is cleared.
2: This bit holds the R/W bit information following the last address match. This bit is only valid from the
address match to the next Start bit, Stop bit or not ACK bit.
3: ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSPx is in Active mode.
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REGISTER 19-6: SSPxCON 1: MSSP x CON TRO L REGISTE R 1 (I2C™ MOD E) ( A CCESS FC6h, F72h)
R/W-0 R/C-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
WCOL SSPOV SSPEN(1) CKP SSPM3(2) SSPM2(2) SSPM1(2) SSPM0(2)
bit 7 bit 0
Legend: C = Clearable bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WCOL: Write Collision Detect bit
In Master Transmit mode:
1 = A write to the SSPxBUF register was attempted while the I2C conditions were not valid for a
transmission to be started (must be cleared in software)
0 = No collision
In Slave Transmit mode:
1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in
software)
0 = No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit.
bit 6 SSPOV: Receive Overflow Indicator bit
In Receive mode:
1 = A byte is received while the SSPxBUF register is still holding the previous byte (must be cleared
in software)
0 = No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode.
bit 5 SSPEN: Master Synchronous Serial Port Enable bit(1)
1 = Enables the serial port and configures the SDAx and SCLx pins as the serial port pins
0 = Disables serial port and configures these pins as I/O port pins
bit 4 CKP: SCKx Release Control bit
In Slave mode:
1 = Releases clock
0 = Holds clock low (clock stretch); used to ensure data setup time
In Master mode:
Unused in this mode.
bit 3-0 SSPM<3:0>: Master Synchronous Serial Port Mode Select bits(2)
1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1011 = I2C Firmware Controlled Master mode (slave Idle)
1001 = Load SSPxMSK register at SSPxADD SFR address(3,4)
1000 = I2C Master mode, Clock = FOSC/(4 * (SSPxADD + 1))
0111 = I2C Slave mode, 10-bit address
0110 = I2C Slave mode, 7-bit address
Note 1: When enabled, the SDAx and SCLx pins must be configured as inputs.
2: Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
3: When SSPM<3:0> = 1001, any reads or writes to the SSPxADD SFR address actually accesses the
SSPxMSK register.
4: This mode is only available when 7-Bit Address Masking mode is selected (MSSPMSK Configuration bit is ‘1’).
2011 Microchip Technology Inc. DS39931D-page 291
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REGISTER 19-7: SSPxCON2: MSSPx CONTROL REGISTER 2 (I2C™ MASTER MODE)
(ACCESS FC5h, F71h)
R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
GCEN(3) ACKSTAT ACKDT(1) ACKEN(2) RCEN(2) PEN(2) RSEN(2) SEN(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 GCEN: General Call Enable bit (Slave mode only)(3)
1 = Enable interrupt when a general call address (0000h) is received in the SSPxSR
0 = General call address is disabled
bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only)
1 = Acknowledge was not received from slave
0 = Acknowledge was received from slave
bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only)(1)
1 = Not Acknowledged
0 = Acknowledge
bit 4 ACKEN: Acknowledge Sequence Enable bit(2)
1 = Initiates Acknowledge sequence on SDAx and SCLx pins and transmits ACKDT data bit;
automatically cleared by hardware
0 = Acknowledge sequence is Idle
bit 3 RCEN: Receive Enable bit (Master Receive mode only)(2)
1 = Enables Receive mode for I2C
0 = Receive is Idle
bit 2 PEN: Stop Condition Enable bit(2)
1 = Initiates Stop condition on SDAx and SCLx pins; automatically cleared by hardware
0 = Stop condition is Idle
bit 1 RSEN: Repeated Start Condition Enable bit(2)
1 = Initiates Repeated Start condition on SDAx and SCLx pins; automatically cleared by hardware
0 = Repeated Start condition is Idle
bit 0 SEN: Start Condition Enable bit(2)
1 = Initiates Start condition on SDAx and SCLx pins; automatically cleared by hardware
0 = Start condition is Idle
Note 1: Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive.
2: If the I2C module is active, these bits may not be set (no spooling) and the SSPxBUF may not be written
(or writes to the SSPxBUF are disabled).
3: This bit is not implemented in I2C Master mode.
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REGISTER 19-9: SSPxMSK: I2C™ SLAVE ADDRESS MASK REGISTER (7-BIT MASKING MODE)
(ACCESS FC8h, F74h)(1)
REGISTER 19-8: SSPxCON2: MSSPx CONTROL REGISTER 2 (I2C™ SLAVE MODE)
(ACCESS FC5h, F71h)
R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
GCEN ACKSTAT(2) ADMSK5 ADMSK4 ADMSK3 ADMSK2 ADMSK1 SEN(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 GCEN: General Call Enable bit (Slave mode only)
1 = Enables interrupt when a general call address (0000h) is received in the SSPxSR
0 = General call address is disabled
bit 6 ACKSTAT: Acknowledge Status bit(2)
Unused in Slave mode.
bit 5-2 ADMSK<5:2>: Slave Address Mask Select bits (5-Bit Address Masking)
1 = Masking of corresponding bits of SSPxADD is enabled
0 = Masking of corresponding bits of SSPxADD is disabled
bit 1 ADMSK1: Slave Address Least Significant bit(s) Mask Select bit
In 7-Bit Addressing mode:
1 = Masking of SSPxADD<1> only is enabled
0 = Masking of SSPxADD<1> only is disabled
In 10-Bit Addressing mode:
1 = Masking of SSPxADD<1:0> is enabled
0 = Masking of SSPxADD<1:0> is disabled
bit 0 SEN: Start Condition Enable/Stretch Enable bit(1)
1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled)
0 = Clock stretching is disabled
Note 1: If the I2C module is active, these bits may not be set (no spooling) and the SSPxBUF may not be written
(or writes to the SSPxBUF are disabled).
2: This bit is unimplemented in I2C Slave mode.
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0(2)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set 0’ = Bit is cleared x = Bit is unknown
bit 7-0 MSK<7:0>: Slave Address Mask Select bits
1 = Masking of corresponding bit of SSPxADD is enabled
0 = Masking of corresponding bit of SSPxADD is disabled
Note 1: This register shares the same SFR address as SSPxADD and is only addressable in select MSSP
operating modes. See Section 19.5.3.4 “7-Bit Address Masking Mode” for more details.
2: MSK0 is not used as a mask bit in 7-bit addressing.
2011 Microchip Technology Inc. DS39931D-page 293
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19.5.2 OPERATION
The MSSP module functions are enabled by setting the
MSSP Enable bit, SSPEN (SSPxCON1<5>).
The SSPxCON1 register allows control of the I2C
operation. Four mode selection bits (SSPxCON1<3:0>)
allow one of the following I2C modes to be selected:
•I
2C Master mode, clock
•I
2C Slave mode (7-bit address)
•I
2C Slave mode (10-bit address)
•I
2C Slave mode (7-bit address) with Start and
Stop bit interrupts enabled
•I
2C Slave mode (10-bit address) with Start and
Stop bit interrupts enabled
•I
2C Firmware Controlled Master mode, slave is
Idle
Selection of any I2C mode with the SSPEN bit set
forces the SCLx and SDAx pins to be open-drain,
provided these pins are programmed as inputs by
setting the appropriate TRISB or TRISD bits. To ensure
proper operation of the module, pull-up resistors must
be provided externally to the SCLx and SDAx pins.
19.5.3 SLAVE MODE
In Slave mode, the SCLx and SDAx pins must be
configured as inputs (TRISB<5:4> set). The MSSP
module will override the input state with the output data
when required (slave-transmitter).
The I2C Slave mode hardware will always generate an
interrupt on an address match. Address masking will
allow the hardware to generate an interrupt for more
than one address (up to 31 in 7-bit addressing and up
to 63 in 10-bit addressing). Through the mode select
bits, the user can also choose to interrupt on Start and
Stop bits.
When an address is matched, or the data transfer after
an address match is received, the hardware auto-
matically will generate the Acknowledge (ACK) pulse
and load the SSPxBUF register with the received value
currently in the SSPxSR register.
Any combination of the following conditions will cause
the MSSP module not to give this ACK pulse:
The Buffer Full bit, BF (SSPxSTAT<0>), was set
before the transfer was received.
The overflow bit, SSPOV (SSPxCON1<6>), was
set before the transfer was received.
In this case, the SSPxSR register value is not loaded
into the SSPxBUF, but bit SSPxIF is set. The BF bit is
cleared by reading the SSPxBUF register, while bit
SSPOV is cleared through software.
The SCLx clock input must have a minimum high and
low for proper operation. The high and low times of the
I2C specification, as well as the requirement of the
MSSP module, are shown in timing Parameter 100 and
Parameter 101.
19.5.3.1 Addressing
Once the MSSP module has been enabled, it waits for
a Start condition to occur. Following the Start condition,
the 8 bits are shifted into the SSPxSR register. All
incoming bits are sampled with the rising edge of the
clock (SCLx) line. The value of register, SSPxSR<7:1>,
is compared to the value of the SSPxADD register. The
address is compared on the falling edge of the eighth
clock (SCLx) pulse. If the addresses match and the BF
and SSPOV bits are clear, the following events occur:
1. The SSPxSR register value is loaded into the
SSPxBUF register.
2. The Buffer Full bit, BF, is set.
3. An ACK pulse is generated.
4. The MSSPx Interrupt Flag bit, SSPxIF, is set
(and interrupt is generated, if enabled) on the
falling edge of the ninth SCLx pulse.
In 10-Bit Addressing mode, two address bytes need to
be received by the slave. The five Most Significant bits
(MSbs) of the first address byte specify if this is a 10-bit
address. Bit, R/W (SSPxSTAT<2>), must specify a
write so the slave device will receive the second
address byte. For a 10-bit address, the first byte would
equal ‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the
two MSbs of the address. The sequence of events for
10-bit addressing is as follows, with Steps 7 through 9
for the slave-transmitter:
1. Receive first (high) byte of address (bits,
SSPxIF, BF and UA, are set on address match).
2. Update the SSPxADD register with second (low)
byte of address (clears bit, UA, and releases the
SCLx line).
3. Read the SSPxBUF register (clears bit, BF) and
clear flag bit, SSPxIF.
4. Receive second (low) byte of address (bits,
SSPxIF, BF and UA, are set).
5. Update the SSPxADD register with the first
(high) byte of address. If match releases SCLx
line, this will clear bit, UA.
6. Read the SSPxBUF register (clears bit, BF) and
clear flag bit, SSPxIF.
7. Receive Repeated Start condition.
8. Receive first (high) byte of address (bits,
SSPxIF and BF, are set).
9. Read the SSPxBUF register (clears bit, BF) and
clear flag bit, SSPxIF.
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19.5.3.2 Address Masking Modes
Masking an address bit causes that bit to become a
“don’t care”. When one address bit is masked, two
addresses will be Acknowledged and cause an inter-
rupt. It is possible to mask more than one address bit at
a time, which greatly expands the number of addresses
Acknowledged.
The I2C slave behaves the same way, whether address
masking is used or not. However, when address mask-
ing is used, the I2C slave can Acknowledge multiple
addresses and cause interrupts. When this occurs, it is
necessary to determine which address caused the
interrupt by checking SSPxBUF.
The PIC18F46J50 family of devices is capable of using
two different Address Masking modes in I2C slave
operation: 5-Bit Address Masking and 7-Bit Address
Masking. The Masking mode is selected at device
configuration using the MSSPMSK Configuration bit.
The default device configuration is 7-Bit Address
Masking.
Both Masking modes, in turn, support address masking
of 7-bit and 10-bit addresses. The combination of
Masking modes and addresses provide different
ranges of Acknowledgable addresses for each
combination.
While both Masking modes function in roughly the
same manner, the way they use address masks is
different.
19.5.3.3 5-Bit Address Masking Mode
As the name implies, 5-Bit Address Masking mode uses
an address mask of up to five bits to create a range of
addresses to be Acknowledged, using bits, 5 through 1,
of the incoming address. This allows the module to
Acknowledge up to 31 addresses when using 7-bit
addressing, or 63 addresses with 10-bit addressing (see
Example 19-3). This Masking mode is selected when
the MSSPMSK Configuration bit is programmed (‘0’).
The address mask in this mode is stored in the
SSPxCON2 register, which stops functioning as a control
register in I2C Slave mode (Register 19-8). In 7-Bit
Address Masking mode, address mask bits,
ADMSK<5:1> (SSPxCON2<5:1>), mask the
corresponding address bits in the SSPxADD register. For
any ADMSK bits that are set (ADMSK<n> = 1), the cor-
responding address bit is ignored (SSPxADD<n> = x).
For the module to issue an address Acknowledge, it is
sufficient to match only on addresses that do not have an
active address mask.
In 10-Bit Address Masking mode, bits, ADMSK<5:2>,
mask the corresponding address bits in the SSPxADD
register. In addition, ADMSK1 simultaneously masks
the two LSbs of the address (SSPxADD<1:0>). For any
ADMSK bits that are active (ADMSK<n> = 1), the cor-
responding address bit is ignored (SPxADD<n> = x).
Also note, that although in 10-Bit Address Masking
mode, the upper address bits reuse part of the
SSPxADD register bits. The address mask bits do not
interact with those bits; they only affect the lower
address bits.
EXAMPLE 19-3: ADDRESS MASKING EXAMPLES IN 5-BIT MASKING MODE
Note 1: ADMSK1 masks the two Least Significant
bits of the address.
2: The two MSbs of the address are not
affected by address masking.
7-Bit Addressing:
SSPxADD<7:1> = A0h (1010000) (SSPxADD<0> is assumed to be ‘0’.)
ADMSK<5:1> = 00111
Addresses Acknowledged: A0h, A2h, A4h, A6h, A8h, AAh, ACh, AEh
10-Bit Addressing :
SSPxADD<7:0> = A0h (10100000) (The two MSbs of the address are ignored in this example, since
they are not affected by masking.)
ADMSK<5:1> = 00111
Addresses Acknowledged: A0h, A1h, A2h, A3h, A4h, A5h, A6h, A7h, A8h, A9h, AAh, ABh, ACh, ADh,
AEh, AFh
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19.5.3.4 7-Bit Address Masking Mode
Unlike 5-Bit Address Masking mode, 7-Bit Address
Masking mode uses a mask of up to eight bits (in 10-bit
addressing) to define a range of addresses than can be
Acknowledged, using the lowest bits of the incoming
address. This allows the module to Acknowledge up to
127 different addresses with 7-bit addressing, or
255 with 10-bit addressing (see Example 19-4). This
mode is the default configuration of the module, and is
selected when MSSPMSK is unprogrammed (‘1’).
The address mask for 7-Bit Address Masking mode is
stored in the SSPxMSK register, instead of the
SSPxCON2 register. SSPxMSK is a separate hard-
ware register within the module, but it is not directly
addressable. Instead, it shares an address in the SFR
space with the SSPxADD register. To access the
SSPxMSK register, it is necessary to select MSSP
mode,1001’ (SSPCON1<3:0> = 1001), and then read
or write to the location of SSPxADD.
To use 7-Bit Address Masking mode, it is necessary to
initialize SSPxMSK with a value before selecting the
I2C Slave Addressing mode. Thus, the required
sequence of events is:
1. Select SSPxMSK Access mode
(SSPxCON2<3:0> = 1001).
2. Write the mask value to the appropriate
SSPxADD register address (FC8h for MSSP1,
F6Eh for MSSP2).
3. Set the appropriate I2C Slave mode
(SSPxCON2<3:0> = 0111 for 10-bit addressing,
0110 for 7-bit addressing).
Setting or clearing mask bits in SSPxMSK behaves in
the opposite manner of the ADMSK bits in 5-Bit
Address Masking mode. That is, clearing a bit in
SSPxMSK causes the corresponding address bit to be
masked; setting the bit requires a match in that
position. SSPxMSK resets to all ‘1s upon any Reset
condition, and therefore, has no effect on the standard
MSSP operation until written with a mask value.
With 7-Bit Address Masking mode, SSPxMSK<7:1>
bits mask the corresponding address bits in the
SSPxADD register. For any SSPxMSK bits that are
active (SSPxMSK<n> = 0), the corresponding
SSPxADD address bit is ignored (SSPxADD<n> = x).
For the module to issue an address Acknowledge, it is
sufficient to match only on addresses that do not have
an active address mask.
With 10-Bit Address Masking mode, SSPxMSK<7:0>
bits mask the corresponding address bits in the
SSPxADD register. For any SSPxMSK bits that are
active (= 0), the corresponding SSPxADD address bit
is ignored (SSPxADD<n> = x).
EXAMPLE 19-4: ADDRESS MASKING EXAMPLES IN 7-BIT MASKING MODE
Note: The two MSbs of the address are not
affected by address masking.
7-Bit Addressing:
SSPxADD<7:1> = 1010 000
SSPxMSK<7:1> = 1111 001
Addresses Acknowledged = ACh, A8h, A4h, A0h
10-Bit Addressing :
SSPxADD<7:0> = 1010 0000 (The two MSbs are ignored in this example since they are not affected.)
SSPxMSK<7:0> = 1111 0011
Addresses Acknowledged = ACh, A8h, A4h, A0h
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19.5.3.5 Reception
When the R/W bit of the address byte is clear and an
address match occurs, the R/W bit of the SSPxSTAT
register is cleared. The received address is loaded into
the SSPxBUF register and the SDAx line is held low
(ACK).
When the address byte overflow condition exists, then
the no Acknowledge (ACK) pulse is given. An overflow
condition is defined as either bit, BF (SSPxSTAT<0>),
is set or bit, SSPOV (SSPxCON1<6>), is set.
An MSSP interrupt is generated for each data transfer
byte. The interrupt flag bit, SSPxIF, must be cleared in
software. The SSPxSTAT register is used to determine
the status of the byte.
If SEN is enabled (SSPxCON2<0> = 1), SCLx will be
held low (clock stretch) following each data transfer.
The clock must be released by setting bit, CKP
(SSPxCON1<4>). See Section 19.5.4 “Clock
Stretching” for more details.
19.5.3.6 Transmission
When the R/W bit of the incoming address byte is set
and an address match occurs, the R/W bit of the
SSPxSTAT register is set. The received address is
loaded into the SSPxBUF register. The ACK pulse will
be sent on the ninth bit and pin SCLx is held low regard-
less of SEN (see Section 19.5.4 “Clock Stretching”
for more details). By stretching the clock, the master
will be unable to assert another clock pulse until the
slave is done preparing the transmit data. The transmit
data must be loaded into the SSPxBUF register, which
also loads the SSPxSR register. Then, the SCLx pin
should be enabled by setting bit, CKP
(SSPxCON1<4>). The eight data bits are shifted out on
the falling edge of the SCLx input. This ensures that the
SDAx signal is valid during the SCLx high time
(Figure 19-10).
The ACK pulse from the master-receiver is latched on
the rising edge of the ninth SCLx input pulse. If the SDAx
line is high (not ACK), then the data transfer is complete.
In this case, when the ACK is latched by the slave, the
slave monitors for another occurrence of the Start bit. If
the SDAx line was low (ACK), the next transmit data
must be loaded into the SSPxBUF register. Again, the
SCLx pin must be enabled by setting bit, CKP.
An MSSP interrupt is generated for each data transfer
byte. The SSPxIF bit must be cleared in software and
the SSPxSTAT register is used to determine the status
of the byte. The SSPxIF bit is set on the falling edge of
the ninth clock pulse.
2011 Microchip Technology Inc. DS39931D-page 297
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FIGURE 19-8: I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
S1 234 567 89 1 2 345 67 89 1 2345 7 89 P
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0
ACK
Receiving Data
ACK
Receiving Data
R/W = 0
ACK
Receiving Address
Cleared in software
SSPxBUF is read
Bus master
terminates
transfer
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
D2
6
CKP (SSPxCON1<4>)
(CKP does not reset to ‘0’ when SEN = 0)
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FIGURE 19-9: I2C™ SLAVE MODE TIMING WITH SEN = 0 AND ADMSK<5:1> = 01011
(RECEPTION, 7-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
S12345678912345678912345 789 P
A7 A6 A5 X A3 X X D7D6 D5D4D3D2D1 D0 D7D6D5D4D3 D1D0
ACK
Receiving Data
ACK
Receiving Data
R/W = 0
ACK
Receiving Address
Cleared in software
SSPxBUF is read
Bus master
terminates
transfer
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
D2
6
CKP (SSPxCON1<4>)
(CKP does not reset to ‘0’ when SEN = 0)
Note 1: x = Don’t care (i.e., address bit can either be a ‘1’ or a ‘0’).
2: In this example, an address equal to A7.A6.A5.X.A3.X.X will be Acknowledged and cause an interrupt.
2011 Microchip Technology Inc. DS39931D-page 299
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FIGURE 19 - 10: I2C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
SDA
SCL
SSPIF (PIR1<3>)
BF (SSPSTAT<0>)
A6 A5 A4 A3 A2 A1 D6 D5 D4 D3 D2 D1 D0
1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9
SSPBUF is written in software
Cleared in software
Data in
sampled
S
ACK
Transmitting Data
R/W =
1
ACK
Receiving Address
A7 D7
9 1
D6 D5 D4 D3 D2 D1 D0
2 3 4 5 6 7 8 9
SSPBUF is written in software
Cleared in software
From SSPIF ISR
Transmitting Data
D7
1
CKP
P
ACK
CKP is set in software CKP is set in software
SCL held low
while CPU
responds to SSPIF
Clear by reading
From SSPIF ISR
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FIGURE 19-11: I2C™ SLAVE MODE TIMING WITH SEN = 0 AND ADMSK<5:1> = 01001
(RECEPTION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S123456789 123456789 12345 789 P
1 1 1 1 0 A9 A8 A7 A6 A5 X A3 A2 X X D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
D2
6
Cleared in software
Receive Second Byte of Address
Cleared by hardware
when SSPxADD is updated
with low byte of address
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address
SSPxBUF is written with
contents of SSPxSR
Dummy read of SSPxBUF
to clear BF flag
ACK
CKP (SSPxCON1<4>)
12345 789
D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
Bus master
terminates
transfer
D2
6
ACK
Cleared in software Cleared in software
SSPOV (SSPxCON1<6>)
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
(CKP does not reset to ‘0’ when SEN = 0)
Clock is held low until
update of SSPxADD has
taken place
Note 1: x = Don’t care (i.e., address bit can either be a ‘1’ or a ‘0’).
2: In this example, an address equal to A9.A8.A7.A6.A5.X.A3.A2.X.X will be Acknowledged and cause an interrupt.
3: Note that the Most Significant bits of the address are not affected by the bit masking.
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FIGURE 19 - 12: I2C™ SLAVE MO DE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S123456789 123456789 12345 789 P
1 1 1 1 0 A9A8 A7 A6A5 A4A3A2A1 A0 D7 D6D5D4D3 D1D0
Receive Data Byte
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
D2
6
Cleared in software
Receive Second Byte of Address
Cleared by hardware
when SSPxADD is updated
with low byte of address
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address
SSPxBUF is written with
contents of SSPxSR
Dummy read of SSPxBUF
to clear BF flag
ACK
CKP (SSPxCON1<4>)
12345 789
D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
Bus master
terminates
transfer
D2
6
ACK
Cleared in software Cleared in software
SSPOV (SSPxCON1<6>)
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
(CKP does not reset to ‘0’ when SEN = 0)
Clock is held low until
update of SSPxADD has
taken place
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FIGURE 19 - 13: I2C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S1234 5 6789 1 23 45 678 9 12345 7 89 P
1 1 1 1 0 A9A8 A7 A6A5A4A3A2A1 A0 1 1 1 1 0 A8
R/W = 1
ACK
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
Bus master
terminates
transfer
A9
6
Receive Second Byte of Address
Cleared by hardware when
SSPxADD is updated with low
byte of address
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address.
SSPxBUF is written with
contents of SSPxSR
Dummy read of SSPxBUF
to clear BF flag
Receive First Byte of Address
12345 789
D7 D6 D5 D4 D3 D1
ACK
D2
6
Transmitting Data Byte
D0
Dummy read of SSPxBUF
to clear BF flag
Sr
Cleared in software
Write of SSPxBUF
initiates transmit
Cleared in software
Completion of
clears BF flag
CKP (SSPxCON1<4>)
CKP is set in software
CKP is automatically cleared in hardware, holding SCLx low
Clock is held low until
update of SSPxADD has
taken place
data transmission
Clock is held low until
CKP is set to ‘1
third address sequence
BF flag is clear
at the end of the
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19.5.4 CLOCK STRETCHING
Both 7-Bit and 10-Bit Slave modes implement
automatic clock stretching during a transmit sequence.
The SEN bit (SSPxCON2<0>) allows clock stretching
to be enabled during receives. Setting SEN will cause
the SCLx pin to be held low at the end of each data
receive sequence.
19.5.4.1 Clock Stretching for 7-Bit Slave
Receive Mode (SEN = 1)
In 7-Bit Slave Receive mode, on the falling edge of the
ninth clock at the end of the ACK sequence, if the BF
bit is set, the CKP bit in the SSPxCON1 register is
automatically cleared, forcing the SCLx output to be
held low. The CKP bit being cleared to ‘0’ will assert
the SCLx line low. The CKP bit must be set in the
user’s ISR before reception is allowed to continue. By
holding the SCLx line low, the user has time to service
the ISR and read the contents of the SSPxBUF before
the master device can initiate another receive
sequence. This will prevent buffer overruns from
occurring (see Figure 19-15).
19.5.4.2 Clock Stretching for 10-Bit Slave
Receive Mode (SEN = 1)
In 10-Bit Slave Receive mode, during the address
sequence, clock stretching automatically takes place
but CKP is not cleared. During this time, if the UA bit is
set after the ninth clock, clock stretching is initiated.
The UA bit is set after receiving the upper byte of the
10-bit address and following the receive of the second
byte of the 10-bit address, with the R/W bit cleared to
0’. The release of the clock line occurs upon updating
SSPxADD. Clock stretching will occur on each data
receive sequence as described in 7-bit mode.
19.5.4.3 Clock Stretching for 7-Bit Slave
Transmit Mode
The 7-Bit Slave Transmit mode implements clock
stretching by clearing the CKP bit after the falling edge
of the ninth clock if the BF bit is clear. This occurs
regardless of the state of the SEN bit.
The user’s Interrupt Service Routine (ISR) must set
the CKP bit before transmission is allowed to continue.
By holding the SCLx line low, the user has time to
service the ISR and load the contents of the SSPxBUF
before the master device can initiate another transmit
sequence (see Figure 19-10).
19.5.4.4 Clock Stretching for 10-Bit Slave
Transmit Mode
In 10-Bit Slave Transmit mode, clock stretching is
controlled during the first two address sequences by
the state of the UA bit, just as it is in 10-Bit Slave
Receive mode. The first two addresses are followed
by a third address sequence, which contains the
high-order bits of the 10-bit address and the R/W bit
set to1’. After the third address sequence is
performed, the UA bit is not set, the module is now
configured in Transmit mode and clock stretching is
controlled by the BF flag, as in 7-Bit Slave Transmit
mode (see Figure 19-13).
Note 1: If the user reads the contents of the
SSPxBUF before the falling edge of the
ninth clock, thus clearing the BF bit, the
CKP bit will not be cleared and clock
stretching will not occur.
2: The CKP bit can be set in software
regardless of the state of the BF bit. The
user should be careful to clear the BF bit
in the ISR before the next receive
sequence in order to prevent an overflow
condition.
Note: If the user polls the UA bit and clears it by
updating the SSPxADD register before the
falling edge of the ninth clock occurs, and
if the user has not cleared the BF bit by
reading the SSPxBUF register before that
time, then the CKP bit will still NOT be
asserted low. Clock stretching on the basis
of the state of the BF bit only occurs during
a data sequence, not an address
sequence.
Note 1: If the user loads the contents of
SSPxBUF, setting the BF bit before the
falling edge of the ninth clock, the CKP bit
will not be cleared and clock stretching
will not occur.
2: The CKP bit can be set in software
regardless of the state of the BF bit.
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19.5.4.5 Clock Synchronization and CKP bit
When the CKP bit is cleared, the SCLx output is forced
to ‘0’. However, clearing the CKP bit will not assert the
SCLx output low until the SCLx output is already
sampled low. Therefore, the CKP bit will not assert the
SCLx line until an external I2C master device has
already asserted the SCLx line. The SCLx output will
remain low until the CKP bit is set and all other
devices on the I2C bus have deasserted SCLx. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCLx (see
Figure 19-14).
FIGURE 19-14: CLOCK SYNCHRONIZATION TIMING
SDAx
SCLx
DX – 1
DX
WR
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
SSPxCON1
CKP
Master device
deasserts clock
Master device
asserts clock
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FIGURE 19 - 15: I2C™ SLAVE MO DE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
S1 234 567 89 1 2345 67 89 1 23 45 7 89 P
A7 A6 A5 A4 A3 A2 A1 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D1 D0
ACK
Receiving Data
ACK
Receiving Data
R/W = 0
ACK
Receiving Address
Cleared in software
SSPxBUF is read
Bus master
terminates
transfer
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
D2
6
CKP (SSPxCON1<4>)
CKP
written
to ‘1’ in
If BF is cleared
prior to the falling
edge of the 9th clock,
CKP will not be reset
to ‘0’ and no clock
stretching will occur
software
Clock is held low until
CKP is set to ‘1
Clock is not held low
because buffer full bit is
clear prior to falling edge
of 9th clock
Clock is not held low
because ACK =
1
BF is set after falling
edge of the 9th clock,
CKP is reset to ‘0’ and
clock stretching occurs
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FIGURE 19 - 16: I2C™ SLAVE MO DE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF (PIR1<3> or PIR3<7>)
BF (SSPxSTAT<0>)
S123456789 123456789 12345 789 P
1 1 1 1 0 A9A8 A7 A6A5A4A3A2A1 A0 D7D6D5D4D3 D1D0
Receive Data Byte
ACK
R/W = 0
ACK
Receive First Byte of Address
Cleared in software
D2
6
Cleared in software
Receive Second Byte of Address
Cleared by hardware when
SSPxADD is updated with low
byte of address after falling edge
UA (SSPxSTAT<1>)
Clock is held low until
update of SSPxADD has
taken place
UA is set indicating that
the SSPxADD needs to be
updated
UA is set indicating that
SSPxADD needs to be
updated
Cleared by hardware when
SSPxADD is updated with high
byte of address after falling edge
SSPxBUF is written with
contents of SSPxSR Dummy read of SSPxBUF
to clear BF flag
ACK
CKP (SSPxCON1<4>)
12345 789
D7 D6 D5 D4 D3 D1 D0
Receive Data Byte
Bus master
terminates
transfer
D2
6
ACK
Cleared in software Cleared in software
SSPOV (SSPxCON1<6>)
CKP written to
1
Note: An update of the SSPxADD register before
the falling edge of the ninth clock will have no
effect on UA and UA will remain set.
Note: An update of the SSPxADD
register before the falling
edge of the ninth clock will
have no effect on UA and
UA will remain set.
in software
Clock is held low until
update of SSPxADD has
taken place
of ninth clock
of ninth clock
SSPOV is set
because SSPxBUF is
still full. ACK is not sent.
Dummy read of SSPxBUF
to clear BF flag
Clock is held low until
CKP is set to
1
Clock is not held low
because ACK =
1
2011 Microchip Technology Inc. DS39931D-page 307
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19.5.5 GENERAL CALL ADDRESS
SUPPORT
The addressing procedure for the I2C bus is such that
the first byte after the Start condition usually determines
which device will be the slave addressed by the master.
The exception is the general call address which can
address all devices. When this address is used, all
devices should, in theory, respond with an Acknowledge.
The general call address is one of eight addresses
reserved for specific purposes by the I2C protocol. It
consists of all0’s with R/W = 0.
The general call address is recognized when the
General Call Enable bit, GCEN, is enabled
(SSPxCON2<7> is set). Following a Start bit detect,
8 bits are shifted into the SSPxSR and the address is
compared against the SSPxADD. It is also compared to
the general call address and fixed in hardware.
If the general call address matches, the SSPxSR is
transferred to the SSPxBUF, the BF flag bit is set (eighth
bit), and on the falling edge of the ninth bit (ACK bit), the
SSPxIF interrupt flag bit is set.
When the interrupt is serviced, the source for the
interrupt can be checked by reading the contents of the
SSPxBUF. The value can be used to determine if the
address was device-specific or a general call address.
In 10-bit mode, the SSPxADD is required to be updated
for the second half of the address to match and the UA
bit is set (SSPxSTAT<1>). If the general call address is
sampled when the GCEN bit is set, while the slave is
configured in 10-Bit Addressing mode, then the second
half of the address is not necessary, the UA bit will not
be set and the slave will begin receiving data after the
Acknowledge (Figure 19-17).
FIGURE 19-17: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE
(7-BIT OR 10-BIT ADDRESSING MODE)
SDAx
SCLx
S
SSPxIF
BF (SSPxSTAT<0>)
SSPOV (SSPxCON1<6>)
Cleared in software
SSPxBUF is read
R/W = 0
ACK
General Call Address
Address is compared to General Call Address
GCEN (SSPxCON2<7>)
Receiving Data ACK
123456789123456789
D7 D6 D5 D4 D3 D2 D1 D0
after ACK, set interrupt
0
1
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19.5.6 MASTER MODE
Master mode is enabled by setting and clearing the
appropriate SSPM bits in SSPxCON1 and by setting
the SSPEN bit. In Master mode, the SCLx and SDAx
lines are manipulated by the MSSP hardware if the
TRIS bits are set.
Master mode of operation is supported by interrupt
generation on the detection of the Start and Stop con-
ditions. The Start (S) and Stop (P) bits are cleared from
a Reset or when the MSSP module is disabled. Control
of the I2C bus may be taken when the Stop bit is set, or
the bus is Idle, with both the Start and Stop bits clear.
In Firmware Controlled Master mode, user code
conducts all I2C bus operations based on Start and
Stop bit conditions.
Once Master mode is enabled, the user has six
options.
1. Assert a Start condition on SDAx and SCLx.
2. Assert a Repeated Start condition on SDAx and
SCLx.
3. Write to the SSPxBUF register initiating
transmission of data/address.
4. Configure the I2C port to receive data.
5. Generate an Acknowledge condition at the end
of a received byte of data.
6. Generate a Stop condition on SDAx and SCLx.
The following events will cause the MSSP Interrupt
Flag bit, SSPxIF, to be set (and MSSP interrupt, if
enabled):
Start condition
Stop condition
Data transfer byte transmitted/received
Acknowledge transmitted
Repeated Start
FIGURE 19-18: MSSP x BLOCK DIAGRAM (I2C™ MASTER MODE)
Note: The MSSP module, when configured in
I2C Master mode, does not allow queueing
of events. For instance, the user is not
allowed to initiate a Start condition and
immediately write the SSPxBUF register
to initiate transmission before the Start
condition is complete. In this case, the
SSPxBUF will not be written to and the
WCOL bit will be set, indicating that a write
to the SSPxBUF did not occur.
Read Write
SSPxSR
Start bit, Stop bit,
SSPxBUF
Internal
Data Bus
Set/Reset S, P (SSPxSTAT), WCOL (SSPxCON1)
Shift
Clock
MSb LSb
SDAx
Acknowledge
Generate
Stop bit Detect
Write Collision Detect
Clock Arbitration
State Counter for
End of XMIT/RCV
SCLx
SCLx In
Bus Collision
SDAx In
Receive Enable
Clock Cntl
Clock Arbitrate/WCOL Detect
(hold off clock source)
SSPxADD<6:0>
Baud
Set SSPxIF, BCLxIF
Reset ACKSTAT, PEN (SSPxCON2)
Rate
Generator
SSPM<3:0>
Start bit Detect
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19.5.6.1 I2C Master Mode Operation
The master device generates all of the serial clock
pulses and the Start and Stop conditions. A transfer is
ended with a Stop condition or with a Repeated Start
condition. Since the Repeated Start condition is also
the beginning of the next serial transfer, the I2C bus will
not be released.
In Master Transmitter mode, serial data is output
through SDAx while SCLx outputs the serial clock. The
first byte transmitted contains the slave address of the
receiving device (7 bits) and the Read/Write (R/W) bit.
In this case, the R/W bit will be logic ‘0. Serial data is
transmitted 8 bits at a time. After each byte is transmit-
ted, an Acknowledge bit is received. S and P conditions
are output to indicate the beginning and the end of a
serial transfer.
In Master Receive mode, the first byte transmitted
contains the slave address of the transmitting device
(7 bits) and the R/W bit. In this case, the R/W bit will be
logic ‘1’. Thus, the first byte transmitted is a 7-bit slave
address, followed by a ‘1’ to indicate the receive bit.
Serial data is received via SDAx, while SCLx outputs
the serial clock. Serial data is received 8 bits at a time.
After each byte is received, an Acknowledge bit is
transmitted. S and P conditions indicate the beginning
and end of transmission.
The BRG, used for the SPI mode operation, is used to
set the SCLx clock frequency for either 100 kHz,
400 kHz or 1 MHz I2C operation. See Section 19.5.7
“Baud Rate” for more details.
A typical transmit sequence would go as follows:
1. The user generates a Start condition by setting
the Start Enable bit, SEN (SSPxCON2<0>).
2. SSPxIF is set. The MSSP module will wait for
the required start time before any other
operation takes place.
3. The user loads the SSPxBUF with the slave
address to transmit.
4. Address is shifted out of the SDAx pin until all
8 bits are transmitted.
5. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
SSPxCON2 register (SSPxCON2<6>).
6. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
7. The user loads the SSPxBUF with 8 bits of data.
8. Data is shifted out the SDAx pin until all 8 bits
are transmitted.
9. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
SSPxCON2 register (SSPxCON2<6>).
10. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
11. The user generates a Stop condition by setting
the Stop Enable bit, PEN (SSPxCON2<2>).
12. Interrupt is generated once the Stop condition is
complete.
19.5.7 BAUD RATE
In I2C Master mode, the BRG reload value is placed in
the lower seven bits of the SSPxADD register
(Figure 19-19). When a write occurs to SSPxBUF, the
Baud Rate Generator will automatically begin counting.
The BRG counts down to 0 and stops until another
reload has taken place. The BRG count is decre-
mented, twice per instruction cycle (T
CY), on the Q2
and Q4 clocks. In I2C Master mode, the BRG is
reloaded automatically.
Once the given operation is complete (i.e., transmis-
sion of the last data bit is followed by ACK), the internal
clock will automatically stop counting and the SCLx pin
will remain in its last state.
Table 19-3 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPxADD. The SSPxADD value of ‘0x00’ is not
supported; values > 0x01 should be used instead.
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19.5.7.1 Baud Rate and Module
Interdependence
Because MSSP1 and MSSP2 are independent, they
can operate simultaneously in I2C Master mode at
different baud rates. This is done by using different
BRG reload values for each module.
Because this mode derives its basic clock source from
the system clock, any changes to the clock will affect
both modules in the same proportion. It may be
possible to change one or both baud rates back to a
previous value by changing the BRG reload value.
FIGURE 19-19: BAUD RATE GENERATOR BLOCK DIAGRAM
TABLE 19-3: I2C™ CLOCK RATE w/BRG
FOSC FCY FCY * 2 BRG Value FSCL
(2 Rollovers of BRG)
48 MHz 12 MHz 24 MHz 77h 100 kHz
40 MHz 10 MHz 20 MHz 18h 400 kHz(1)
40 MHz 10 MHz 20 MHz 63h 100 kHz
16 MHz 4 MHz 8 MHz 03h 1 MHz(1)
16 MHz 4 MHz 8 MHz 09h 400 kHz(1)
16 MHz 4 MHz 8 MHz 0Ch 308 kHz
16 MHz 4 MHz 8 MHz 27h 100 kHz
4 MHz 1 MHz 2 MHz 02h 333 kHz(1)
4 MHz 1 MHz 2 MHz 09h 100 kHz
Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than
100 kHz) in all details, but may be used with care where higher rates are required by the application.
SSPM<3:0>
BRG Down Counter
CLKO FOSC/4
SSPxADD<6:0>
SSPM<3:0>
SCLx
Reload
Control
Reload
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19.5.7.2 Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
deasserts the SCLx pin (SCLx allowed to float high).
When the SCLx pin is allowed to float high, the BRG is
suspended from counting until the SCLx pin is actually
sampled high. When the SCLx pin is sampled high, the
BRG is reloaded with the contents of SSPxADD<6:0>
and begins counting. This ensures that the SCLx high
time will always be at least one BRG rollover count in
the event that the clock is held low by an external
device (Figure 19-20).
FIGUR E 19-20 : BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
19.5.8 I2C MASTER MODE START
CONDITION TIMING
To initiate a Start condition, the user sets the Start
Enable bit, SEN (SSPxCON2<0>). If the SDAx and
SCLx pins are sampled high, the BRG is reloaded with
the contents of SSPxADD<6:0> and starts its count. If
SCLx and SDAx are both sampled high, when the Baud
Rate Generator times out (TBRG), the SDAx pin is
driven low. The action of the SDAx being driven low
while SCLx is high is the Start condition and causes the
Start bit (SSPxSTAT<3>) to be set. Following this, the
BRG is reloaded with the contents of SSPxADD<6:0>
and resumes its count. When the BRG times out
(TBRG), the SEN bit (SSPxCON2<0>) will be
automatically cleared by hardware. The BRG is sus-
pended, leaving the SDAx line held low and the Start
condition is complete.
19.5.8.1 WCOL Status Flag
If the user writes the SSPxBUF when a Start sequence
is in progress, the WCOL bit is set and the contents of
the buffer are unchanged (the write does not occur).
FIGURE 19-21: FIRST START BIT TIMING
SDAx
SCLx
SCLx deasserted but slave holds
DX – 1DX
BRG
SCLx is sampled high, reload takes
place and BRG starts its count
03h 02h 01h 00h (hold off) 03h 02h
Reload
BRG
Value
SCLx low (clock arbitration)
SCLx allowed to transition high
BRG decrements on
Q2 and Q4 cycles
Note: If, at the beginning of the Start condition, the
SDAx and SCLx pins are already sampled
low, or if during the Start condition, the SCLx
line is sampled low before the SDAx line is
driven low, a bus collision occurs, the Bus
Collision Interrupt Flag, BCLxIF, is set, the
Start condition is aborted and the I2C
module is reset into its Idle state.
Note: Because queueing of events is not
allowed, writing to the lower five bits of
SSPxCON2 is disabled until the Start
condition is complete.
SDAx
SCLx
S
TBRG
1st bit 2nd bit
TBRG
SDAx = 1, At completion of Start bit,
SCLx = 1
Write to SSPxBUF occurs here
TBRG
hardware clears SEN bit
TBRG
Write to SEN bit occurs here Set S bit (SSPxSTAT<3>)
and sets SSPxIF bit
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19.5.9 I2C MASTER MODE REPEATED
START CONDITION TIMING
A Repeated Start condition occurs when the RSEN bit
(SSPxCON2<1>) is programmed high and the I2C logic
module is in the Idle state. When the RSEN bit is set,
the SCLx pin is asserted low. When the SCLx pin is
sampled low, the BRG is loaded with the contents of
SSPxADD<5:0> and begins counting. The SDAx pin is
released (brought high) for one BRG count (TBRG).
When the BRG times out, and if SDAx is sampled high,
the SCLx pin will be deasserted (brought high). When
SCLx is sampled high, the BRG is reloaded with the
contents of SSPxADD<6:0> and begins counting.
SDAx and SCLx must be sampled high for one TBRG.
This action is then followed by assertion of the SDAx
pin (SDAx = 0) for one TBRG while SCLx is high.
Following this, the RSEN bit (SSPxCON2<1>) will be
automatically cleared and the BRG will not be
reloaded, leaving the SDAx pin held low. As soon as a
Start condition is detected on the SDAx and SCLx pins,
the Start bit (SSPxSTAT<3>) will be set. The SSPxIF bit
will not be set until the BRG has timed out.
Immediately following the SSPxIF bit getting set, the
user may write the SSPxBUF with the 7-bit address in
7-bit mode, or the default first address in 10-bit mode.
After the first eight bits are transmitted and an ACK is
received, the user may then transmit an additional 8 bits
of address (10-bit mode) or 8 bits of data (7-bit mode).
19.5.9.1 WCOL Status Flag
If the user writes the SSPxBUF when a Repeated Start
sequence is in progress, the WCOL is set and the
contents of the buffer are unchanged (the write does
not occur).
FIGURE 19-22: REPEATED START CONDITION WAVEFORM
Note 1: If RSEN is programmed while any other
event is in progress, it will not take effect.
2: A bus collision during the Repeated Start
condition occurs if:
SDAx is sampled low when SCLx
goes from low-to-high.
SCLx goes low before SDAx is
asserted low. This may indicate that
another master is attempting to
transmit a data ‘1’.
Note: Because queueing of events is not
allowed, writing of the lower five bits of
SSPxCON2 is disabled until the Repeated
Start condition is complete.
SDAx
SCLx
Sr = Repeated Start
Write to SSPxCON2
Write to SSPxBUF occurs here
on falling edge of ninth clock,
end of XMIT
At completion of Start bit,
hardware clears RSEN bit
1st bit
S bit set by hardware
TBRG
SDAx = 1,
SDAx = 1,
SCLx (no change).
SCLx = 1
occurs here:
and sets SSPxIF
RSEN bit set by hardware
TBRG
TBRG TBRG TBRG
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19.5.10 I2C MASTER MODE
TRANSMISSION
Transmission of a data byte, a 7-bit address or the
other half of a 10-bit address, is accomplished by
simply writing a value to the SSPxBUF register. This
action will set the Buffer Full flag bit, BF, and allow the
BRG to begin counting and start the next transmission.
Each bit of address/data will be shifted out onto the
SDAx pin after the falling edge of SCLx is asserted (see
data hold time specification Parameter 106). SCLx is
held low for one BRG rollover count (TBRG). Data
should be valid before SCLx is released high (see data
setup time specification Parameter 107). When the
SCLx pin is released high, it is held that way for TBRG.
The data on the SDAx pin must remain stable for that
duration and some hold time after the next falling edge
of SCLx. After the eighth bit is shifted out (the falling
edge of the eighth clock), the BF flag is cleared and the
master releases SDAx. This allows the slave device
being addressed to respond with an ACK bit during the
ninth bit time if an address match occurred, or if data
was received properly. The status of ACK is written into
the ACKDT bit on the falling edge of the ninth clock.
If the master receives an Acknowledge, the Acknowl-
edge Status bit, ACKSTAT, is cleared; if not, the bit is
set. After the ninth clock, the SSPxIF bit is set and the
master clock (BRG) is suspended until the next data
byte is loaded into the SSPxBUF, leaving SCLx low and
SDAx unchanged (Figure 19-23).
After the write to the SSPxBUF, each bit of the address
will be shifted out on the falling edge of SCLx until all
seven address bits and the R/W bit are completed. On
the falling edge of the eighth clock, the master will
deassert the SDAx pin, allowing the slave to respond
with an Acknowledge. On the falling edge of the ninth
clock, the master will sample the SDAx pin to see if the
address was recognized by a slave. The status of the
ACK bit is loaded into the ACKSTAT status bit
(SSPxCON2<6>). Following the falling edge of the
ninth clock transmission of the address, the SSPxIF
flag is set, the BF flag is cleared and the BRG is turned
off until another write to the SSPxBUF takes place,
holding SCLx low and allowing SDAx to float.
19.5.10.1 BF Status Flag
In Transmit mode, the BF bit (SSPxSTAT<0>) is set
when the CPU writes to SSPxBUF and is cleared when
all eight bits are shifted out.
19.5.10.2 WCOL Status Flag
If the user writes the SSPxBUF when a transmit is
already in progress (i.e., SSPxSR is still shifting out a
data byte), the WCOL bit is set and the contents of the
buffer are unchanged (the write does not occur) after
2TCY after the SSPxBUF write. If SSPxBUF is rewritten
within 2 TCY, the WCOL bit is set and SSPxBUF is
updated. This may result in a corrupted transfer.
The user should verify that the WCOL bit is clear after
each write to SSPxBUF to ensure the transfer is correct.
In all cases, WCOL must be cleared in software.
19.5.10.3 ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit (SSPxCON2<6>)
is cleared when the slave has sent an Acknowledge
(ACK =0) and is set when the slave does not Acknowl-
edge (ACK = 1). A slave sends an Acknowledge when
it has recognized its address (including a general call),
or when the slave has properly received its data.
19.5.11 I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the
Receive Enable bit, RCEN (SSPxCON2<3>).
The BRG begins counting and on each rollover, the
state of the SCLx pin changes (high-to-low/low-to-high)
and data is shifted into the SSPxSR. After the falling
edge of the eighth clock, the receive enable flag is
automatically cleared, the contents of the SSPxSR are
loaded into the SSPxBUF, the BF flag bit is set, the
SSPxIF flag bit is set and the BRG is suspended from
counting, holding SCLx low. The MSSP is now in Idle
state awaiting the next command. When the buffer is
read by the CPU, the BF flag bit is automatically
cleared. The user can then send an Acknowledge bit at
the end of reception by setting the Acknowledge
Sequence Enable bit, ACKEN (SSPxCON2<4>).
19.5.11.1 BF Status Flag
In receive operation, the BF bit is set when an address
or data byte is loaded into SSPxBUF from SSPxSR. It
is cleared when the SSPxBUF register is read.
19.5.11.2 SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits
are received into the SSPxSR and the BF flag bit is
already set from a previous reception.
19.5.11.3 WCOL Status Flag
If users write the SSPxBUF when a receive is already
in progress (i.e., SSPxSR is still shifting in a data byte),
the WCOL bit is set and the contents of the buffer are
unchanged (the write does not occur).
Note: The MSSP module must be in an inactive
state before the RCEN bit is set or the
RCEN bit will be disregarded.
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FIGURE 19 - 23: I2C™ MASTER MODE W AVEFORM (TRANSMISSION, 7-B IT OR 10-BIT ADDRESS)
SDAx
SCLx
SSPxIF
BF (SSPxSTAT<0>)
SEN
A7 A6 A5 A4 A3 A2 A1 ACK = 0D7 D6 D5 D4 D3 D2 D1 D0
ACK
Transmitting Data or Second Half
R/W = 0Transmit Address to Slave
123456789 123456789 P
Cleared in software service routine
SSPxBUF is written in software
from MSSP interrupt
After Start condition, SEN cleared by hardware
S
SSPxBUF written with 7-bit address and R/W,
start transmit
SCLx held low
while CPU
responds to SSPxIF
SEN = 0
of 10-bit Address
Write SSPxCON2<0> (SEN = 1),
Start condition begins From slave, clear ACKSTAT bit (SSPxCON2<6>)
ACKSTAT in
SSPxCON2 = 1
Cleared in software
SSPxBUF written
PEN
R/W
Cleared in software
2011 Microchip Technology Inc. DS39931D-page 315
PIC18F46J50 FAMILY
FIGURE 19 - 24: I2C™ MASTER MO DE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
P
9
87
6
5
D0
D1
D2
D3D4
D5
D6D7
S
A7 A6 A5 A4 A3 A2 A1
SDAx
SCLx 12
345678912345678 9 1234
Bus master
terminates
transfer
ACK
Receiving Data from Slave
Receiving Data from Slave
D0
D1
D2
D3D4
D5
D6D7
ACK
R/W = 1
Transmit Address to Slave
SSPxIF
BF
ACK is not sent
Write to SSPxCON2<0> (SEN = 1),
Write to SSPxBUF occurs here, ACK from Slave
Master configured as a receiver
by programming SSPxCON2<3> (RCEN = 1)
PEN bit = 1
written here
Data shifted in on falling edge of CLK
Cleared in software
start XMIT
SEN = 0
SSPOV
SDAx = 0, SCLx = 1,
while CPU
(SSPxSTAT<0>)
ACK
Cleared in software
Cleared in software
Set SSPxIF interrupt
at end of receive
Set P bit
(SSPxSTAT<4>)
and SSPxIF
ACK from master,
Set SSPxIF at end
Set SSPxIF interrupt
at end of Acknowledge
sequence
Set SSPxIF interrupt
at end of Acknowledge
sequence
of receive
Set ACKEN, start Acknowledge sequence,
SDAx = ACKDT = 1
RCEN cleared
automatically
RCEN = 1, start
next receive
Write to SSPxCON2<4>
to start Acknowledge sequence,
SDAx = ACKDT (SSPxCON2<5>) = 0
RCEN cleared
automatically
responds to SSPxIF
ACKEN
begin Start condition
Cleared in software
SDAx = ACKDT = 0
Last bit is shifted into SSPxSR and
contents are unloaded into SSPxBUF
Cleared in
software
SSPOV is set because
SSPxBUF is still full
PIC18F46J50 FAMILY
DS39931D-page 316 2011 Microchip Technology Inc.
19.5.12 ACKNOWLEDGE SEQUENCE
TIMING
An Acknowledge sequence is enabled by setting the
Acknowledge Sequence Enable bit, ACKEN
(SSPxCON2<4>). When this bit is set, the SCLx pin is
pulled low and the contents of the Acknowledge data bit
are presented on the SDAx pin. If the user wishes to
generate an Acknowledge, then the ACKDT bit should
be cleared. If not, the user should set the ACKDT bit
before starting an Acknowledge sequence. The BRG
then counts for one rollover period (TBRG) and the SCLx
pin is deasserted (pulled high). When the SCLx pin is
sampled high (clock arbitration), the BRG counts for
TBRG; the SCLx pin is then pulled low. Following this, the
ACKEN bit is automatically cleared, the BRG is turned
off and the MSSP module then goes into an inactive
state (Figure 19-25).
19.5.12.1 WCOL Status Flag
If the user writes the SSPxBUF when an Acknowledge
sequence is in progress, then WCOL is set and the
contents of the buffer are unchanged (the write does
not occur).
19.5.13 STOP CONDITION TIMING
A Stop bit is asserted on the SDAx pin at the end of a
receive/transmit by setting the Stop Sequence Enable
bit, PEN (SSPxCON2<2>). At the end of a
receive/transmit, the SCLx line is held low after the
falling edge of the ninth clock. When the PEN bit is set,
the master will assert the SDAx line low. When the
SDAx line is sampled low, the BRG is reloaded and
counts down to 0. When the BRG times out, the SCLx
pin will be brought high and one Baud Rate Generator
rollover count (TBRG) later, the SDAx pin will be
deasserted. When the SDAx pin is sampled high while
SCLx is high, the Stop bit (SSPxSTAT<4>) is set. A
TBRG later, the PEN bit is cleared and the SSPxIF bit is
set (Figure 19-26).
19.5.13.1 WCOL Status Flag
If the user writes the SSPxBUF when a Stop sequence
is in progress, then the WCOL bit is set and the
contents of the buffer are unchanged (the write does
not occur).
FIGURE 19-25: ACKNOWLEDGE SEQUENCE WAVEFORM
FIGURE 19-26: STOP CONDITION RECEIVE OR TRANSMIT MODE
SDAx
SCLx
SSPxIF set at
Acknowledge sequence starts here,
write to SSPxCON2, ACKEN automatically cleared
Cleared in
TBRG TBRG
the end of receive
8
ACKEN = 1, ACKDT = 0
D0
9
SSPxIF
software SSPxIF set at the end
of Acknowledge sequence
Cleared in
software
ACK
Note: TBRG = One Baud Rate Generator Period.
SCLx
SDAx
SDAx asserted low before rising edge of clock
Write to SSPxCON2,
set PEN
Falling edge of
SCLx = 1 for TBRG, followed by SDAx = 1 for TBRG
9th clock
SCLx brought high after TBRG
TBRG TBRG
after SDAx sampled high. P bit (SSPxSTAT<4>) is set
TBRG
to set up Stop condition
ACK
P
TBRG
PEN bit (SSPxCON2<2>) is cleared by
hardware and the SSPxIF bit is set
Note: TBRG = One Baud Rate Generator Period.
2011 Microchip Technology Inc. DS39931D-page 317
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19.5.14 SLEEP OPERATION
While in Sleep mode, the I2C module can receive
addresses or data and when an address match or
complete byte transfer occurs, wake the processor
from Sleep (if the MSSP interrupt is enabled).
19.5.15 EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
19.5.16 MULTI-MASTER MODE
In Multi-Master mode, the interrupt generation on the
detection of the Start and Stop conditions allows the
determination of when the bus is free. The Start and
Stop bits are cleared from a Reset or when the MSSP
module is disabled. Control of the I2C bus may be taken
when the P bit (SSPxSTAT<4>) is set, or the bus is Idle,
with both the Start and Stop bits clear. When the bus is
busy, enabling the MSSP interrupt will generate the
interrupt when the Stop condition occurs.
In multi-master operation, the SDAx line must be
monitored for arbitration to see if the signal level is the
expected output level. This check is performed in
hardware with the result placed in the BCLxIF bit.
The states where arbitration can be lost are:
Address Transfer
Data Transfer
A Start Condition
A Repeated Start Condition
An Acknowledge Condition
19.5.17 MULTI -MASTER COMMUNICATION,
BUS COLLISION AND BUS
ARBITRATION
Multi-Master mode support is achieved by bus arbitra-
tion. When the master outputs address/data bits onto the
SDAx pin, arbitration takes place when the master out-
puts a 1’ on SDAx, by letting SDAx float high and
another master asserts a ‘0’. When the SCLx pin floats
high, data should be stable. If the expected data on
SDAx is a ‘1’ and the data sampled on the SDAx pin = 0,
then a bus collision has taken place. The master will set
the Bus Collision Interrupt Flag, BCLxIF, and reset the
I2C port to its Idle state (Figure 19-27).
If a transmit was in progress when the bus collision
occurred, the transmission is halted, the BF flag is
cleared, the SDAx and SCLx lines are deasserted and
the SSPxBUF can be written to. When the user services
the bus collision Interrupt Service Routine and if the I2C
bus is free, the user can resume communication by
asserting a Start condition.
If a Start, Repeated Start, Stop or Acknowledge condition
was in progress when the bus collision occurred, the con-
dition is aborted, the SDAx and SCLx lines are
deasserted and the respective control bits in the
SSPxCON2 register are cleared. When the user services
the bus collision Interrupt Service Routine (ISR), and if
the I2C bus is free, the user can resume communication
by asserting a Start condition.
The master will continue to monitor the SDAx and SCLx
pins. If a Stop condition occurs, the SSPxIF bit will be set.
A write to the SSPxBUF will start the transmission of
data at the first data bit regardless of where the
transmitter left off when the bus collision occurred.
In Multi-Master mode, the interrupt generation on the
detection of Start and Stop conditions allows the deter-
mination of when the bus is free. Control of the I2C bus
can be taken when the Stop bit is set in the SSPxSTAT
register, or the bus is Idle and the Start and Stop bits
are cleared.
FIGUR E 19-27: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
SDAx
SCLx
BCLxIF
SDAx released
SDAx line pulled low
by another source
Sample SDAx. While SCLx is high,
data doesn’t match what is driven
bus collision has occurred
Set bus collision
interrupt (BCLxIF)
by the master;
by master
Data changes
while SCLx = 0
PIC18F46J50 FAMILY
DS39931D-page 318 2011 Microchip Technology Inc.
19.5.17.1 Bus Collision During a Start
Condition
During a Start condition, a bus collision occurs if:
a) SDAx or SCLx is sampled low at the beginning
of the Start condition (Figure 19-28).
b) SCLx is sampled low before SDAx is asserted
low (Figure 19-29).
During a Start condition, both the SDAx and the SCLx
pins are monitored.
If the SDAx pin is already low, or the SCLx pin is
already low, then all of the following occur:
The Start condition is aborted
The BCLxIF flag is set
The MSSP module is reset to its inactive state
(Figure 19-28)
The Start condition begins with the SDAx and SCLx
pins deasserted. When the SDAx pin is sampled high,
the BRG is loaded from SSPxADD<6:0> and counts
down to 0. If the SCLx pin is sampled low while SDAx
is high, a bus collision occurs because it is assumed
that another master is attempting to drive a data1
during the Start condition.
If the SDAx pin is sampled low during this count, the
BRG is reset and the SDAx line is asserted early
(Figure 19-30). If, however, a ‘1’ is sampled on the
SDAx pin, the SDAx pin is asserted low at the end of
the BRG count. The BRG is then reloaded and counts
down to 0. If the SCLx pin is sampled as0’ during this
time, a bus collision does not occur. At the end of the
BRG count, the SCLx pin is asserted low.
FIGURE 19-28: BUS COLLISION DURING START CONDITION (SDAx ONLY)
Note: The reason that bus collision is not a fac-
tor during a Start condition is that no two
bus masters can assert a Start condition
at the exact same time. Therefore, one
master will always assert SDAx before the
other. This condition does not cause a bus
collision because the two masters must be
allowed to arbitrate the first address
following the Start condition. If the address
is the same, arbitration must be allowed to
continue into the data portion, Repeated
Start or Stop conditions.
SDAx
SCLx
SEN
SDAx sampled low before
SDAx goes low before the SEN bit is set.
S bit and SSPxIF set because
MSSPx module reset into Idle state.
SEN cleared automatically because of bus collision.
S bit and SSPxIF set because
Set SEN, enable Start
condition if SDAx = 1, SCLx = 1
SDAx = 0, SCLx = 1.
BCLxIF
S
SSPxIF
SDAx = 0, SCLx = 1.
SSPxIF and BCLxIF are
cleared in software
SSPxIF and BCLxIF are
cleared in software
Set BCLxIF,
Start condition. Set BCLxIF.
2011 Microchip Technology Inc. DS39931D-page 319
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FIGURE 19-29: BUS COLLISION DURING START CONDITION (SCLx = 0)
FIGURE 19-30: BRG RESET DUE TO SDAx ARBITRATION DURING START CONDITION
SDAx
SCLx
SEN bus collision occurs. Set BCLxIF.
SCLx = 0 before SDAx = 0,
Set SEN, enable Start
sequence if SDAx = 1, SCLx = 1
TBRG TBRG
SDAx = 0, SCLx = 1
BCLxIF
S
SSPxIF
Interrupt cleared
in software
bus collision occurs. Set BCLxIF.
SCLx = 0 before BRG time-out,
0’‘0
00
SDAx
SCLx
SEN
Set S
Less than TBRG TBRG
SDAx = 0, SCLx = 1
BCLxIF
S
SSPxIF
S
Interrupts cleared
in software
set SSPxIF
SDAx = 0, SCLx = 1,
SCLx pulled low after BRG
time-out
Set SSPxIF
0
SDAx pulled low by other master.
Reset BRG and assert SDAx.
Set SEN, enable Start
sequence if SDAx = 1, SCLx = 1
PIC18F46J50 FAMILY
DS39931D-page 320 2011 Microchip Technology Inc.
19.5.17.2 Bus Collision During a Repeated
Start Condition
During a Repeated Start condition, a bus collision
occurs if:
a) A low level is sampled on SDAx when SCLx
goes from a low level to a high level.
b) SCLx goes low before SDAx is asserted low,
indicating that another master is attempting to
transmit a data ‘1’.
When the user deasserts SDAx and the pin is allowed
to float high, the BRG is loaded with SSPxADD<6:0>
and counts down to 0. The SCLx pin is then deasserted
and when sampled high, the SDAx pin is sampled.
If SDAx is low, a bus collision has occurred (i.e., another
master is attempting to transmit a data ‘0’; see
Figure 19-31). If SDAx is sampled high, the BRG is
reloaded and begins counting. If SDAx goes from
high-to-low before the BRG times out, no bus collision
occurs because no two masters can assert SDAx at
exactly the same time.
If SCLx goes from high-to-low before the BRG times
out and SDAx has not already been asserted, a bus
collision occurs. In this case, another master is
attempting to transmit a data ‘1’ during the Repeated
Start condition (see Figure 19-32).
If, at the end of the BRG time-out, both SCLx and SDAx
are still high, the SDAx pin is driven low and the BRG is
reloaded and begins counting. At the end of the count,
regardless of the status of the SCLx pin, the SCLx pin is
driven low and the Repeated Start condition is complete.
FIGURE 19-31: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
FIGURE 19-32: BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
SDAx
SCLx
RSEN
BCLxIF
S
SSPxIF
Sample SDAx when SCLx goes high.
If SDAx = 0, set BCLxIF and release SDAx and SCLx.
Cleared in software
0
0
SDAx
SCLx
BCLxIF
RSEN
S
SSPxIF
Interrupt cleared
in software
SCLx goes low before SDAx,
set BCLxIF. Release SDAx and SCLx.
TBRG TBRG
0
2011 Microchip Technology Inc. DS39931D-page 321
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19.5.17.3 Bus Collision During a Stop
Condition
Bus collision occurs during a Stop condition if:
a) After the SDAx pin has been deasserted and
allowed to float high, SDAx is sampled low after
the BRG has timed out.
b) After the SCLx pin is deasserted, SCLx is
sampled low before SDAx goes high.
The Stop condition begins with SDAx asserted low.
When SDAx is sampled low, the SCLx pin is allowed to
float. When the pin is sampled high (clock arbitration),
the BRG is loaded with SSPxADD<6:0> and counts
down to 0. After the BRG times out, SDAx is sampled. If
SDAx is sampled low, a bus collision has occurred. This
is due to another master attempting to drive a data ‘0
(Figure 19-33). If the SCLx pin is sampled low before
SDAx is allowed to float high, a bus collision occurs. This
is another case of another master attempting to drive a
data ‘0’ (Figure 19-34).
FIGURE 19-33: BUS COLLISION DURING A STOP CONDITION (CASE 1)
FIGURE 19-34: BUS COLLISION DURING A STOP CONDITION (CASE 2)
SDAx
SCLx
BCLxIF
PEN
P
SSPxIF
TBRG TBRG TBRG
SDAx asserted low
SDAx sampled
low after TBRG,
set BCLxIF
0
0
SDAx
SCLx
BCLxIF
PEN
P
SSPxIF
TBRG TBRG TBRG
Assert SDAx SCLx goes low before SDAx goes high,
set BCLxIF
0
0
PIC18F46J50 FAMILY
DS39931D-page 322 2011 Microchip Technology Inc.
TABLE 19-4: REGISTERS ASSOCIATED WITH I2C™ OPERATION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(3) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(3) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(3) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 72
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 72
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 72
TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 72
SSP1BUF MSSP1 Receive Buffer/Transmit Register 72
SSPxADD MSSP1 Address Register (I2C™ Slave mode), MSSP1 Baud Rate Reload Register (I2C Master mode) 70, 73
SSPxMSK(1) MSK7 MSK6 MSK5 MSK4 MSK3 MSK2 MSK1 MSK0 70, 73
SSPxCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 70, 73
SSPxCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 70, 73
GCEN ACKSTAT ADMSK5(2) ADMSK4(2) ADMSK3(2) ADMSK2(2) ADMSK1(2) SEN 70, 73
SSPxSTAT SMP CKE D/A PSR/WUA BF 70, 73
SSP2BUF MSSP2 Receive Buffer/Transmit Register 73
SSP2ADD MSSP2 Address Register (I2C Slave mode), MSSP2 Baud Rate Reload Register (I2C Master mode) 73
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the MSSPx module in I2C™ mode.
Note 1: SSPxMSK shares the same address in SFR space as SSPxADD, but is only accessible in certain I2C Slave mode
operations in 7-Bit Masking mode. See Section 19.5.3.4 “7-Bit Address Masking Mode” for more details.
2: Alternate bit definitions for use in I2C Slave mode operations only.
3: These bits are only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 323
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20.0 ENHANCED UNIVER SA L
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (EUSART)
The Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART) module is one of two
serial I/O modules. (Generically, the EUSART is also
known as a Serial Communications Interface or SCI.)
The EUSART can be configured as a full-duplex
asynchronous system that can communicate with
peripheral devices, such as CRT terminals and
personal computers. It can also be configured as a
half-duplex synchronous system that can communicate
with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs and so on.
The Enhanced USART module implements additional
features, including automatic baud rate detection and
calibration, automatic wake-up on Sync Break recep-
tion and 12-bit Break character transmit. These make it
ideally suited for use in Local Interconnect Network bus
(LIN/J2602 bus) systems.
All members of the PIC18F46J50 family are equipped
with two independent EUSART modules, referred to as
EUSART1 and EUSART2. They can be configured in
the following modes:
Asynchronous (full-duplex) with:
- Auto-wake-up on character reception
- Auto-baud calibration
- 12-bit Break character transmission
Synchronous – Master (half-duplex) with
selectable clock polarity
Synchronous – Slave (half-duplex) with selectable
clock polarity
The pins of EUSART1 and EUSART2 are multiplexed
with the functions of PORTC (RC6/TX1/CK1/RP17 and
RC7/RX1/DT1/SDO1/RP18) and remapped
(RPn1/TX2/CK2 and RPn2/RX2/DT2), respectively. In
order to configure these pins as an EUSART:
For EUSART1:
- SPEN bit (RCSTA1<7>) must be set (= 1)
- TRISC<7> bit must be set (= 1)
- TRISC<6> bit must be cleared (= 0) for
Asynchronous and Synchronous Master
modes
- TRISC<6> bit must be set (= 1) for
Synchronous Slave mode
For EUSART2:
- SPEN bit (RCSTA2<7>) must be set (= 1)
- TRIS bit for RPn2/RX2/DT2 = 1
- TRIS bit for RPn1/TX2/CK2 = 0 for
Asynchronous and Synchronous Master
modes
- TRISC<6> bit must be set (= 1) for
Synchronous Slave mode
The TXx/CKx I/O pins have an optional open-drain
output capability. By default, when this pin is used by
the EUSART as an output, it will function as a standard
push-pull CMOS output. The TXx/CKx I/O pins’
open-drain, output feature can be enabled by setting
the corresponding UxOD bit in the ODCON2 register.
For more details, see Section 19.3.3 “Open-Drain
Output Option”.
The operation of each Enhanced USART module is
controlled through three registers:
Transmit Status and Control (TXSTAx)
Receive Status and Control (RCSTAx)
Baud Rate Control (BAUDCONx)
These are covered in detail in Register 20-1,
Register 20-2 and Register 20-3, respectively.
Note: The EUSART control will automatically
reconfigure the pin from input to output as
needed.
Note: Throughout this section, references to
register and bit names that may be asso-
ciated with a specific EUSART module are
referred to generically by the use of ‘x’ in
place of the specific module number.
Thus, “RCSTAx” might refer to the
Receive Status register for either
EUSART1 or EUSART2.
PIC18F46J50 FAMILY
DS39931D-page 324 2011 Microchip Technology Inc.
REGISTER 20-1: TXSTAx: TRANSMIT STATUS AND CONTROL REGISTER (ACCESS FADh, FA8h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-1 R/W-0
CSRC TX9 TXEN(1) SYNC SENDB BRGH TRMT TX9D
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care.
Synchronous mode:
1 = Master mode (clock generated internally from BRG)
0 = Slave mode (clock from external source)
bit 6 TX9: 9-Bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5 TXEN: Transmit Enable bit(1)
1 = Transmit is enabled
0 = Transmit is disabled
bit 4 SYNC: EUSART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3 SENDB: Send Break Character bit
Asynchronous mode:
1 = Send Sync Break on next transmission (cleared by hardware upon completion)
0 = Sync Break transmission has completed
Synchronous mode:
Don’t care.
bit 2 BRGH: High Baud Rate Select bit
Asynchronous mode:
1 = High speed
0 = Low speed
Synchronous mode:
Unused in this mode.
bit 1 TRMT: Transmit Shift Register Status bit
1 = TSR is empty
0 = TSR is full
bit 0 TX9D: 9th bit of Transmit Data
Can be address/data bit or a parity bit.
Note 1: SREN/CREN overrides TXEN in Sync mode.
2011 Microchip Technology Inc. DS39931D-page 325
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REGISTER 20-2: RCSTAx: RECEIVE STATUS AND CONTROL REGISTER (ACCES S FACh, F9Ch)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x
SPEN RX9 SREN CREN ADDEN FERR OERR RX9D
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 SPEN: Serial port Enable bit
1 = Serial port is enabled
0 = Serial port is disabled (held in Reset)
bit 6 RX9: 9-Bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5 SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care.
Synchronous mode – Master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave:
Don’t care.
bit 4 CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables receiver
0 = Disables receiver
Synchronous mode:
1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3 ADDEN: Address Detect Enable bit
Asynchronous mode 9-Bit (RX9 = 1):
1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set
0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit
Asynchronous mode 8-Bit (RX9 = 0):
Don’t care.
bit 2 FERR: Framing Error bit
1 = Framing error (can be cleared by reading RCREGx register and receiving next valid byte)
0 = No framing error
bit 1 OERR: Overrun Error bit
1 = Overrun error (can be cleared by clearing bit, CREN)
0 = No overrun error
bit 0 RX9D: 9th bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
PIC18F46J50 FAMILY
DS39931D-page 326 2011 Microchip Technology Inc.
REGISTER 20-3: BAUDCONx: BAUD RATE CONTROL REGISTER (ACCESS F7Eh, F7Ch)
R/W-0 R-1 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0
ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ABDOVF: Auto-Baud Acquisition Rollover Status bit
1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software)
0 = No BRG rollover has occurred
bit 6 RCIDL: Receive Operation Idle Status bit
1 = Receive operation is Idle
0 = Receive operation is active
bit 5 RXDTP: Data/Receive Polarity Select bit
Asynchronous mode:
1 = Receive data (RXx) is inverted (active-low)
0 = Receive data (RXx) is not inverted (active-high)
Synchronous mode:
1 = Data (DTx) is inverted (active-low)
0 = Data (DTx) is not inverted (active-high)
bit 4 TXCKP: Synchronous Clock Polarity Select bit
Asynchronous mode:
1 = Idle state for transmit (TXx) is a low level
0 = Idle state for transmit (TXx) is a high level
Synchronous mode:
1 = Idle state for clock (CKx) is a high level
0 = Idle state for clock (CKx) is a low level
bit 3 BRG16: 16-Bit Baud Rate Register Enable bit
1 = 16-bit Baud Rate Generator – SPBRGHx and SPBRGx
0 = 8-bit Baud Rate Generator – SPBRGx only (Compatible mode), SPBRGHx value is ignored
bit 2 Unimplemented: Read as ‘0
bit 1 WUE: Wake-up Enable bit
Asynchronous mode:
1 = EUSART will continue to sample the RXx pin – interrupt is generated on falling edge; bit is cleared
in hardware on following rising edge
0 = RXx pin not monitored or rising edge detected
Synchronous mode:
Unused in this mode.
bit 0 ABDEN: Auto-Baud Detect Enable bit
Asynchronous mode:
1 = Enable baud rate measurement on the next character; requires reception of a Sync field (55h);
cleared in hardware upon completion
0 = Baud rate measurement is disabled or completed
Synchronous mode:
Unused in this mode.
2011 Microchip Technology Inc. DS39931D-page 327
PIC18F46J50 FAMILY
20.1 Baud Rate Generator (BRG)
The BRG is a dedicated, 8-bit or 16-bit generator that
supports both the Asynchronous and Synchronous
modes of the EUSART. By default, the BRG operates
in 8-bit mode. Setting the BRG16 bit (BAUDCONx<3>)
selects 16-bit mode.
The SPBRGHx:SPBRGx register pair controls the period
of a free-running timer. In Asynchronous mode, bits,
BRGH (TXSTAx<2>) and BRG16 (BAUDCONx<3>),
also control the baud rate. In Synchronous mode, BRGH
is ignored.
Ta b l e 2 0 - 1 provides the formula for computation of the
baud rate for different EUSART modes, which only apply
in Master mode (internally generated clock).
Given the desired baud rate and FOSC, the nearest
integer value for the SPBRGHx:SPBRGx registers can
be calculated using the formulas in Tabl e 2 0-1. From
this, the error in baud rate can be determined. An
example calculation is provided in Example 20-1.
Typical baud rates and error values for the various
Asynchronous modes are provided in Table 20-2. It
may be advantageous to use the high baud rate
(BRGH = 1) or the 16-bit BRG to reduce the baud rate
error, or achieve a slow baud rate for a fast oscillator
frequency.
Writing a new value to the SPBRGHx:SPBRGx
registers causes the BRG timer to be reset (or cleared).
This ensures the BRG does not wait for a timer
overflow before outputting the new baud rate.
When operated in the Synchronous mode,
SPBRGH:SPBRG values of 0000h and 0001h are not
supported. In the Asynchronous mode, all BRG values
may be used.
20.1.1 OPERATION IN POWER-MANAGED
MODES
The device clock is used to generate the desired baud
rate. When one of the power-managed modes is
entered, the new clock source may be operating at a
different frequency. This may require an adjustment to
the value in the SPBRGx register pair.
20.1.2 SAMPLING
The data on the RXx pin (either
RC7/PMA4/RX1/DT1/SDO1/RP18 or RPn/RX2/DT2)
is sampled three times by a majority detect circuit to
determine if a high or a low level is present at the RXx
pin.
TABLE 20-1: BAUD RATE FORMULAS
Configuration Bits BRG/EUSART Mode Baud Rate Formula
SYNC BRG16 BRGH
000 8-bit/Asynchronous FOSC/[64 (n + 1)]
001 8-bit/Asynchronous FOSC/[16 (n + 1)]
010 16-bit/Asynchronous
011 16-bit/Asynchronous
FOSC/[4 (n + 1)]10x 8-bit/Synchronous
11x 16-bit/Synchronous
Legend: x = Don’t care, n = value of SPBRGHx:SPBRGx register pair
PIC18F46J50 FAMILY
DS39931D-page 328 2011 Microchip Technology Inc.
EXAMPLE 20-1: CALCULATING BAUD RATE ERROR
TABLE 20-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset V alues
on Pag e:
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 71
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 71
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 73
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 71
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.
For a device with Fosc of 16 MHz, desired baud rate of 9600, Asynchronous mode, and
8-bit BRG:
Desired Baud Rate = Fosc/(64 ([SPBRGHx:SPBRGx] + 1))
Solving for SPBRGHx:SPBRGx:
X = ((Fosc/Desired Baud Rate)/64) – 1
= ((16000000/9600)/64) – 1
= [25.042] = 25
Calculated Baud Rate=16000000/(64 (25 + 1))
= 9615
Error = (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate
= (9615 – 9600)/9600 = 0.16%
2011 Microchip Technology Inc. DS39931D-page 329
PIC18F46J50 FAMILY
TABLE 20-3: BAUD RATES FOR ASYNCHRONOUS MODES
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 0
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3————————
1.2 1.221 1.73 255 1.202 0.16 129 1.201 -0.16 103
2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2.403 -0.16 51
9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9.615 -0.16 12
19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7
57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2
115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 0
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.16 207 0.300 -0.16 103 0.300 -0.16 51
1.2 1.202 0.16 51 1.201 -0.16 25 1.201 -0.16 12
2.4 2.404 0.16 25 2.403 -0.16 12
9.6 8.929 -6.99 6
19.2 20.833 8.51 2
57.6 62.500 8.51 0
115.2 62.500 -45.75 0
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 0
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3————————
1.2————————
2.4 2.441 1.73 255 2.403 -0.16 207
9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9615. -0.16 51
19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25
57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8
115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 0
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 -0.16 207
1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51
2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25
9.6 9.615 0.16 25 9.615 -0.16 12
19.2 19.231 0.16 12
57.6 62.500 8.51 3
115.2 125.000 8.51 1
PIC18F46J50 FAMILY
DS39931D-page 330 2011 Microchip Technology Inc.
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 1
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 0.300 -0.04 1665
1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1.201 -0.16 415
2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2.403 -0.16 207
9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51
19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25
57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8
115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4
BAUD
RATE
(K)
SYNC = 0, BRGH = 0, BRG16 = 1
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.04 832 0.300 -0.16 415 0.300 -0.16 207
1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51
2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25
9.6 9.615 0.16 25 9.615 -0.16 12
19.2 19.231 0.16 12
57.6 62.500 8.51 3
115.2 125.000 8.51 1
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 40.000 MHz FOSC = 20.000 MHz FOSC = 10.000 MHz FOSC = 8.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.00 33332 0.300 0.00 16665 0.300 0.00 8332 0.300 -0.01 6665
1.2 1.200 0.00 8332 1.200 0.02 4165 1.200 0.02 2082 1.200 -0.04 1665
2.4 2.400 0.02 4165 2.400 0.02 2082 2.402 0.06 1040 2.400 -0.04 832
9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9.615 -0.16 207
19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19.230 -0.16 103
57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57.142 0.79 34
115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117.647 -2.12 16
BAUD
RATE
(K)
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
Actual
Rate
(K)
%
Error
SPBRG
value
(decimal)
0.3 0.300 0.01 3332 0.300 -0.04 1665 0.300 -0.04 832
1.2 1.200 0.04 832 1.201 -0.16 415 1.201 -0.16 207
2.4 2.404 0.16 415 2.403 -0.16 207 2.403 -0.16 103
9.6 9.615 0.16 103 9.615 -0.16 51 9.615 -0.16 25
19.2 19.231 0.16 51 19.230 -0.16 25 19.230 -0.16 12
57.6 58.824 2.12 16 55.555 3.55 8
115.2 111.111 -3.55 8
TABLE 20-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
2011 Microchip Technology Inc. DS39931D-page 331
PIC18F46J50 FAMILY
20.1.3 AUTO-BAUD RATE DETECT
The Enhanced USART module supports the automatic
detection and calibration of baud rate. This feature is
active only in Asynchronous mode and while the WUE
bit is clear.
The automatic baud rate measurement sequence
(Figure 20-1) begins whenever a Start bit is received
and the ABDEN bit is set. The calculation is
self-averaging.
In the Auto-Baud Rate Detect (ABD) mode, the clock to
the BRG is reversed. Rather than the BRG clocking the
incoming RXx signal, the RXx signal is timing the BRG.
In ABD mode, the internal BRG is used as a counter to
time the bit period of the incoming serial byte stream.
Once the ABDEN bit is set, the state machine will clear
the BRG and look for a Start bit. The ABD must receive
a byte with the value, 55h (ASCII “U”, which is also the
LIN/J2602 bus Sync character), in order to calculate the
proper bit rate. The measurement is taken over both a
low and high bit time in order to minimize any effects
caused by asymmetry of the incoming signal. After a
Start bit, the SPBRGx begins counting up, using the pre-
selected clock source on the first rising edge of RXx.
After eight bits on the RXx pin or the fifth rising edge, an
accumulated value, totalling the proper BRG period, is
left in the SPBRGHx:SPBRGx register pair. Once the 5th
edge is seen (this should correspond to the Stop bit), the
ABDEN bit is automatically cleared.
If a rollover of the BRG occurs (an overflow from FFFFh
to 0000h), the event is trapped by the ABDOVF status
bit (BAUDCONx<7>). It is set in hardware by BRG roll-
overs and can be set or cleared by the user in software.
ABD mode remains active after rollover events and the
ABDEN bit remains set (Figure 20-2).
While calibrating the baud rate period, the BRG registers
are clocked at 1/8th the preconfigured clock rate. Note
that the BRG clock can be configured by the BRG16 and
BRGH bits. The BRG16 bit must be set to use both
SPBRGx and SPBRGHx as a 16-bit counter. This allows
the user to verify that no carry occurred for 8-bit modes
by checking for 00h in the SPBRGHx register. Refer to
Table 20-4 for counter clock rates to the BRG.
While the ABD sequence takes place, the EUSART
state machine is held in Idle. The RCxIF interrupt is set
once the fifth rising edge on RXx is detected. The value
in the RCREGx needs to be read to clear the RCxIF
interrupt. The contents of RCREGx should be
discarded.
TABLE 20-4: BRG COUNTER
CLOCK RATES
20.1.3.1 ABD and EUSART Transmission
Since the BRG clock is reversed during ABD acquisi-
tion, the EUSART transmitter cannot be used during
ABD. This means that whenever the ABDEN bit is set,
TXREGx cannot be written to. Users should also
ensure that ABDEN does not become set during a
transmit sequence. Failing to do this may result in
unpredictable EUSART operation.
Note 1: If the WUE bit is set with the ABDEN bit,
Auto-Baud Rate Detection will occur on
the byte following the Break character.
2: It is up to the user to determine that the
incoming character baud rate is within the
range of the selected BRG clock source.
Some combinations of oscillator fre-
quency and EUSART baud rates are not
possible due to bit error rates. Overall sys-
tem timing and communication baud rates
must be taken into consideration when
using the Auto-Baud Rate Detection
feature.
3: To maximize the baud rate range, it is
recommended to set the BRG16 bit if the
auto-baud feature is used.
BRG16 BRGH BRG Counter Clock
00 FOSC/512
01 FOSC/128
10 FOSC/128
11 FOSC/32
Note: During the ABD sequence, SPBRGx and
SPBRGHx are both used as a 16-bit
counter, independent of the BRG16 setting.
PIC18F46J50 FAMILY
DS39931D-page 332 2011 Microchip Technology Inc.
FIGURE 20-1: AUTOMATIC BAUD RATE CALCULATION
FIGUR E 20-2: BRG OVERFLOW SEQUENCE
BRG Value
RXx Pin
ABDEN bit
RCxIF bit
Bit 0 Bit 1
(Interrupt)
Read
RCREGx
BRG Clock
Start
Auto-Cleared
Set by User
XXXXh 0000h
Edge #1
Bit 2 Bit 3
Edge #2
Bit 4 Bit 5
Edge #3
Bit 6 Bit 7
Edge #4
001Ch
Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.
SPBRGx XXXXh 1Ch
SPBRGHx XXXXh 00h
Edge #5
Stop Bit
Start Bit 0
XXXXh 0000h 0000h
FFFFh
BRG Clock
ABDEN bit
RXx Pin
ABDOVF bit
BRG Value
2011 Microchip Technology Inc. DS39931D-page 333
PIC18F46J50 FAMILY
20.2 EUSART Asynchronous Mode
The Asynchronous mode of operation is selected by
clearing the SYNC bit (TXSTAx<4>). In this mode, the
EUSART uses standard Non-Return-to-Zero (NRZ)
format (one Start bit, eight or nine data bits and one
Stop bit). The most common data format is 8 bits. An
on-chip, dedicated 8-bit/16-bit BRG can be used to
derive standard baud rate frequencies from the
oscillator.
The EUSART transmits and receives the LSb first. The
EUSART’s transmitter and receiver are functionally
independent but use the same data format and baud
rate. The BRG produces a clock, either x16 or x64 of
the bit shift rate, depending on the BRGH and BRG16
bits (TXSTAx<2> and BAUDCONx<3>). Parity is not
supported by the hardware but can be implemented in
software and stored as the ninth data bit.
When operating in Asynchronous mode, the EUSART
module consists of the following important elements:
Baud Rate Generator
Sampling Circuit
Asynchronous Transmitter
Asynchronous Receiver
Auto-Wake-up on Sync Break Character
12-Bit Break Character Transmit
Auto-Baud Rate Detection
20.2.1 EUSART ASYNCHRONOUS
TRANSMITTER
Figure 20-3 displays the EUSART transmitter block
diagram.
The heart of the transmitter is the Transmit (Serial) Shift
Register (TSR). The Shift register obtains its data from
the Read/Write Transmit Buffer register, TXREGx. The
TXREGx register is loaded with data in software. The
TSR register is not loaded until the Stop bit has been
transmitted from the previous load. As soon as the Stop
bit is transmitted, the TSR is loaded with new data from
the TXREGx register (if available).
Once the TXREGx register transfers the data to the
TSR register (occurs in one T
CY), the TXREGx register
is empty and the TXxIF flag bit is set. This interrupt can
be enabled or disabled by setting or clearing the inter-
rupt enable bit, TXxIE. TXxIF will be set regardless of
the state of TXxIE; it cannot be cleared in software.
TXxIF is also not cleared immediately upon loading
TXREGx, but becomes valid in the second instruction
cycle following the load instruction. Polling TXxIF
immediately following a load of TXREGx will return
invalid results.
While TXxIF indicates the status of the TXREGx
register; another bit, TRMT (TXSTAx<1>), shows the
status of the TSR register. TRMT is a read-only bit,
which is set when the TSR register is empty. No inter-
rupt logic is tied to this bit so the user has to poll this bit
in order to determine if the TSR register is empty.
To set up an Asynchronous Transmission:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is desired, set transmit bit,
TX9. Can be used as address/data bit.
5. Enable the transmission by setting bit, TXEN,
which will also set bit, TXxIF.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Load data to the TXREGx register (starts
transmission).
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
Note 1: The TSR register is not mapped in data
memory, so it is not available to the user.
2: Flag bit, TXxIF, is set when enable bit,
TXEN, is set.
PIC18F46J50 FAMILY
DS39931D-page 334 2011 Microchip Technology Inc.
FIGURE 20-3: EUSART TRANSMIT BLOCK DIAGRAM
FIGURE 20-4: ASYNCHRONOUS TRANSMISSION
FIGUR E 20-5: ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
TXxIF
TXxIE
Interrupt
TXEN Baud Rate CLK
SPBRGx
Baud Rate Generator TX9D
MSb LSb
Data Bus
TXREGx Register
TSR Register
(8) 0
TX9
TRMT SPEN
TXx pin
Pin Buffer
and Control
8

SPBRGHx
BRG16
Word 1
Word 1
Transmit Shift Reg
Start bit bit 0 bit 1 bit 7/8
Write to TXREGx
BRG Output
(Shift Clock)
TXx (pin)
TXxIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
1 TCY
Stop bit
Word 1
Transmit Shift Reg.
Write to TXREGx
BRG Output
(Shift Clock)
TXx (pin)
TXxIF bit
(Interrupt Reg. Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1 Word 2
Word 1 Word 2
Stop bit Start bit
Transmit Shift Reg.
Word 1 Word 2
bit 0 bit 1 bit 7/8 bit 0
Note: This timing diagram shows two consecutive transmissions.
1 TCY
1 TCY
Start bit
2011 Microchip Technology Inc. DS39931D-page 335
PIC18F46J50 FAMILY
TABLE 20-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 71
TXREGx EUSARTx Transmit Register 71
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 71
BAUDCONx ABDOVF RCIDL RXDTP TXDTP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 71
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 71
ODCON2 U2OD U1OD 74
Legend: = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
Note 1: These bits are only available on 44-pin devices.
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DS39931D-page 336 2011 Microchip Technology Inc.
20.2.2 EUSART ASYNCHRONOUS
RECEIVER
The receiver block diagram is displayed in Figure 20-6.
The data is received on the RXx pin and drives the data
recovery block. The data recovery block is actually a
high-speed shifter operating at x16 times the baud rate,
whereas the main receive serial shifter operates at the
bit rate or at FOSC. This mode would typically be used
in RS-232 systems.
20.2.2.1 Receiving Data
The receiver data recovery circuit initiates character
reception on the falling edge of the first bit. The first bit,
also known as the Start bit, is always a zero (after
accounting for the RXDTP setting). Following the Start
bit will be the Least Significant bit of the data character
being received. As each bit is received, the value will
be sampled and shifted into the Receive Shift Register
(RSR). After all 8 or 9 data bits (user-selectable option)
of the character have been shifted in, one final bit time
is measured and the level is sampled. This is the Stop
bit, which should always be a ‘1’ (after accounting for
the RXDTP setting). If the data recovery circuit
samples a 0’ in the Stop bit position, then a Framing
Error (FERR) is set for this character; otherwise, the
framing error is cleared for this character.
Once all data bits of the character and the Stop bit have
been received, the data bits in the RSR will immediately
be transferred to a two-character First-In-First-Out
(FIFO) memory. The FIFO buffering allows reception of
two complete characters before software is required to
service the EUSART receiver. The RSR register is not
directly accessible by software. Firmware can read
data from the FIFO by reading the RCREGx register.
Each firmware initiated read from the RCREGx register
will advance the FIFO by one character, and will clear
the Receive Interrupt Flag (RCxIF), if no additional data
exists in the FIFO.
20.2.2.2 Receive Overrun Error
If the user firmware allows the FIFO to become full, and
a third character is received before the firmware reads
from RCREGx, a buffer overrun error condition will
occur. In this case, the hardware will block the RSR con-
tents (the third byte received) from being copied into the
receive FIFO, the character will be lost and the OERR
status bit in the RCSTAx register will become set. If an
OERR condition is allowed to occur, firmware must clear
the condition by clearing and then resetting CREN,
before additional characters can be successfully
received.
20.2.2.3 Setting Up Asynchronous Receive
To set up an Asynchronous Reception:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
3. If interrupts are desired, set enable bit, RCxIE.
4. If 9-bit reception is desired, set bit, RX9.
5. Enable the reception by setting bit, CREN.
6. Flag bit, RCxIF, will be set when reception is
complete and an interrupt will be generated if
enable bit, RCxIE, was set.
7. Read the RCSTAx register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
8. Read the 8-bit received data by reading the
RCREGx register.
9. If any error occurred, clear the error by clearing
enable bit, CREN.
10. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
20.2.2.4 Setting Up 9-Bit Mode with Address
Detect
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
3. If interrupts are required, set the RCEN bit and
select the desired priority level with the RCxIP bit.
4. Set the RX9 bit to enable 9-bit reception.
5. Set the ADDEN bit to enable address detect.
6. Enable reception by setting the CREN bit.
7. The RCxIF bit will be set when reception is
complete. The interrupt will be Acknowledged if
the RCxIE and GIE bits are set.
8. Read the RCSTAx register to determine if any
error occurred during reception, as well as read
Bit 9 of data (if applicable).
9. Read RCREGx to determine if the device is
being addressed.
10. If any error occurred, clear the CREN bit.
11. If the device has been addressed, clear the
ADDEN bit to allow all received data into the
receive buffer and interrupt the CPU.
Note: If the receive FIFO is overrun, no addi-
tional characters will be received until the
overrun condition is cleared.
2011 Microchip Technology Inc. DS39931D-page 337
PIC18F46J50 FAMILY
FIGURE 20-6: EUSARTx RECEIVE BLOCK DIAGRAM
FIGURE 20-7: ASYNCHRONOUS RECEPTION
x64 Baud Rate CLK
Baud Rate Generator
RXx
Pin Buffer
and Control
SPEN
Data
Recovery
CREN OERR FERR
RSR Register
MSb LSb
RX9D RCREGx Register
2-Entry FIFO
Interrupt RCxIF
RCxIE
Data Bus
8
64
16
or
Stop Start
(8) 7 1 0
RX9

SPBRGxSPBRGHx
BRG16
or
4
{
RXDTP Unread Data
in FIFO
Start
bit bit 7/8
bit 1bit 0 bit 7/8 bit 0
Stop
bit
Start
bit
Start
bit
bit 7/8 Stop
bit
RXx (pin)
Rcv Buffer Reg
Rcv Shift Reg
Read Rcv
Buffer Reg
RCREGx
RCxIF
(Interrupt Flag)
OERR bit
CREN
Word 1
RCREGx
Word 2
RCREGx
Stop
bit
Note: This timing diagram shows three words appearing on the RXx input. The RCREGx (Receive Buffer) is read after
the third word, causing the OERR (Overrun) bit to be set.
PIC18F46J50 FAMILY
DS39931D-page 338 2011 Microchip Technology Inc.
TABLE 20-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
20.2.3 AUTO-WAKE-UP ON SYNC BREAK
CHARACTER
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the BRG is inactive and a
proper byte reception cannot be performed. The
auto-wake-up feature allows the controller to wake-up
due to activity on the RXx/DTx line while the EUSART
is operating in Asynchronous mode.
The auto-wake-up feature is enabled by setting the
WUE bit (BAUDCONx<1>). Once set, the typical
receive sequence on RXx/DTx is disabled and the
EUSART remains in an Idle state, monitoring for a
wake-up event independent of the CPU mode. A
wake-up event consists of a high-to-low transition on
the RXx/DTx line. (This coincides with the start of a
Sync Break or a Wake-up Signal character for the
LIN/J2602 support protocol.)
Following a wake-up event, the module generates an
RCxIF interrupt. The interrupt is generated synchro-
nously to the Q clocks in normal operating modes
(Figure 20-8) and asynchronously if the device is in
Sleep mode (Figure 20-9). The interrupt condition is
cleared by reading the RCREGx register.
The WUE bit is automatically cleared once a
low-to-high transition is observed on the RXx line
following the wake-up event. At this point, the EUSART
module is in Idle mode and returns to normal operation.
This signals to the user that the Sync Break event is
over.
20.2.3.1 Special Considerations Using
Auto-Wake-up
Since auto-wake-up functions by sensing rising edge
transitions on RXx/DTx, information with any state
changes before the Stop bit may signal a false
End-of-Character (EOC) and cause data or framing
errors. To work properly, therefore, the initial character
in the transmission must be all ‘0’s. This can be 00h
(8 bits) for standard RS-232 devices or 000h (12 bits)
for LIN/J2602 bus.
Oscillator start-up time must also be considered,
especially in applications using oscillators with
longer start-up intervals (i.e., HS or HSPLL mode).
The Sync Break (or Wake-up Signal) character must
be of sufficient length, and be followed by a sufficient
interval, to allow enough time for the selected
oscillator to start and provide proper initialization of
the EUSART.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 71
RCREGx EUSARTx Receive Register 71
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 71
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 71
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 71
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
Note 1: These bits are only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 339
PIC18F46J50 FAMILY
20.2.3.2 Special Considerations Using the
WUE Bit
The timing of WUE and RCxIF events may cause some
confusion when it comes to determining the validity of
received data. As noted, setting the WUE bit places the
EUSART in an Idle mode. The wake-up event causes a
receive interrupt by setting the RCxIF bit. The WUE bit
is cleared after this when a rising edge is seen on
RXx/DTx. The interrupt condition is then cleared by
reading the RCREGx register. Ordinarily, the data in
RCREGx will be dummy data and should be discarded.
The fact that the WUE bit has been cleared (or is still
set) and the RCxIF flag is set should not be used as an
indicator of the integrity of the data in RCREGx. Users
should consider implementing a parallel method in
firmware to verify received data integrity.
To assure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process. If
a receive operation is not occurring, the WUE bit may
then be set just prior to entering the Sleep mode.
FIGURE 20-8: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION
FIGURE 20-9: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit(1)
RXx/DTx Line
RCxIF
Note 1: The EUSART remains in Idle while the WUE bit is set.
Bit set by user
Cleared due to user read of RCREGx
Auto-Cleared
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit(2)
RXx/DTx Line
RCxIF
Cleared due to user read of RCREGx
SLEEP Command Executed
Note 1: If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur before the
oscillator is ready. This sequence should not depend on the presence of Q clocks.
2: The EUSART remains in Idle while the WUE bit is set.
Sleep Ends
Note 1
Auto-Cleared
Bit set by user
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DS39931D-page 340 2011 Microchip Technology Inc.
20.2.4 BREAK CHARACTER SEQUENCE
The EUSART module has the capability of sending the
special Break character sequences that are required by
the LIN/J2602 bus standard. The Break character
transmit consists of a Start bit, followed by twelve ‘0
bits and a Stop bit. The Frame Break character is sent
whenever the SENDB and TXEN bits (TXSTAx<3> and
TXSTAx<5>) are set while the Transmit Shift Register
is loaded with data.
Note that the value of data written to TXREGx will be
ignored and all ‘0s will be transmitted.
The SENDB bit is automatically reset by hardware after
the corresponding Stop bit is sent. This allows the user
to preload the transmit FIFO with the next transmit
byte, following the Break character (typically, the Sync
character in the LIN/J2602 specification).
Note that the data value written to the TXREGx for the
Break character is ignored. The write simply serves the
purpose of initiating the proper sequence.
The TRMT bit indicates when the transmit operation is
active or Idle, just as it does during normal transmis-
sion. See Figure 20-10 for the timing of the Break
character sequence.
20.2.4.1 Break and Sync Transmit Sequence
The following sequence will send a message frame
header made up of a Break, followed by an Auto-Baud
Sync byte. This sequence is typical of a LIN/J2602 bus
master.
1. Configure the EUSART for the desired mode.
2. Set the TXEN and SENDB bits to set up the
Break character.
3. Load the TXREGx with a dummy character to
initiate transmission (the value is ignored).
4. Write ‘55h’ to TXREGx to load the Sync
character into the transmit FIFO buffer.
5. After the Break has been sent, the SENDB bit is
reset by hardware. The Sync character now
transmits in the preconfigured mode.
When the TXREGx becomes empty, as indicated by the
TXxIF, the next data byte can be written to TXREGx.
20.2.5 RECEIVING A BREAK CHARACTER
The Enhanced USART module can receive a Break
character in two ways.
The first method forces configuration of the baud rate
at a frequency of 9/13 the typical speed. This allows for
the Stop bit transition to be at the correct sampling
location (13 bits for Break versus Start bit and 8 data
bits for typical data).
The second method uses the auto-wake-up feature
described in Section 20.2.3 “Auto-Wake-up on Sync
Break Character”. By enabling this feature, the
EUSART will sample the next two transitions on
RXx/DTx, cause an RCxIF interrupt and receive the
next data byte followed by another interrupt.
Note that following a Break character, the user will
typically want to enable the Auto-Baud Rate Detect
feature. For both methods, the user can set the ABDEN
bit once the TXxIF interrupt is observed.
FIGURE 20-10: SEND BREAK CHARACTER SEQUENCE
Write to TXREGx
BRG Output
(Shift Clock)
Start Bit Bit 0 Bit 1 Bit 11 Stop Bit
Break
TXxIF bit
(Transmit Buffer
Reg. Empty Flag)
TXx (pin)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
SENDB bit
(Transmit Shift
Reg. Empty Flag)
SENDB sampled here Auto-Cleared
Dummy Write
2011 Microchip Technology Inc. DS39931D-page 341
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20.3 EUSART Synchronous Master
Mode
The Synchronous Master mode is entered by setting
the CSRC bit (TXSTAx<7>). In this mode, the data is
transmitted in a half-duplex manner (i.e., transmission
and reception do not occur at the same time). When
transmitting data, the reception is inhibited and vice
versa. Synchronous mode is entered by setting bit,
SYNC (TXSTAx<4>). In addition, enable bit, SPEN
(RCSTAx<7>), is set in order to configure the TXx and
RXx pins to CKx (clock) and DTx (data) lines,
respectively.
The Master mode indicates that the processor trans-
mits the master clock on the CKx line. Clock polarity is
selected with the TXCKP bit (BAUDCONx<4>). Setting
TXCKP sets the Idle state on CKx as high, while clear-
ing the bit sets the Idle state as low. This option is
provided to support Microwire devices with this module.
20.3.1 EUSART SYNCHRONOUS MASTER
TRANSMISSION
The EUSART transmitter block diagram is shown in
Figure 20-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSR). The Shift register obtains
its data from the Read/Write Transmit Buffer register,
TXREGx. The TXREGx register is loaded with data in
software. The TSR register is not loaded until the last
bit has been transmitted from the previous load. As
soon as the last bit is transmitted, the TSR is loaded
with new data from the TXREGx (if available).
Once the TXREGx register transfers the data to the
TSR register (occurs in one TCY), the TXREGx is empty
and the TXxIF flag bit is set. The interrupt can be
enabled or disabled by setting or clearing the interrupt
enable bit, TXxIE. TXxIF is set regardless of the state
of enable bit, TXxIE; it cannot be cleared in software. It
will reset only when new data is loaded into the
TXREGx register.
While flag bit, TXxIF, indicates the status of the TXREGx
register, another bit, TRMT (TXSTAx<1>), shows the
status of the TSR register. TRMT is a read-only bit which
is set when the TSR is empty. No interrupt logic is tied to
this bit, so the user must poll this bit in order to determine
if the TSR register is empty. The TSR is not mapped in
data memory so it is not available to the user.
To set up a Synchronous Master Transmission:
1. Initialize the SPBRGHx:SPBRGx registers for the
appropriate baud rate. Set or clear the BRG16
bit, as required, to achieve the required baud
rate.
2. Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is required, set bit, TX9.
5. Enable the transmission by setting bit, TXEN.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Start transmission by loading data to the
TXREGx register.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
FIGURE 20-11: SYNCHRONOUS TRANSMISSION
bit 0 bit 1 bit 7
Word 1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
bit 2 bit 0 bit 1 bit 7
RC7/RX1/DT1/
RC6/TX1/CK1/RP17 pin
Write to
TXREG1 Reg
TX1IF bit
(Interrupt Flag)
TXEN bit 1 1
Word 2
TRMT bit
Write Word 1 Write Word 2
Note: Sync Master mode, SPBRGx = 0, continuous transmission of two 8-bit words. This example is equally applicable to
EUSART2 (RPn1/TX2/CK2 and RPn2/RX2/DT2).
RC6/TX1/CK1/RP17 pin
(TXCKP = 0)
(TXCKP = 1)
SDO1/RP18
PIC18F46J50 FAMILY
DS39931D-page 342 2011 Microchip Technology Inc.
FIGURE 20 - 1 2: SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
TABLE 20-7: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 72
TXREGx EUSARTx Transmit Register 72
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 72
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 72
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 72
ODCON2 U2OD U1OD 74
Legend: = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
Note 1: These pins are only available on 44-pin devices.
RC7/RX1/DT1/
RC6/TX1/CK1/RP17 pin
Write to
TXREG1 reg
TX1IF bit
TRMT bit
bit 0 bit 1 bit 2 bit 6 bit 7
TXEN bit
Note: This example is equally applicable to EUSART2 (RPn1/TX2/CK2 and RPn2/RX2/DT2).
SDO1/RP18 pin
2011 Microchip Technology Inc. DS39931D-page 343
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20.3.2 EUSART SYNCHRONOUS MASTER
RECEPTION
Once Synchronous mode is selected, reception is
enabled by setting either the Single Receive Enable bit,
SREN (RCSTAx<5>) or the Continuous Receive
Enable bit, CREN (RCSTAx<4>). Data is sampled on
the RXx pin on the falling edge of the clock.
If enable bit, SREN, is set, only a single word is
received. If enable bit, CREN, is set, the reception is
continuous until CREN is cleared. If both bits are set,
then CREN takes precedence.
To set up a Synchronous Master Reception:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRG16 bit, as required, to achieve the desired
baud rate.
2. Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
3. Ensure bits, CREN and SREN, are clear.
4. If interrupts are desired, set enable bit, RCxIE.
5. If 9-bit reception is desired, set bit, RX9.
6. If a single reception is required, set bit, SREN.
For continuous reception, set bit, CREN.
7. Interrupt flag bit, RCxIF, will be set when
reception is complete and an interrupt will be
generated if the enable bit, RCxIE, was set.
8. Read the RCSTAx register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREGx register.
10. If any error occurred, clear the error by clearing
bit, CREN.
11. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
FIGURE 20-13: SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
CREN bit
RC7/RX1/DT1/
RC6/TX1/CK1/RP17
Write to
bit SREN
SREN bit
RC1IF bit
(Interrupt)
Read
RCREG1
Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
0
bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7
0
Q1 Q2 Q3 Q4
Note: Timing diagram demonstrates Sync Master mode with bit, SREN = 1, and bit, BRGH = 0. This example is equally
applicable to EUSART2 (RPn1/TX2/CK2 and RPn2/RX2/DT2).
RC6/TX1/CK1/RP17
SDO1/RP18 pin
pin (TXCKP = 0)
pin (TXCKP = 1)
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DS39931D-page 344 2011 Microchip Technology Inc.
TABLE 20-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 72
RCREGx EUSARTx Receive Register 72
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 72
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 72
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 72
ODCON2 U2OD U1OD 74
Legend: = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
Note 1: These pins are only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 345
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20.4 EUSART Synchronous Slave
Mode
Synchronous Slave mode is entered by clearing bit,
CSRC (TXSTAx<7>). This mode differs from the
Synchronous Master mode in that the shift clock is sup-
plied externally at the CKx pin (instead of being supplied
internally in Master mode). This allows the device to
transfer or receive data while in any low-power mode.
20.4.1 EUSART SYNCHRONOUS SLAVE
TRANSMISSION
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep mode.
If two words are written to the TXREGx and then the
SLEEP instruction is executed, the following will occur:
a) The first word will immediately transfer to the
TSR register and transmit.
b) The second word will remain in the TXREGx
register.
c) Flag bit, TXxIF, will not be set.
d) When the first word has been shifted out of TSR,
the TXREGx register will transfer the second word
to the TSR and flag bit, TXxIF, will now be set.
e) If enable bit, TXxIE, is set, the interrupt will wake
the chip from Sleep. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
To set up a Synchronous Slave Transmission:
1. Enable the synchronous slave serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
2. Clear bits, CREN and SREN.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is desired, set bit, TX9.
5. Enable the transmission by setting enable bit,
TXEN.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Start transmission by loading data to the
TXREGx register.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 20-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 72
TXREGx EUSARTx Transmit Register 72
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 72
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 72
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 72
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
Note 1: These pins are only available on 44-pin devices.
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DS39931D-page 346 2011 Microchip Technology Inc.
20.4.2 EUSART SYNCHRONOUS SLAVE
RECEPTION
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep or any
Idle mode, and bit, SREN, which is a “don’t care” in
Slave mode.
If receive is enabled by setting the CREN bit, prior to
entering Sleep or any Idle mode, then a word may be
received while in this low-power mode. Once the word
is received, the RSR register will transfer the data to the
RCREGx register. If the RCxIE enable bit is set, the
interrupt generated will wake the chip from the
low-power mode. If the global interrupt is enabled, the
program will branch to the interrupt vector.
To set up a Synchronous Slave Reception:
1. Enable the synchronous master serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
2. If interrupts are desired, set enable bit, RCxIE.
3. If 9-bit reception is desired, set bit, RX9.
4. To enable reception, set enable bit, CREN.
5. Flag bit, RCxIF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RCxIE, was set.
6. Read the RCSTAx register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
7. Read the 8-bit received data by reading the
RCREGx register.
8. If any error occurred, clear the error by clearing
bit, CREN.
9. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 20-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR3 SSP2IF BCL2IF RC2IF TX2IF TMR4IF CTMUIF TMR3GIF RTCCIF 72
PIE3 SSP2IE BCL2IE RC2IE TX2IE TMR4IE CTMUIE TMR3GIE RTCCIE 72
IPR3 SSP2IP BCL2IP RC2IP TX2IP TMR4IP CTMUIP TMR3GIP RTCCIP 72
RCSTAx SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 72
RCREGx EUSARTx Receive Register 72
TXSTAx CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 72
BAUDCONx ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 73
SPBRGHx EUSARTx Baud Rate Generator Register High Byte 72
SPBRGx EUSARTx Baud Rate Generator Register Low Byte 72
Legend: = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
Note 1: These pins are only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 347
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21.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) Converter module has
10 inputs for the 28-pin devices and 13 for the 44-pin
devices. Additionally, two internal channels are available
for sampling the VDDCORE and VBG absolute reference
voltage. This module allows conversion of an analog
input signal to a corresponding 10-bit digital number.
The module has six registers:
A/D Control Register 0 (ADCON0)
A/D Control Register 1 (ADCON1)
A/D Port Configuration Register 2 (ANCON0)
A/D Port Configuration Register 1 (ANCON1)
A/D Result Registers (ADRESH and ADRESL)
The ADCON0 register, in Register 21-1, controls the
operation of the A/D module. The ADCON1 register, in
Register 21-2, configures the A/D clock source,
programmed acquisition time and justification.
The ANCON0 and ANCON1 registers, in Register 21-3
and Register 21-4, configure the functions of the port
pins.
REGISTER 21-1: ADCON0: A/D CONTROL REGISTER 0 (ACCESS FC2h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
VCFG1 VCFG0 CHS3(2) CHS2(2) CHS1(2) CHS0(2) GO/DONE(3) ADON
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 VCFG1: Voltage Reference Configuration bit (VREF- source)
1 = VREF- (AN2)
0 = AVSS(4)
bit 6 VCFG0: Voltage Reference Configuration bit (VREF+ source)
1 = VREF+ (AN3)
0 = AVDD(4)
bit 5-2 CHS<3:0>: Analog Channel Select bits(2)
0000 = Channel 00 (AN0)
0001 = Channel 01 (AN1)
0010 = Channel 02 (AN2)
0011 = Channel 03 (AN3)
0100 = Channel 04 (AN4)
0101 = Channel 05 (AN5)(1)
0110 = Channel 06 (AN6)(1)
0111 = Channel 07 (AN7)(1)
1000 = Channel 08 (AN8)
1001 = Channel 09 (AN9)
1010 = Channel 10 (AN10)
1011 = Channel 11 (AN11)
1100 = Channel 12 (AN12)
1101 = (Reserved)
1110 = VDDCORE
1111 = VBG Absolute Reference (~1.2V)(3)
bit 1 GO/DONE: A/D Conversion Status bit
When ADON = 1:
1 = A/D conversion in progress
0 = A/D Idle
Note 1: These channels are not implemented on 28-pin devices.
2: Performing a conversion on unimplemented channels will return random values.
3: For best accuracy, the band gap reference circuit should be enabled (ANCON1<7> = 1) at least 10 ms
before performing a conversion on this channel.
4: On package types that have AVDD and AVSS pins, these pins should be externally connected to VDD and
VSS levels at the circuit board level. Package types that do not have AVDD and AVSS pins, tie AVDD and
AVSS to VDD and VSS internally.
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DS39931D-page 348 2011 Microchip Technology Inc.
bit 0 ADON: A/D On bit
1 = A/D Converter module is enabled
0 = A/D Converter module is disabled
REGISTER 21-1: ADCON0: A/D CONTROL REGISTER 0 (ACCESS FC2h)
Note 1: These channels are not implemented on 28-pin devices.
2: Performing a conversion on unimplemented channels will return random values.
3: For best accuracy, the band gap reference circuit should be enabled (ANCON1<7> = 1) at least 10 ms
before performing a conversion on this channel.
4: On package types that have AVDD and AVSS pins, these pins should be externally connected to VDD and
VSS levels at the circuit board level. Package types that do not have AVDD and AVSS pins, tie AVDD and
AVSS to VDD and VSS internally.
REGISTER 21-2: ADCON1: A/D CONTROL REGISTER 1 (ACCESS FC1h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ADFM ADCAL ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 ADFM: A/D Result Format Select bit
1 = Right justified
0 = Left justified
bit 6 ADCAL: A/D Calibration bit
1 = Calibration is performed on next A/D conversion
0 = Normal A/D Converter operation
bit 5-3 ACQT<2:0>: A/D Acquisition Time Select bits
111 = 20 T
AD
110 = 16 TAD
101 = 12 TAD
100 = 8 TAD
011 = 6 TAD
010 = 4 TAD
001 = 2 TAD
000 = 0 TAD
bit 2-0 ADCS<2:0>: A/D Conversion Clock Select bits
110 = FOSC/64
101 = FOSC/16
100 = FOSC/4
011 = FRC (clock derived from A/D RC oscillator)(1)
010 = FOSC/32
001 = FOSC/8
000 = FOSC/2
Note 1: If the A/D FRC clock source is selected, a delay of one T
CY (instruction cycle) is added before the A/D
clock starts. This allows the SLEEP instruction to be executed before starting a conversion.
2011 Microchip Technology Inc. DS39931D-page 349
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The ANCON0 and ANCON1 registers are used to
configure the operation of the I/O pin associated with
each analog channel. Setting any one of the PCFG bits
configures the corresponding pin to operate as a digital
only I/O. Clearing a bit configures the pin to operate as
an analog input for either the A/D Converter or the
comparator module; all digital peripherals are disabled
and digital inputs read as ‘0’. As a rule, I/O pins that are
multiplexed with analog inputs default to analog
operation on device Resets.
In order to correctly perform A/D conversions on the VBG
band gap reference (ADCON0<5:2> = 1111), the refer-
ence circuit must be powered on first. The VBGEN bit in
the ANCON1 register allows the firmware to manually
request that the band gap reference circuit should be
enabled. For best accuracy, firmware should allow a
settling time of at least 10 ms prior to performing the first
acquisition on this channel after enabling the band gap
reference.
The reference circuit may already have been turned on
if some other hardware module (such as the on-chip
voltage regulator, comparators or HLVD) has already
requested it. In this case, the initial turn-on settling time
may have already elapsed and firmware does not need
to wait as long before measuring VBG. Once the acqui-
sition is complete, firmware may clear the VBGEN bit,
which will save a small amount of power if no other
modules are still requesting the VBG reference.
REGISTER 21-3: ANCON0: A/D PORT CONFIGURATION REGISTER 2 (BANKED F48h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
PCFG7(1) PCFG6(1) PCFG5(1) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 PCFG<7:0>: Analog Port Configuration bits (AN7-AN0)
1 = Pin configured as a digital port
0 = Pin configured as an analog channel – digital input is disabled and reads ‘0
Note 1: These bits are only available on 44-pin devices.
REGISTER 21-4: ANCON1: A/D PORT CONFIGURATION REGISTER 1 (BANKED F49h)
R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
VBGEN r PCFG12 PCFG11 PCFG10 PCFG9 PCFG8
bit 7 bit 0
Legend: r = Reserved bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 VBGEN: 1.2V Band Gap Reference Enable bit
1 = 1.2V band gap reference is powered on
0 = 1.2V band gap reference is turned off to save power (if no other modules are requesting it)
bit 6 Reserved: Always maintain as ‘0’ for lowest power consumption
bit 5 Unimplemented: Read as ‘0
bit 4-0 PCFG<12:8>: Analog Port Configuration bits (AN12-AN8)
1 = Pin configured as a digital port
0 = Pin configured as an analog channel – digital input is disabled and reads ‘0
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DS39931D-page 350 2011 Microchip Technology Inc.
The analog reference voltage is
software-selectable to either the device’s positive
and negative supply voltage (AVDD and AVSS), or
the voltage level on the RA3/AN3/VREF+/C1INB and
RA2/AN2/VREF-/CVREF/C2INB pins.
The A/D Converter has a unique feature of being able
to operate while the device is in Sleep mode. To
operate in Sleep, the A/D conversion clock must be
derived from the A/D’s internal RC oscillator.
The output of the sample and hold is the input into the
converter, which generates the result via Successive
Approximation (SAR).
Each port pin associated with the A/D Converter can be
configured as an analog input or as a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0<1>) is
cleared and the A/D Interrupt Flag bit, ADIF, is set.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted. The value in the
ADRESH:ADRESL register pair is not modified for a
Power-on Reset (POR). These registers will contain
unknown data after a POR.
Figure 21-1 provides the block diagram of the A/D
module.
FIGUR E 21-1: A/D BLOCK DIAGRAM
(Input Voltage)
VAIN
VREF+
Reference
Voltage
VDD(2)
VCFG<1:0>
CHS<3:0>
AN7(1)
AN4
AN3
AN2
AN1
AN0
0111
0100
0011
0010
0001
0000
10-Bit
A/D
VREF-
VSS(2)
Converter
VBG
VDDCORE/VCAP
AN12
AN11
AN10
1111
1110
1100
1011
1010
Note 1: Channels, AN5, AN6 and AN7, are not available on 28-pin devices.
2: I/O pins have diode protection to VDD and VSS.
AN6(1)
0110
AN5(1)
0101
AN9
1001
AN8
1000
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After the A/D module has been configured as desired,
the selected channel must be acquired before the
conversion is started. The analog input channels must
have their corresponding TRIS bits selected as an
input. To determine acquisition time, see Section 21.1
“A/D Acquisition Requirements”. After this acquisi-
tion time has elapsed, the A/D conversion can be
started. An acquisition time can be programmed to
occur between setting the GO/DONE bit and the actual
start of the conversion.
The following steps should be followed to do an A/D
conversion:
1. Configure the A/D module:
Configure the required ADC pins as analog
pins using ANCON0, ANCON1
Set voltage reference using ADCON0
Select A/D input channel (ADCON0)
Select A/D acquisition time (ADCON1)
Select A/D conversion clock (ADCON1)
Turn on A/D module (ADCON0)
2. Configure the A/D interrupt (if desired):
Clear ADIF bit
Set ADIE bit
•Set GIE bit
3. Wait the required acquisition time (if required).
4. Start conversion:
Set GO/DONE bit (ADCON0<1>)
5. Wait for the A/D conversion to complete, by either:
Polling for the GO/DONE bit to be cleared
OR
Waiting for the A/D interrupt
6. Read A/D Result registers (ADRESH:ADRESL);
clear bit, ADIF, if required.
7. For next conversion, go to Step 1 or Step 2, as
required. The A/D conversion time per bit is
defined as T
AD. A minimum Wait of 2 TAD is
required before the next acquisition starts.
FIGURE 21-2: ANALOG INPUT MODEL
VAIN CPIN
RSANx
5 pF
VDD
VT = 0.6V
VT = 0.6V ILEAKAGE
RIC 1k
Sampling
Switch
SS RSS
CHOLD = 25 pF
VSS
Sampling Switch
1234
(k)
VDD
±100 nA
Legend: CPIN
VT
ILEAKAGE
RIC
SS
CHOLD
= Input Capacitance
= Threshold Voltage
= Leakage Current at the pin due to
= Interconnect Resistance
= Sampling Switch
= Sample/Hold Capacitance (from DAC)
various junctions
= Sampling Switch ResistanceRSS
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21.1 A/D Acquisition Requirements
For the A/D Converter to meet its specified accuracy,
the charge holding capacitor (CHOLD) must be allowed
to fully charge to the input channel voltage level. The
analog input model is illustrated in Figure 21-2. The
source impedance (RS) and the internal sampling
switch (RSS) impedance directly affect the time
required to charge the capacitor CHOLD. The sampling
switch (RSS) impedance varies over the device voltage
(VDD). The source impedance affects the offset voltage
at the analog input (due to pin leakage current). The
maximum recommended impedance for analog
sources is 2.5 k. After the analog input channel is
selected (changed), the channel must be sampled for
at least the minimum acquisition time before starting a
conversion.
To calculate the minimum acquisition time,
Equation 21-1 may be used. This equation assumes
that 1/2 LSb error is used (1024 steps for the A/D). The
1/2 LSb error is the maximum error allowed for the A/D
to meet its specified resolution.
Equation 21-3 provides the calculation of the minimum
required acquisition time, T
ACQ. This calculation is
based on the following application system
assumptions:
CHOLD =25 pF
Rs = 2.5 k
Conversion Error 1/2 LSb
VDD =3VRss = 2 k
Temperature = 85C (system max.)
EQUATION 21-1: ACQUISITION TIME
EQUATION 21-2: A/D MINIMUM CHARGING TIME
EQUATION 21-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
Note: When the conversion is started, the
holding capacitor is disconnected from the
input pin.
TACQ = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
=T
AMP + TC + TCOFF
VHOLD = (VREF – (VREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS)))
or
TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048)
TACQ =TAMP + TC + TCOFF
TAMP =0.2 s
TCOFF = (Temp – 25°C)(0.02 s/°C)
(85°C – 25°C)(0.02 s/°C)
1.2 s
Temperature coefficient is only required for temperatures > 25°C. Below 25°C, TCOFF = 0 s.
TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048) s
-(25 pF) (1 k + 2 k + 2.5 k) ln(0.0004883) s
1.05 s
TACQ =0.2 s + 1.05 s + 1.2 s
2.45 s
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21.2 Selecting and Configuring
Auto mati c A c q u is i tion Time
The ADCON1 register allows the user to select an
acquisition time that occurs each time the GO/DONE
bit is set.
When the GO/DONE bit is set, sampling is stopped and
a conversion begins. The user is responsible for ensur-
ing the required acquisition time has passed between
selecting the desired input channel and setting the
GO/DONE bit. This occurs when the ACQT<2:0> bits
(ADCON1<5:3>) remain in their Reset state (‘000’) and
is compatible with devices that do not offer
programmable acquisition times.
If desired, the ACQT bits can be set to select a pro-
grammable acquisition time for the A/D module. When
the GO/DONE bit is set, the A/D module continues to
sample the input for the selected acquisition time, then
automatically begins a conversion. Since the acquisi-
tion time is programmed, there may be no need to wait
for an acquisition time between selecting a channel and
setting the GO/DONE bit.
In either case, when the conversion is completed, the
GO/DONE bit is cleared, the ADIF flag is set and the
A/D begins sampling the currently selected channel
again. If an acquisition time is programmed, there is
nothing to indicate if the acquisition time has ended or
if the conversion has begun.
21.3 Selecting the A/D Conversion
Clock
The A/D conversion time per bit is defined as TAD. The
A/D conversion requires 11 T
AD per 10-bit conversion.
The source of the A/D conversion clock is
software-selectable.
There are seven possible options for TAD:
•2 T
OSC
•4 TOSC
•8 TOSC
•16 TOSC
•32 TOSC
•64 T
OSC
Internal RC Oscillator
For correct A/D conversions, the A/D conversion clock
(T
AD) must be as short as possible but greater than the
minimum TAD (see Parameter 130 in Table 30-32 for
more information).
Table 21-1 provides the resultant T
AD times derived
from the device operating frequencies and the A/D
clock source selected.
TABLE 21-1: TAD vs. DEVICE OPERATING
FREQUENCIES
21.4 Configuring Analog Port Pins
The ANCON0, ANCON1 and TRISA registers control
the operation of the A/D port pins. The port pins needed
as analog inputs must have their corresponding TRIS
bits set (input). If the TRIS bit is cleared (output), the
digital output level (VOH or VOL) will be converted.
The A/D operation is independent of the state of the
CHS<3:0> bits and the TRIS bits.
AD Clock Source (TAD)Maximum
Device
Frequency
Operation ADCS<2:0>
2 T
OSC 000 2.86 MHz
4 T
OSC 100 5.71 MHz
8 TOSC 001 11.43 MHz
16 TOSC 101 22.86 MHz
32 TOSC 010 45.71 MHz
64 TOSC 110 48.0 MHz
RC(2) 011 1.00 MHz(1)
Note 1: The RC source has a typical TAD time of
4s.
2: For device frequencies above 1 MHz, the
device must be in Sleep mode for the
entire conversion or the A/D accuracy may
be out of specification.
Note 1: When reading the PORT register, all pins
configured as analog input channels will
read as cleared (a low level). Pins config-
ured as digital inputs will convert an
analog input. Analog levels on a digitally
configured input will be accurately
converted.
2: Analog levels on any pin defined as a
digital input may cause the digital input
buffer to consume current out of the
device’s specification limits.
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21.5 A/D Conversions
Figure 21-3 displays the operation of the A/D Converter
after the GO/DONE bit has been set and the
ACQT<2:0> bits are cleared. A conversion is started
after the following instruction to allow entry into Sleep
mode before the conversion begins.
Figure 21-4 displays the operation of the A/D Converter
after the GO/DONE bit has been set, the ACQT<2:0>
bits are set to ‘010’ and selecting a 4 TAD acquisition
time before the conversion starts.
Clearing the GO/DONE bit during a conversion will
abort the current conversion. The A/D Result register
pair will NOT be updated with the partially completed
A/D conversion sample. This means the
ADRESH:ADRESL registers will continue to contain
the value of the last completed conversion (or the last
value written to the ADRESH:ADRESL registers).
After the A/D conversion is completed or aborted, a
2T
AD Wait is required before the next acquisition can
be started. After this Wait, acquisition on the selected
channel is automatically started.
21.6 Use of the ECCP2 Trigger
An A/D conversion can be started by the Special Event
Trigger of the ECCP2 module. This requires that the
CCP2M<3:0> bits (CCP2CON<3:0>) be programmed
as ‘1011and that the A/D module is enabled (ADON
bit is set). When the trigger occurs, the GO/DONE bit
will be set, starting the A/D acquisition and conversion,
and the Timer1 (or Timer3) counter will be reset to zero.
Timer1 (or Timer3) is reset to automatically repeat the
A/D acquisition period with minimal software overhead
(moving ADRESH/ADRESL to the desired location).
The appropriate analog input channel must be selected
and the minimum acquisition period is either timed by
the user, or an appropriate TACQ time is selected before
the Special Event Trigger sets the GO/DONE bit (starts
a conversion).
If the A/D module is not enabled (ADON is cleared), the
Special Event Trigger will be ignored by the A/D module
but will still reset the Timer1 (or Timer3) counter.
FIGURE 21- 3 : A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)
FIGURE 21- 4 : A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)
Note: The GO/DONE bit should NOT be set in
the same instruction that turns on the A/D.
TAD1 TAD2TAD3TAD4 TAD5TAD6 TAD7TAD8TAD11
Set GO/DONE bit
Holding capacitor is disconnected from analog input (typically 100 ns)
TAD9 TAD10
TCY - TAD
Next Q4: ADRESH/ADRESL are loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
Conversion starts
b0
b9 b6 b5 b4 b3 b2 b1
b8 b7
1234567811
Set GO/DONE bit
(Holding capacitor is disconnected)
910
Next Q4: ADRESH:ADRESL are loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is reconnected to analog input.
Conversion starts
123 4
(Holding capacitor continues
acquiring input)
TACQT Cycles TAD Cycles
Automatic
Acquisition
Time
b0b9 b6 b5 b4 b3 b2 b1
b8 b7
2011 Microchip Technology Inc. DS39931D-page 355
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21.7 A/D Converter Calibration
The A/D Converter in the PIC18F46J50 family of
devices includes a self-calibration feature, which com-
pensates for any offset generated within the module.
The calibration process is automated and is initiated by
setting the ADCAL bit (ADCON1<6>). The next time
the GO/DONE bit is set, the module will perform a
“dummy” conversion (that is, with reading none of the
input channels) and store the resulting value internally
to compensate for the offset. Thus, subsequent offsets
will be compensated.
Example 21-1 provides an example of a calibration
routine.
The calibration process assumes that the device is in a
relatively steady-state operating condition. If A/D
calibration is used, it should be performed after each
device Reset or if there are other major changes in
operating conditions.
21.8 Operation in Power-Managed
Modes
The selection of the automatic acquisition time and A/D
conversion clock is determined, in part, by the clock
source and frequency while in a power-managed
mode.
If the A/D is expected to operate while the device is in
a power-managed mode, the ACQT<2:0> and
ADCS<2:0> bits in ADCON1 should be updated in
accordance with the power-managed mode clock that
will be used. After the power-managed mode is entered
(either of the power-managed Run modes), an A/D
acquisition or conversion may be started. Once an
acquisition or conversion is started, the device should
continue to be clocked by the same power-managed
mode clock source until the conversion has been com-
pleted. If desired, the device may be placed into the
corresponding power-managed Idle mode during the
conversion.
If the power-managed mode clock frequency is less
than 1 MHz, the A/D RC clock source should be
selected.
Operation in Sleep mode requires the A/D RC clock to
be selected. If bits, ACQT<2:0>, are set to000’ and a
conversion is started, the conversion will be delayed
one instruction cycle to allow execution of the SLEEP
instruction and entry to Sleep mode. The IDLEN and
SCS bits in the OSCCON register must have already
been cleared prior to starting the conversion.
EXAMPLE 21-1: SAMPLE A/D CALIBRATION ROUTINE
BCF ANCON0,PCFG0 ;Make Channel 0 analog
BSF ADCON0,ADON ;Enable A/D module
BSF ADCON1,ADCAL ;Enable Calibration
BSF ADCON0,GO ;Start a dummy A/D conversion
CALIBRATION ;
BTFSC ADCON0,GO ;Wait for the dummy conversion to finish
BRA CALIBRATION ;
BCF ADCON1,ADCAL ;Calibration done, turn off calibration enable
;Proceed with the actual A/D conversion
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DS39931D-page 356 2011 Microchip Technology Inc.
TABLE 21-2: SUMMARY OF A/D REGISTERS
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
V alues
on Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR1 PMPIF(1) ADIF RC1IF TX1IF SSP1IF CCP1IF TMR2IF TMR1IF 72
PIE1 PMPIE(1) ADIE RC1IE TX1IE SSP1IE CCP1IE TMR2IE TMR1IE 72
IPR1 PMPIP(1) ADIP RC1IP TX1IP SSP1IP CCP1IP TMR2IP TMR1IP 72
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 72
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 72
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 72
ADRESH A/D Result Register High Byte 70
ADRESL A/D Result Register Low Byte 70
ADCON0 VCFG1 VCFG0 CHS3 CHS3 CHS1 CHS0 GO/DONE ADON 70
ANCON0 PCFG7(1) PCFG6(1) PCFG5(1) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 74
ADCON1 ADFM ADCAL ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 70
ANCON1 VBGEN r PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 74
CCP2CON P2M1 P2M0 DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 71
PORTA RA7 RA6 RA5 RA3 RA2 RA1 RA0 72
TRISA TRISA7 TRISA6 TRISA5 TRISA3 TRISA2 TRISA1 TRISA0 72
Legend: — = unimplemented, read as ‘0’, r = reserved. Shaded cells are not used for A/D conversion.
Note 1: These bits are only available on 44-pin devices.
2011 Microchip Technology Inc. DS39931D-page 357
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22.0 UNIVERSAL SERIAL BUS
(USB)
This section describes the details of the USB peripheral.
Because of the very specific nature of the module,
knowledge of USB is expected. Some high-level USB
information is provided in Section 22.9 “Overview of
USB” only for application design reference. Designers
are encouraged to refer to the official specification
published by the USB Implementers Forum (USB-IF) for
the latest information. “USB Specification Revision 2.0”
is the most current specification at the time of publication
of this document.
22.1 Overview of the USB Peripheral
PIC18F46J50 family devices contain a full-speed and
low-speed, compatible USB Serial Interface Engine
(SIE) that allows fast communication between any USB
host and the PIC® MCU. The SIE can be interfaced
directly to the USB, utilizing the internal transceiver.
Some special hardware features have been included to
improve performance. Dual access port memory in the
device’s data memory space (USB RAM) has been
supplied to share direct memory access between the
microcontroller core and the SIE. Buffer descriptors are
also provided, allowing users to freely program end-
point memory usage within the USB RAM space.
Figure 22-1 provides a general overview of the USB
peripheral and its features.
FIGURE 22-1: USB PERIPHERAL AND OPTIONS
3.8-Kbyte
USB RAM
USB
SIE
USB Control and
Transceiver
P
P
D+
D-
Internal Pull-ups
External 3.3V
Supply
FSEN
UPUEN
UTRDIS
USB Clock from the
Oscillator Module
Optional
External
Pull-ups(1)
(Low
(Full
PIC18F46J50 Family
USB Bus
FS
Speed) Speed)
Note 1: The internal pull-up resistors should be disabled (UPUEN = 0) if external pull-up resistors are used.
Configuration
VUSB
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DS39931D-page 358 2011 Microchip Technology Inc.
22.2 USB Status and Control
The operation of the USB module is configured and
managed through three control registers. In addition, a
total of 22 registers are used to manage the actual USB
transactions. The registers are:
USB Control register (UCON)
USB Configuration register (UCFG)
USB Transfer Status register (USTAT)
USB Device Address register (UADDR)
Frame Number registers (UFRMH:UFRML)
Endpoint Enable registers 0 through 15 (UEPn)
22.2.1 USB CONTROL REGISTER (UCON)
The USB Control register (Register 22-1) contains the
bits needed to control the module behavior during
transfers. The register contains bits that control the
following:
Main USB Peripheral Enable
Ping-Pong Buffer Pointer Reset
Control of the Suspend mode
Packet Transfer Disable
In addition, the USB Control register contains a status
bit, SE0 (UCON<5>), which is used to indicate the
occurrence of a single-ended zero on the bus. When
the USB module is enabled, this bit should be
monitored to determine whether the differential data
lines have come out of a single-ended zero condition.
This helps to differentiate the initial power-up state from
the USB Reset signal.
The overall operation of the USB module is controlled
by the USBEN bit (UCON<3>). Setting this bit activates
the module and resets all of the PPBI bits in the Buffer
Descriptor Table (BDT) to ‘0’. This bit also activates the
internal pull-up resistors, if they are enabled. Thus, this
bit can be used as a soft attach/detach to the USB.
Although all status and control bits are ignored when
this bit is clear, the module needs to be fully preconfig-
ured prior to setting this bit. The USB clock source
should have been already configured for the correct
frequency and running. If the PLL is being used, it
should be enabled at least 2 ms (enough time for the
PLL to lock) before attempting to set the USBEN bit.
Note: When disabling the USB module, make
sure the SUSPND bit (UCON<1>) is clear
prior to clearing the USBEN bit. Clearing
the USBEN bit when the module is in the
suspended state may prevent the module
from fully powering down
2011 Microchip Technology Inc. DS39931D-page 359
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REGISTER 22-1: UCON: USB CONTROL REGISTER (ACCESS F65h)
U-0 R/W-0 R-x R/C-0 R/W-0 R/W-0 R/W-0 U-0
PPBRST SE0 PKTDIS USBEN(1) RESUME SUSPND
bit 7 bit 0
Legend: C = Clearable bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6 PPBRST: Ping-Pong Buffers Reset bit
1 = Reset all Ping-Pong Buffer Pointers to the Even Buffer Descriptor (BD) banks
0 = Ping-Pong Buffer Pointers are not being reset
bit 5 SE0: Live Single-Ended Zero Flag bit
1 = Single-ended zero is active on the USB bus
0 = No single-ended zero is detected
bit 4 PKTDIS: Packet Transfer Disable bit
1 = SIE token and packet processing are disabled, automatically set when a SETUP token is received
0 = SIE token and packet processing are enabled
bit 3 USBEN: USB Module Enable bit(1)
1 = USB module and supporting circuitry are enabled (device attached)
0 = USB module and supporting circuitry are disabled (device detached)
bit 2 RESUME: Resume Signaling Enable bit
1 = Resume signaling is activated
0 = Resume signaling is disabled
bit 1 SUSPND: Suspend USB bit
1 = USB module and supporting circuitry are in Power Conserve mode, SIE clock is inactive
0 = USB module and supporting circuitry are in normal operation, SIE is clocked at the configured rate
bit 0 Unimplemented: Read as0
Note 1: Make sure the USB clock source is correctly configured before setting this bit.
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DS39931D-page 360 2011 Microchip Technology Inc.
The PPBRST bit (UCON<6>) controls the Reset status
when Double-Buffering mode (ping-pong buffering) is
used. When the PPBRST bit is set, all Ping-Pong
Buffer Pointers are set to the Even buffers. PPBRST
has to be cleared by firmware. This bit is ignored in
buffering modes not using ping-pong buffering.
The PKTDIS bit (UCON<4>) is a flag indicating that the
SIE has disabled packet transmission and reception.
This bit is set by the SIE when a SETUP token is
received to allow setup processing. This bit cannot be
set by the microcontroller, only cleared; clearing it
allows the SIE to continue transmission and/or
reception. Any pending events within the Buffer
Descriptor Table will still be available, indicated within
the USTAT register’s FIFO buffer.
The RESUME bit (UCON<2>) allows the peripheral to
perform a remote wake-up by executing resume signal-
ing. To generate a valid remote wake-up, firmware must
set RESUME for 10 ms and then clear the bit. For more
information on resume signaling, see Sections 7.1.7.5,
11.4.4 and 11.9 in the “USB 2.0 Specifi cation”.
The SUSPND bit (UCON<1>) places the module and
supporting circuitry in a low-power mode. The input
clock to the SIE is also disabled. This bit should be set
by the software in response to an IDLEIF interrupt. It
should be reset by the microcontroller firmware after an
ACTVIF interrupt is observed. When this bit is active,
the device remains attached to the bus, but the trans-
ceiver outputs remain Idle. The voltage on the VUSB pin
may vary depending on the value of this bit. Setting this
bit, before a IDLEIF request, will result in unpredictable
bus behavior.
22.2.2 USB CONFIGURATION REGISTER
(UCFG)
Prior to communicating over USB, the module’s
associated internal and/or external hardware must be
configured. Most of the configuration is performed with
the UCFG register (Register 22-2).The UFCG register
contains most of the bits that control the system level
behavior of the USB module. These include:
Bus Speed (full speed versus low speed)
On-Chip Pull-up Resistor Enable
On-Chip Transceiver Enable
Ping-Pong Buffer Usage
The UCFG register also contains two bits which aid in
module testing, debugging and USB certifications.
These bits control output enable state monitoring and
eye pattern generation.
22.2.2.1 Internal Transceiver
The USB peripheral has a built-in, USB 2.0, full-speed
and low-speed capable transceiver, internally con-
nected to the SIE. This feature is useful for low-cost,
single chip applications. The UTRDIS bit (UCFG<3>)
controls the transceiver; it is enabled by default
(UTRDIS = 0). The FSEN bit (UCFG<2>) controls the
transceiver speed; setting the bit enables full-speed
operation.
The on-chip USB pull-up resistors are controlled by the
UPUEN bit (UCFG<4>). They can only be selected
when the on-chip transceiver is enabled.
The internal USB transceiver obtains power from the
VUSB pin. In order to meet USB signalling level specifi-
cations, VUSB must be supplied with a voltage source
between 3.0V and 3.6V. The best electrical signal
quality is obtained when a 3.3V supply is used and
locally bypassed with a high-quality ceramic capacitor
(ex: 0.1 F). The capacitor should be placed as close
as possible to the VUSB and VSS pins.
VUSB should always be maintained VDD. If the USB
module is not used, but RC4 or RC5 are used as
general purpose inputs, VUSB should still be connected
to a power source (such as VDD). The input thresholds
for the RC4 and RC5 pins are dependent upon the
VUSB supply level.
The D+ and D- signal lines can be routed directly to their
respective pins on the USB connector or cable (for
hard-wired applications). No additional resistors,
capacitors or magnetic components are required as the
D+ and D- drivers have controlled slew rate and output
impedance, intended to match with the
characteristic impedance of the USB cable.
In order to achieve optimum USB signal quality, the D+
and D- traces between the microcontroller and USB
connector (or cable) should be less than 19 cm long.
Both traces should be equal in length and they should
be routed parallel to each other. Ideally, these traces
should be designed to have a characteristic impedance
matching that of the USB cable.
Note: While in Suspend mode, a typical
bus-powered USB device is limited to
2.5 mA of average current. This is the
complete current which may be drawn by
the PIC device and its supporting circuitry.
Care should be taken to assure minimum
current draw when the device enters
Suspend mode.
Note: The USB speed, transceiver and pull-up
should only be configured during the
module setup phase. It is not recom-
mended to switch these settings while the
module is enabled.
2011 Microchip Technology Inc. DS39931D-page 361
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REGISTER 22-2: UCFG: USB CONFIGURATION REGISTER (BANKED F39h)
R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
UTEYE UOEMON UPUEN(1,2) UTRDIS(1,3) FSEN(1) PPB1 PPB0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 UTEYE: USB Eye Pattern Test Enable bit
1 = Eye pattern test is enabled
0 = Eye pattern test is disabled
bit 6 UOEMON: USB OE Monitor Enable bit
1 =UOE
signal is active, indicating intervals during which the D+/D- lines are driving
0 =UOE
signal is inactive
bit 5 Unimplemented: Read as ‘0
bit 4 UPUEN: USB On-Chip Pull-up Enable bit(1,2)
1 = On-chip pull-up is enabled (pull-up on D+ with FSEN = 1 or D- with FSEN = 0)
0 = On-chip pull-up is disabled
bit 3 UTRDIS: On-Chip Transceiver Disable bit(1,3)
1 = On-chip transceiver is disabled
0 = On-chip transceiver is active
bit 2 FSEN: Full-Speed Enable bit(1)
1 = Full-speed device: controls transceiver edge rates; requires input clock at 48 MHz
0 = Low-speed device: controls transceiver edge rates; requires input clock at 6 MHz
bit 1-0 PPB<1:0>: Ping-Pong Buffers Configuration bits
11 = Even/Odd ping-pong buffers are enabled for Endpoints 1 to 15
10 = Even/Odd ping-pong buffers are enabled for all endpoints
01 = Even/Odd ping-pong buffer are enabled for OUT Endpoint 0
00 = Even/Odd ping-pong buffers are disabled
Note 1: The UPUEN, UTRDIS and FSEN bits should never be changed while the USB module is enabled. These
values must be preconfigured prior to enabling the module.
2: This bit is only valid when the on-chip transceiver is active (UTRDIS = 0); otherwise, it is ignored.
3: If UTRDIS is set, the UOE signal will be active, independent of the UOEMON bit setting.
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DS39931D-page 362 2011 Microchip Technology Inc.
22.2.2.2 Internal Pull-up Resistors
The PIC18F46J50 family devices have built-in pull-up
resistors designed to meet the requirements for
low-speed and full-speed USB. The UPUEN bit
(UCFG<4>) enables the internal pull-ups. Figure 22-1
shows the pull-ups and their control.
22.2.2.3 External Pull-up Resistors
External pull-ups may also be used. The VUSB pin may
be used to pull up D+ or D-. The pull-up resistor must be
1.5 k (±5%) as required by the USB specifications.
Figure 22-2 provides an example of external circuitry.
FIGURE 22-2: EX TERN AL CIRCUITRY
22.2.2.4 Ping-Pong Buffer Configuration
The usage of ping-pong buffers is configured using the
PPB<1:0> bits. Refer to Section 22.4.4 “Ping-Pong
Buffering” for a complete explanation of the ping-pong
buffers.
22.2.2.5 Eye Pattern Test Enable
An automatic eye pattern test can be generated by the
module when the UCFG<7> bit is set. The eye pattern
output will be observable based on module settings,
meaning that the user is first responsible for configuring
the SIE clock settings, pull-up resistor and Transceiver
mode. In addition, the module has to be enabled.
Once UTEYE is set, the module emulates a switch from
a receive to transmit state and will start transmitting a
J-K-J-K bit sequence (K-J-K-J for full speed). The
sequence will be repeated indefinitely while the Eye
Pattern Test mode is enabled.
Note that this bit should never be set while the module
is connected to an actual USB system. This Test mode
is intended for board verification to aid with USB certi-
fication tests. It is intended to show a system developer
the noise integrity of the USB signals which can be
affected by board traces, impedance mismatches and
proximity to other system components. It does not
properly test the transition from a receive to a transmit
state. Although the eye pattern is not meant to replace
the more complex USB certification test, it should aid
during first order system debugging.
Note: A compliant USB device should never
source any current onto the +5V VBUS line
of the USB cable. Additionally, USB
devices should not source any current on
the D+ and D- data lines whenever the +5V
VBUS line is less than 1.17V. In order to be
USB compliant, applications which are not
purely bus-powered should monitor the
VBUS line and avoid turning on the USB
module and the D+ or D- pull-up resistor
until VBUS is greater than 1.17V. VBUS can
be connected to, and monitored, by a 5V
tolerant I/O pin, or if a resistive divider is
used, by an analog capable pin.
PIC®MCU Host
Controller/HUB
VUSB
D+
D-
Note: The above setting shows a typical connection
for a full-speed configuration using an on-chip
regulator and an external pull-up resistor.
1.5 k
2011 Microchip Technology Inc. DS39931D-page 363
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22.2.3 USB STATUS REGISTER (USTAT)
The USB Status register reports the transaction status
within the SIE. When the SIE issues a USB transfer
complete interrupt, USTAT should be read to determine
the status of the transfer. USTAT contains the transfer
endpoint number, direction and Ping-Pong Buffer
Pointer value (if used).
The USTAT register is actually a read window into a
four-byte status FIFO, maintained by the SIE. It allows
the microcontroller to process one transfer while the
SIE processes additional endpoints (Figure 22-3).
When the SIE completes using a buffer for reading or
writing data, it updates the USTAT register. If another
USB transfer is performed before a transaction
complete interrupt is serviced, the SIE will store the
status of the next transfer into the status FIFO.
Clearing the Transfer Complete Flag bit, TRNIF,
causes the SIE to advance the FIFO. If the next data in
the FIFO holding register is valid, the SIE will reassert
the interrupt within 5 TCY of clearing TRNIF. If no addi-
tional data is present, TRNIF will remain clear and
USTAT data will no longer be reliable.
FIGURE 22-3: USTAT FIFO
Note: The data in the USB Status register is
valid only when the TRNIF interrupt flag is
asserted.
Note: If an endpoint request is received while the
USTAT FIFO is full, the SIE will
automatically issue a NAK back to the host.
Data Bus
USTAT from SIE
4-Byte FIFO
for USTAT
Clearing TRNIF
Advances FIFO
REGISTER 22-3: USTAT: USB STATUS REGISTER (ACCESS F64h)
U-0 R-x R-x R-x R-x R-x R-x U-0
ENDP3 ENDP2 ENDP1 ENDP0 DIR PPBI(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6-3 ENDP<3:0>: Encoded Number of Last Endpoint Activity bits
(represents the number of the BDT updated by the last USB transfer)
1111 = Endpoint 15
1110 = Endpoint 14
.
.
.
0001 = Endpoint 1
0000 = Endpoint 0
bit 2 DIR: Last BD Direction Indicator bit
1 = The last transaction was an IN token
0 = The last transaction was an OUT or SETUP token
bit 1 PPBI: Ping-Pong BD Pointer Indicator bit(1)
1 = The last transaction was to the Odd BD bank
0 = The last transaction was to the Even BD bank
bit 0 Unimplemented: Read as ‘0
Note 1: This bit is only valid for endpoints with available Even and Odd BD registers.
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DS39931D-page 364 2011 Microchip Technology Inc.
22.2.4 USB ENDPOINT CONTROL
Each of the 16 possible bidirectional endpoints has its
own independent control register, UEPn (where ‘n
represents the endpoint number). Each register has an
identical complement of control bits. Register 22-4
provides the prototype.
The EPHSHK bit (UEPn<4>) controls handshaking for
the endpoint. Setting this bit enables USB handshak-
ing. Typically, this bit is always set except when using
isochronous endpoints.
The EPCONDIS bit (UEPn<3>) is used to enable or
disable USB control operations (SETUP) through the
endpoint. Clearing this bit enables SETUP transac-
tions. Note that the corresponding EPINEN and
EPOUTEN bits must be set to enable IN and OUT
transactions. For Endpoint 0, this bit should always be
cleared since the USB specifications identify
Endpoint 0 as the default control endpoint.
The EPOUTEN bit (UEPn<2>) is used to enable or
disable USB OUT transactions from the host. Setting
this bit enables OUT transactions. Similarly, the
EPINEN bit (UEPn<1>) enables or disables USB IN
transactions from the host.
The EPSTALL bit (UEPn<0>) is used to indicate a
STALL condition for the endpoint. If a STALL is issued
on a particular endpoint, the EPSTALL bit for that end-
point pair will be set by the SIE. This bit remains set
until it is cleared through firmware or until the SIE is
reset.
REGISTER 22-4: UEPn: USB ENDPOINT n CONTROL REGISTER (UEP0 THROUGH UEP15)
(BANKED F26h-F35h)
U-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 Unimplemented: Read as ‘0
bit 4 EPHSHK: Endpoint Handshake Enable bit
1 = Endpoint handshake is enabled
0 = Endpoint handshake is disabled (typically used for isochronous endpoints)
bit 3 EPCONDIS: Bidirectional Endpoint Control bit
If EPOUTEN = 1 and EPINEN = 1:
1 = Disable Endpoint n from control transfers; only IN and OUT transfers are allowed
0 = Enable Endpoint n for control (SETUP) transfers; IN and OUT transfers are also allowed
bit 2 EPOUTEN: Endpoint Output Enable bit
1 = Endpoint n output is enabled
0 = Endpoint n output is disabled
bit 1 EPINEN: Endpoint Input Enable bit
1 = Endpoint n input is enabled
0 = Endpoint n input is disabled
bit 0 EPSTALL: Endpoint Stall Indicator bit
1 = Endpoint n has issued one or more STALL packets
0 = Endpoint n has not issued any STALL packets
2011 Microchip Technology Inc. DS39931D-page 365
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22.2.5 USB ADDRESS REGISTER
(UADDR)
The USB Address register contains the unique USB
address that the peripheral will decode when active.
UADDR is reset to 00h when a USB Reset is received,
indicated by URSTIF, or when a Reset is received from
the microcontroller. The USB address must be written
by the microcontroller during the USB setup phase
(enumeration) as part of the Microchip USB firmware
support.
22.2.6 USB FRAME NUMBER REGISTERS
(UFRMH:UFRML)
The Frame Number registers contain the 11-bit frame
number. The low-order byte is contained in UFRML,
while the three high-order bits are contained in
UFRMH. The register pair is updated with the current
frame number whenever a SOF token is received. For
the microcontroller, these registers are read-only. The
Frame Number registers are primarily used for
isochronous transfers. The contents of the UFRMH and
UFRML registers are only valid when the 48 MHz SIE
clock is active (i.e., contents are inaccurate when the
SUSPND (UCON<1>) bit = 1).
22.3 USB RAM
USB data moves between the microcontroller core and
the SIE through a memory space known as the USB
RAM. This is a special dual access memory that is
mapped into the normal data memory space in Banks 0
through 14 (00h to EBFh) for a total of 3.8 Kbytes
(Figure 22-4).
Bank 4 (400h through 4FFh) is used specifically for
endpoint buffer control, while Banks 0 through 3 and
Banks 5 through 14 are available for USB data.
Depending on the type of buffering being used, all but
8 bytes of Bank 4 may also be available for use as USB
buffer space.
Although USB RAM is available to the microcontroller
as data memory, the sections that are being accessed
by the SIE should not be accessed by the
microcontroller. A semaphore mechanism is used to
determine the access to a particular buffer at any given
time. This is discussed in Section 22.4.1.1 “Buffer
Ownership”.
FIGURE 22-4: IMPLEMENTATION OF
USB RAM IN DATA
MEMORY SPACE
400h
4FFh
500h
USB Data or
Buffer Descriptors,
USB Data or User Data
User Data
USB Data or
SFRs
3FFh
000h
FFFh
Banks 0
(USB RAM)
to 14
Access Ram
060h
05Fh
EC0h
EBFh
User Data
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22.4 Buffer Descriptors and the Buffer
Descriptor Table
The registers in Bank 4 are used specifically for end-
point buffer control in a structure known as the Buffer
Descriptor Table (BDT). This provides a flexible method
for users to construct and control endpoint buffers of
various lengths and configuration.
The BDT is composed of Buffer Descriptors (BD) which
are used to define and control the actual buffers in the
USB RAM space. Each BD, in turn, consists of four
registers, where n represents one of the 64 possible
BDs (range of 0 to 63):
BDnSTAT: BD Status register
BDnCNT: BD Byte Count register
BDnADRL: BD Address Low register
BDnADRH: BD Address High register
BDs always occur as a four-byte block in
the sequence:
BDnSTAT:BDnCNT:BDnADRL:BDnADRH.
The address
of BDnSTAT is always an offset of (4n – 1) (in hexa-
decimal) from 400h, with n being the buffer descriptor
number.
Depending on the buffering configuration used
(Section 22.4.4 “Ping-Pong Buffering”), there are up
to 32, 33 or 64 sets of buffer descriptors. At a minimum,
the BDT must be at least 8 bytes long. This is because
the USB specification mandates that every device must
have Endpoint 0, with both input and output for initial
setup. Depending on the endpoint and buffering
configuration, the BDT can be as long as 256 bytes.
Although they can be thought of as Special Function
Registers, the Buffer Descriptor Status and Address
registers are not hardware mapped, as conventional
microcontroller SFRs in Bank 15 are. If the endpoint cor-
responding to a particular BD is not enabled, its registers
are not used. Instead of appearing as unimplemented
addresses, however, they appear as available RAM.
Only when an endpoint is enabled by setting the
UEPn<1> bit does the memory at those addresses
become functional as BD registers. As with any address
in the data memory space, the BD registers have an
indeterminate value on any device Reset.
Figure 22-5 provides an example of a BD for a 64-byte
buffer, starting at 500h. A particular set of BD registers
is only valid if the corresponding endpoint has been
enabled using the UEPn register. All BD registers are
available in USB RAM. The BD for each endpoint
should be set up prior to enabling the endpoint.
22.4.1 BD STATUS AND CONFIGURATION
Buffer descriptors not only define the size of an end-
point buffer, but also determine its configuration and
control. Most of the configuration is done with the BD
Status register, BDnSTAT. Each BD has its own unique
and correspondingly numbered BDnSTAT register.
FIGURE 22-5: EXAMPLE OF A BUFFER
DESCRIPTOR
Unlike other control registers, the bit configuration for
the BDnSTAT register is context-sensitive. There are
two distinct configurations, depending on whether the
microcontroller or the USB module is modifying the BD
and buffer at a particular time; only 3-bit definitions are
shared between the two.
22.4.1.1 Buffer Ownership
Because the buffers and their BDs are shared between
the CPU and the USB module, a simple semaphore
mechanism is used to distinguish which is allowed to
update the BD and associated buffers in memory.
This is done by using the UOWN bit (BDnSTAT<7>) as
a semaphore to distinguish which is allowed to update
the BD and associated buffers in memory. UOWN is the
only bit that is shared between the two configurations
of BDnSTAT.
When UOWN is clear, the BD entry is “owned” by the
microcontroller core. When the UOWN bit is set, the BD
entry and the buffer memory are “owned” by the USB
peripheral. The core should not modify the BD or its
corresponding data buffer during this time. Note that
the microcontroller core can still read BDnSTAT, while
the SIE owns the buffer and vice versa.
The buffer descriptors have a different meaning based
on the source of the register update. Prior to placing
ownership with the USB peripheral, the user can
configure the basic operation of the peripheral through
the BDnSTAT bits. During this time, the byte count and
buffer location registers can also be set.
When UOWN is set, the user can no longer depend on
the values that were written to the BDs. From this point,
the SIE updates the BDs as necessary, overwriting the
original BD values. The BDnSTAT register is updated
by the SIE with the token PID and the transfer count,
BDnCNT, is updated.
400h
USB Data
Buffer
Buffer
BD0STAT
BD0CNT
BD0ADRL
BD0ADRH
401h
402h
403h
500h
53Fh
Descriptor
Note: Memory regions are not to scale.
40h
00h
05h Starting
Size of Block
(xxh)
RegistersAddress Contents
Address
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The BDnSTAT byte of the BDT should always be the
last byte updated when preparing to arm an endpoint.
The SIE will clear the UOWN bit when a transaction
has completed.
No hardware mechanism exists to block access when
the UOWN bit is set. Thus, unexpected behavior can
occur if the microcontroller attempts to modify memory
when the SIE owns it. Similarly, reading such memory
may produce inaccurate data until the USB peripheral
returns ownership to the microcontroller.
22.4.1.2 BDnSTAT Register (CPU Mode)
When UOWN = 0, the microcontroller core owns the
BD. At this point, the other seven bits of the register
take on control functions.
The Data Toggle Sync Enable bit, DTSEN
(BDnSTAT<3>), controls data toggle parity checking.
Setting DTSEN enables data toggle synchronization by
the SIE. When enabled, it checks the data packet’s par-
ity against the value of DTS (BDnSTAT<6>). If a packet
arrives with an incorrect synchronization, the data will
essentially be ignored. It will not be written to the USB
RAM and the USB transfer complete interrupt flag will
not be set. The SIE will send an ACK token back to the
host to Acknowledge receipt, however. The effects of
the DTSEN bit on the SIE are summarized in
Table 22-1.
The Buffer Stall bit, BSTALL (BDnSTAT<2>), provides
support for control transfers, usually one-time stalls on
Endpoint 0. It also provides support for the
SET_FEATURE/CLEAR_FEATURE commands speci-
fied in Chapter 9 of the USB specification; typically,
continuous STALLs to any endpoint other than the
default control endpoint.
The BSTALL bit enables buffer stalls. Setting BSTALL
causes the SIE to return a STALL token to the host if a
received token would use the BD in that location. The
EPSTALL bit in the corresponding UEPn control
register is set and a STALL interrupt is generated when
a STALL is issued to the host. The UOWN bit remains
set and the BDs are not changed unless a SETUP
token is received. In this case, the STALL condition is
cleared and the ownership of the BD is returned to the
microcontroller core.
The BD<9:8> bits (BDnSTAT<1:0>) store the two most
significant digits of the SIE byte count; the lower 8 digits
are stored in the corresponding BDnCNT register. See
Section 22.4.2 “BD Byte Count” for more
information.
TABLE 22-1: EFFECT OF DTSEN BIT ON ODD/EVEN (DATA0/DATA1) PACKET RECEPTION
OUT Packet
from Host
BDnSTAT Settings Device Response after Receiving Packet
DTSEN DTS Handshake UOWN TRNIF BDnSTAT and USTAT Status
DATA0 10ACK 01 Updated
DATA1 10ACK 10 Not Updated
DATA0 11ACK 10 Not Updated
DATA1 11ACK 01 Updated
Either 0xACK 01 Updated
Either, with error xx(None) 10 Not Updated
Legend: x = don’t care
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REGISTER 22-5: BDnSTAT: BUFFER DESCRIPTOR n STATUS REGISTER (BD0STAT THROUGH
BD63STAT), CPU MODE (BANKED 4xxh)
R/W-x R/W-x R/W-0 R/W-0 R/W-x R/W-x R/W-x R/W-x
UOWN(1) DTS(2) r(3) r(3) DTSEN BSTALL BC9 BC8
bit 7 bit 0
Legend: r = Reserved bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 UOWN: USB Own bit(1)
0 = The microcontroller core owns the BD and its corresponding buffer
bit 6 DTS: Data Toggle Synchronization bit(2)
1 = Data 1 packet
0 = Data 0 packet
bit 5-4 Reserved: These bits should always be programmed to ‘0(3)
bit 3 DTSEN: Data Toggle Synchronization Enable bit
1 = Data toggle synchronization is enabled; data packets with an incorrect Sync value will be ignored,
except for a SETUP transaction, which is accepted even if the data toggle bits do not match
0 = No data toggle synchronization is performed
bit 2 BSTALL: Buffer Stall Enable bit
1 = Buffer stall is enabled; STALL handshake issued if a token is received that would use the BD in
the given location (UOWN bit remains set, BD value is unchanged)
0 = Buffer stall is disabled
bit 1-0 BC<9:8>: Byte Count 9 and 8 bits
The byte count bits represent the number of bytes that will be transmitted for an IN token or received
during an OUT token. Together with BC<7:0>, the valid byte counts are 0-1023.
Note 1: This bit must be initialized by the user to the desired value prior to enabling the USB module.
2: This bit is ignored unless DTSEN = 1.
3: If these bits are set, USB communication may not work. Hence, these bits should always be maintained as ‘0’.
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22.4.1.3 BDnSTAT Register (SIE Mode)
When the BD and its buffer are owned by the SIE, most
of the bits in BDnSTAT take on a different meaning. The
configuration is shown in Register 22-6. Once UOWN
is set, any data or control settings previously written
there by the user will be overwritten with data from the
SIE.
The BDnSTAT register is updated by the SIE with the
token Packet Identifier (PID) which is stored in
BDnSTAT<5:2>. The transfer count in the correspond-
ing BDnCNT register is updated. Values that overflow
the 8-bit register carry over to the two most significant
digits of the count, stored in BDnSTAT<1:0>.
22.4.2 BD BYTE COUNT
The byte count represents the total number of bytes
that will be transmitted during an IN transfer. After an IN
transfer, the SIE will return the number of bytes sent to
the host.
For an OUT transfer, the byte count represents the
maximum number of bytes that can be received and
stored in USB RAM. After an OUT transfer, the SIE will
return the actual number of bytes received. If the
number of bytes received exceeds the corresponding
byte count, the data packet will be rejected and a NAK
handshake will be generated. When this happens, the
byte count will not be updated.
The 10-bit byte count is distributed over two registers.
The lower 8 bits of the count reside in the BDnCNT
register. The upper two bits reside in BDnSTAT<1:0>.
This represents a valid byte range of 0 to 1023.
22.4.3 BD ADDRESS VALIDATION
The BD Address register pair contains the starting RAM
address location for the corresponding endpoint buffer.
No mechanism is available in hardware to validate the
BD address.
If the value of the BD address does not point to an
address in the USB RAM, or if it points to an address
within another endpoint’s buffer, data is likely to be lost
or overwritten. Similarly, overlapping a receive buffer
(OUT endpoint) with a BD location in use can yield
unexpected results. When developing USB
applications, the user may want to consider the
inclusion of software-based address validation in their
code.
REGISTER 22-6: BDnSTAT: BUFFER DESCRIPTOR n STATUS REGISTER (BD0STAT THROUGH
BD63STAT), SIE MODE (DATA RETURNED BY THE SIE TO THE MCU)
(BANKED 4xxh)
R/W-x r-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
UOWN r PID3 PID2 PID1 PID0 BC9 BC8
bit 7 bit 0
Legend: r = Reserved bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 UOWN: USB Own bit
1 = The SIE owns the BD and its corresponding buffer
bit 6 Reserved: Not written by the SIE
bit 5-2 PID<3:0>: Packet Identifier bits
The received token PID value of the last transfer (IN, OUT or SETUP transactions only).
bit 1-0 BC<9:8>: Byte Count 9 and 8 bits
These bits are updated by the SIE to reflect the actual number of bytes received on an OUT transfer
and the actual number of bytes transmitted on an IN transfer.
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22.4.4 PING-PONG BUFFERING
An endpoint is defined to have a ping-pong buffer when
it has two sets of BD entries: one set for an Even
transfer and one set for an Odd transfer. This allows the
CPU to process one BD while the SIE is processing the
other BD. Double-buffering BDs in this way allows for
maximum throughput to/from the USB.
The USB module supports four modes of operation:
No ping-pong support
Ping-pong buffer support for OUT Endpoint 0 only
Ping-pong buffer support for all endpoints
Ping-pong buffer support for all other endpoints
except Endpoint 0
The ping-pong buffer settings are configured using the
PPB<1:0> bits in the UCFG register.
The USB module keeps track of the Ping-Pong Pointer,
individually for each endpoint. All pointers are initially
reset to the Even BD when the module is enabled. After
the completion of a transaction (UOWN cleared by the
SIE), the pointer is toggled to the Odd BD. After the
completion of the next transaction, the pointer is
toggled back to the Even BD and so on.
The Even/Odd status of the last transaction is stored in
the PPBI bit of the USTAT register. The user can reset
all Ping-Pong Pointers to Even using the PPBRST bit.
Figure 22-6 shows the four different modes of
operation and how USB RAM is filled with the BDs.
BDs have a fixed relationship to a particular endpoint,
depending on the buffering configuration. Tab l e 2 2- 2
provides the mapping of BDs to endpoints. This
relationship also means that gaps may occur in the
BDT if endpoints are not enabled contiguously. This
theoretically means that the BDs for disabled endpoints
could be used as buffer space. In practice, users
should avoid using such spaces in the BDT unless a
method of validating BD addresses is implemented.
FIGURE 22-6: BUFFER DESCRIPTOR TABLE MAPPING FOR BUFFERING MODES
EP1 IN Even
EP1 OUT Even
EP1 OUT Odd
EP1 IN Odd
Descriptor
Descriptor
Descriptor
Descriptor
EP1 IN
EP15 IN
EP1 OUT
EP0 OUT
PPB<1:0> = 00
EP0 IN
EP1 IN
No Pi ng - P ong
EP15 IN
EP0 IN
EP0 OUT Even
PPB<1:0> = 01
EP0 OUT Odd
EP1 OUT
Ping-Pong Buffer
EP15 IN Odd
EP0 IN Even
EP0 OUT Even
PPB<1:0> = 10
EP0 OUT Odd
EP0 IN Odd
Ping-Pong Buffers
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
400h
4FFh 4FFh 4FFh
400h 400h
47Fh
483h
Available
as
Data RAM Available
as
Data RAM
Maximum Memory
Used: 128 Bytes
Maximum BDs:
32 (BD0 to BD31)
Maximum Memory
Used: 132 Bytes
Maximum BDs:
33 (BD0 to BD32)
Maximum Memory
Used: 256 Bytes
Maximum BDs: 6
4 (BD0 to BD63)
Note: Memory area is not shown to scale.
Descriptor
Descriptor
Descriptor
Descriptor
Buffers on EP0 OUT on all EPs
EP1 IN Even
EP1 OUT Even
EP1 OUT Odd
EP1 IN Odd
Descriptor
Descriptor
Descriptor
Descriptor
EP15 IN Odd
EP0 OUT
PPB<1:0> = 11
EP0 IN
Ping-Pong Buffers
Descriptor
Descriptor
Descriptor
4FFh
400h
Maximum Memory
Used: 248 Bytes
Maximum BDs:
62 (BD0 to BD61)
on all Ot her EPs
Except EP0
Available
as
Data RAM
4F7h
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TABLE 22-2: ASSIGNMENT OF BUFFER DESCRIPTORS FOR THE DIFFERENT
BUFFERING MODES
TABLE 22-3: SUMMARY OF USB BUFFER DESCRIPTOR TABLE REGISTERS
Endpoint
BDs Assi gned to Endpoint
Mode 0
(No Ping-Pong) Mode 1
(Ping- Pong on EP0 OUT) Mo de 2
(Ping-Pong on all EPs)
Mode 3
(Ping-P ong on all other EPs,
except EP0)
Out In Out In Out In Out In
0 0 1 0 (E), 1 (O) 2 0 (E), 1 (O) 2 (E), 3 (O) 0 1
1 2 3 3 4 4 (E), 5 (O) 6 (E), 7 (O) 2 (E), 3 (O) 4 (E), 5 (O)
2 4 5 5 6 8 (E), 9 (O) 10 (E), 11 (O) 6 (E), 7 (O) 8 (E), 9 (O)
3 6 7 7 8 12 (E), 13 (O) 14 (E), 15 (O) 10 (E), 11 (O) 12 (E), 13 (O)
4 8 9 9 10 16 (E), 17 (O) 18 (E), 19 (O) 14 (E), 15 (O) 16 (E), 17 (O)
5 10 11 11 12 20 (E), 21 (O) 22 (E), 23 (O) 18 (E), 19 (O) 20 (E), 21 (O)
6 12 13 13 14 24 (E), 25 (O) 26 (E), 27 (O) 22 (E), 23 (O) 24 (E), 25 (O)
7 14 15 15 16 28 (E), 29 (O) 30 (E), 31 (O) 26 (E), 27 (O) 28 (E), 29 (O)
8 16 17 17 18 32 (E), 33 (O) 34 (E), 35 (O) 30 (E), 31 (O) 32 (E), 33 (O)
9 18 19 19 20 36 (E), 37 (O) 38 (E), 39 (O) 34 (E), 35 (O) 36 (E), 37 (O)
10 20 21 21 22 40 (E), 41 (O) 42 (E), 43 (O) 38 (E), 39 (O) 40 (E), 41 (O)
11 22 23 23 24 44 (E), 45 (O) 46 (E), 47 (O) 42 (E), 43 (O) 44 (E), 45 (O)
12 24 25 25 26 48 (E), 49 (O) 50 (E), 51 (O) 46 (E), 47 (O) 48 (E), 49 (O)
13 26 27 27 28 52 (E), 53 (O) 54 (E), 55 (O) 50 (E), 51 (O) 52 (E), 53 (O)
14 28 29 29 30 56 (E), 57 (O) 58 (E), 59 (O) 54 (E), 55 (O) 56 (E), 57 (O)
15 30 31 31 32 60 (E), 61 (O) 62 (E), 63 (O) 58 (E), 59 (O) 60 (E), 61 (O)
Legend: (E) = Even transaction buffer, (O) = Odd transaction buffer
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
BDnSTAT(1) UOWN DTS(4) PID3(2) PID2(2) PID1(2)
DTSEN(3) PID0(2)
BSTALL(3) BC9 BC8
BDnCNT(1) Byte Count
BDnADRL(1) Buffer Address Low
BDnADRH(1) Buffer Address High
Note 1: For buffer descriptor registers, n may have a value of 0 to 63. For the sake of brevity, all 64 registers are
shown as one generic prototype. All registers have indeterminate Reset values (xxxx xxxx).
2: Bits, 5 through 2, of the BDnSTAT register are used by the SIE to return PID<3:0> values once the register
is turned over to the SIE (UOWN bit is set). Once the registers have been under SIE control, the values
written for DTSEN and BSTALL are no longer valid.
3: Prior to turning the buffer descriptor over to the SIE (UOWN bit is cleared), bits, 5 through 2, of the
BDnSTAT register are used to configure the DTSEN and BSTALL settings.
4: This bit is ignored unless DTSEN = 1.
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22.5 USB Interrupts
The USB module can generate multiple interrupt condi-
tions. To accommodate all of these interrupt sources,
the module is provided with its own interrupt logic struc-
ture, similar to that of the microcontroller. USB interrupts
are enabled with one set of control registers and
trapped with a separate set of flag registers. All sources
are funneled into a single USB interrupt request, USBIF
(PIR2<4>), in the microcontroller’s interrupt logic.
Figure 22-7 provides the interrupt logic for the USB
module. There are two layers of interrupt registers in
the USB module. The top level consists of overall USB
status interrupts. These interrupts are enabled and
flagged in the UIE and UIR registers, respectively. The
second level consists of USB error conditions, which
are enabled and flagged in the UEIR and UEIE
registers. An interrupt condition in any of these areas
triggers a USB Error Interrupt Flag (UERRIF) in the
top level.
Interrupts may be used to trap routine events in a USB
transaction. Figure 22-8 provides some common
events within a USB frame and their corresponding
interrupts.
FIGURE 22-7: USB INTERRUPT LOGIC FUNNEL
FIGURE 22-8: EXAMPLE OF A USB TRANSACTION AND INTERRUPT EVENTS
BTSEF
BTSEE
BTOEF
BTOEE
DFN8EF
DFN8EE
CRC16EF
CRC16EE
CRC5EF
CRC5EE
PIDEF
PIDEE
SOFIF
SOFIE
TRNIF
TRNIE
IDLEIF
IDLEIE
STALLIF
STALLIE
ACTVIF
ACTVIE
URSTIF
URSTIE
UERRIF
UERRIE
USBIF
Second Level USB Interrupts
(USB Error Conditions)
UEIR (Flag) and UEIE (Enable) Registers
Top Level USB Interrupts
(USB Status Interrupts)
UIR (Flag) and UIE (Enable) Registers
USB Reset
SOFRESET SETUP DATA STATUS SOF
SETUP Token Data ACK
OUT Token Empty Data ACK
Start-of-Frame (SOF)
IN Token Data ACK
SOFIF
URSTIF
1 ms Frame
Differential Data
From Host From Host To Ho s t
From Host To Host From Host
From Host From Host To Ho st
Transaction
Control Transfer(1)
Transaction
Complete
Note 1: The control transfer shown here is only an example showing events that can occur for every transaction. Typical
control transfers will spread across multiple frames.
Set TRNIF
Set TRNIF
Set TRNIF
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22.5.1 USB INTERRUPT STATUS
REGISTER (UIR)
The USB Interrupt Status register (Register 22-7) con-
tains the flag bits for each of the USB status interrupt
sources. Each of these sources has a corresponding
interrupt enable bit in the UIE register. All of the USB
status flags are ORed together to generate the USBIF
interrupt flag for the microcontroller’s interrupt funnel.
Once an interrupt bit has been set by the SIE, it must
be cleared by software by writing a ‘0. The flag bits
can also be set in software, which can aid in firmware
debugging.
When the USB module is in the Low-Power Suspend
mode (UCON<1> = 1), the SIE does not get clocked.
When in this state, the SIE cannot process packets,
and therefore, cannot detect new interrupt conditions
other than the Activity Detect Interrupt, ACTVIF. The
ACTVIF bit is typically used by USB firmware to detect
when the microcontroller should bring the USB module
out of the Low-Power Suspend mode (UCON<1> = 0).
REGISTER 22-7: UIR: USB INTERRUPT STATUS REGISTER (ACCESS F62h)
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R/W-0
SOFIF STALLIF IDLEIF(1) TRNIF(2) ACTVIF(3) UERRIF(4) URSTIF
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6 SOFIF: Start-of-Frame Token Interrupt bit
1 = A Start-of-Frame token was received by the SIE
0 = No Start-of-Frame token was received by the SIE
bit 5 STALLIF: A STALL Handshake Interrupt bit
1 = A STALL handshake was sent by the SIE
0 = A STALL handshake has not been sent
bit 4 IDLEIF: Idle Detect Interrupt bit(1)
1 = Idle condition was detected (constant Idle state of 3 ms or more)
0 = No Idle condition was detected
bit 3 TRNIF: Transaction Complete Interrupt bit(2)
1 = Processing of pending transaction is complete; read USTAT register for endpoint information
0 = Processing of pending transaction is not complete or no transaction is pending
bit 2 ACTVIF: Bus Activity Detect Interrupt bit(3)
1 = Activity on the D+/D- lines was detected
0 = No activity was detected on the D+/D- lines
bit 1 UERRIF: USB Error Condition Interrupt bit(4)
1 = An unmasked error condition has occurred
0 = No unmasked error condition has occurred.
bit 0 URSTIF: USB Reset Interrupt bit
1 = Valid USB Reset occurred; 00h is loaded into UADDR register
0 = No USB Reset has occurred
Note 1: Once an Idle state is detected, the user may want to place the USB module in Suspend mode.
2: Clearing this bit will cause the USTAT FIFO to advance (valid only for IN, OUT and SETUP tokens).
3: This bit is typically unmasked only following the detection of a UIDLE interrupt event.
4: Only error conditions enabled through the UEIE register will set this bit. This bit is a status bit only and
cannot be set or cleared by the user.
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22.5.1.1 Bus Activity Detect Interrupt Bit
(ACTVIF)
The ACTVIF bit cannot be cleared immediately after
the USB module wakes up from Suspend or while the
USB module is suspended. A few clock cycles are
required to synchronize the internal hardware state
machine before the ACTVIF bit can be cleared by
firmware. Clearing the ACTVIF bit before the internal
hardware is synchronized may not have an effect on
the value of ACTVIF. Additionally, if the USB module
uses the clock from the 96 MHz PLL source, then after
clearing the SUSPND bit, the USB module may not be
immediately operational while waiting for the 96 MHz
PLL to lock. The application code should clear the
ACTVIF flag as provided in Example 22-1.
EXAMPLE 22-1: CLEARING ACTVIF BIT (UIR<2>)
Note: Only one ACTVIF interrupt is generated
when resuming from the USB bus Idle con-
dition. If user firmware clears the ACTVIF
bit, the bit will not immediately become set
again, even when there is continuous bus
traffic. Bus traffic must cease long enough
to generate another IDLEIF condition
before another ACTVIF interrupt can be
generated.
Assembly:
BCF UCON, SUSPND
LOOP:
BTFSS UIR, ACTVIF
BRA DONE
BCF UIR, ACTVIF
BRA LOOP
DONE:
C:
UCONbits.SUSPND = 0;
while (UIRbits.ACTVIF) { UIRbits.ACTVIF = 0; }
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22.5.2 USB INTERRUPT ENABLE
REGISTER (UIE)
The USB Interrupt Enable (UIE) register
(Register 22-8) contains the enable bits for the USB
status interrupt sources. Setting any of these bits will
enable the respective interrupt source in the UIR
register.
The values in this register only affect the propagation
of an interrupt condition to the microcontroller’s inter-
rupt logic. The flag bits are still set by their interrupt
conditions, allowing them to be polled and serviced
without actually generating an interrupt.
REGISTER 22-8: UIE : USB INTERRUPT ENABLE REGISTER (BANKED F36h)
U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
SOFIE STALLIE IDLEIE TRNIE ACTVIE UERRIE URSTIE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Unimplemented: Read as ‘0
bit 6 SOFIE: Start-of-Frame Token Interrupt Enable bit
1 = Start-of-Frame token interrupt is enabled
0 = Start-of-Frame token interrupt is disabled
bit 5 STALLIE: STALL Handshake Interrupt Enable bit
1 = STALL interrupt is enabled
0 = STALL interrupt is disabled
bit 4 IDLEIE: Idle Detect Interrupt Enable bit
1 = Idle detect interrupt is enabled
0 = Idle detect interrupt is disabled
bit 3 TRNIE: Transaction Complete Interrupt Enable bit
1 = Transaction interrupt is enabled
0 = Transaction interrupt is disabled
bit 2 ACTVIE: Bus Activity Detect Interrupt Enable bit
1 = Bus activity detect interrupt is enabled
0 = Bus activity detect interrupt is disabled
bit 1 UERRIE: USB Error Interrupt Enable bit
1 = USB error interrupt is enabled
0 = USB error interrupt is disabled
bit 0 URSTIE: USB Reset Interrupt Enable bit
1 = USB Reset interrupt is enabled
0 = USB Reset interrupt is disabled
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22.5.3 USB ERROR INTERRUPT STATUS
REGISTER (UEIR)
The USB Error Interrupt Status register (Register 22-9)
contains the flag bits for each of the error sources
within the USB peripheral. Each of these sources is
controlled by a corresponding interrupt enable bit in
the UEIE register. All of the USB error flags are ORed
together to generate the USB Error Interrupt Flag
(UERRIF) at the top level of the interrupt logic.
Each error bit is set as soon as the error condition is
detected. Thus, the interrupt will typically not
correspond with the end of a token being processed.
Once an interrupt bit has been set by the SIE, it must
be cleared by software by writing a ‘0’.
REGISTER 22-9: UEIR: USB ERROR INTERR UPT STATUS REGISTER (ACCESS F63h)
R/C-0 U-0 U-0 R/C-0 R/C-0 R/C-0 R/C-0 R/C-0
BTSEF BTOEF DFN8EF CRC16EF CRC5EF PIDEF
bit 7 bit 0
Legend:
R = Readable bit C = Clearable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 BTSEF: Bit Stuff Error Flag bit
1 = A bit stuff error has been detected
0 = No bit stuff error has been detected
bit 6-5 Unimplemented: Read as ‘0
bit 4 BTOEF: Bus Turnaround Time-out Error Flag bit
1 = Bus turnaround time-out has occurred (more than 16 bit times of Idle from previous EOP elapsed)
0 = No bus turnaround time-out has occurred
bit 3 DFN8EF: Data Field Size Error Flag bit
1 = The data field was not an integral number of bytes
0 = The data field was an integral number of bytes
bit 2 CRC16EF: CRC16 Failure Flag bit
1 = The CRC16 failed
0 = The CRC16 passed
bit 1 CRC5EF: CRC5 Host Error Flag bit
1 = The token packet was rejected due to a CRC5 error
0 = The token packet was accepted
bit 0 PIDEF: PID Check Failure Flag bit
1 = PID check failed
0 = PID check passed
2011 Microchip Technology Inc. DS39931D-page 377
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22.5.4 USB ERROR INTERRUPT ENABLE
REGISTER (UEIE)
The USB Error Interrupt Enable register
(Register 22-10) contains the enable bits for each of
the USB error interrupt sources. Setting any of these
bits will enable the respective error interrupt source in
the UEIR register to propagate into the UERR bit at
the top level of the interrupt logic.
As with the UIE register, the enable bits only affect the
propagation of an interrupt condition to the micro-
controller’s interrupt logic. The flag bits are still set by
their interrupt conditions, allowing them to be polled
and serviced without actually generating an interrupt.
REGISTER 22-10: UEIE: USB ERROR INTERRUPT ENABLE REGISTER (BANKED F37h)
R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
BTSEE BTOEE DFN8EE CRC16EE CRC5EE PIDEE
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 BTSEE: Bit Stuff Error Interrupt Enable bit
1 = Bit stuff error interrupt is enabled
0 = Bit stuff error interrupt is disabled
bit 6-5 Unimplemented: Read as ‘0
bit 4 BTOEE: Bus Turnaround Time-out Error Interrupt Enable bit
1 = Bus turnaround time-out error interrupt is enabled
0 = Bus turnaround time-out error interrupt is disabled
bit 3 DFN8EE: Data Field Size Error Interrupt Enable bit
1 = Data field size error interrupt is enabled
0 = Data field size error interrupt is disabled
bit 2 CRC16EE: CRC16 Failure Interrupt Enable bit
1 = CRC16 failure interrupt is enabled
0 = CRC16 failure interrupt is disabled
bit 1 CRC5EE: CRC5 Host Error Interrupt Enable bit
1 = CRC5 host error interrupt is enabled
0 = CRC5 host error interrupt is disabled
bit 0 PIDEE: PID Check Failure Interrupt Enable bit
1 = PID check failure interrupt is enabled
0 = PID check failure interrupt is disabled
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22.6 USB Power Modes
Many USB applications will likely have several different
sets of power requirements and configuration. The
most common power modes encountered are Bus
Power Only, Self-Power Only and Dual Power with
Self-Power Dominance. The most common cases are
presented here. Also provided is a means of estimating
the current consumption of the USB transceiver.
22.6.1 BUS POWER ONLY
In Bus Power Only mode, all power for the application
is drawn from the USB (Figure 22-9). This is effectively
the simplest power method for the device.
In order to meet the inrush current requirements of the
“USB 2.0 Specification”, the total effective capacitance
appearing across VBUS and ground must be no more
than 10 µF. If not, some kind of inrush timing is
required. For more details, see Section 7.2.4 of the
“USB 2.0 Specification”.
According to the “USB 2.0 Specification”, all USB
devices must also support a Low-Power Suspend
mode. In the USB Suspend mode, devices must
consume no more than 2.5 mA from the 5V VBUS line
of the USB cable.
The host signals the USB device to enter the Suspend
mode by stopping all USB traffic to that device for more
than 3 ms. This condition will cause the IDLEIF bit in
the UIR register to become set.
During the USB Suspend mode, the D+ or D- pull-up
resistor must remain active, which will consume some
of the allowed suspend current: 2.5 mA budget.
FIGURE 22-9: BUS POWER ONLY
22.6.2 SELF-POWER ONLY
In Self-Power Only mode, the USB application provides
its own power, with very little power being pulled from
the USB. See Figure 22-10 for an example.
Note that an attach indication is added to indicate when
the USB has been connected and the host is actively
powering VBUS.
In order to meet compliance specifications, the USB
module (and the D+ or D- pull-up resistor) should not be
enabled until the host actively drives VBUS high. One of
the 5.5V tolerant I/O pins may be used for this purpose.
The application should never source any current onto
the 5V VBUS pin of the USB cable.
FIGURE 22-10: SELF-POWER ONLY
22.6.3 DUAL POWER WITH SELF-POWER
DOMINANCE
Some applications may require a dual power option.
This allows the application to use internal power
primarily, but switch to power from the USB when no
internal power is available. See Figure 22-11 for a
simple Dual Power with Self-Power Dominance mode
example, which automatically switches between
Self-Power Only and USB Bus Power Only modes.
Dual power devices must also meet all of the special
requirements for inrush current and Suspend mode
current, and must not enable the USB module until
VBUS is driven high. See Secti on 22.6. 1 “Bu s Powe r
Only” and Section 22.6.2 “Self-Power Only” for
descriptions of those requirements. Additionally, dual
power devices must never source current onto the 5V
VBUS pin of the USB cable.
FIGURE 22-11: DUAL POWER EXAMPLE
VDD
VUSB
VSS
VBUS
~5V
3.3V
Low IQ Regulator
Note: Users should keep in mind the limits for
devices drawing power from the USB.
According to “USB Specification 2.0”, this
cannot exceed 100 mA per low-power
device or 500 mA per high-power device.
VDD
VUSB
VSS
VSELF
~3.3V
Attach Sense
100 k
100 k
VBUS
~5V
5.5V Tolerant
I/O Pin
VDD
VUSB
I/O pin
VSS
Attach Sense
VBUS
VSELF
100 k
~3.3V
~5V
100 k
3.3V
Low IQ
Regulator
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22.6.4 USB TRANSCEIVER CURRENT
CONSUMPTION
The USB transceiver consumes a variable amount of
current depending on the characteristic impedance of
the USB cable, the length of the cable, the VUSB supply
voltage and the actual data patterns moving across the
USB cable. Longer cables have larger capacitances
and consume more total energy when switching output
states.
Data patterns that consist of “IN” traffic consume far
more current than “OUT” traffic. IN traffic requires the
PIC® MCU to drive the USB cable, whereas OUT traffic
requires that the host drive the USB cable.
The data that is sent across the USB cable is NRZI
encoded. In the NRZI encoding scheme, ‘0’ bits cause
a toggling of the output state of the transceiver (either
from a “J” state to a “K” state, or vise versa). With the
exception of the effects of bit stuffing, NRZI encoded ‘1
bits do not cause the output state of the transceiver to
change. Therefore, IN traffic consisting of data bits of
value, ‘0’, causes the most current consumption, as the
transceiver must charge/discharge the USB cable in
order to change states.
More details about NRZI encoding and bit stuffing can
be found in the USB specification’s Section 7.1,
although knowledge of such details is not required to
make USB applications using the PIC18F46J50 family
of microcontrollers. Among other things, the SIE handles
bit stuffing/unstuffing, NRZI encoding/decoding and
CRC generation/checking in hardware.
The total transceiver current consumption will be
application-specific. However, to help estimate how
much current actually may be required in full-speed
applications, Equation 22-1 can be used.
See Equation 22-2 to know how this equation can be
used for a theoretical application.
EQUATION 22-1: ESTIMATING USB TRANSCEIVER CURRENT CONSUMPTION
IXCVR =+ IPULLUP
(40 mA • VUSB • PZERO • PIN • LCABLE)
(3.3V • 5m)
Legend: VUSB – Voltage applied to the VUSB pin in volts (should be 3.0V to 3.6V).
PZERO – Percentage (in decimal) of the IN traffic bits sent by the PIC® MCU that are a value of ‘0’.
PIN – Percentage (in decimal) of total bus bandwidth that is used for IN traffic.
LCABLE – Length (in meters) of the USB cable. The “USB 2.0 Specification” requires that full-speed
applications use cables no longer than 5m.
IPULLUP – Current which the nominal, 1.5 k pull-up resistor (when enabled) must supply to the USB
cable. On the host or hub end of the USB cable, 15 k nominal resistors (14.25 k to 24.8 k) are
present which pull both the D+ and D- lines to ground. During bus Idle conditions (such as between
packets or during USB Suspend mode), this results in up to 218 A of quiescent current drawn at 3.3V.
IPULLUP is also dependant on bus traffic conditions and can be as high as 2.2 mA when the USB bandwidth
is fully utilized (either IN or OUT traffic) for data that drives the lines to the “K” state, most of the time.
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EQUATION 22-2: CALCULATING USB TRANSCEIVER CURRENT
For this example, the following assumptions are made about the application:
3.3V will be applied to VUSB and VDD, with the core voltage regulator enabled.
This is a full-speed application that uses one interrupt IN endpoint that can send one packet of 64 bytes every
1 ms, with no restrictions on the values of the bytes being sent. The application may or may not have additional
traffic on OUT endpoints.
A regular USB “B” or “mini-B” connector will be used on the application circuit board.
In this case, PZERO = 100% = 1, because there should be no restriction on the value of the data moving through the
IN endpoint. All 64 kbps of data could potentially be bytes of value, 00h. Since 0’ bits cause toggling of the output state
of the transceiver, they cause the USB transceiver to consume extra current charging/discharging the cable. In this
case, 100% of the data bits sent can be of value, ‘0’. This should be considered the “max” value, as normal data will
consist of a fair mix of ones and zeros.
This application uses 64 kbps for IN traffic out of the total bus bandwidth of 1.5 Mbps (12 Mbps), therefore:
Since a regular “B” or “mini-B” connector is used in this application, the end user may plug in any type of cable, up to
the maximum allowed 5m length. Therefore, we use the worst-case length:
LCABLE = 5 meters
Assume IPULLUP = 2.2 mA. The actual value of IPULLUP will likely be closer to 218 A, but allow for the worst-case.
USB bandwidth is shared between all the devices which are plugged into the root port (via hubs). If the application is
plugged into a USB 1.1 hub that has other devices plugged into it, your device may see host to device traffic on the
bus, even if it is not addressed to your device. Since any traffic, regardless of source, can increase the IPULLUP current
above the base 218 A, it is safest to allow for the worst-case of 2.2 mA.
Therefore:
The calculated value should be considered an approximation and additional guardband or
application-specific product testing is recommended. The transceiver current is “in addition to” the
rest of the current consumed by the PIC18F46J50 family device that is needed to run the core,
drive the other I/O lines, power the various modules, etc.
Pin = 64 kbps
1.5 Mbps = 4.3% = 0.043
IXCVR = + 2.2 mA = 3.9 mA
(40 mA • 3.3V • 1 • 0.043 • 5m)
(3.3V • 5m)
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22.7 Oscillator
The USB module has specific clock requirements. For
full-speed operation, the clock source must be 48 MHz.
Even so, the microcontroller core and other peripherals
are not required to run at that clock speed. Available
clocking options are described in detail in Section 3.3
“Oscillator Settings for USB.
22.8 USB Firmware and Drivers
Microchip provides a number of application-specific
resources, such as USB firmware and driver support.
Refer to www.microchip.com for the latest firmware and
driver support.
TABLE 22-4: REGISTERS ASSOCIATED WITH USB MODULE OPERATION(1)
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Details on
Page:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 71
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 71
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 71
UCON PPBRST SE0 PKTDIS USBEN RESUME SUSPND 73
UCFG UTEYE UOEMON UPUEN UTRDIS FSEN PPB1 PPB0 74
USTAT ENDP3 ENDP2 ENDP1 ENDP0 DIR PPBI 73
UADDR ADDR6 ADDR5 ADDR4 ADDR3 ADDR2 ADDR1 ADDR0 74
UFRML FRM7 FRM6 FRM5 FRM4 FRM3 FRM2 FRM1 FRM0 73
UFRMH ———— FRM10 FRM9 FRM8 73
UIR SOFIF STALLIF IDLEIF TRNIF ACTVIF UERRIF URSTIF 73
UIE SOFIE STALLIE IDLEIE TRNIE ACTVIE UERRIE URSTIE 74
UEIR BTSEF BTOEF DFN8EF CRC16EF CRC5EF PIDEF 73
UEIE BTSEE BTOEE DFN8EE CRC16EE CRC5EE PIDEE 74
UEP0 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP1 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP2 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP3 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP4 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP5 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP6 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 75
UEP7 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP8 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP9 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP10 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP11 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP12 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP13 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP14 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
UEP15 —— EPHSHK EPCONDIS EPOUTEN EPINEN EPSTALL 74
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the USB module.
Note 1: This table includes only those hardware mapped SFRs located in Bank 15 of the data memory space. The Buffer
Descriptor registers, which are mapped into Bank 4 and are not true SFRs, are listed separately in Table 22-3.
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22.9 Overview of USB
This section presents some of the basic USB concepts
and useful information necessary to design a USB
device. Although much information is provided in this
section, there is a plethora of information provided
within the USB specifications and class specifications.
Thus, the reader is encouraged to refer to the USB
specifications for more information (www.usb.org). If
you are very familiar with the details of USB, then this
section serves as a basic, high-level refresher of USB.
22.9.1 LAYERED FRAMEWORK
USB device functionality is structured into a layered
framework, graphically illustrated in Figure 22-12.
Each level is associated with a functional level within
the device. The highest layer, other than the device, is
the configuration. A device may have multiple configu-
rations. For example, a particular device may have
multiple power requirements based on Self-Power Only
or Bus Power Only modes.
For each configuration, there may be multiple
interfaces. Each interface could support a particular
mode of that configuration.
Below the interface is the endpoint(s). Data is directly
moved at this level. There can be as many as
16 bidirectional endpoints. Endpoint 0 is always a
control endpoint, and by default, when the device is on
the bus, Endpoint 0 must be available to configure the
device.
22.9.2 FRAMES
Information communicated on the bus is grouped into
1 ms time slots, referred to as frames. Each frame can
contain many transactions to various devices and
endpoints. See Figure 22-8 for an example of a
transaction within a frame.
22.9.3 TRANSFERS
There are four transfer types defined in the USB
specification.
Isochronous: This type provides a transfer
method for large amounts of data (up to
1023 bytes) with timely delivery ensured;
however, the data integrity is not ensured. This is
good for streaming applications where small data
loss is not critical, such as audio.
Bulk: This type of transfer method allows for large
amounts of data to be transferred with ensured
data integrity; however, the delivery timeliness is
not ensured.
Interrupt: This type of transfer provides for
ensured timely delivery for small blocks of data,
plus data integrity is ensured.
Control: This type provides for device setup
control.
While full-speed devices support all transfer types,
low-speed devices are limited to interrupt and control
transfers only.
22.9.4 POWER
Power is available from the USB. The USB specifica-
tion defines the bus power requirements. Devices may
either be self-powered or bus-powered. Self-powered
devices draw power from an external source, while
bus-powered devices use power supplied from the bus.
FIGURE 22-12 : USB LAYERS
Device
Configuration
Interface
Endpoint
Interface
Endpoint Endpoint Endpoint Endpoint
To Other Configurations (if any)
To Other Interfaces (if any)
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The USB specification limits the power taken from the
bus. Each device is ensured 100 mA at approximately
5V (one unit load). Additional power may be requested,
up to a maximum of 500 mA.
Note that power above one unit load is a request and
the host or hub is not obligated to provide the extra cur-
rent. Thus, a device capable of consuming more than
one unit load must be able to maintain a low-power
configuration of a 1-unit load or less, if necessary.
The USB specification also defines a Suspend mode.
In this situation, current must be limited to 500 A,
averaged over one second. A device must enter a
suspend state after 3 ms of inactivity (i.e., no SOF
tokens for 3 ms). A device entering Suspend mode
must drop current consumption within 10 ms after
suspend. Likewise, when signaling a wake-up, the
device must signal a wake-up within 10 ms of drawing
current above the suspend limit.
22.9.5 ENUMERATION
When the device is initially attached to the bus, the host
enters an enumeration process in an attempt to identify
the device. Essentially, the host interrogates the device,
gathering information, such as power consumption, data
rates and sizes, protocol, and other descriptive
information; descriptors contain this information. A
typical enumeration process would be as follows:
1. USB Reset – Reset the device. Thus, the device
is not configured and does not have an address
(Address 0).
2. Get Device Descriptor – The host requests a
small portion of the device descriptor.
3. USB Reset – Reset the device again.
4. Set Address – The host assigns an address to
the device.
5. Get Device Descriptor – The host retrieves the
device descriptor, gathering information, such
as manufacturer, type of device and maximum
control packet size.
6. Get configuration descriptors.
7. Get any other descriptors.
8. Set a configuration.
The exact enumeration process depends on the host.
22.9.6 DESCRIPTORS
There are eight different standard descriptor types, of
which, five are most important for this device.
22.9.6.1 Device Descriptor
The device descriptor provides general information,
such as manufacturer, product number, serial number,
the class of the device and the number of configurations.
There is only one device descriptor.
22.9.6.2 Configuration Descriptor
The configuration descriptor provides information on
the power requirements of the device and how many
different interfaces are supported when in this configu-
ration. There may be more than one configuration for a
device (i.e., low-power and high-power configurations).
22.9.6.3 Interface Descriptor
The interface descriptor details the number of end-
points used in this interface, as well as the class of the
interface. There may be more than one interface for a
configuration.
22.9.6.4 Endpoint Descriptor
The endpoint descriptor identifies the transfer type
(Section 22.9.3 “Transfers”) and direction, and some
other specifics for the endpoint. There may be many
endpoints in a device and endpoints may be shared in
different configurations.
22.9.6.5 String Descriptor
Many of the previous descriptors reference one or
more string descriptors. String descriptors provide
human readable information about the layer
(Section 22.9.1 “Layered Framework”) they
describe. Often, these strings show up in the host to
help the user identify the device. String descriptors are
generally optional to save memory and are encoded in
a unicode format.
22.9.7 BUS SPEED
Each USB device must indicate its bus presence and
speed to the host. This is accomplished through a
1.5 k resistor, which is connected to the bus at the
time of the attachment event.
Depending on the speed of the device, the resistor
pulls up either the D+ or D- line to 3.3V. For a
low-speed device, the pull-up resistor is connected to
the D- line. For a full-speed device, the pull-up resistor
is connected to the D+ line.
22.9.8 CLASS SPECIFICATIONS AND
DRIVERS
USB specifications include class specifications, which
operating system vendors optionally support.
Examples of classes include Audio, Mass Storage,
Communications and Human Interface (HID). In most
cases, a driver is required at the host side to ‘talk’ to the
USB device. In custom applications, a driver may need
to be developed. Fortunately, drivers are available for
most common host systems for the most common
classes of devices. Thus, these drivers can be reused.
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NOTES:
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23.0 COMPARATOR MODULE
The analog comparator module contains two compara-
tors that can be independently configured in a variety of
ways. The inputs can be selected from the analog inputs
and two internal voltage references. The digital outputs
are available at the pin level and can also be read
through the control register. Multiple output and interrupt
event generation is also available. Figure 23-1 provides
a generic single comparator from the module.
Key features of the module are:
Independent comparator control
Programmable input configuration
Output to both pin and register levels
Programmable output polarity
Independent interrupt generation for each
comparator with configurable interrupt-on-change
23.1 Registers
The CMxCON registers (Register 23-1) select the input
and output configuration for each comparator, as well
as the settings for interrupt generation.
The CMSTAT register (Register 23-2) provides the out-
put results of the comparators. The bits in this register
are read-only.
FIGURE 23-1: COMPARATOR SIMPLIFIED BLOCK DIAGRAM
Cx
VIN-
VIN+
COE CxOUT
0
3
0
1
CCH<1:0>
CxINB
VIRV
CxINA
CVREF
CON
Interrupt
Logic
EVPOL<4:3>
COUTx
(CMSTAT<1:0>)
CMxIF
CPOL
Polarity
Logic
CREF
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REGISTER 23-1: CMxCON: COMPARATOR CONTROL x REGISTER (ACCESS FD2h, FD1h)
R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CON: Comparator Enable bit
1 = Comparator is enabled
0 = Comparator is disabled
bit 6 COE: Comparator Output Enable bit
1 = Comparator output is present on the CxOUT pin (assigned in the PPS module)
0 = Comparator output is internal only
bit 5 CPOL: Comparator Output Polarity Select bit
1 = Comparator output is inverted
0 = Comparator output is not inverted
bit 4-3 EVPOL<1:0>: Interrupt Polarity Select bits
11 = Interrupt generation on any change of the output(1)
10 = Interrupt generation only on high-to-low transition of the output
01 = Interrupt generation only on low-to-high transition of the output
00 = Interrupt generation is disabled
bit 2 CREF: Comparator Reference Select bit (non-inverting input)
1 = Non-inverting input connects to internal CVREF voltage
0 = Non-inverting input connects to CxINA pin
bit 1-0 CCH<1:0>: Comparator Channel Select bits
11 = Inverting input of the comparator connects to VIRV (0.6V)
00 = Inverting input of the comparator connects to CxINB pin
Note 1: The CMxIF bit is automatically set any time this mode is selected and must be cleared by the application
after the initial configuration.
REGISTER 23-2: CMSTAT: COMPARATOR STATUS REGISTER (ACCESS F70h)
U-0 U-0 U-0 U-0 U-0 U-0 R-1 R-1
COUT2 COUT1
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 Unimplemented: Read as0
bit 1-0 COUT<2:1>: Comparator x Status bits
If CPOL = 0 (non-inverted polarity):
1 = Comparator VIN+ > VIN-
0 = Comparator VIN+ < VIN-
If CPOL = 1 (inverted polarity):
1 = Comparator VIN+ < VIN-
0 = Comparator VIN+ > VIN-
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23.2 Comparator Operation
A single comparator is shown in Figure 23-2, along with
the relationship between the analog input levels and
the digital output. When the analog input at VIN+ is less
than the analog input, VIN-, the output of the compara-
tor is a digital low level. When the analog input at VIN+
is greater than the analog input, VIN-, the output of the
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 23-2 represent
the uncertainty due to input offsets and response time.
FIGURE 23-2: SI NGLE COMPARATOR
23.3 Comparator Response Time
Response time is the minimum time, after selecting a
new reference voltage or input source, before the
comparator output has a valid level. The response time
of the comparator differs from the settling time of the
voltage reference. Therefore, both of these times must
be considered when determining the total response to
a comparator input change. Otherwise, the maximum
delay of the comparators should be used (see
Section 30.0 “Electrical Characteristics”).
23.4 Analog Input Connection
Considerations
Figure 23-3 provides a simplified circuit for an analog
input. Since the analog pins are connected to a digital
output, they have reverse biased diodes to VDD and VSS.
The analog input, therefore, must be between VSS and
VDD. If the input voltage deviates from this range by
more than 0.6V in either direction, one of the diodes is
forward biased and a latch-up condition may occur. A
maximum source impedance of 10 k is recommended
for the analog sources. Any external component con-
nected to an analog input pin, such as a capacitor or a
Zener diode, should have very little leakage current.
FIGURE 23-3: COMPARATOR ANALOG INPUT MODEL
Output
VIN-
VIN+
+
VIN+
VIN-
Output
VA
RS < 10k
AIN
CPIN
5 pF
VDD
VT = 0.6V
VT = 0.6V
RIC
ILEAKAGE
±100 nA
VSS
Legend: CPIN = Input Capacitance
VT= Threshold Voltage
ILEAKAGE = Leakage Current at the pin due to various junctions
RIC = Interconnect Resistance
RS= Source Impedance
VA = Analog Voltage
Comparator
Input
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23.5 Comparator Control and
Configuration
Each comparator has up to eight possible combina-
tions of inputs: up to four external analog inputs and
one of two internal voltage references.
Both comparators allow a selection of the signal from
pin, CxINA, or the voltage from the comparator refer-
ence (CVREF) on the non-inverting channel. This is
compared to either CxINB, CTMU or the microcon-
troller’s fixed internal reference voltage (VIRV, 0.6V
nominal) on the inverting channel.
Table 23-1 provides the comparator inputs and outputs
tied to fixed I/O pins.
TABLE 23-1: COMPARATOR INPUTS AND
OUTPUTS
23.5.1 COMPARATOR ENABLE AND
INPUT SELECTION
Setting the CON bit of the CMxCON register
(CMxCON<7>) enables the comparator for operation.
Clearing the CON bit disables the comparator, resulting
in minimum current consumption.
The CCH<1:0> bits in the CMxCON register
(CMxCON<1:0>) direct either one of three analog input
pins, or the Internal Reference Voltage (VIRV), to the
comparator, VIN-. Depending on the comparator oper-
ating mode, either an external or internal voltage
reference may be used. The analog signal present at
VIN- is compared to the signal at VIN+ and the digital
output of the comparator is adjusted accordingly.
The external reference is used when CREF = 0
(CMxCON<2>) and VIN+ is connected to the CxINA
pin. When external voltage references are used, the
comparator module can be configured to have the
reference sources externally. The reference signal
must be between VSS and VDD, and can be applied to
either pin of the comparator.
The comparator module also allows the selection of an
internally generated voltage reference (CVREF) from
the comparator voltage reference module. This module
is described in more detail in Section 23.0 “Compa ra-
tor Module”. The reference from the comparator
voltage reference module is only available when
CREF = 1. In this mode, the internal voltage reference
is applied to the comparator’s VIN+ pin.
23.5.2 COMPARATOR ENABLE AND
OUTPUT SELECTION
The comparator outputs are read through the CMSTAT
register. The CMSTAT<0> bit reads the Comparator 1
output and CMSTAT<1> bit reads the Comparator 2
output. These bits are read-only.
The comparator outputs may also be directly output to
the RPn I/O pins by setting the COE bit (CMxCON<6>).
When enabled, multiplexers in the output path of the
pins switch to the output of the comparator.
By default, the comparator’s output is at logic high
whenever the voltage on VIN+ is greater than on VIN-.
The polarity of the comparator outputs can be inverted
using the CPOL bit (CMxCON<5>).
The uncertainty of each of the comparators is related to
the input offset voltage and the response time given in
the specifications, as discussed in Section 23.2
“Comp arator Operation”.
Comparator Input or Output I/O Pin
1
C1INA (VIN+) RA0
C1INB (VIN-) RA3
C1OUT Remapped
RPn
2
C2INA(VIN+) RA1
C2INB(VIN-) RA2
C2OUT Remapped
RPn
Note: The comparator input pin selected by
CCH<1:0> must be configured as an input
by setting both the corresponding TRIS
and PCFG bits in the ANCON1 register.
2011 Microchip Technology Inc. DS39931D-page 389
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23.6 Comparator Interrupts
The comparator interrupt flag is set whenever any of
the following occurs:
- Low-to-high transition of the comparator
output
- High-to-low transition of the comparator
output
- Any change in the comparator output
The comparator interrupt selection is done by the
EVPOL<1:0> bits in the CMxCON register
(CMxCON<4:3>).
In order to provide maximum flexibility, the output of the
comparator may be inverted using the CPOL bit in the
CMxCON register (CMxCON<5>). This is functionally
identical to reversing the inverting and non-inverting
inputs of the comparator for a particular mode.
An interrupt is generated on the low-to-high or high-to-
low transition of the comparator output. This mode of
interrupt generation is dependent on EVPOL<1:0> in
the CMxCON register. When EVPOL<1:0> = 01 or 10,
the interrupt is generated on a low-to-high or high-to-
low transition of the comparator output. Once the
interrupt is generated, it is required to clear the interrupt
flag by software.
When EVPOL<1:0> = 11, the comparator interrupt flag
is set whenever there is a change in the output value of
either comparator. Software will need to maintain
information about the status of the output bits, as read
from CMSTAT<1:0>, to determine the actual change
that occurred. The CMxIF bits (PIR2<6:5>) are the
Comparator Interrupt Flags. The CMxIF bits must be
reset by clearing them. Since it is also possible to write
a ‘1’ to this register, a simulated interrupt may be
initiated.
Table 23-2 provides the interrupt generation
corresponding to comparator input voltages and
EVPOL bit settings.
Both the CMxIE bits (PIE2<6:5>) and the PEIE bit
(INTCON<6>) must be set to enable the interrupt. In
addition, the GIE bit (INTCON<7>) must also be set.
If any of these bits are clear, the interrupt is not
enabled, though the CMxIF bits will still be set if an
interrupt condition occurs.
Figure 23-3 provides a simplified diagram of the
interrupt section.
TABLE 23-2: COMPARATOR INTERRUPT GENERATION
CPOL EVPOL<1:0> Comparator
Input Change COUTx Transition Interrupt
Generated
0
00 VIN+ > VIN- Low-to-High No
VIN+ < VIN-High-to-Low No
01 VIN+ > VIN- Low-to-High Yes
VIN+ < VIN-High-to-Low No
10 VIN+ > VIN- Low-to-High No
VIN+ < VIN-High-to-Low Yes
11 VIN+ > VIN- Low-to-High Yes
VIN+ < VIN-High-to-Low Yes
1
00 VIN+ > VIN-High-to-Low No
VIN+ < VIN- Low-to-High No
01 VIN+ > VIN-High-to-Low No
VIN+ < VIN- Low-to-High Yes
10 VIN+ > VIN-High-to-Low Yes
VIN+ < VIN- Low-to-High No
11 VIN+ > VIN-High-to-Low Yes
VIN+ < VIN- Low-to-High Yes
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23.7 Comparator Operation During
Sleep
When a comparator is active and the device is placed
in Sleep mode, the comparator remains active and the
interrupt is functional if enabled. This interrupt will
wake-up the device from Sleep mode when enabled.
Each operational comparator will consume additional
current. To minimize power consumption while in Sleep
mode, turn off the comparators (CON = 0) before
entering Sleep. If the device wakes up from Sleep, the
contents of the CMxCON register are not affected.
23.8 Effects of a Reset
A device Reset forces the CMxCON registers to their
Reset state. This forces both comparators and the
voltage reference to the OFF state.
TABLE 23-3: REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Pag e:
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 71
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 71
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 71
CMxCON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 70
CVRCON CVREN CVROE CVRR r CVR3 CVR2 CVR1 CVR0 74
CMSTAT COUT2 COUT1 73
ANCON0 PCFG7(1) PCFG6(1) PCFG5(1) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 74
TRISA TRISA7 TRISA6 TRISA5 TRISA3 TRISA2 TRISA1 TRISA0 72
Legend: = unimplemented, read as ‘0’, r = reserved. Shaded cells are not related to comparator operation.
Note 1: These bits and/or registers are not implemented on 28-pin devices.
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24.0 COMPARATOR VOLTAGE
REFERENC E MODULE
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
Figure 24-1 provides a block diagram of the module.
The resistor ladder is segmented to provide two ranges
of CVREF values and has a power-down function to
conserve power when the reference is not being used.
The module’s supply reference is provided by VDD/VSS.
FIGU RE 24-1 : C OM PARATOR VOLTAGE REF ER E NC E B L OCK D IA G RA M
16-to-1 MUX
CVR<3:0>
8R
R
CVREN
8R
R
R
R
R
R
R
16 Steps
CVRR
CVREF
VDD
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24.1 Configuring the Comparator
Voltage Reference
The comparator voltage reference module is controlled
through the CVRCON register (Register 24-1). The
comparator voltage reference provides two ranges of
output voltage, each with 16 distinct levels. The range
to be used is selected by the CVRR bit (CVRCON<5>).
The primary difference between the ranges is the size
of the steps selected by the CVREF Selection bits
(CVR<3:0>), with one range offering finer resolution.
The equations used to calculate the output of the
comparator voltage reference are as follows:
EQUATION 24-1: CALCULATING OUTPUT
OF THE COMPARATOR
VOLTAGE REFERENCE
The settling time of the comparator voltage reference
must be considered when changing the CVREF
output (see Table 30-3 in Section 30.0 “Electrical
Characteristics).
When CVRR = 1:
CVREF = ((CVR<3:0>)/24) x (VDD)
When CVRR = 0:
CVREF =(VDD/4) + ((CVR<3:0>)/32) x (VDD)
REGISTER 24-1: CVRCON: COMPARA TOR VOLTAGE REFERENCE CONTROL REGISTER
(BANKED F53h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
CVREN CVROE(1) CVRR r CVR3 CVR2 CVR1 CVR0
bit 7 bit 0
Legend: r = Reserved bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CVREN: Comparator Voltage Reference Enable bit
1 =CV
REF circuit is powered on
0 =CV
REF circuit is powered down
bit 6 CVROE: Comparator VREF Output Enable bit(1)
1 =CVREF voltage level is also output on the RA2/AN2/VREF-/CVREF/C2INB pin
0 =CV
REF voltage is disconnected from the RA2/AN2/VREF-/CVREF/C2INB pin
bit 5 CVRR: Comparator VREF Range Selection bit
1 = 0 to 0.667 VDD, with VDD/24 step size (low range)
0 = 0.25 VDD to 0.75 VDD, with VDD/32 step size (high range)
bit 4 Reserved: Always maintain as ‘0
bit 3-0 CVR<3:0>: Comparator VREF Value Selection bits (0 (CVR<3:0>) 15)
When CVRR = 1:
CVREF = ((CVR<3:0>)/24) (VDD)
When CVRR = 0:
CVREF = (VDD/4) + ((CVR<3:0>)/32) (VDD)
Note 1: CVROE overrides the TRIS bit setting.
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24.2 Voltage Reference Accuracy/Error
The full range of voltage reference cannot be realized
due to the construction of the module. The transistors
on the top and bottom of the resistor ladder network
(see Figure 24-1) keep CVREF from approaching the
reference source rails. The voltage reference is derived
from the reference source; therefore, the CVREF output
changes with fluctuations in that source. The accuracy
of the voltage reference can be found in Section 30.0
“Electrical Char acte ristic s” .
24.3 Connection Considerations
The voltage reference module operates independently
of the comparator module. The output of the reference
generator may be connected to the RA2 pin if the
CVROE bit is set. Enabling the voltage reference out-
put onto RA2 when it is configured as a digital input will
increase current consumption.
The RA2 pin can be used as a simple D/A output with
limited drive capability. Due to the limited current drive
capability, a buffer must be used on the voltage
reference output for external connections to VREF. See
Figure 24-2 for an example buffering technique.
24.4 Operation During Sleep
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the CVRCON register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
24.5 Effects of a Reset
A device Reset disables the voltage reference by
clearing bit, CVREN (CVRCON<7>). This Reset also
disconnects the reference from the RA2 pin by clearing
bit, CVROE (CVRCON<6>) and selects the high-voltage
range by clearing bit, CVRR (CVRCON<5>). The CVR
value select bits are also cleared.
FIGU RE 24-2: C OMP A RAT OR VOLTAGE REFE RENC E OUT PUT BU FFER EXAMP LE
TABLE 24-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page:
CVRCON CVREN CVROE CVRR r CVR3 CVR2 CVR1 CVR0 74
CM1CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 70
CM2CON CON COE CPOL EVPOL1 EVPOL0 CREF CCH1 CCH0 70
TRISA TRISA7 TRISA6 TRISA5 TRISA3 TRISA2 TRISA1 TRISA0 72
ANCON0 PCFG7(1) PCFG6(1) PCFG5(1) PCFG4 PCFG3 PCFG2 PCFG1 PCFG0 74
ANCON1 VBGEN r PCFG12 PCFG11 PCFG10 PCFG9 PCFG8 74
Legend: — = unimplemented, read as ‘0’, r = reserved. Shaded cells are not used with the comparator voltage
reference.
Note 1: These bits are only available on 44-pin devices.
CVREF Output
+
CVREF
Module
Voltage
Reference
Output
Impedance
R(1)
RA2
Note 1: R is dependent upon the Comparator Voltage Reference Configuration bits, CVRCON<5> and CVRCON<3:0>.
PIC18F46J50
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NOTES:
2011 Microchip Technology Inc. DS39931D-page 395
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25.0 HIGH/LOW VOLT AGE DETECT
(HLVD)
The High/Low-Voltage Detect (HLVD) module can be
used to monitor the absolute voltage on VDD or the
HLVDIN pin. This is a programmable circuit that allows
the user to specify both a device voltage trip point and
the direction of change from that point.
If the module detects an excursion past the trip point in
that direction, an interrupt flag is set. If the interrupt is
enabled, the program execution will branch to the inter-
rupt vector address and the software can then respond
to the interrupt.
The High/Low-Voltage Detect Control register
(Register 25-1) completely controls the operation of the
HLVD module. This allows the circuitry to be “turned
off” by the user under software control, which
minimizes the current consumption for the device.
Figure 25-1 provides a block diagram for the HLVD
module.
The module is enabled by setting the HLVDEN bit.
Each time the module is enabled, the circuitry requires
some time to stabilize. The IRVST bit is a read-only bit
that indicates when the circuit is stable. The module
can generate an interrupt only after the circuit is stable
and IRVST is set.
The VDIRMAG bit determines the overall operation of
the module. When VDIRMAG is cleared, the module
monitors for drops in VDD below a predetermined set
point. When the bit is set, the module monitors for rises
in VDD above the set point.
REGISTER 25-1: HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER (ACCESS F85h)
R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
VDIRMAG BGVST IRVST HLVDEN HLVDL3(1) HLVDL2(1) HLVDL1(1) HLVDL0(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 VDIRMAG: Voltage Direction Magnitude Select bit
1 = Event occurs when voltage equals or exceeds trip point (HLVDL<3:0>)
0 = Event occurs when voltage equals or falls below trip point (HLVDL<3:0>)
bit 6 BGVST: Band Gap Reference Voltages Stable Status Flag bit
1 = Indicates internal band gap voltage references are stable
0 = Indicates internal band gap voltage references are not stable
bit 5 IRVST: Internal Reference Voltage Stable Flag bit
1 = Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range
0 = Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage
range and the HLVD interrupt should not be enabled
bit 4 HLVDEN: High/Low-Voltage Detect Power Enable bit
1 = HLVD enabled
0 = HLVD disabled
bit 3-0 HLVDL<3:0>: Voltage Detection Limit bits(1)
1111 = External analog input is used (input comes from the HLVDIN pin)
1110 = Maximum setting
.
.
.
1000 = Minimum setting
0xxx = Reserved
Note 1: See Table 30-8 in Section 30.0 “ Ele ctric al Cha racte r istic s” for specifications.
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25.1 Operation
When the HLVD module is enabled, a comparator uses
an internally generated reference voltage as the set
point. The set point is compared with the trip point,
where each node in the resistor divider represents a
trip point voltage. The “trip point” voltage is the voltage
level at which the device detects a high or low-voltage
event, depending on the configuration of the module.
When the supply voltage is equal to the trip point, the
voltage tapped off of the resistor array is equal to the
internal reference voltage generated by the voltage
reference module. The comparator then generates an
interrupt signal by setting the HLVDIF bit.
The trip point voltage is software-programmable to any
one of 8 values. The trip point is selected by
programming the HLVDL<3:0> bits (HLVDCON<3:0>).
Additionally, the HLVD module allows the user to
supply the trip voltage to the module from an external
source. This mode is enabled when bits, HLVDL<3:0>,
are set to ‘1111’. In this state, the comparator input is
multiplexed from the external input pin, HLVDIN. This
gives users flexibility because it allows them to
configure the HLVD interrupt to occur at any voltage in
the valid operating range.
FIGU RE 25-1: HLVD MODU L E B L OCK D IA G RA M (W I TH E XT ERN AL IN P UT)
Set
VDD
16-to-1 MUX
HLVDCON
HLVDL<3:0> Register
HLVDIN
VDD
Externally Generated
Trip Point
HLVDIF
HLVDEN
Inter na l Voltage
Reference
VDIRMAG
1.2V Typical
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25.2 HLVD Setup
To set up the HLVD module:
1. Disable the module by clearing the HLVDEN bit
(HLVDCON<4>).
2. Write the value to the HLVDL<3:0> bits that
selects the desired HLVD trip point.
3. Set the VDIRMAG bit to detect one of the
following:
High voltage (VDIRMAG = 1)
Low voltage (VDIRMAG = 0)
4. Enable the HLVD module by setting the
HLVDEN bit.
5. Clear the HLVD Interrupt Flag, HLVDIF
(PIR2<2>), which may have been set from a
previous interrupt.
6. If interrupts are desired, enable the HLVD inter-
rupt by setting the HLVDIE and GIE/GIEH bits
(PIE2<2> and INTCON<7>).
An interrupt will not be generated until the
IRVST bit is set.
25.3 Current Consumption
When the module is enabled, the HLVD comparator
and voltage divider are enabled and will consume static
current. The total current consumption, when enabled,
is specified in electrical specification Parameter D022B
(IHLVD) (Sect ion 30. 2 “DC Char acteris tics: Po wer-
Down and Supply Current PIC18F46J50 Family
(Industrial)”).
Depending on the application, the HLVD module does
not need to operate constantly. To decrease the current
requirements, the HLVD circuitry may only need to be
enabled for short periods where the voltage is checked.
After doing the check, the HLVD module may be
disabled.
25.4 HLVD Start-up Ti me
The internal reference voltage of the HLVD module,
specified in electrical specification Parameter D420 (see
Table 30-8 in Section 30.0 “Electrical Characteris-
tics”), may be used by other internal circuitry, such as
the programmable Brown-out Reset (BOR).
If the HLVD, or other circuits using the voltage
reference, are disabled to lower the device’s current
consumption, the reference voltage circuit will require
time to become stable before a low or high-voltage con-
dition can be reliably detected. This start-up time,
TIRVST, is an interval that is independent of device
clock speed. It is specified in electrical specification
Parameter 36 (Table 30-13).
The HLVD interrupt flag is not enabled until TIRVST has
expired and a stable reference voltage is reached. For
this reason, brief excursions beyond the set point may
not be detected during this interval. Refer to Figure 25-2
or Figure 25-3.
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FIGU RE 25- 2: L OW -VOL TAGE DETE C T O PE R ATI ON (V DI RMA G = 0)
VHLVD
VDD
HLVDIF
VHLVD
VDD
Enable HLVD
TIRVST
HLVDIF may not be set
Enable HLVD
HLVDIF
HLVDIF cleared in software
HLVDIF cleared in software
HLVDIF cleared in software,
CAS E 1:
CAS E 2:
HLVDIF remains set since HLVD condition still exists
TIRVST
Internal Reference is stable
Internal Reference is stable
IRVST
IRVST
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FIGURE 25-3: HIGH-VOLT AGE DETECT OPERATION (VDIRMAG = 1)
25.5 Applications
In many applications, it is desirable to have the ability to
detect a drop below, or rise above, a particular threshold.
For example, the HLVD module could be enabled
periodically to detect Universal Serial Bus (USB) attach
or detach.
For general battery applications, Figure 25-4 provides
a possible voltage curve.
Over time, the device voltage decreases. When the
device voltage reaches voltage, VA, the HLVD logic
generates an interrupt at time, T
A. The interrupt could
cause the execution of an ISR, which would allow the
application to perform “housekeeping tasks” and
perform a controlled shutdown before the device
voltage exits the valid operating range at TB.
Thus, the HLVD would give the application a time
window, represented by the difference between T
A and
TB, to safely exit.
FIGU RE 25- 4: TYPICA L HIGH /
LOW-VOLTAGE DETECT
APPLIC ATION
VHLVD
VDD
HLVDIF
VHLVD
VDD
Enable HLVD
TIRVST
HLVDIF may not be set
Enable HLVD
HLVDIF
HLVDIF cleared in software
HLVDIF cleared in software
HLVDIF cleared in software,
CASE 1:
CASE 2:
HLVDIF remains set since HLVD condition still exists
TIRVST
IRVST
Internal Reference is stable
Internal Reference is stable
IRVST
Time
Voltage
VA
VB
TATB
VA = HLVD trip point
VB = Minimum valid device
operating voltage
Legend:
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25.6 Operation During Sleep
When enabled, the HLVD circuitry continues to operate
during Sleep. If the device voltage crosses the trip
point, the HLVDIF bit will be set and the device will
wake-up from Sleep. Device execution will continue
from the interrupt vector address if interrupts have
been globally enabled.
25.7 Effects of a Reset
A device Reset forces all registers to their Reset state.
This forces the HLVD module to be turned off.
TABLE 25-1: REGISTERS ASSOCIATED WITH HIGH/LOW-VOLTAGE DETECT MODULE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Page
HLVDCON VDIRMAG BGVST IRVST HLVDEN HLVDL3 HLVDL2 HLVDL1 HLVDL0 72
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 69
PIR2 OSCFIF CM2IF CM1IF USBIF BCL1IF HLVDIF TMR3IF CCP2IF 71
PIE2 OSCFIE CM2IE CM1IE USBIE BCL1IE HLVDIE TMR3IE CCP2IE 71
IPR2 OSCFIP CM2IP CM1IP USBIP BCL1IP HLVDIP TMR3IP CCP2IP 71
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the HLVD module.
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26.0 CHARGE TIME
MEASUREMENT UNIT (CTMU)
The Charge Time Measurement Unit (CTMU) is a
flexible analog module that provides accurate differen-
tial time measurement between pulse sources, as well
as asynchronous pulse generation. By working with
other on-chip analog modules, the CTMU can be used
to precisely measure time, measure capacitance,
measure relative changes in capacitance or generate
output pulses with a specific time delay. The CTMU is
ideal for interfacing with capacitive-based sensors.
The module includes the following key features:
Up to 13 channels available for capacitive or time
measurement input
On-chip precision current source
Four-edge input trigger sources
Polarity control for each edge source
Control of edge sequence
Control of response to edges
Time measurement resolution of 1 nanosecond
High-precision time measurement
Time delay of external or internal signal
asynchronous to system clock
Accurate current source suitable for capacitive
measurement
The CTMU works in conjunction with the A/D Converter
to provide up to 13 channels for time or charge
measurement, depending on the specific device and
the number of A/D channels available. When config-
ured for time delay, the CTMU is connected to one of
the analog comparators. The level-sensitive input edge
sources can be selected from four sources: two
external inputs, Timer1 or Output Compare Module 1.
Figure 26-1 provides a block diagram of the CTMU.
FIGURE 26-1: CTMU BLOCK DIAGRAM
CTED1
CTED2
Current Source
Edge
Control
Logic
Pulse
Generator
A/D Converter Comparator 2
Input
Timer1
ECCP1
Current
Control
ITRIM<5:0>
IRNG<1:0>
CTMUICON
CTMU
Control
Logic
EDGEN
EDGSEQEN
EDG1POL
EDG2POL
EDG1STAT
EDG2STAT
TGEN
IDISSEN
CTPLS
Comparator 2 Output
CTMUCONH:CTMUCONL
EDG1SEL<1:0>
EDG2SEL<1:0>
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DS39931D-page 402 2011 Microchip Technology Inc.
26.1 CTMU Operation
The CTMU works by using a fixed current source to
charge a circuit. The type of circuit depends on the type
of measurement being made. In the case of charge
measurement, the current is fixed, and the amount of
time the current is applied to the circuit is fixed. The
amount of voltage read by the A/D is then a measure-
ment of the capacitance of the circuit. In the case of
time measurement, the current, as well as the capaci-
tance of the circuit, is fixed. In this case, the voltage
read by the A/D is then representative of the amount of
time elapsed from the time the current source starts
and stops charging the circuit.
If the CTMU is being used as a time delay, both capaci-
tance and current source are fixed, as well as the voltage
supplied to the comparator circuit. The delay of a signal
is determined by the amount of time it takes the voltage
to charge to the comparator threshold voltage.
26.1.1 THEORY OF OPERATION
The operation of the CTMU is based on this equation
for charge:
More simply, the amount of charge (Q), measured in
coulombs in a circuit, is defined as current in amperes
(I) multiplied by the amount of time in seconds that the
current flows (t). Charge is also defined as the
capacitance in farads (C), multiplied by the voltage of
the circuit (V). It follows that:
The CTMU module provides a constant, known current
source. The A/D Converter is used to measure (V) in
the equation, leaving two unknowns: capacitance (C)
and time (t). The above equation can be used to calcu-
late capacitance or time by either relationship using the
known fixed capacitance of the circuit:
or by:
using a fixed time that the current source is applied to
the circuit.
26.1.2 CURRENT SOURCE
At the heart of the CTMU is a precision current source,
designed to provide a constant reference for measure-
ments. The level of current is user-selectable across
three ranges or a total of two orders of magnitude, with
the ability to trim the output in ±2% increments
(nominal). The current range is selected by the
IRNG<1:0> bits (CTMUICON<1:0>), with a value of
01’ representing the lowest range.
Current trim is provided by the ITRIM<5:0> bits
(CTMUICON<7:2>). These six bits allow trimming of
the current source in steps of approximately 2% per
step. Note that half of the range adjusts the current
source positively and the other half reduces the current
source. A value of ‘000000’ is the neutral position (no
change). A value of ‘100001’ is the maximum negative
adjustment (approximately -62%) and011111’ is the
maximum positive adjustment (approximately +62%).
26.1.3 EDGE SELECTION AND CONTROL
CTMU measurements are controlled by edge events
occurring on the module’s two input channels. Each
channel, referred to as Edge 1 and Edge 2, can be con-
figured to receive input pulses from one of the edge
input pins (CTED1 and CTED2), Timer1 or Output
Compare Module 1. The input channels are level-
sensitive, responding to the instantaneous level on the
channel rather than a transition between levels. The
inputs are selected using the EDG1SEL and EDG2SEL
bit pairs (CTMUCONL<3:2 and 6:5>).
In addition to source, each channel can be configured for
event polarity using the EDGE2POL and EDGE1POL
bits (CTMUCONL<7,4>). The input channels can also
be filtered for an edge event sequence (Edge 1 occur-
ring before Edge 2) by setting the EDGSEQEN bit
(CTMUCONH<2>).
26.1.4 EDGE STATUS
The CTMUCONL register also contains two status bits:
EDG2STAT and EDG1STAT (CTMUCONL<1:0>).
Their primary function is to show if an edge response
has occurred on the corresponding channel. The
CTMU automatically sets a particular bit when an edge
response is detected on its channel. The level-sensitive
nature of the input channels also means that the status
bits become set immediately if the channel’s configura-
tion is changed and is the same as the channel’s
current state.
The module uses the edge status bits to control the cur-
rent source output to external analog modules (such as
the A/D Converter). Current is only supplied to external
modules when only one (but not both) of the status bits
is set, and shuts current off when both bits are either
set or cleared. This allows the CTMU to measure cur-
rent only during the interval between edges. After both
status bits are set, it is necessary to clear them before
another measurement is taken. Both bits should be
cleared simultaneously, if possible, to avoid re-enabling
the CTMU current source.
In addition to being set by the CTMU hardware, the
edge status bits can also be set by software. This is
also the user’s application to manually enable or
disable the current source. Setting either one (but not
both) of the bits enables the current source. Setting or
clearing both bits at once disables the source.
IC
dV
dT
-------=
ItCV.=
tCVI=
CItV=
2011 Microchip Technology Inc. DS39931D-page 403
PIC18F46J50 FAMILY
26.1.5 INTERRUPTS
The CTMU sets its interrupt flag (PIR3<2>) whenever
the current source is enabled, then disabled. An inter-
rupt is generated only if the corresponding interrupt
enable bit (PIE3<2>) is also set. If edge sequencing is
not enabled (i.e., Edge 1 must occur before Edge 2), it
is necessary to monitor the edge status bits and
determine which edge occurred last and caused the
interrupt.
26.2 CTMU Module Initialization
The following sequence is a general guideline used to
initialize the CTMU module:
1. Select the current source range using the IRNG
bits (CTMUICON<1:0>).
2. Adjust the current source trim using the ITRIM
bits (CTMUICON<7:2>).
3. Configure the edge input sources for Edge 1 and
Edge 2 by setting the EDG1SEL and EDG2SEL
bits (CTMUCONL<3:2 and 6:5>).
4. Configure the input polarities for the edge inputs
using the EDG1POL and EDG2POL bits
(CTMUCONL<4,7>). The default configuration
is for negative edge polarity (high-to-low
transitions).
5. Enable edge sequencing using the EDGSEQEN
bit (CTMUCONH<2>). By default, edge
sequencing is disabled.
6. Select the operating mode (Measurement or
Time Delay) with the TGEN bit
(CTMUCONH<4>). The default mode is Time/
Capacitance Measurement.
7. Discharge the connected circuit by setting the
IDISSEN bit (CTMUCONH<1>); after waiting a
sufficient time for the circuit to discharge, clear
IDISSEN.
8. Disable the module by clearing the CTMUEN bit
(CTMUCONH<7>).
9. Enable the module by setting the CTMUEN bit.
10. Clear the Edge Status bits: EDG2STAT and
EDG1STAT (CTMUCONL<1:0>). Both bits
should be cleared simultaneously, if possible, to
avoid re-enabling the CTMU current source.
11. Enable both edge inputs by setting the EDGEN
bit (CTMUCONH<3>).
Depending on the type of measurement or pulse
generation being performed, one or more additional
modules may also need to be initialized and configured
with the CTMU module:
Edge Source Generation: In addition to the
external edge input pins, both Timer1 and the
Output Compare/PWM1 module can be used as
edge sources for the CTMU.
Capacitance or Time Measurement: The CTMU
module uses the A/D Converter to measure the
voltage across a capacitor that is connected to one
of the analog input channels.
Pulse Generation: When generating system clock
independent output pulses, the CTMU module
uses Comparator 2 and the associated
comparator voltage reference.
26.3 Calibrating the CTMU Module
The CTMU requires calibration for precise measure-
ments of capacitance and time, as well as for accurate
time delay. If the application only requires measurement
of a relative change in capacitance or time, calibration is
usually not necessary. An example of this type of appli-
cation would include a capacitive touch switch, in which
the touch circuit has a baseline capacitance, and the
added capacitance of the human body changes the
overall capacitance of a circuit.
If actual capacitance or time measurement is required,
two hardware calibrations must take place: the current
source needs calibration to set it to a precise current,
and the circuit being measured needs calibration to
measure and/or nullify all other capacitance other than
that to be measured.
26.3.1 CURRENT SOURCE CALIBRATION
The current source on board the CTMU module has a
range of ±62% nominal for each of three current
ranges. Therefore, for precise measurements, it is pos-
sible to measure and adjust this current source by
placing a high-precision resistor, RCAL, onto an unused
analog channel. An example circuit is shown in
Figure 26-2. The current source measurement is
performed using the following steps:
1. Initialize the A/D Converter.
2. Initialize the CTMU.
3. Enable the current source by setting EDG1STAT
(CTMUCONL<0>).
4. Issue a time delay for voltage across RCAL to
stabilize and the ADC sample/hold capacitor to
charge.
5. Perform A/D conversion.
6. Calculate the effective source current using
I=V/R
CAL, where RCAL is a high-precision
resistance and V is measured by performing an
A/D conversion.
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DS39931D-page 404 2011 Microchip Technology Inc.
The CTMU current source may be trimmed with the
trim bits in CTMUICON, using an iterative process to
get an exact desired current. Alternatively, the nominal
value without adjustment may be used; it may be
stored by the software for use in all subsequent
capacitive or time measurements.
To calculate the optimal value for RCAL, the nominal cur-
rent must be chosen. For example, if the A/D Converter
reference voltage is 3.3V, use 70% of full scale, or
2.31V as the desired approximate voltage to be read by
the A/D Converter. If the range of the CTMU current
source is selected to be 0.55 A, the resistor value
needed is calculated as RCAL = 2.31V/0.55 A, for a
value of 4.2 M. Similarly, if the current source is cho-
sen to be 5.5 A, RCAL would be 420,000 and
42,000 if the current source is set to 55 A.
FIGURE 26-2: CTMU CURRENT SOURCE
CALIBRATION CIRCUIT
A value of 70% of full-scale voltage is chosen to make
sure that the A/D Converter is in a range that is well
above the noise floor. Keep in mind that if an exact cur-
rent is chosen that is to incorporate the trimming bits
from CTMUICON, the resistor value of RCAL may need
to be adjusted accordingly. RCAL may also be adjusted
to allow for available resistor values. RCAL should be of
the highest precision available, keeping in mind the
amount of precision needed for the circuit that the
CTMU will be used to measure. A recommended
minimum would be 0.1% tolerance.
The following examples show one typical method for
performing a CTMU current calibration. Example 26-1
demonstrates how to initialize the A/D Converter and
the CTMU. This routine is typical for applications using
both modules. Example 26-2 demonstrates one
method for the actual calibration routine.
PIC18F46J50 Device
A/D Converter
CTMU
ANx
RCAL
Current Source
MUX
A/D
2011 Microchip Technology Inc. DS39931D-page 405
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EXAMPLE 26-1: SETUP FOR CTMU CALIBRATION ROUTINES
#include <p18cxxx.h>
/**************************************************************************/
/*Setup CTMU *****************************************************************/
/**************************************************************************/
void setup(void)
{ //CTMUCON - CTMU Control register
CTMUCONH = 0x00; //make sure CTMU is disabled
CTMUCONL = 0x90;
//CTMU continues to run when emulator is stopped,CTMU continues
//to run in idle mode,Time Generation mode disabled, Edges are blocked
//No edge sequence order, Analog current source not grounded
//Edge2 polarity = positive level, Edge2 source =
//source 0, Edge1 polarity = positive level, Edge1 source = source 0,
//CTMUICON - CTMU Current Control Register
CTMUICON = 0x01; //0.55uA, Nominal - No Adjustment
/**************************************************************************/
//Setup AD converter;
/**************************************************************************/
TRISA=0x04; //set channel 2 as an input
// Configured AN2 as an analog channel
// ANCON0
ANCON0 = 0xFB;
// ANCON1
ANCON1 = 0x1F;
// ADCON1
ADCON1bits.ADFM=1; // Result format 1= Right justified
ADCON1bits.ADCAL=0; // Normal A/D conversion operation
ADCON1bits.ACQT=1; // Acquisition time 7 = 20TAD 2 = 4TAD 1=2TAD
ADCON1bits.ADCS=2; // Clock conversion bits 6= FOSC/64 2=FOSC/32
ANCON1bits.VBGEN=1; // Turn on the Bandgap (if not already on)
// ADCON0
ADCON0bits.VCFG0 =0; // Vref+ = AVdd
ADCON0bits.VCFG1 =0; // Vref- = AVss
ADCON0bits.CHS=2; // Select ADC channel
ADCON0bits.ADON=1; // Turn on ADC
}
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DS39931D-page 406 2011 Microchip Technology Inc.
EXAMPLE 26-2: CURRENT CALIBRATION ROUTINE
#include <p18cxxx.h>
#define COUNT 500 //@ 8MHz = 125uS.
#define DELAY for(i=0;i<COUNT;i++)
#define RCAL .027 //R value is 4200000 (4.2M)
//scaled so that result is in
//1/100th of uA
#define ADSCALE 1023 //for unsigned conversion 10 sig bits
#define ADREF 3.3 //Vdd connected to A/D Vr+
void main(void)
{
int i;
int j = 0; //index for loop
unsigned int Vread = 0;
double VTot = 0;
float Vavg=0, Vcal=0, CTMUISrc = 0; //float values stored for calcs
//assume CTMU and A/D have been setup correctly
//see Example 25-1 for CTMU & A/D setup
setup();
CTMUCONHbits.CTMUEN = 1; //Enable the CTMU
CTMUCONLbits.EDG1STAT = 0; //Set Edge status bits to zero
CTMUCONLbits.EDG2STAT = 0;
for(j=0;j<10;j++)
{ CTMUCONHbits.IDISSEN = 1; //drain charge on the circuit
DELAY; //wait 125us
CTMUCONHbits.IDISSEN = 0; //end drain of circuit
CTMUCONLbits.EDG1STAT = 1; //Begin charging the circuit
//using CTMU current source
DELAY; //wait for 125us
CTMUCONLbits.EDG1STAT = 0; //Stop charging circuit
PIR1bits.ADIF = 0; //make sure A/D Int not set
ADCON0bits.GO=1; //and begin A/D conv.
while(!PIR1bits.ADIF); //Wait for A/D convert complete
Vread = ADRES; //Get the value from the A/D
PIR1bits.ADIF = 0; //Clear A/D Interrupt Flag
VTot += Vread; //Add the reading to the total
}
Vavg = (float)(VTot/10.000); //Average of 10 readings
Vcal = (float)(Vavg/ADSCALE*ADREF);
CTMUISrc = Vcal/RCAL; //CTMUISrc is in 1/100ths of uA
}
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26.3.2 CAPACITANCE CALIBRATION
There is a small amount of capacitance from the inter-
nal A/D Converter sample capacitor as well as stray
capacitance from the circuit board traces and pads that
affect the precision of capacitance measurements. A
measurement of the stray capacitance can be taken by
making sure the desired capacitance to be measured
has been removed. The measurement is then
performed using the following steps:
1. Initialize the A/D Converter and the CTMU.
2. Set EDG1STAT (= 1).
3. Wait for a fixed delay of time, t.
4. Clear EDG1STAT.
5. Perform an A/D conversion.
6. Calculate the stray and A/D sample capacitances:
where I is known from the current source measurement
step, t is a fixed delay and V is measured by performing
an A/D conversion.
This measured value is then stored and used for
calculations of time measurement or subtracted for
capacitance measurement. For calibration, it is
expected that the capacitance of CSTRAY +CAD is
approximately known; CAD is approximately 4 pF.
An iterative process may need to be used to adjust the
time, t, that the circuit is charged to obtain a reasonable
voltage reading from the A/D Converter. The value of t
may be determined by setting COFFSET to a theoretical
value, then solving for t. For example, if CSTRAY is
theoretically calculated to be 11 pF, and V is expected
to be 70% of VDD, or 2.31V, then t would be
or 63 s.
See Example 26-3 for a typical routine for CTMU
capacitance calibration.
COFFSET CSTRAY CAD
+ItV==
(4 pF + 11 pF) • 2.31V/0.55 mA
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DS39931D-page 408 2011 Microchip Technology Inc.
EXAMPLE 26-3: CAPACITANCE CALIBRATION ROUTINE
#include <p18cxxx.h>
#define COUNT 25 //@ 8MHz INTFRC = 62.5 us.
#define ETIME COUNT*2.5 //time in uS
#define DELAY for(i=0;i<COUNT;i++)
#define ADSCALE 1023 //for unsigned conversion 10 sig bits
#define ADREF 3.3 //Vdd connected to A/D Vr+
#define RCAL .027 //R value is 4200000 (4.2M)
//scaled so that result is in
//1/100th of uA
void main(void)
{
int i;
int j = 0; //index for loop
unsigned int Vread = 0;
float CTMUISrc, CTMUCap, Vavg, VTot, Vcal;
//assume CTMU and A/D have been setup correctly
//see Example 25-1 for CTMU & A/D setup
setup();
CTMUCONHbits.CTMUEN = 1; // Enable the CTMU
CTMUCONLbits.EDG1STAT = 0; // Set Edge status bits to zero
CTMUCONLbits.EDG2STAT = 0;
for(j=0;j<10;j++)
{
CTMUCONHbits.IDISSEN = 1; //drain charge on the circuit
DELAY; //wait 125us
CTMUCONHbits.IDISSEN = 0; //end drain of circuit
CTMUCONLbits.EDG1STAT = 1; //Begin charging the circuit
//using CTMU current source
DELAY; //wait for 125us
CTMUCONLbits.EDG1STAT = 0; //Stop charging circuit
PIR1bits.ADIF = 0; //make sure A/D Int not set
ADCON0bits.GO=1; //and begin A/D conv.
while(!PIR1bits.ADIF); //Wait for A/D convert complete
Vread = ADRES; //Get the value from the A/D
PIR1bits.ADIF = 0; //Clear A/D Interrupt Flag
VTot += Vread; //Add the reading to the total
}
Vavg = (float)(VTot/10.000); //Average of 10 readings
Vcal = (float)(Vavg/ADSCALE*ADREF);
CTMUISrc = Vcal/RCAL; //CTMUISrc is in 1/100ths of uA
CTMUCap = (CTMUISrc*ETIME/Vcal)/100;
}
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26.4 Measuring Capacitance with the
CTMU
There are two separate methods of measuring capaci-
tance with the CTMU. The first is the absolute method,
in which the actual capacitance value is desired. The
second is the relative method, in which the actual
capacitance is not needed, rather an indication of a
change in capacitance is required.
26.4.1 ABSOLUTE CAPACITANCE
MEASUREMENT
For absolute capacitance measurements, both the
current and capacitance calibration steps found in
Section 26.3 “Calibrating the CTMU Module”
should be followed. Capacitance measurements are
then performed using the following steps:
1. Initialize the A/D Converter.
2. Initialize the CTMU.
3. Set EDG1STAT.
4. Wait for a fixed delay, T.
5. Clear EDG1STAT.
6. Perform an A/D conversion.
7. Calculate the total capacitance, CTOTAL = (I * T)/V,
where I is known from the current source
measurement step (see Section 26.3.1 “Current
Sourc e Calibrat ion”), T is a fixed delay and V is
measured by performing an A/D conversion.
8. Subtract the stray and A/D capacitance
(COFFSET from Section 26.3.2 “Capacitance
Calibration”) from CTOTAL to determine the
measured capacitance.
26.4.2 RELATIVE CHARGE
MEASUREMENT
An application may not require precise capacitance
measurements. For example, when detecting a valid
press of a capacitance-based switch, detecting a rela-
tive change of capacitance is of interest. In this type of
application, when the switch is open (or not touched),
the total capacitance is the capacitance of the combina-
tion of the board traces, the A/D Converter, etc. A larger
voltage will be measured by the A/D Converter. When
the switch is closed (or is touched), the total
capacitance is larger due to the addition of the
capacitance of the human body to the above listed
capacitances, and a smaller voltage will be measured
by the A/D Converter.
Detecting capacitance changes is easily accomplished
with the CTMU using these steps:
1. Initialize the A/D Converter and the CTMU.
2. Set EDG1STAT.
3. Wait for a fixed delay.
4. Clear EDG1STAT.
5. Perform an A/D conversion.
The voltage measured by performing the A/D conver-
sion is an indication of the relative capacitance. Note
that in this case, no calibration of the current source or
circuit capacitance measurement is needed. See
Example 26-4 for a sample software routine for a
capacitive touch switch.
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DS39931D-page 410 2011 Microchip Technology Inc.
EXAMPLE 26-4: ROUTINE FOR CAPACITIVE TOUCH SWITCH
#include <p18cxxx.h>
#define COUNT 500 //@ 8MHz = 125uS.
#define DELAY for(i=0;i<COUNT;i++)
#define OPENSW 1000 //Un-pressed switch value
#define TRIP 300 //Difference between pressed
//and un-pressed switch
#define HYST 65 //amount to change
//from pressed to un-pressed
#define PRESSED 1
#define UNPRESSED 0
void main(void)
{
unsigned int Vread; //storage for reading
unsigned int switchState;
int i;
//assume CTMU and A/D have been setup correctly
//see Example 25-1 for CTMU & A/D setup
setup();
CTMUCONHbits.CTMUEN = 1; // Enable the CTMU
CTMUCONLbits.EDG1STAT = 0; // Set Edge status bits to zero
CTMUCONLbits.EDG2STAT = 0;
CTMUCONHbits.IDISSEN = 1; //drain charge on the circuit
DELAY; //wait 125us
CTMUCONHbits.IDISSEN = 0; //end drain of circuit
CTMUCONLbits.EDG1STAT = 1; //Begin charging the circuit
//using CTMU current source
DELAY; //wait for 125us
CTMUCONLbits.EDG1STAT = 0; //Stop charging circuit
PIR1bits.ADIF = 0; //make sure A/D Int not set
ADCON0bits.GO=1; //and begin A/D conv.
while(!PIR1bits.ADIF); //Wait for A/D convert complete
Vread = ADRES; //Get the value from the A/D
if(Vread < OPENSW - TRIP)
{
switchState = PRESSED;
}
else if(Vread > OPENSW - TRIP + HYST)
{
switchState = UNPRESSED;
}
}
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26.5 Measuring Time with the CTMU
Module
Time can be precisely measured after the ratio (C/I) is
measured from the current and capacitance calibration
step by following these steps:
1. Initialize the A/D Converter and the CTMU.
2. Set EDG1STAT.
3. Set EDG2STAT.
4. Perform an A/D conversion.
5. Calculate the time between edges as T = (C/I) * V,
where I is calculated in the current calibration step
(Section 26.3.1 “Current Source Calibration”),
C is calculated in the capacitance calibration step
(S ection 26.3.2 “Cap acit ance Calib ration”) and
V is measured by performing the A/D conversion.
It is assumed that the time measured is small enough
that the capacitance, CAD + CEXT, provides a valid volt-
age to the A/D Converter. For the smallest time
measurement, always set the A/D Channel Select reg-
ister (AD1CHS) to an unused A/D channel; the
corresponding pin which is not connected to any circuit
board trace. This minimizes added stray capacitance,
keeping the total circuit capacitance close to that of the
A/D Converter itself. To measure longer time intervals,
an external capacitor may be connected to an A/D
channel and this channel selected when making a time
measurement.
FIGU RE 26-3 : TYPI CA L C O NN ECT I ON S AN D IN T ERN AL CO NFI G UR AT ION F OR TIME
MEASUREMENT
A/D Converter
CTMU
CTED1
CTED2
ANX
EDG1
EDG2
CAD
Current Source
PIC18F46J50 Device
A/D Voltage
CEXT
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DS39931D-page 412 2011 Microchip Technology Inc.
26.6 Creating a Delay with the CTMU
Module
A unique feature on board the CTMU module is its
ability to generate system clock independent output
pulses, based on an external capacitor value. This is
accomplished using the internal comparator voltage
reference module, Comparator 2 input pin and an
external capacitor. The pulse is output onto the CTPLS
pin. To enable this mode, set the TGEN bit.
See Figure 26-4 for an example circuit. CPULSE is
chosen by the user to determine the output pulse width
on CTPLS. The pulse width is calculated by
T=(CPULSE/I)*V, where I is known from the current
source measurement step (Section 26.3.1 “Current
Source Calibration”) and V is the internal reference
voltage (CVREF).
An example use of this feature is for interfacing with
variable capacitive-based sensors, such as a humidity
sensor. As the humidity varies, the pulse width output
on CTPLS will vary. The CTPLS output pin can be
connected to an input capture pin and the varying pulse
width is measured to determine the humidity in the
application.
Follow these steps to use this feature:
1. Initialize Comparator 2 (with CPOL = 1).
2. Initialize the comparator voltage reference.
3. Initialize the CTMU and enable time delay
generation by setting the TGEN bit.
4. Set EDG1STAT.
5. When CPULSE charges to the value of the voltage
reference trip point, an output pulse is generated
on CTPLS.
FIGURE 26-4: TYPICAL CONNECTIONS AND INTERNAL CONFIGURATION FOR PULSE
DELAY GENERATION
26.7 Operation During Sleep/Idle
Modes
26.7.1 SLEEP MODE AND DEEP SLEEP
MODES
When the device enters any Sleep mode, the CTMU
module current source is always disabled. If the CTMU
is performing an operation that depends on the current
source when Sleep mode is invoked, the operation may
not terminate correctly. Capacitance and time
measurements may return erroneous values.
26.7.2 IDLE MODE
The behavior of the CTMU in Idle mode is determined
by the CTMUSIDL bit (CTMUCONH<5>). If CTMUSIDL
is cleared, the module will continue to operate in Idle
mode. If CTMUSIDL is set, the module’s current source
is disabled when the device enters Idle mode. If the
module is performing an operation when Idle mode is
invoked, in this case, the results will be similar to those
with Sleep mode.
26.8 Effects of a Reset on CTMU
Upon Reset, all registers of the CTMU are cleared. This
leaves the CTMU module disabled, its current source is
turned off and all configuration options return to their
default settings. The module needs to be re-initialized
following any Reset.
If the CTMU is in the process of taking a measurement at
the time of Reset, the measurement will be lost. A partial
charge may exist on the circuit that was being measured,
and should be properly discharged before the CTMU
makes subsequent attempts to make a measurement.
The circuit is discharged by setting and then clearing the
IDISSEN bit (CTMUCONH<1>) while the A/D Converter
is connected to the appropriate channel.
C2
CVREF
CTPLS
PIC18F46J50 Device
Current Source
Comparator
CTMU
CTED1
C2INB
CPULSE
EDG1
2011 Microchip Technology Inc. DS39931D-page 413
PIC18F46J50 FAMILY
26.9 Registers
There are three control registers for the CTMU:
CTMUCONH
CTMUCONL
CTMUICON
The CTMUCONH and CTMUCONL registers
(Register 26-1 and Register 26-2) contain control bits
for configuring the CTMU module edge source selec-
tion, edge source polarity selection, edge sequencing,
A/D trigger, analog circuit capacitor discharge and
enables. The CTMUICON register (Register 26-3) has
bits for selecting the current source range and current
source trim.
REGISTER 26-1: CTMUCONH: CTMU CONTROL REGISTER HIGH (ACCESS FB3h)
R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0
CTMUEN CTMUSIDL TGEN EDGEN EDGSEQEN IDISSEN r
bit 7 bit 0
Legend: r = Reserved bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 CTMUEN: CTMU Enable bit
1 = Module is enabled
0 = Module is disabled
bit 6 Unimplemented: Read as ‘0
bit 5 CTMUSIDL: Stop in Idle Mode bit
1 = Discontinue module operation when device enters Idle mode
0 = Continue module operation in Idle mode
bit 4 TGEN: Time Generation Enable bit
1 = Enables edge delay generation
0 = Disables edge delay generation
bit 3 EDGEN: Edge Enable bit
1 = Edges are not blocked
0 = Edges are blocked
bit 2 EDGSEQEN: Edge Sequence Enable bit
1 = Edge 1 event must occur before Edge 2 event can occur
0 = No edge sequence is needed
bit 1 IDISSEN: Analog Current Source Control bit
1 = Analog current source output is grounded
0 = Analog current source output is not grounded
bit 0 Reserved: Write as0
PIC18F46J50 FAMILY
DS39931D-page 414 2011 Microchip Technology Inc.
REGISTER 26-2: CTMUCONL: CTMU CONTROL REGISTER LOW (ACCESS FB2h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x R/W-x
EDG2POL EDG2SEL1 EDG2SEL0 EDG1POL EDG1SEL1 EDG1SEL0 EDG2STAT EDG1STAT
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 EDG2POL: Edge 2 Polarity Select bit
1 = Edge 2 is programmed for a positive edge response
0 = Edge 2 is programmed for a negative edge response
bit 6-5 EDG2SEL<1:0>: Edge 2 Source Select bits
11 = CTED1 pin
10 = CTED2 pin
01 = ECCP1 Output Compare module
00 = Timer1 module
bit 4 EDG1POL: Edge 1 Polarity Select bit
1 = Edge 1 is programmed for a positive edge response
0 = Edge 1 is programmed for a negative edge response
bit 3-2 EDG1SEL<1:0>: Edge 1 Source Select bits
11 = CTED1 pin
10 = CTED2 pin
01 = ECCP1 Output Compare module
00 = Timer1 module
bit 1 EDG2STAT: Edge 2 Status bit
1 = Edge 2 event has occurred
0 = Edge 2 event has not occurred
bit 0 EDG1STAT: Edge 1 Status bit
1 = Edge 1 event has occurred
0 = Edge 1 event has not occurred
2011 Microchip Technology Inc. DS39931D-page 415
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TABLE 26-1: REGISTERS ASSOCIATED WITH CTMU MODULE
REGISTER 26-3: CTMUICON: CTMU CURRENT CONTROL REGISTER (ACCESS FB1h)
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
ITRIM5 ITRIM4 ITRIM3 ITRIM2 ITRIM1 ITRIM0 IRNG1 IRNG0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-2 ITRIM<5:0>: Current Source Trim bits
011111 = Maximum positive change from nominal current
011110
.
.
.
000001 = Minimum positive change from nominal current
000000 = Nominal current output specified by IRNG<1:0>
111111 = Minimum negative change from nominal current
.
.
.
100010
100001 = Maximum negative change from nominal current
bit 1-0 IRNG<1:0>: Current Source Range Select bits
11 = 100 Base current
10 = 10 Base current
01 = Base current level (0.55 A nominal)
00 = Current source disabled
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset
Values
on Pag e:
CTMUCONH CTMUEN CTMUSIDL TGEN EDGEN EDGSEQEN IDISSEN r71
CTMUCONL EDG2POL EDG2SEL1 EDG2SEL0 EDG1POL EDG1SEL1 EDG1SEL0 EDG2STAT EDG1STAT 71
CTMUICON ITRIM5 ITRIM4 ITRIM3 ITRIM2 ITRIM1 ITRIM0 IRNG1 IRNG0 71
Legend: — = unimplemented, read as 0’, r = reserved bit. Shaded cells are not used during ECCP operation.
PIC18F46J50 FAMILY
DS39931D-page 416 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 417
PIC18F46J50 FAMILY
27.0 SPECIAL FEATURES OF THE
CPU
PIC18F46J50 family devices include several features
intended to maximize reliability and minimize cost
through elimination of external components. These are:
Oscillator Selection
Resets:
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
Interrupts
Watchdog Timer (WDT)
Fail-Safe Clock Monitor (FSCM)
Two-Speed Start-up
Code Protection
In-Circuit Serial Programming (ICSP)
The oscillator can be configured for the application
depending on frequency, power, accuracy and cost. All
of the options are discussed in detail in Section 3.0
“Oscillator Configurations”.
A complete discussion of device Resets and interrupts
is available in previous sections of this data sheet. In
addition to their Power-up and Oscillator Start-up
Timers provided for Resets, the PIC18F46J50 family of
devices has a configurable Watchdog Timer (WDT),
which is controlled in software.
The inclusion of an internal RC oscillator also provides
the additional benefits of a Fail-Safe Clock Monitor
(FSCM) and Two-Speed Start-up. FSCM provides for
background monitoring of the peripheral clock and
automatic switchover in the event of its failure.
Two-Speed Start-up enables code to be executed
almost immediately on start-up, while the primary clock
source completes its start-up delays.
All of these features are enabled and configured by
setting the appropriate Configuration register bits.
27.1 Configuration Bits
The Configuration bits can be programmed to select
various device configurations. The configuration data is
stored in the last four words of Flash program memory;
Figure 6-1 depicts this. The configuration data gets
loaded into the volatile Configuration registers,
CONFIG1L through CONFIG4H, which are readable
and mapped to program memory starting at location,
300000h.
Table 27-2 provides a complete list. A detailed explana-
tion of the various bit functions is provided in
Register 27-1 through Register 27-6.
27.1.1 CONSIDERATIONS FOR
CONFIGURING THE PIC18F46J50
FAMILY DEVICES
Unlike some previous PIC18 microcontrollers, devices of
the PIC18F46J50 family do not use persistent memory
registers to store configuration information. The Configu-
ration registers, CONFIG1L through CONFIG4H, are
implemented as volatile memory.
Immediately after power-up, or after a device Reset,
the microcontroller hardware automatically loads the
CONFIG1L through CONFIG4L registers with configu-
ration data stored in nonvolatile Flash program
memory. The last four words of Flash program memory,
known as the Flash Configuration Words (FCW), are
used to store the configuration data.
Table 27-1 provides the Flash program memory, which
will be loaded into the corresponding Configuration
register.
When creating applications for these devices, users
should always specifically allocate the location of the
FCW for configuration data. This is to make certain that
program code is not stored in this address when the
code is compiled.
The four Most Significant bits (MSb) of the FCW, corre-
sponding to CONFIG1H, CONFIG2H, CONFIG3H and
CONFIG4H, should always be programmed to ‘1111’.
This makes these FCWs appear to be NOP instructions
in the remote event that their locations are ever
executed by accident.
The four MSbs of the CONFIG1H, CONFIG2H,
CONFIG3H and CONFIG4H registers are not imple-
mented, so writing ‘1’s to their corresponding FCW has
no effect on device operation.
To prevent inadvertent configuration changes during
code execution, the Configuration registers,
CONFIG1L through CONFIG4L, are loaded only once
per power-up or Reset cycle. User’s firmware can still
change the configuration by using self-reprogramming
to modify the contents of the FCW.
Modifying the FCW will not change the active contents
being used in the CONFIG1L through CONFIG4H
registers until after the device is reset.
PIC18F46J50 FAMILY
DS39931D-page 418 2011 Microchip Technology Inc.
TABLE 27-1: MAPPING OF THE FLASH CONFIGURATION WORDS TO THE CONFIGURATION
REGISTERS
TABLE 27-2: CONFIGURATION BITS AND DEVICE IDs
Configuration Re gis ter
(Volatile) Configuration Regis ter
Address Flash Configuration Byte Address
CONFIG1L 300000h XXXF8h
CONFIG1H 300001h XXXF9h
CONFIG2L 300002h XXXFAh
CONFIG2H 300003h XXXFBh
CONFIG3L 300004h XXXFCh
CONFIG3H 300005h XXXFDh
CONFIG4L 300006h XXXFEh
CONFIG4H 300007h XXXFFh
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Default/
Unprog.
Value(1)
300000h CONFIG1L DEBUG XINST STVREN PLLDIV2 PLLDIV1 PLLDIV0 WDTEN 111- 1111
300001h CONFIG1H (2) (2) (2) (2) CP0 CPDIV1 CPDIV0 1111 -111
300002h CONFIG2L IESO FCMEN LPT1OSC T1DIG FOSC2 FOSC1 FOSC0 11-1 1111
300003h CONFIG2H (2) (2) (2) (2) WDTPS3 WDTPS2 WDTPS1 WDTPS0 1111 1111
300004h CONFIG3L DSWDTPS3 DSWDTPS2 DSWDTPS1 DSWDTPS0 DSWDTEN DSBOREN RTCOSC DSWDTOSC 1111 1111
300005h CONFIG3H (2) (2) (2) (2) MSSPMSK IOL1WAY 1111 1--1
300006h CONFIG4L WPCFG WPEND WPFP5 WPFP4 WPFP3 WPFP2 WPFP1 WPFP0 1111 1111
300007h CONFIG4H (2) (2) (2) (2) —WPDIS1111 ---1
3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 xxx0 0000(3)
3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0100 00xx(3)
Legend: x = unknown, u = unchanged, — = unimplemented. Shaded cells are unimplemented, read as ‘0’.
Note 1: Values reflect the unprogrammed state as received from the factory and following Power-on Resets. In all other Reset states, the
configuration bytes maintain their previously programmed states.
2: The value of these bits in program memory should always be programmed to ‘1’. This ensures that the location is executed as a NOP if it
is accidentally executed.
3: See Register 27-9 and Register 27-10 for DEVID values. These registers are read-only and cannot be programmed by the user.
2011 Microchip Technology Inc. DS39931D-page 419
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REGISTER 27-1: CONFIG1L: CONFIGURATION REGISTER 1 LOW (BYTE ADDRESS 300000h)
R/WO-1 R/WO-1 R/WO-1 U-0 R/WO-1 R/WO-1 R/WO-1 R/WO-1
DEBUG XINST STVREN PLLDIV2 PLLDIV1 PLLDIV0 WDTEN
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 DEBUG: Background Debugger Enable bit
1 = Background debugger is disabled; RB6 and RB7 are configured as general purpose I/O pins
0 = Background debugger is enabled; RB6 and RB7 are dedicated to In-Circuit Debug
bit 6 XINST: Extended Instruction Set Enable bit
1 = Instruction set extension and Indexed Addressing mode are enabled
0 = Instruction set extension and Indexed Addressing mode are disabled
bit 5 STVREN: Stack Overflow/Underflow Reset Enable bit
1 = Reset on stack overflow/underflow is enabled
0 = Reset on stack overflow/underflow is disabled
bit 4 Unimplemented: Read as ‘0
bit 3-1 PLLDIV<2:0>: Oscillator Selection bits
Divider must be selected to provide a 4 MHz input into the 96 MHz PLL.
111 = No divide – oscillator used directly (4 MHz input)
110 = Oscillator divided by 2 (8 MHz input)
101 = Oscillator divided by 3 (12 MHz input)
100 = Oscillator divided by 4 (16 MHz input)
011 = Oscillator divided by 5 (20 MHz input)
010 = Oscillator divided by 6 (24 MHz input)
001 = Oscillator divided by 10 (40 MHz input)
000 = Oscillator divided by 12 (48 MHz input)
bit 0 WDTEN: Watchdog Timer Enable bit
1 = WDT is enabled
0 = WDT is disabled (control is placed on SWDTEN bit)
PIC18F46J50 FAMILY
DS39931D-page 420 2011 Microchip Technology Inc.
REGISTER 27-2: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
U-1 U-1 U-1 U-1 U-0 R/WO-1 R/WO-1 R/WO-1
CP0 CPDIV1 CPDIV0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 Unimplemented: Program the corresponding Flash Configuration bit to ‘1
bit 3 Unimplemented: Maintain as ‘0
bit 2 CP0: Code Protection bit
1 = Program memory is not code-protected
0 = Program memory is code-protected
bit 1-0 CPDIV<1:0>: CPU System Clock Selection bits
11 = No CPU system clock divide
10 = CPU system clock is divided by 2
01 = CPU system clock is divided by 3
00 = CPU system clock is divided by 6
2011 Microchip Technology Inc. DS39931D-page 421
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REGISTER 27-3: CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h)
R/WO-1 R/WO-1 U-0 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1
IESO FCMEN LPT1OSC T1DIG FOSC2 FOSC1 FOSC0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 IESO: Two-Speed Start-up (Internal/External Oscillator Switchover) Control bit
1 = Two-Speed Start-up is enabled
0 = Two-Speed Start-up is disabled
bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit
1 = Fail-Safe Clock Monitor is enabled
0 = Fail-Safe Clock Monitor is disabled
bit 5 Unimplemented: Read as ‘0
bit 4 LPT1OSC: Low-Power Timer1 Oscillator Enable bit
1 = Timer1 oscillator is configured for high-power operation
0 = Timer1 oscillator is configured for low-power operation
bit 3 T1DIG: Secondary Clock Source T1OSCEN Enforcement bit
1 = Secondary oscillator clock source may be selected (OSCCON<1:0> = 01) regardless of the
(T1CON<3>) T1OSCEN state
0 = Secondary oscillator clock source may not be selected unless T1CON<3> = 1
bit 2-0 FOSC<2:0>: Oscillator Selection bits
111 = ECPLL oscillator with PLL software controlled, CLKO on RA6
110 = EC oscillator with CLKO on RA6
101 = HSPLL oscillator with PLL software controlled
100 = HS oscillator
011 = INTOSCPLLO, internal oscillator with PLL software controlled, CLKO on RA6, port function on
RA7
010 = INTOSCPLL, internal oscillator with PLL software controlled, port function on RA6 and RA7
001 = INTOSCO internal oscillator block (INTRC/INTOSC) with CLKO on RA6, port function on RA7
000 = INTOSC internal oscillator block (INTRC/INTOSC), port function on RA6 and RA7
PIC18F46J50 FAMILY
DS39931D-page 422 2011 Microchip Technology Inc.
REGISTER 27-4: CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h)
U-1 U-1 U-1 U-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1
WDTPS3 WDTPS2 WDTPS1 WDTPS0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 Unimplemented: Program the corresponding Flash Configuration bit to ‘1
bit 3-0 WDTPS<3:0>: Watchdog Timer Postscale Select bits
1111 = 1:32,768
1110 = 1:16,384
1101 = 1:8,192
1100 = 1:4,096
1011 = 1:2,048
1010 = 1:1,024
1001 = 1:512
1000 = 1:256
0111 = 1:128
0110 = 1:64
0101 = 1:32
0100 = 1:16
0011 = 1:8
0010 = 1:4
0001 = 1:2
0000 = 1:1
2011 Microchip Technology Inc. DS39931D-page 423
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REGISTER 27-5: CONFIG3L: CONFIGURATION REGISTER 3 LOW (BYTE ADDRESS 300004h)
R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1
DSWDTPS3(1) DSWDTPS2(1) DSWDTPS1(1) DSWDTPS0(1) DSWDTEN(1) DSBOREN RTCOSC DSWDTOSC(1)
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 DSWDTPS<3:0>: Deep Sleep Watchdog Timer Postscale Select bits(1)
The DSWDT prescaler is 32. This creates an approximate base time unit of 1 ms.
1111 = 1:2,147,483,648 (25.7 days)
1110 = 1:536,870,912 (6.4 days)
1101 = 1:134,217,728 (38.5 hours)
1100 = 1:33,554,432 (9.6 hours)
1011 = 1:8,388,608 (2.4 hours)
1010 = 1:2,097,152 (36 minutes)
1001 = 1:524,288 (9 minutes)
1000 = 1:131,072 (135 seconds)
0111 = 1:32,768 (34 seconds)
0110 = 1:8,192 (8.5 seconds)
0101 = 1:2,048 (2.1 seconds)
0100 = 1:512 (528 ms)
0011 = 1:128 (132 ms)
0010 = 1:32 (33 ms)
0001 = 1:8 (8.3 ms)
0000 = 1:2 (2.1 ms)
bit 3 DSWDTEN: Deep Sleep Watchdog Timer Enable bit(1)
1 = DSWDT is enabled
0 = DSWDT is disabled
bit 2 DSBOREN: “F” Device Deep Sleep BOR Enable bit, “LF” Device VDD BOR Enable bit
For “F” Devices:
1 = VDD sensing BOR is enabled in Deep Sleep
0 = VDD sensing BOR circuit is always disabled
For “LF” Devices:
1 = VDD sensing BOR circuit is always enabled
0 = VDD sensing BOR circuit is always disabled
bit 1 RTCOSC: RTCC Reference Clock Select bit
1 = RTCC uses T1OSC/T1CKI as reference clock
0 = RTCC uses INTRC as reference clock
bit 0 DSWDTOSC: DSWDT Reference Clock Select bit(1)
1 = DSWDT uses INTRC as reference clock
0 = DSWDT uses T1OSC/T1CKI as reference clock
Note 1: These functions are not available on “LF” devices.
PIC18F46J50 FAMILY
DS39931D-page 424 2011 Microchip Technology Inc.
REGISTER 27-6: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h)
U-1 U-1 U-1 U-1 R/WO-1 U-0 U-0 R/WO-1
MSSPMSK —IOL1WAY
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 Unimplemented: Program the corresponding Flash Configuration bit to ‘1
bit 3 MSSPMSK: MSSP 7-Bit Address Masking Mode Enable bit
1 = 7-Bit Address Masking mode is enabled
0 = 5-Bit Address Masking mode is enabled
bit 2-1 Unimplemented: Read as ‘0
bit 0 IOL1WAY: IOLOCK One-Way Set Enable bit
1 = IOLOCK bit (PPSCON<0>) can be set once, provided the unlock sequence has been completed.
Once set, the Peripheral Pin Select registers cannot be written to a second time.
0 = IOLOCK bit (PPSCON<0>) can be set and cleared as needed, provided the unlock sequence has
been completed
REGISTER 27-7: CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h)
R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1 R/WO-1
WPCFG WPEND WPFP5(2) WPFP4(3) WPFP3 WPFP2 WPFP1 WPFP0
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 WPCFG: Write/Erase Protect Configuration Region Select bit
1 = Configuration Words page is not erase/write-protected unless WPEND and WPFP<5:0> settings
include the Configuration Words page (and WPDIS = 0)(1)
0 = Configuration Words page is erase/write-protected, regardless of WPDIS, WPEND and
WPFP<5:0>(1)
bit 6 WPEND: Write/Erase Protect Region Select bit (valid when WPDIS = 0)
1 = Flash pages, WPFP<5:0> to Configuration Words page, are erase/write-protected
0 = Flash pages, 0 to WPFP<5:0>, are erase/write-protected
bit 5-0 WPFP<5:0>: Write/Erase Protect Page Start/End Location bits
Used with WPEND bit to define which pages in Flash will be erase/write-protected.
Note 1: The “Configuration Words page” contains the FCWs and is the last page of implemented Flash memory on
a given device. Each page consists of 1,024 bytes. For example, on a device with 64 Kbytes of Flash, the
first page is 0 and the last page (Configuration Words page) is 63 (3Fh).
2: Implemented in 64-Kbyte devices (PIC18FX6J50). This bit is reserved on 32-Kbyte and 16-Kbyte devices
(PIC18FX5J50 and PIC18FX4J50) and should always be programmed to ‘0’ for proper operation on these
devices.
3: Implemented in 64-Kbyte and 32-Kbyte devices. This bit is reserved on 16-Kbyte devices (PIC18FX4J50)
and should always be programmed to0’ for proper operation on these devices.
2011 Microchip Technology Inc. DS39931D-page 425
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REGISTER 27-8: CONFIG4H: CONFIGURATION REGISTER 4 HIGH (BYTE ADDRESS 300007h)
U-1 U-1 U-1 U-1 U-0 U-0 U-0 R/WO-1
—WPDIS
bit 7 bit 0
Legend:
R = Readable bit WO = Write-Once bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 Unimplemented: Program the corresponding Flash Configuration bit to ‘1
bit 3-1 Unimplemented: Read as ‘0
bit 0 WPDIS: Write-Protect Disable bit
1 = WPFP<5:0> and WPEND bits are ignored; the specified region is not erase/write-protected
0 = WPFP<5:0> and WPEND bits are enabled; erase/write-protect is active for the selected region
REGISTER 27-9: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F46J50 FAMILY DEVICES
(BYTE ADDRESS 3FFFFEh)
RRRRRRRR
DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-5 DEV<2:0>: Device ID bits
These bits are used with the DEV<10:3> bits in Device ID Register 2 to identify the part number. See
Register 27-10.
bit 4-0 REV<4:0>: Revision ID bits
These bits are used to indicate the device revision.
PIC18F46J50 FAMILY
DS39931D-page 426 2011 Microchip Technology Inc.
REGISTER 27-10: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F46J50 FAMILY DEVICES
(BYTE ADDRESS 3FFFFFh)
RRRRRRRR
DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-0 DEV<10:3>: Device ID bits
These bits are used with the DEV<2:0> bits in the Device ID Register 1 to identify the part number.
2011 Microchip Technology Inc. DS39931D-page 427
PIC18F46J50 FAMILY
27.2 Watchdog Timer (WDT)
PIC18F46J50 family devices have both a conventional
WDT circuit and a dedicated, Deep Sleep capable
Watchdog Timer. When enabled, the conventional
WDT operates in normal Run, Idle and Sleep modes.
This data sheet section describes the conventional
WDT circuit.
The dedicated, Deep Sleep capable WDT can only be
enabled in Deep Sleep mode. This timer is described in
Section 4.6.4 “Deep Sleep Watchdog Timer
(DSWDT)”.
The conventional WDT is driven by the INTRC oscilla-
tor. When the WDT is enabled, the clock source is also
enabled. The nominal WDT period is 4 ms and has the
same stability as the INTRC oscillator.
The 4 ms period of the WDT is multiplied by a 16-bit
postscaler. Any output of the WDT postscaler is
selected by a multiplexer, controlled by the WDTPS bits
in Configuration Register 2H. Available periods range
from about 4 ms to 135 seconds (2.25 minutes
depending on voltage, temperature and WDT
postscaler). The WDT and postscaler are cleared
whenever a SLEEP or CLRWDT instruction is executed,
or a clock failure (primary or Timer1 oscillator) has
occurred.
27.2.1 CONTROL REGISTER
The WDTCON register (Register 27-11) is a readable
and writable register. The SWDTEN bit enables or dis-
ables WDT operation. This allows software to override
the WDTEN Configuration bit and enable the WDT only
if it has been disabled by the Configuration bit.
LVDSTAT is a read-only status bit that is continuously
updated and provides information about the current
level of VDDCORE. This bit is only valid when the on-chip
voltage regulator is enabled.
FIGU RE 27-1 : WD T B LOC K DI AG R AM
Note 1: The CLRWDT and SLEEP instructions
clear the WDT and postscaler counts
when executed.
2: When a CLRWDT instruction is executed,
the postscaler count will be cleared.
INTRC Oscillator
WDT
Wake-up from
Reset
WDT
WDT Counter
Programmable Postscaler
1:1 to 1:32,768
Enable WDT
WDTPS<3:0>
SWDTEN
CLRWDT
4
Power-Managed
Reset
All Device Resets
Sleep
INTRC Control
128
Modes
PIC18F46J50 FAMILY
DS39931D-page 428 2011 Microchip Technology Inc.
TABLE 27-3: SUMMARY OF WATCHDOG TIMER REGISTERS
REGISTER 27-11: WDTCON: WATCHDOG TIMER CONTROL REGISTER (ACCESS FC0h)
R/W-1 R-x R-x U-0 R-q R/W-0 R/W-0 R/W-0
REGSLP LVDSTAT(2) ULPLVL DS ULPEN ULPSINK SWDTEN(1)
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as 0 q = Depends on condition
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 REGSLP: Voltage Regulator Low-Power Operation Enable bit
1 = On-chip regulator enters low-power operation when device enters Sleep mode
0 = On-chip regulator is active even in Sleep mode
bit 6 LVDSTAT: Low-Voltage Detect Status bit(2)
1 = VDDCORE > 2.45V nominal
0 = VDDCORE < 2.45V nominal
bit 5 ULPLVL: Ultra Low-Power Wake-up Output bit (not valid unless ULPEN = 1)
1 = Voltage on RA0 > ~0.5V
0 = Voltage on RA0 < ~0.5V
bit 4 Unimplemented: Read as ‘0
bit 3 DS: Deep Sleep Wake-up Status bit (used in conjunction with RCON, POR and BOR bits to determine
Reset source)(2)
1 = If the last exit from Reset was caused by a normal wake-up from Deep Sleep
0 = If the last exit from Reset was not due to a wake-up from Deep Sleep
bit 2 ULPEN: Ultra Low-Power Wake-up Module Enable bit
1 = Ultra Low-Power Wake-up module is enabled; ULPLVL bit indicates the comparator output
0 = Ultra Low-Power Wake-up module is disabled
bit 1 ULPSINK: Ultra Low-Power Wake-up Current Sink Enable bit
1 = Ultra Low-Power Wake-up current sink is enabled
0 = Ultra Low-Power Wake-up current sink is disabled
bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit(1)
1 = Watchdog Timer is on
0 = Watchdog Timer is off
Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled.
2: Not available on devices where the on-chip voltage regulator is disabled (“LF” devices).
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values
on Page:
RCON IPEN CM RI TO PD POR BOR 70
WDTCON REGSLP LVDSTAT ULPLVL DS ULPEN ULPSINK SWDTEN 70
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.
2011 Microchip Technology Inc. DS39931D-page 429
PIC18F46J50 FAMILY
27.3 On-Chip Voltage Regulator
The digital core logic of the PIC18F46J50 family
devices is designed on an advanced manufacturing
process, which requires 2.0V to 2.7V. The digital core
logic obtains power from the VDDCORE/VCAP power
supply pin.
However, in many applications it may be inconvenient
to run the I/O pins at the same core logic voltage, as it
would restrict the ability of the device to interface with
other, higher voltage devices, such as those run at a
nominal 3.3V. Therefore, all PIC18F46J50 family
devices implement a dual power supply rail topology.
The core logic obtains power from the VDDCORE/VCAP
pin, while the general purpose I/O pins obtain power
from the VDD pin of the microcontroller, which may be
supplied with a voltage between 2.15V to 3.6V (“F”
device) or 2.0V to 3.6V (“LF” device).
This dual supply topology allows the microcontroller to
interface with standard 3.3V logic devices, while
running the core logic at a lower voltage of nominally
2.5V.
In order to make the microcontroller more convenient to
use, an integrated 2.5V low dropout, low quiescent
current linear regulator has been integrated on the die
inside PIC18F46J50 family devices. This regulator is
designed specifically to supply the core logic of the
device. It allows PIC18F46J50 family devices to
effectively run from a single power supply rail, without
the need for external regulators.
The on-chip voltage regulator is always enabled on “F”
devices. The VDDCORE/VCAP pin serves simultaneously
as the regulator output pin and the core logic supply
power input pin. A capacitor should be connected to the
VDDCORE/VCAP pin to ground and is necessary for regu-
lator stability. For example connections for PIC18F and
PIC18LF devices, see Figure 27-2.
On “LF” devices, the on-chip regulator is always
disabled. This allows the device to save a small amount
of quiescent current consumption, which may be
advantageous in some types of applications, such as
those which will entirely be running at a nominal 2.5V.
On “LF” devices, the VDDCORE/VCAP pin still serves as
the core logic power supply input pin, and therefore,
must be connected to a 2.0V to 2.7V supply rail at the
application circuit board level. On these devices, the
I/O pins may still optionally be supplied with a voltage
between 2.0V to 3.6V, provided that VDD is always
greater than, or equal to, VDDCORE/VCAP. For example
connections for PIC18F and PIC18LF devices, see
Figure 27-2.
The specifications for core voltage and capacitance
are listed in Section 30.3 “DC Characteristics:
PIC18F46J50 Fami ly (Industria l)”.
27.3.1 VOLTAGE REGULATOR TRACKING
MODE AND LOW-VOLTAGE
DETECTION
When it is enabled, the on-chip regulator provides a con-
stant voltage of 2.5V nominal to the digital core logic.
The regulator can provide this level from a VDD of about
2.5V, all the way up to the device’s VDDMAX. It does not
have the capability to boost VDD levels below 2.5V.
When the VDD supply input voltage drops too low to
regulate 2.5V, the regulator enters Tracking mode. In
Tracking mode, the regulator output follows VDD, with a
typical voltage drop of 100 mV or less.
The on-chip regulator includes a simple Low-Voltage
Detect (LVD) circuit. This circuit is separate and
independent of the High/Low-Voltage Detect (HLVD)
module described in Se ction 25.0 “High/Lo w Voltag e
Detect (HL VD)”. The on-chip regulator LVD circuit con-
tinuously monitors the VDDCORE voltage level and
updates the LVDSTAT bit in the WDTCON register. The
LVD detect threshold is set slightly below the normal
regulation set point of the on-chip regulator.
Application firmware may optionally poll the LVDSTAT
bit to determine when it is safe to run at maximum rated
frequency, so as not to inadvertently violate the voltage
versus frequency requirements provided by
Figure 30-1.
The VDDCORE monitoring LVD circuit is only active
when the on-chip regulator is enabled. On “LF”
devices, the Analog-to-Digital Converter and the HLVD
module can still be used to provide firmware with VDD
and VDDCORE voltage level information.
Note 1: The on-chip voltage regulator is only
available on parts designated with an “F”,
such as PIC18F25J50. The on-chip
regulator is disabled on devices with “LF”
in their part number.
2: The VDDCORE/VCAP pin must never be left
floating. On “F” devices, it must be con-
nected to a capacitor, of size, CEFC, to
ground. On “LF” devices, VDDCORE/VCAP
must be connected to a power supply
source between 2.0V and 2.7V. Note: In parts designated with an “LF”, such as
PIC18LF46J50, VDDCORE must never
exceed VDD.
PIC18F46J50 FAMILY
DS39931D-page 430 2011 Microchip Technology Inc.
FIGURE 27-2: CONNECTIONS FOR THE
ON-CHIP REGULATOR 27.3.2 ON-CHIP REGULATOR AND BOR
When the on-chip regulator is enabled, PIC18F46J50
family devices also have a simple brown-out capability.
If the voltage supplied to the regulator is inadequate to
maintain a minimum output level; the regulator Reset
circuitry will generate a Brown-out Reset (BOR). This
event is captured by the BOR flag bit (RCON<0>).
The operation of the BOR is described in more detail in
Section 5.4 “Brown-out Reset (BOR)” and
Section 5.4.1 “Detecting BOR”. The brown-out voltage
levels are specific in Section 30.1 “DC Characteristics:
Supply Voltage PIC18F 46 J5 0 F am ily (Industri al)” .
27.3.3 POWER-UP REQUIREMENTS
The on-chip regulator is designed to meet the power-up
requirements for the device. If the application does not
use the regulator, then strict power-up conditions must
be adhered to. While powering up, VDDCORE should not
exceed VDD by 0.3 volts.
27.3.4 OPERATION IN SLEEP MODE
When enabled, the on-chip regulator always consumes
a small incremental amount of current over IDD. This
includes when the device is in Sleep mode, even
though the core digital logic does not require much
power. To provide additional savings in applications
where power resources are critical, the regulator can
be configured to automatically enter a lower quiescent
draw Standby mode whenever the device goes into
Sleep mode. This feature is controlled by the REGSLP
bit (WDTCON<7>, Register 27-11). If this bit is set
upon entry into Sleep mode, the regulator will transition
into a lower power state. In this state, the regulator still
provides a regulated output voltage necessary to
maintain SRAM state information, but consumes less
quiescent current.
Substantial Sleep mode power savings can be
obtained by setting the REGSLP bit, but device
wake-up time will increase in order to insure the
regulator has enough time to stabilize.
VDD
VDDCORE/VCAP
VSS
PIC18LFXXJ50
3.3V
2.5V
VDD
VDDCORE/VCAP
VSS
CF
3.3V
Or
VDD
VDDCORE/VCAP
VSS
2.5V
PIC18FXXJ50 Devices (Regu lator Enabled ):
PIC18LFXXJ50 Devices (Regulator Disabled):
PIC18FXXJ50
PIC18LFXXJ50
2011 Microchip Technology Inc. DS39931D-page 431
PIC18F46J50 FAMILY
27.4 Two-Speed S tart-up
The Two-Speed Start-up feature helps to minimize the
latency period, from oscillator start-up to code execu-
tion, by allowing the microcontroller to use the INTRC
oscillator as a clock source until the primary clock
source is available. It is enabled by setting the IESO
Configuration bit.
Two-Speed Start-up should be enabled only if the
primary oscillator mode is HS or HSPLL
(Crystal-Based) modes. Since the EC and ECPLL
modes do not require an Oscillator Start-up Timer
(OST) delay, Two-Speed Start-up should be disabled.
When enabled, Resets and wake-ups from Sleep mode
cause the device to configure itself to run from the inter-
nal oscillator block as the clock source, following the
time-out of the Power-up Timer after a Power-on Reset
is enabled. This allows almost immediate code
execution while the primary oscillator starts and the
OST is running. Once the OST times out, the device
automatically switches to PRI_RUN mode.
In all other power-managed modes, Two-Speed
Start-up is not used. The device will be clocked by the
currently selected clock source until the primary clock
source becomes available. The setting of the IESO bit
is ignored.
FIGURE 27-3: TIMING TRANSITION FOR TWO-SPEED START-UP (INTRC TO HSPLL)
27.4.1 SPECIAL CONSIDERATIONS FOR
USING TWO-SPEED START-UP
While using the INTRC oscillator in Two-Speed
Start-up, the device still obeys the normal command
sequences for entering power-managed modes,
including serial SLEEP instructions (refer to
Section 4.1.4 “Multiple Sleep Commands”). In
practice, this means that user code can change the
SCS<1:0> bit settings or issue SLEEP instructions
before the OST times out. This would allow an applica-
tion to briefly wake-up, perform routine “housekeeping”
tasks and return to Sleep before the device starts to
operate from the primary oscillator.
User code can also check if the primary clock source is
currently providing the device clocking by checking the
status of the OSTS bit (OSCCON<3>). If the bit is set,
the primary oscillator is providing the clock. Otherwise,
the internal oscillator block is providing the clock during
wake-up from Reset or Sleep mode.
27.5 Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the micro-
controller to continue operation in the event of an
external oscillator failure by automatically switching the
device clock to the internal oscillator block. The FSCM
function is enabled by setting the FCMEN
Configuration bit.
When FSCM is enabled, the INTRC oscillator runs at
all times to monitor clocks to peripherals and provide a
backup clock in the event of a clock failure. Clock
monitoring (shown in Figure 27-4) is accomplished by
creating a sample clock signal, which is the INTRC out-
put divided by 64. This allows ample time between
FSCM sample clocks for a peripheral clock edge to
occur. The peripheral device clock and the sample
clock are presented as inputs to the clock monitor latch.
The clock monitor is set on the falling edge of the
device clock source but cleared on the rising edge of
the sample clock.
Q1 Q3 Q4
OSC1
Peripheral
Program PC PC + 2
INTRC
PLL Clock
Q1
PC + 6
Q2
Output
Q3 Q4 Q1
CPU Clock
PC + 4
Clock
Counter
Q2 Q2 Q3
Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
Wake from Interrupt Event
TPLL(1)
12 n-1n
Clock
OSTS bit Set
Transition
TOST(1)
PIC18F46J50 FAMILY
DS39931D-page 432 2011 Microchip Technology Inc.
FIGURE 27-4: FSCM BLOCK DIAGRAM
Clock failure is tested for on the falling edge of the
sample clock. If a sample clock falling edge occurs
while the clock monitor is still set, and a clock failure
has been detected (Figure 27-5), the following results:
The FSCM generates an oscillator fail interrupt by
setting bit, OSCFIF (PIR2<7>).
The device clock source is switched to the internal
oscillator block (OSCCON is not updated to show
the current clock source – this is the Fail-safe
condition).
•The WDT is reset.
During switchover, the postscaler frequency from the
internal oscillator block may not be sufficiently stable
for timing-sensitive applications. In these cases, it may
be desirable to select another clock configuration and
enter an alternate power-managed mode. This can be
done to attempt a partial recovery or execute a
controlled shutdown. See Section 4.1.4 “Multiple
Sleep Commands” and Section 27.4.1 “Special
Considerations for Using Two-Speed Start-up” for
more details.
The FSCM will detect failures of the primary or secondary
clock sources only. If the internal oscillator block fails, no
failure would be detected, nor would any action be
possible.
27.5.1 FSCM AND THE WATCHDOG TIMER
Both the FSCM and the WDT are clocked by the
INTRC oscillator. Since the WDT operates with a
separate divider and counter, disabling the WDT has
no effect on the operation of the INTRC oscillator when
the FSCM is enabled.
As already noted, the clock source is switched to the
INTRC clock when a clock failure is detected; this may
mean a substantial change in the speed of code execu-
tion. If the WDT is enabled with a small prescale value,
a decrease in clock speed allows a WDT time-out to
occur and a subsequent device Reset. For this reason,
Fail-Safe Clock Monitor events also reset the WDT and
postscaler, allowing it to start timing from when execu-
tion speed was changed and decreasing the likelihood
of an erroneous time-out.
FIGU RE 27-5: FSC M TIMING DI AG R AM
Peripheral
INTRC ÷ 64
S
C
Q
(32 s) 488 Hz
(2.048 ms)
Clock Monitor
Latch
(edge-triggered)
Clock
Failure
Detected
Source
Clock
Q
OSCFIF
Clock Monitor
Device
Clock
Output
Sample Clock
Failure
Detected
Oscillator
Failure
Note: The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in
this example have been chosen for clarity.
Output (Q)
Clock Monitor Test Clock Monitor Test Clock Monitor Test
2011 Microchip Technology Inc. DS39931D-page 433
PIC18F46J50 FAMILY
27.5.2 EXITING FAIL-SAFE OPERATION
The Fail-Safe Clock Monitor condition is terminated by
either a device Reset or by entering a power-managed
mode. On Reset, the controller starts the primary clock
source specified in Configuration Register 2H (with any
required start-up delays that are required for the oscil-
lator mode, such as the OST or PLL timer). The INTRC
oscillator provides the device clock until the primary
clock source becomes ready (similar to a Two-Speed
Start-up). The clock source is then switched to the
primary clock (indicated by the OSTS bit in the
OSCCON register becoming set). The FSCM then
resumes monitoring the peripheral clock.
The primary clock source may never become ready
during start-up. In this case, operation is clocked by the
INTRC oscillator. The OSCCON register will remain in
its Reset state until a power-managed mode is entered.
27.5.3 FSCM INTERRUPTS IN
POWER-MANAGED MODES
By entering a power-managed mode, the clock
multiplexer selects the clock source selected by the
OSCCON register. FSCM of the power-managed clock
source resumes in the power-managed mode.
If an oscillator failure occurs during power-managed
operation, the subsequent events depend on whether
or not the oscillator failure interrupt is enabled. If
enabled (OSCFIF = 1), code execution will be clocked
by the INTRC multiplexer. An automatic transition back
to the failed clock source will not occur.
If the interrupt is disabled, subsequent interrupts while
in Idle mode will cause the CPU to begin executing
instructions while being clocked by the INTRC source.
27.5.4 POR OR WAKE-UP FROM SLEEP
The FSCM is designed to detect oscillator failure at any
point after the device has exited Power-on Reset (POR)
or low-power Sleep mode. When the primary device
clock is either the EC or INTRC modes, monitoring can
begin immediately following these events.
For HS or HSPLL modes, the situation is somewhat
different. Since the oscillator may require a start-up
time considerably longer than the FSCM sample clock
time, a false clock failure may be detected. To prevent
this, the internal oscillator block is automatically config-
ured as the device clock and functions until the primary
clock is stable (the OST and PLL timers have timed
out). This is identical to Two-Speed Start-up mode.
Once the primary clock is stable, the INTRC returns to
its role as the FSCM source.
As noted in Section 27.4.1 “Special Considerations
for Using Two-Speed Start-up”, it is also possible to
select another clock configuration and enter an alternate
power-managed mode while waiting for the primary
clock to become stable. When the new power-managed
mode is selected, the primary clock is disabled.
27.6 Program Verification and Code
Protection
For all devices in the PIC18F46J50 family, the on-chip
program memory space is treated as a single block.
Code protection for this block is controlled by one Con-
figuration bit, CP0. This bit inhibits external reads and
writes to the program memory space. It has no direct
effect in normal execution mode.
27.6.1 CONFIGURATION REGISTER
PROTECTION
The Configuration registers are protected against
untoward changes or reads in two ways. The primary
protection is the write-once feature of the Configuration
bits, which prevents reconfiguration once the bit has
been programmed during a power cycle. To safeguard
against unpredictable events, Configuration bit
changes resulting from individual cell level disruptions
(such as ESD events) will cause a parity error and
trigger a device Reset. This is seen by the user as a
Configuration Mismatch (CM) Reset.
The data for the Configuration registers is derived from
the FCW in program memory. When the CP0 bit is set,
the source data for device configuration is also
protected as a consequence.
Note: The same logic that prevents false
oscillator failure interrupts on POR, or
wake-up from Sleep, will also prevent the
detection of the oscillator’s failure to start
at all following these events. This can be
avoided by monitoring the OSTS bit and
using a timing routine to determine if the
oscillator is taking too long to start. Even
so, no oscillator failure interrupt will be
flagged.
PIC18F46J50 FAMILY
DS39931D-page 434 2011 Microchip Technology Inc.
27.7 In-Circuit Serial Programming
(ICSP)
PIC18F46J50 family microcontrollers can be serially
programmed while in the end application circuit. This is
simply done with two lines for clock and data, and three
other lines for power, ground and the programming
voltage. This allows customers to manufacture boards
with unprogrammed devices and then program the
microcontroller just before shipping the product. This
also allows the most recent firmware or a custom
firmware to be programmed.
27.8 In-Circuit Debugger
When the DEBUG Configuration bit is programmed to
a ‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB® IDE. When the microcontroller has
this feature enabled, some resources are not available
for general use.
Table 27-4 lists the resources required by the
background debugger.
TABLE 27-4: DEBUGGER RESOURCES
I/O pins: RB6, RB7
Stack: TOSx register reserved
2011 Microchip Technology Inc. DS39931D-page 435
PIC18F46J50 FAMILY
28.0 INSTR UCTION SET SUMMARY
The PIC18F46J50 family of devices incorporates the
standard set of 75 PIC18 core instructions, and an
extended set of eight new instructions for the optimiza-
tion of code that is recursive or that utilizes a software
stack. The extended set is discussed later in this
section.
28.1 Standard Instruction Set
The standard PIC18 instruction set adds many
enhancements to the previous PIC® MCU instruction
sets, while maintaining an easy migration from these
PIC MCU instruction sets. Most instructions are a
single program memory word (16 bits), but there are
four instructions that require two program memory
locations.
Each single-word instruction is a 16-bit word divided
into an opcode, which specifies the instruction type and
one or more operands, which further specify the
operation of the instruction.
The instruction set is highly orthogonal and is grouped
into four basic categories:
Byte-oriented operations
Bit-oriented operations
Literal operations
Control operations
The PIC18 instruction set summary in Table 28-2 lists
the byte-oriented, bit-oriented, literal and control
operations.
Table 28-1 provides the opcode field descriptions.
Most Byte-oriented instructions have three operands:
1. The file register (specified by ‘f’)
2. The destination of the result (specified by ‘d’)
3. The accessed memory (specified by ‘a’)
The file register designator, ‘f’, specifies which file
register is to be used by the instruction. The destination
designator, ‘d’, specifies where the result of the
operation is to be placed. If ‘d’ is ‘0’, the result is placed
in the WREG register. If ‘d’ is ‘1, the result is placed in
the file register specified in the instruction.
All Bit-oriented instructions have three operands:
1. The file register (specified by ‘f’)
2. The bit in the file register (specified by ‘b’)
3. The accessed memory (specified by ‘a’)
The bit field designator, ‘b’, selects the number of the bit
affected by the operation, while the file register desig-
nator, ‘f’, represents the number of the file in which the
bit is located.
The Literal instructions may use some of the following
operands:
A literal value to be loaded into a file register
(specified by ‘k’)
The desired FSR register to load the literal value
into (specified by ‘f’)
No operand required (specified by ‘—’)
The Control instructions may use some of the
following operands:
A program memory address (specified by ‘n’)
The mode of the CALL or RETURN instructions
(specified by ‘s’)
The mode of the table read and table write
instructions (specified by ‘m’)
No operand required (specified by ‘—’)
All instructions are a single word, except for four
double-word instructions. These instructions were
made double-word to contain the required information
in 32 bits. In the second word, the 4 MSbs are 1’s. If
this second word is executed as an instruction (by
itself), it will execute as a NOP.
All single-word instructions are executed in a single
instruction cycle, unless a conditional test is true or the
Program Counter (PC) is changed as a result of the
instruction. In these cases, the execution takes two
instruction cycles with the additional instruction
cycle(s) executed as a NOP.
The double-word instructions execute in two instruction
cycles.
One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 s. If a conditional test is
true, or the Program Counter is changed as a result of
an instruction, the instruction execution time is 2 s.
Two-word branch instructions (if true) would take 3 s.
Figure 28-1 provides the general formats that the
instructions can have. All examples use the convention
‘nnh’ to represent a hexadecimal number.
The instruction set summary, provided in Table 28-2,
lists the standard instructions recognized by the
Microchip MPASMTM Assembler.
Section 28.1.1 “Standard Instruction Set” provides
a description of each instruction.
PIC18F46J50 FAMILY
DS39931D-page 436 2011 Microchip Technology Inc.
TABLE 28-1: OPCODE FIELD DESCRIPTIONS
Field Description
aRAM access bit:
a = 0: RAM location in Access RAM (BSR register is ignored)
a = 1: RAM bank is specified by BSR register
bbb Bit address within an 8-bit file register (0 to 7)
BSR Bank Select Register. Used to select the current RAM bank
C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative
dDestination select bit:
d = 0: store result in WREG
d = 1: store result in file register f
dest Destination: either the WREG register or the specified register file location
f8-bit register file address (00h to FFh), or 2-bit FSR designator (0h to 3h)
fs12-bit register file address (000h to FFFh). This is the source address
fd12-bit register file address (000h to FFFh). This is the destination address
GIE Global Interrupt Enable bit
kLiteral field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value)
label Label name
mm The mode of the TBLPTR register for the table read and table write instructions
Used only with table read and table write instructions
*No Change to register (such as TBLPTR with table reads and writes)
*+ Post-Increment register (such as TBLPTR with table reads and writes)
*- Post-Decrement register (such as TBLPTR with table reads and writes)
+* Pre-Increment register (such as TBLPTR with table reads and writes)
nThe relative address (2’s complement number) for relative branch instructions or the direct address for
Call/Branch and Return instructions
PC Program Counter
PCL Program Counter Low Byte
PCH Program Counter High Byte
PCLATH Program Counter High Byte Latch
PCLATU Program Counter Upper Byte Latch
PD Power-Down bit
PRODH Product of Multiply High Byte
PRODL Product of Multiply Low Byte
sFast Call/Return mode select bit:
s = 0: do not update into/from shadow registers
s = 1: certain registers loaded into/from shadow registers (Fast mode)
TBLPTR 21-Bit Table Pointer (points to a program memory location)
TABLAT 8-Bit Table Latch
TO Time-out bit
TOS Top-of-Stack
uUnused or Unchanged
WDT Watchdog Timer
WREG Working register (accumulator)
xDon’t care (‘0’ or ‘1’). The assembler will generate code with x = 0; it is the recommended form of use for
compatibility with all Microchip software tools
zs7-bit offset value for Indirect Addressing of register files (source)
zd7-bit offset value for Indirect Addressing of register files (destination)
{ } Optional argument
[text] Indicates Indexed Addressing
(text) The contents of text
[expr]<n> Specifies bit n of the register indicated by the pointer, expr
Assigned to
< > Register bit field
In the set of
italics User-defined term (font is Courier New)
2011 Microchip Technology Inc. DS39931D-page 437
PIC18F46J50 FAMILY
EXAMPLE 28-1: GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations
15 10 9 8 7 0
d = 0 for result destination to be WREG register
OPCODE d a f (FILE #)
d = 1 for result destination to be file register (f)
a = 0 to force Access Bank
Bit-oriented file register operations
15 12 11 9 8 7 0
OPCODE b (BIT #) a f (FILE #)
b = 3-bit position of bit in file register (f)
Literal operations
15 8 7 0
OPCODE k (literal)
k = 8-bit immediate value
Byte to Byte move operations (2-word)
15 12 11 0
OPCODE f (Source FILE #)
CALL, GOTO and Branch operations
15 8 7 0
OPCODE n<7:0> (literal)
n = 20-bit immediate value
a = 1 for BSR to select bank
f = 8-bit file register address
a = 0 to force Access Bank
a = 1 for BSR to select bank
f = 8-bit file register address
15 12 11 0
1111 n<19:8> (literal)
15 12 11 0
1111 f (Destination FILE #)
f = 12-bit file register address
Control operations
Example Instruction
ADDWF MYREG, W, B
MOVFF MYREG1, MYREG2
BSF MYREG, bit, B
MOVLW 7Fh
GOTO Label
15 8 7 0
OPCODE n<7:0> (literal)
15 12 11 0
1111 n<19:8> (literal)
CALL MYFUNC
15 11 10 0
OPCODE n<10:0> (literal)
S = Fast bit
BRA MYFUNC
15 8 7 0
OPCODE n<7:0> (literal) BC MYFUNC
S
PIC18F46J50 FAMILY
DS39931D-page 438 2011 Microchip Technology Inc.
TABLE 28-2: PIC18F46J50 FAMILY INSTRUCTION SET
Mnemonic,
Operands Description Cycles 16-Bit Inst ruction Word Status
Affected Notes
MSb LSb
BYTE-ORIENT ED OPERATIONS
ADDWF
ADDWFC
ANDWF
CLRF
COMF
CPFSEQ
CPFSGT
CPFSLT
DECF
DECFSZ
DCFSNZ
INCF
INCFSZ
INFSNZ
IORWF
MOVF
MOVFF
MOVWF
MULWF
NEGF
RLCF
RLNCF
RRCF
RRNCF
SETF
SUBFWB
SUBWF
SUBWFB
SWAPF
TSTFSZ
XORWF
f, d, a
f, d, a
f, d, a
f, a
f, d, a
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
f, d, a
fs, fd
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, a
f, d, a
Add WREG and f
Add WREG and Carry bit to f
AND WREG with f
Clear f
Complement f
Compare f with WREG, Skip =
Compare f with WREG, Skip >
Compare f with WREG, Skip <
Decrement f
Decrement f, Skip if 0
Decrement f, Skip if Not 0
Increment f
Increment f, Skip if 0
Increment f, Skip if Not 0
Inclusive OR WREG with f
Move f
Move fs (source) to 1st word
fd (destination) 2nd word
Move WREG to f
Multiply WREG with f
Negate f
Rotate Left f through Carry
Rotate Left f (No Carry)
Rotate Right f through Carry
Rotate Right f (No Carry)
Set f
Subtract f from WREG with
Borrow
Subtract WREG from f
Subtract WREG from f with
Borrow
Swap Nibbles in f
Test f, Skip if 0
Exclusive OR WREG with f
1
1
1
1
1
1 (2 or 3)
1 (2 or 3)
1 (2 or 3)
1
1 (2 or 3)
1 (2 or 3)
1
1 (2 or 3)
1 (2 or 3)
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1 (2 or 3)
1
0010
0010
0001
0110
0001
0110
0110
0110
0000
0010
0100
0010
0011
0100
0001
0101
1100
1111
0110
0000
0110
0011
0100
0011
0100
0110
0101
0101
0101
0011
0110
0001
01da
00da
01da
101a
11da
001a
010a
000a
01da
11da
11da
10da
11da
10da
00da
00da
ffff
ffff
111a
001a
110a
01da
01da
00da
00da
100a
01da
11da
10da
10da
011a
10da
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
C, DC, Z, OV, N
C, DC, Z, OV, N
Z, N
Z
Z, N
None
None
None
C, DC, Z, OV, N
None
None
C, DC, Z, OV, N
None
None
Z, N
Z, N
None
None
None
C, DC, Z, OV, N
C, Z, N
Z, N
C, Z, N
Z, N
None
C, DC, Z, OV, N
C, DC, Z, OV, N
C, DC, Z, OV, N
None
None
Z, N
1, 2
1, 2
1,2
2
1, 2
4
4
1, 2
1, 2, 3, 4
1, 2, 3, 4
1, 2
1, 2, 3, 4
4
1, 2
1, 2
1
1, 2
1, 2
1, 2
1, 2
4
1, 2
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that
value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is
driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if
assigned.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
2011 Microchip Technology Inc. DS39931D-page 439
PIC18F46J50 FAMILY
BIT-ORIENTED OPERATIONS
BCF
BSF
BTFSC
BTFSS
BTG
f, b, a
f, b, a
f, b, a
f, b, a
f, b, a
Bit Clear f
Bit Set f
Bit Test f, Skip if Clear
Bit Test f, Skip if Set
Bit Toggle f
1
1
1 (2 or 3)
1 (2 or 3)
1
1001
1000
1011
1010
0111
bbba
bbba
bbba
bbba
bbba
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
ffff
None
None
None
None
None
1, 2
1, 2
3, 4
3, 4
1, 2
CONTROL OPERATIONS
BC
BN
BNC
BNN
BNOV
BNZ
BOV
BRA
BZ
CALL
CLRWDT
DAW
GOTO
NOP
NOP
POP
PUSH
RCALL
RESET
RETFIE
RETLW
RETURN
SLEEP
n
n
n
n
n
n
n
n
n
n, s
n
n
s
k
s
Branch if Carry
Branch if Negative
Branch if Not Carry
Branch if Not Negative
Branch if Not Overflow
Branch if Not Zero
Branch if Overflow
Branch Unconditionally
Branch if Zero
Call Subroutine 1st word
2nd word
Clear Watchdog Timer
Decimal Adjust WREG
Go to Address 1st word
2nd word
No Operation
No Operation
Pop Top of Return Stack (TOS)
Push Top of Return Stack (TOS)
Relative Call
Software Device Reset
Return from Interrupt Enable
Return with Literal in WREG
Return from Subroutine
Go into Standby mode
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
2
1 (2)
2
1
1
2
1
1
1
1
2
1
2
2
2
1
1110
1110
1110
1110
1110
1110
1110
1101
1110
1110
1111
0000
0000
1110
1111
0000
1111
0000
0000
1101
0000
0000
0000
0000
0000
0010
0110
0011
0111
0101
0001
0100
0nnn
0000
110s
kkkk
0000
0000
1111
kkkk
0000
xxxx
0000
0000
1nnn
0000
0000
1100
0000
0000
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0000
0000
kkkk
kkkk
0000
xxxx
0000
0000
nnnn
1111
0001
kkkk
0001
0000
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0100
0111
kkkk
kkkk
0000
xxxx
0110
0101
nnnn
1111
000s
kkkk
001s
0011
None
None
None
None
None
None
None
None
None
None
TO, PD
C
None
None
None
None
None
None
All
GIE/GIEH,
PEIE/GIEL
None
None
TO, PD
4
TABLE 28-2: PIC18F46J50 FAMILY INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands Description Cycles 16- Bit Inst ru ctio n Wor d Status
Affected Notes
MSb LSb
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that
value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is
driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if
assigned.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
PIC18F46J50 FAMILY
DS39931D-page 440 2011 Microchip Technology Inc.
LITERAL OPERATIONS
ADDLW
ANDLW
IORLW
LFSR
MOVLB
MOVLW
MULLW
RETLW
SUBLW
XORLW
k
k
k
f, k
k
k
k
k
k
k
Add Literal and WREG
AND Literal with WREG
Inclusive OR Literal with WREG
Move Literal (12-bit) 2nd word
to FSR(f) 1st word
Move Literal to BSR<3:0>
Move Literal to WREG
Multiply Literal with WREG
Return with Literal in WREG
Subtract WREG from Literal
Exclusive OR Literal with WREG
1
1
1
2
1
1
1
2
1
1
0000
0000
0000
1110
1111
0000
0000
0000
0000
0000
0000
1111
1011
1001
1110
0000
0001
1110
1101
1100
1000
1010
kkkk
kkkk
kkkk
00ff
kkkk
0000
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
C, DC, Z, OV, N
Z, N
Z, N
None
None
None
None
None
C, DC, Z, OV, N
Z, N
DATA MEMORY PROGRAM MEMORY OPERATIONS
TBLRD*
TBLRD*+
TBLRD*-
TBLRD+*
TBLWT*
TBLWT*+
TBLWT*-
TBLWT+*
Table Read
Table Read with Post-Increment
Table Read with Post-Decrement
Table Read with Pre-Increment
Table Write
Table Write with Post-Increment
Table Write with Post-Decrement
Table Write with Pre-Increment
2
2
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
1000
1001
1010
1011
1100
1101
1110
1111
None
None
None
None
None
None
None
None
TABLE 28-2: PIC18F46J50 FAMILY INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands Description Cycles 16-Bit Inst ruction Word Status
Affected Notes
MSb LSb
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that
value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is
driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if
assigned.
3: If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
2011 Microchip Technology Inc. DS39931D-page 441
PIC18F46J50 FAMILY
28.1.1 STANDARD INSTRUCTION SET
ADDLW ADD Li teral to W
Syntax: ADDLW k
Operands: 0 k 255
Operation: (W) + k W
Status Affected: N, OV, C, DC, Z
Encoding: 0000 1111 kkkk kkkk
Description: The contents of W are added to the
8-bit literal ‘k’ and the result is placed in
W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: ADDLW 0x15
Before Instruction
W = 10h
After Instruction
W = 25h
ADDWF ADD W to f
Syntax: ADDWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) + (f) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0010 01da ffff ffff
Description: Add W to register ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’
(default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: ADDWF REG, 0, 0
Before Instruction
W = 17h
REG = 0C2h
After Instruction
W = 0D9h
REG = 0C2h
Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
PIC18F46J50 FAMILY
DS39931D-page 442 2011 Microchip Technology Inc.
ADDWFC ADD W and Carry bit to f
Syntax: ADDWFC f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) + (f) + (C) dest
Status Affected: N,OV, C, DC, Z
Encoding: 0010 00da ffff ffff
Description: Add W, the Carry flag and data memory
location, ‘f’. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed in data memory location ‘f’.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: ADDWFC REG, 0, 1
Before Instruction
Carry bit = 1
REG = 02h
W=4Dh
After Instruction
Carry bit = 0
REG = 02h
W = 50h
ANDLW AND Literal with W
Syntax: ANDLW k
Operands: 0 k 255
Operation: (W) .AND. k W
Status Affected: N, Z
Encoding: 0000 1011 kkkk kkkk
Description: The contents of W are ANDed with the
8-bit literal ‘k’. The result is placed in
W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’
Process
Data
Write to
W
Example: ANDLW 0x5F
Before Instruction
W=A3h
After Instruction
W = 03h
2011 Microchip Technology Inc. DS39931D-page 443
PIC18F46J50 FAMILY
ANDWF AND W with f
Syntax: ANDWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) .AND. (f) dest
Status Affected: N, Z
Encoding: 0001 01da ffff ffff
Description: The contents of W are ANDed with
register, ‘f’. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: ANDWF REG, 0, 0
Before Instruction
W = 17h
REG = C2h
After Instruction
W = 02h
REG = C2h
BC Branch if Carry
Syntax: BC n
Operands: -128 n 127
Operation: if Carry bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0010 nnnn nnnn
Description: If the Carry bit is ’1’, then the program
will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BC 5
Before Instruction
PC = address (HERE)
After Instruction
If Carry = 1;
PC = address (HERE + 12)
If Carry = 0;
PC = address (HERE + 2)
PIC18F46J50 FAMILY
DS39931D-page 444 2011 Microchip Technology Inc.
BCF Bit Clear f
Syntax: BCF f, b {,a}
Operands: 0 f 255
0 b 7
a [0,1]
Operation: 0 f<b>
Status Affected: None
Encoding: 1001 bbba ffff ffff
Description: Bit ‘b’ in register, ‘f’, is cleared.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: BCF FLAG_REG, 7, 0
Before Instruction
FLAG_REG = C7h
After Instruction
FLAG_REG = 47h
BN Branch if Negative
Syntax: BN n
Operands: -128 n 127
Operation: if Negative bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0110 nnnn nnnn
Description: If the Negative bit is ‘1’, then the
program will branch.
The 2’s complement number,‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BN Jump
Before Instruction
PC = address (HERE)
After Instruction
If Negative = 1;
PC = address (Jump)
If Negative = 0;
PC = address (HERE + 2)
2011 Microchip Technology Inc. DS39931D-page 445
PIC18F46J50 FAMILY
BNC Branch if Not Carry
Syntax: BNC n
Operands: -128 n 127
Operation: if Carry bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0011 nnnn nnnn
Description: If the Carry bit is ‘0’, then the program
will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNC Jump
Before Instruction
PC = address (HERE)
After Instruction
If Carry = 0;
PC = address (Jump)
If Carry = 1;
PC = address (HERE + 2)
BNN Branch if Not Negative
Syntax: BNN n
Operands: -128 n 127
Operation: if Negative bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0111 nnnn nnnn
Description: If the Negative bit is ‘0’, then the
program will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNN Jump
Before Instruction
PC = address (HERE)
After Instruction
If Negative = 0;
PC = address (Jump)
If Negative = 1;
PC = address (HERE + 2)
PIC18F46J50 FAMILY
DS39931D-page 446 2011 Microchip Technology Inc.
BNOV Branch if Not Overflow
Syntax: BNOV n
Operands: -128 n 127
Operation: if Overflow bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0101 nnnn nnnn
Description: If the Overflow bit is ‘0’, then the
program will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNOV Jump
Before Instruction
PC = address (HERE)
After Instruction
If Overflow = 0;
PC = address (Jump)
If Overflow = 1;
PC = address (HERE + 2)
BNZ Branch if Not Zero
Syntax: BNZ n
Operands: -128 n 127
Operation: if Zero bit is ‘0’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0001 nnnn nnnn
Description: If the Zero bit is ‘0’, then the program
will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BNZ Jump
Before Instruction
PC = address (HERE)
After Instruction
If Zero = 0;
PC = address (Jump)
If Zero = 1;
PC = address (HERE + 2)
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BRA Unconditional Br anch
Syntax: BRA n
Operands: -1024 n 1023
Operation: (PC) + 2 + 2n PC
Status Affected: None
Encoding: 1101 0nnn nnnn nnnn
Description: Add the 2’s complement number, ‘2n’,
to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is a
two-cycle instruction.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
Example: HERE BRA Jump
Before Instruction
PC = address (HERE)
After Instruction
PC = address (Jump)
BSF Bit Set f
Syntax: BSF f, b {,a}
Operands: 0 f 255
0 b 7
a [0,1]
Operation: 1 f<b>
Status Affected: None
Encoding: 1000 bbba ffff ffff
Description: Bit ‘b’ in register, ‘f’, is set.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f
Example: BSF FLAG_REG, 7, 1
Before Instruction
FLAG_REG = 0Ah
After Instruction
FLAG_REG = 8Ah
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BTFSC Bit Test Fi le , Skip if C lear
Syntax: BTFSC f, b {,a}
Operands: 0 f 255
0 b 7
a [0,1]
Operation: skip if (f<b>) = 0
Status Affected: None
Encoding: 1011 bbba ffff ffff
Description: If bit ‘b’ in register, ‘f’, is ‘0’, then the
next instruction is skipped. If bit, ‘b’, is
0’, then the next instruction fetched
during the current instruction execu-
tion is discarded and a NOP is executed
instead, making this a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE
FALSE
TRUE
BTFSC
:
:
FLAG, 1, 0
Before Instruction
PC = address (HERE)
After Instruction
If FLAG<1> = 0;
PC = address (TRUE)
If FLAG<1> = 1;
PC = address (FALSE)
BTFSS Bit Tes t File, S k ip if Se t
Syntax: BTFSS f, b {,a}
Operands: 0 f 255
0 b < 7
a [0,1]
Operation: skip if (f<b>) = 1
Status Affected: None
Encoding: 1010 bbba ffff ffff
Description: If bit ‘b’ in register, ‘f’, is ‘1’, then the
next instruction is skipped. If bit, ‘b’, is
1’, then the next instruction fetched
during the current instruction execu-
tion is discarded and a NOP is executed
instead, making this a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE
FALSE
TRUE
BTFSS
:
:
FLAG, 1, 0
Before Instruction
PC = address (HERE)
After Instruction
If FLAG<1> = 0;
PC = address (FALSE)
If FLAG<1> = 1;
PC = address (TRUE)
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BTG Bit T oggle f
Syntax: BTG f, b {,a}
Operands: 0 f 255
0 b < 7
a [0,1]
Operation: (f<b>) f<b>
Status Affected: None
Encoding: 0111 bbba ffff ffff
Description: Bit ‘b’ in data memory location, ‘f’, is
inverted.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Liter a l Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: BTG LATC, 4, 0
Before Instruction:
LATC = 0111 0101 [75h]
After Instruction:
LATC = 0110 0101 [65h]
BOV Branch if O v e r flow
Syntax: BOV n
Operands: -128 n 127
Operation: if Overflow bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0100 nnnn nnnn
Description: If the Overflow bit is ‘1’, then the
program will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BOV Jump
Before Instruction
PC = address (HERE)
After Instruction
If Overflow = 1;
PC = address (Jump)
If Overflow = 0;
PC = address (HERE + 2)
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BZ Branch if Zero
Syntax: BZ n
Operands: -128 n 127
Operation: if Zero bit is ‘1’,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1110 0000 nnnn nnnn
Description: If the Zero bit is ‘1’, then the program
will branch.
The 2’s complement number, ‘2n’, is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example: HERE BZ Jump
Before Instruction
PC = address (HERE)
After Instruction
If Zero = 1;
PC = address (Jump)
If Zero = 0;
PC = address (HERE + 2)
CALL Subroutine Call
Syntax: CALL k {,s}
Operands: 0 k 1048575
s [0,1]
Operation: (PC) + 4 TOS,
k PC<20:1>;
if s = 1,
(W) WS,
(STATUS) STATUSS,
(BSR) BSRS
Status Affected: None
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
1111 110s
k19kkk k7kkk
kkkk kkkk0
kkkk8
Description: Subroutine call of entire 2-Mbyte
memory range. First, return address
(PC + 4) is pushed onto the return
stack. If ‘s’ = 1, the W, STATUS and
BSR
registers are also pushed into their
respective shadow registers, WS,
STATUSS and BSRS. If ‘s’ = 0, no
update occurs (default). Then, the
20-bit value ‘k’ is loaded into
PC<20:1>. CALL is a two-cycle
instruction.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’<7:0>,
Push PC to
stack
Read literal
’k’<19:8>,
Write to PC
No
operation
No
operation
No
operation
No
operation
Example: HERE CALL THERE,1
Before Instruction
PC = address (HERE)
After Instruction
PC = address (THERE)
TOS = address (HERE + 4)
WS = W
BSRS = BSR
STATUSS = STATUS
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CLRF Clear f
Syntax: CLRF f {,a}
Operands: 0 f 255
a [0,1]
Operation: 000h f,
1 Z
Status Affected: Z
Encoding: 0110 101a ffff ffff
Description: Clears the contents of the specified
register.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: CLRF FLAG_REG,1
Before Instruction
FLAG_REG = 5Ah
After Instruction
FLAG_REG = 00h
CLRWDT Clear Watchdog Timer
Syntax: CLRWDT
Operands: None
Operation: 000h WDT,
000h WDT postscaler,
1 TO,
1 PD
Status Affected: TO, PD
Encoding: 0000 0000 0000 0100
Description: CLRWDT instruction resets the
Watchdog Timer. It also resets the
postscaler of the WDT. Status bits, TO
and PD, are set.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
No
operation
Example: CLRWDT
Before Instruction
WDT Counter = ?
After Instruction
WDT Counter = 00h
WDT Postscaler = 0
TO =1
PD =1
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COMF Complement f
Syntax: COMF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: f dest
Status Affected: N, Z
Encoding: 0001 11da ffff ffff
Description: The contents of register, ‘f’, are
complemented. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register, ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: COMF REG, 0, 0
Before Instruction
REG = 13h
After Instruction
REG = 13h
W=ECh
CPFSEQ Compare f with W, Skip if f = W
Syntax: CPFSEQ f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) – (W),
skip if (f) = (W)
(unsigned comparison)
Status Affected: None
Encoding: 0110 001a ffff ffff
Description: Compares the contents of data mem-
ory location, ‘f’, to the contents of W by
performing an unsigned subtraction.
If ‘f’ = W, then the fetched instruction is
discarded and a NOP is executed
instead, making this a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CPFSEQ REG, 0
NEQUAL :
EQUAL :
Before Instruction
PC Address = HERE
W=?
REG = ?
After Instruction
If REG = W;
PC = Address (EQUAL)
If REG W;
PC = Address (NEQUAL)
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CPFSGT Compare f with W, Skip if f > W
Syntax: CPFSGT f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) –W),
skip if (f) > (W)
(unsigned comparison)
Status Affected: None
Encoding: 0110 010a ffff ffff
Description: Compares the contents of data mem-
ory location, ‘f’, to the contents of the W
by performing an unsigned subtraction.
If the contents of ‘f’ are greater than the
contents of WREG, then the fetched
instruction is discarded and a NOP is
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CPFSGT REG, 0
NGREATER :
GREATER :
Before Instruction
PC = Address (HERE)
W= ?
After Instruction
If REG W;
PC = Address (GREATER)
If REG W;
PC = Address (NGREATER)
CPFSLT Compare f with W, Skip if f < W
Syntax: CPFSLT f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) –W),
skip if (f) < (W)
(unsigned comparison)
Status Affected: None
Encoding: 0110 000a ffff ffff
Description: Compares the contents of data mem-
ory location, ‘f’, to the contents of W by
performing an unsigned subtraction.
If the contents of ‘f’ are less than the
contents of W, then the fetched
instruction is discarded and a NOP is
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CPFSLT REG, 1
NLESS :
LESS :
Before Instruction
PC = Address (HERE)
W= ?
After Instruction
If REG < W;
PC = Address (LESS)
If REG W;
PC = Address (NLESS)
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DAW Decimal Adjust W Register
Syntax: DAW
Operands: None
Operation: If [W<3:0> > 9] or [DC = 1] then,
(W<3:0>) + 6 W<3:0>;
else,
(W<3:0>) W<3:0>
If [W<7:4> > 9] or [C = 1] then,
(W<7:4>) + 6 W<7:4>,
C =1;
else,
(W<7:4>) W<7:4>
Status Affected: C
Encoding: 0000 0000 0000 0111
Description: DAW adjusts the eight-bit value in W,
resulting from the earlier addition of two
variables (each in packed BCD format)
and produces a correct packed BCD
result.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register W
Process
Data
Write
W
Example 1: DAW
Before Instruction
W=A5h
C=0
DC = 0
After Instruction
W = 05h
C=1
DC = 0
Example 2:
Before Instruction
W=CEh
C=0
DC = 0
After Instruction
W = 34h
C=1
DC = 0
DECF Decrement f
Syntax: DECF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – 1 dest
Status Affected: C, DC, N, OV, Z
Encoding: 0000 01da ffff ffff
Description: Decrement register, ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register, ‘f’
(default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: DECF CNT, 1, 0
Before Instruction
CNT = 01h
Z=0
After Instruction
CNT = 00h
Z=1
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DECFSZ Decrement f, Skip if 0
Syntax: DECFSZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – 1 dest,
skip if result = 0
Status Affected: None
Encoding: 0010 11da ffff ffff
Description: The contents of register, ‘f’, are
decremented. If ‘d’ is 0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If the result is ‘0’, the next instruction
which is already fetched is discarded
and a NOP is executed instead, making
it a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE DECFSZ CNT, 1, 1
GOTO LOOP
CONTINUE
Before Instruction
PC = Address (HERE)
After Instruction
CNT = CNT – 1
If CNT = 0;
PC = Address (CONTINUE)
If CNT 0;
PC = Address (HERE + 2)
DCFSNZ Decrement f, Skip if not 0
Syntax: DCFSNZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – 1 dest,
skip if result 0
Status Affected: None
Encoding: 0100 11da ffff ffff
Description: The contents of register, ‘f’, are
decremented. If ‘d’ is 0’, the result is
placed in W. If ‘d’ is1’, the result is
placed back in register ‘f’ (default).
If the result is not 0’, the next
instruction which is already fetched is
discarded and a NOP is executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE DCFSNZ TEMP, 1, 0
ZERO :
NZERO :
Before Instruction
TEMP = ?
After Instruction
TEMP = TEMP – 1,
If TEMP = 0;
PC = Address (ZERO)
If TEMP 0;
PC = Address (NZERO)
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GOTO Unconditional Branch
Syntax: GOTO k
Operands: 0 k 1048575
Operation: k PC<20:1>
Status Affected: None
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
1111 1111
k19kkk k7kkk
kkkk kkkk0
kkkk8
Description: GOTO allows an unconditional branch
anywhere within entire 2-Mbyte mem-
ory range. The 20-bit value ‘k’ is loaded
into PC<20:1>. GOTO is always a
two-cycle instruction.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’<7:0>,
No
operation
Read literal
‘k’<19:8>,
Write to PC
No
operation
No
operation
No
operation
No
operation
Example: GOTO THERE
After Instruction
PC = Address (THERE)
INCF Increment f
Syntax: INCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) + 1 dest
Status Affected: C, DC, N, OV, Z
Encoding: 0010 10da ffff ffff
Description: The contents of register, ‘f’, are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register, ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: INCF CNT, 1, 0
Before Instruction
CNT = FFh
Z=0
C=?
DC = ?
After Instruction
CNT = 00h
Z=1
C=1
DC = 1
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INCFSZ Increment f, Skip if 0
Syntax: INCFSZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) + 1 dest,
skip if result = 0
Status Affected: None
Encoding: 0011 11da ffff ffff
Description: The contents of register, ‘f’, are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register, ‘f’ (default).
If the result is ‘0’, the next instruction
which is already fetched is discarded
and a NOP is executed instead, making
it a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE INCFSZ CNT, 1, 0
NZERO :
ZERO :
Before Instruction
PC = Address (HERE)
After Instruction
CNT = CNT + 1
If CNT = 0;
PC = Address (ZERO)
If CNT 0;
PC = Address (NZERO)
INFSNZ Increment f, Skip if not 0
Syntax: INFSNZ f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) + 1 dest,
skip if result 0
Status Affected: None
Encoding: 0100 10da ffff ffff
Description: The contents of register, ‘f’, are
incremented. If ‘d’ is 0’, the result is
placed in W. If ‘d’ is1’, the result is
placed back in register, ‘f’ (default).
If the result is not 0’, the next
instruction which is already fetched is
discarded and a NOP is executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE INFSNZ REG, 1, 0
ZERO
NZERO
Before Instruction
PC = Address (HERE)
After Instruction
REG = REG + 1
If REG 0;
PC = Address (NZERO)
If REG = 0;
PC = Address (ZERO)
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IORLW Inclusive OR Lit e r a l with W
Syntax: IORLW k
Operands: 0 k 255
Operation: (W) .OR. k W
Status Affected: N, Z
Encoding: 0000 1001 kkkk kkkk
Description: The contents of W are ORed with the
eight-bit literal ‘k’. The result is placed
in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: IORLW 35h
Before Instruction
W=9Ah
After Instruction
W=BFh
IOR WF Inclusive OR W with f
Syntax: IORWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) .OR. (f) dest
Status Affected: N, Z
Encoding: 0001 00da ffff ffff
Description: Inclusive OR W with register, ‘f’. If ‘d’ is
0’, the result is placed in W. If ‘d’ is ‘1’,
the result is placed back in register, ‘f’
(default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: IORWF RESULT, 0, 1
Before Instruction
RESULT = 13h
W = 91h
After Instruction
RESULT = 13h
W = 93h
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LFS R Loa d FSR
Syntax: LFSR f, k
Operands: 0 f 2
0 k 4095
Operation: k FSRf
Status Affected: None
Encoding: 1110
1111 1110
0000 00ff
k7kkk k11kkk
kkkk
Description: The 12-bit literal, ‘k’, is loaded into the
file select register pointed to by ‘f’.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘k’ MSB
Process
Data
Write
literal ‘k’
MSB to
FSRfH
Decode Read literal
‘k’ LSB
Process
Data
Write literal
‘k’ to FSRfL
Example: LFSR 2, 0x3AB
After Instruction
FSR2H = 03h
FSR2L = ABh
MOVF Move f
Syntax: MOVF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: f dest
Status Affected: N, Z
Encoding: 0101 00da ffff ffff
Description: The contents of register, ‘f’, are moved
to a destination dependent upon the
status of ‘d’. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is1’, the result is
placed back in register, ‘f’ (default).
Location, ‘f’, can be anywhere in the
256-byte bank.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
W
Example: MOVF REG, 0, 0
Before Instruction
REG = 22h
W=FFh
After Instruction
REG = 22h
W = 22h
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MOVFF Move f to f
Syntax: MOVFF fs,fd
Operands: 0 fs 4095
0 fd 4095
Operation: (fs) fd
Status Affected: None
Encoding:
1st word (source)
2nd word (destin.)
1100
1111 ffff
ffff ffff
ffff ffffs
ffffd
Description: The contents of source register, ‘fs’, are
moved to destination register,‘ fd’.
Location of source ‘fs’ can be anywhere
in the 4096-byte data space (000h to
FFFh) and location of destination, ‘fd’,
can also be anywhere from 000h to
FFFh.
Either source or destination can be W
(a useful special situation).
MOVFF is particularly useful for
transferring a data memory location to
a peripheral register (such as the
transmit buffer or an I/O port).
The MOVFF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
(src)
Process
Data
No
operation
Decode No
operation
No dummy
read
No
operation
Write
register ‘f’
(dest)
Example: MOVFF REG1, REG2
Before Instruction
REG1 = 33h
REG2 = 11h
After Instruction
REG1 = 33h
REG2 = 33h
MOVLB Move Literal to Low Nibble in B SR
Syntax: MOVLB k
Operands: 0 k 255
Operation: k BSR
Status Affected: None
Encoding: 0000 0001 kkkk kkkk
Description: The eight-bit literal, ‘k’, is loaded into
the Bank Select Register (BSR). The
value of BSR<7:4> always remains0
regardless of the value of k7:k4.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write literal
‘k’ to BSR
Example: MOVLB 5
Before Instruction
BSR Register = 02h
After Instruction
BSR Register = 05h
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MOVLW M ov e Lite ral to W
Syntax: MOVLW k
Operands: 0 k 255
Operation: k W
Status Affected: None
Encoding: 0000 1110 kkkk kkkk
Description: The eight-bit literal, ‘k’, is loaded into W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: MOVLW 0x5A
After Instruction
W=5Ah
MOVWF Move W to f
Syntax: MOVWF f {,a}
Operands: 0 f 255
a [0,1]
Operation: (W) f
Status Affected: None
Encoding: 0110 111a ffff ffff
Description: Move data from W to register, ‘f’.
Location ‘f’ can be anywhere in the
256-byte bank.
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Index ed
Literal Offset Mod e” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: MOVWF REG, 0
Before Instruction
W=4Fh
REG = FFh
After Instruction
W=4Fh
REG = 4Fh
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MULLW Multipl y Literal with W
Syntax: MULLW k
Operands: 0 k 255
Operation: (W) x k PRODH:PRODL
Status Affected: None
Encoding: 0000 1101 kkkk kkkk
Description: An unsigned multiplication is carried
out between the contents of W and the
8-bit literal ‘k’. The 16-bit result is
placed in PRODH:PRODL register pair.
PRODH contains the high byte.
W is unchanged.
None of the Status flags are affected.
Note that neither Overflow nor Carry is
possible in this operation. A Zero result
is possible but not detected.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write
registers
PRODH:
PRODL
Example: MULLW 0xC4
Before Instruction
W=E2h
PRODH = ?
PRODL = ?
After Instruction
W=E2h
PRODH = ADh
PRODL = 08h
MULWF Multiply W with f
Syntax: MULWF f {,a}
Operands: 0 f 255
a [0,1]
Operation: (W) x (f) PRODH:PRODL
Status Affected: None
Encoding: 0000 001a ffff ffff
Description: An unsigned multiplication is carried out
between the contents of W and the
register file location, ‘f’. The 16-bit result is
stored in the PRODH:PRODL register
pair. PRODH contains the high byte. Both
W and ‘f’ are unchanged.
None of the Status flags are affected.
Note that neither Overflow nor Carry is
possible in this operation. A Zero result is
possible but not detected.
If ‘a’ is0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Index ed
Literal Offset Mod e” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f
Process
Data
Write
registers
PRODH:
PRODL
Example: MULWF REG, 1
Before Instruction
W=C4h
REG = B5h
PRODH = ?
PRODL = ?
After Instruction
W=C4h
REG = B5h
PRODH = 8Ah
PRODL = 94h
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NEGF Negate f
Syntax: NEGF f {,a}
Operands: 0 f 255
a [0,1]
Operation: (f) + 1 f
Status Affected: N, OV, C, DC, Z
Encoding: 0110 110a ffff ffff
Description: Location, ‘f’, is negated using two’s
complement. The result is placed in the
data memory location, ‘f’.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Liter a l Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f’
Example: NEGF REG, 1
Before Instruction
REG = 0011 1010 [3Ah]
After Instruction
REG = 1100 0110 [C6h]
NOP No Operation
Syntax: NOP
Operands: None
Operation: No operation
Status Affected: None
Encoding: 0000
1111 0000
xxxx 0000
xxxx 0000
xxxx
Description: No operation.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
No
operation
Example:
None.
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POP Pop Top of Return Stack
Syntax: POP
Operands: None
Operation: (TOS) bit bucket
Status Affected: None
Encoding: 0000 0000 0000 0110
Description: The TOS value is pulled off the return
stack and is discarded. The TOS value
then becomes the previous value that
was pushed onto the return stack.
This instruction is provided to enable
the user to properly manage the return
stack to incorporate a software stack.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
POP TOS
value
No
operation
Example: POP
GOTO NEW
Before Instruction
TOS = 0031A2h
Stack (1 level down) = 014332h
After Instruction
TOS = 014332h
PC = NEW
PUSH Push Top of Return Stack
Syntax: PUSH
Operands: None
Operation: (PC + 2) TOS
Status Affected: None
Encoding: 0000 0000 0000 0101
Description: The PC + 2 is pushed onto the top of
the return stack. The previous TOS
value is pushed down on the stack.
This instruction allows implementing a
software stack by modifying TOS and
then pushing it onto the return stack.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode PUSH
PC + 2 onto
return stack
No
operation
No
operation
Example: PUSH
Before Instruction
TOS = 345Ah
PC = 0124h
After Instruction
PC = 0126h
TOS = 0126h
Stack (1 level down) = 345Ah
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RCALL Relative Call
Syntax: RCALL n
Operands: -1024 n 1023
Operation: (PC) + 2 TOS,
(PC) + 2 + 2n PC
Status Affected: None
Encoding: 1101 1nnn nnnn nnnn
Description: Subroutine call with a jump up to 1K
from the current location. First, return
address (PC + 2) is pushed onto the
stack. Then, add the 2’s complement
number ‘2n’ to the PC. Since the PC
will have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is a
two-cycle instruction.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
PUSH PC
to stack
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
Example: HERE RCALL Jump
Before Instruction
PC = Address (HERE)
After Instruction
PC = Address (Jump)
TOS = Address (HERE + 2)
RESET Reset
Syntax: RESET
Operands: None
Operation: Reset all registers and flags that are
affected by a MCLR Reset.
Status Affected: All
Encoding: 0000 0000 1111 1111
Description: This instruction provides a way to
execute a MCLR Reset in software.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Start
reset
No
operation
No
operation
Example: RESET
After Instruction
Registers = Reset Value
Flags* = Reset Value
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RETFIE Return from Interrupt
Syntax: RETFIE {s}
Operands: s [0,1]
Operation: (TOS) PC,
1 GIE/GIEH or PEIE/GIEL;
if s = 1,
(WS) W,
(STATUSS) STATUS,
(BSRS) BSR,
PCLATU, PCLATH are unchanged
Status Affected: GIE/GIEH, PEIE/GIEL.
Encoding: 0000 0000 0001 000s
Description: Return from interrupt. Stack is popped
and Top-of-Stack (TOS) is loaded into
the PC. Interrupts are enabled by
setting either the high or low-priority
Global Interrupt Enable bit. If ‘s’ = 1,
the contents of the shadow registers
WS, STATUSS and BSRS are loaded
into their corresponding registers W,
STATUS and BSR. If ‘s’ = 0, no update
of these registers occurs (default).
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
POP PC
from stack
Set GIEH or
GIEL
No
operation
No
operation
No
operation
No
operation
Example: RETFIE 1
After Interrupt
PC = TOS
W=WS
BSR = BSRS
STATUS = STATUSS
GIE/GIEH, PEIE/GIEL = 1
RETLW Return Literal to W
Syntax: RETLW k
Operands: 0 k 255
Operation: k W,
(TOS) PC,
PCLATU, PCLATH are unchanged
Status Affected: None
Encoding: 0000 1100 kkkk kkkk
Description: W is loaded with the eight-bit literal, ‘k’.
The Program Counter is loaded from
the top of the stack (the return
address). The high address latch
(PCLATH) remains unchanged.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
POP PC
from stack,
write to W
No
operation
No
operation
No
operation
No
operation
Example:
CALL TABLE ; W contains table
; offset value
; W now has
; table value
:
TABLE
ADDWF PCL ; W = offset
RETLW k0 ; Begin table
RETLW k1 ;
:
:RETLW kn ; End of table
Before Instruction
W = 07h
After Instruction
W = value of kn
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RETURN Return from Subroutine
Syntax: RETURN {s}
Operands: s [0,1]
Operation: (TOS) PC;
if s = 1,
(WS) W,
(STATUSS) STATUS,
(BSRS) BSR,
PCLATU, PCLATH are unchanged
Status Affected: None
Encoding: 0000 0000 0001 001s
Description: Return from subroutine. The stack is
popped and the top of the stack (TOS)
is loaded into the Program Counter. If
‘s’= 1, the contents of the shadow
registers WS, STATUSS and BSRS are
loaded into their corresponding
registers W, STATUS and BSR. If
‘s’ = 0, no update of these registers
occurs (default).
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
POP PC
from stack
No
operation
No
operation
No
operation
No
operation
Example: RETURN
After Instruction:
PC = TOS
RLCF Rotate Lef t f through Carry
Syntax: RLCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n + 1>,
(f<7>) C,
(C) dest<0>
Status Affected: C, N, Z
Encoding: 0011 01da ffff ffff
Description: The contents of register, ‘f’, are rotated
one bit to the left through the Carry flag.
If ‘d’ is0’, the result is placed in W. If ‘d’
is ‘1’, the result is stored back in register,
‘f’ (default).
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Index ed
Literal Offset Mod e” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: RLCF REG, 0, 0
Before Instruction
REG = 1110 0110
C=0
After Instruction
REG = 1110 0110
W=1100 1100
C=1
Cregister f
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RLNCF Ro tate Left f (No Carry)
Syntax: RLNCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n + 1>,
(f<7>) dest<0>
Status Affected: N, Z
Encoding: 0100 01da ffff ffff
Description: The contents of register, ‘f’, are rotated
one bit to the left. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is 1’, the result is
stored back in register, ‘f’ (default).
If ‘a’ is0’, the Access Bank is
selected. If ‘a’ is ‘1’, the BSR is used to
select the GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction oper-
ates in Indexed Literal Offset Address-
ing mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: RLNCF REG, 1, 0
Before Instruction
REG = 1010 1011
After Instruction
REG = 0101 0111
register f
RRCF Rotate Right f through Carry
Syntax: RRCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n – 1>,
(f<0>) C,
(C) dest<7>
Status Affected: C, N, Z
Encoding: 0011 00da ffff ffff
Description: The contents of register, ‘f’, are rotated
one bit to the right through the Carry
flag. If ‘d’ is ‘0’, the result is placed in
W. If ‘d’ is ‘1’, the result is placed back
in register, ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: RRCF REG, 0, 0
Before Instruction
REG = 1110 0110
C=0
After Instruction
REG = 1110 0110
W=0111 0011
C=0
Cregister f
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RRNCF Rotate Right f (No Carry)
Syntax: RRNCF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<n>) dest<n – 1>,
(f<0>) dest<7>
Status Affected: N, Z
Encoding: 0100 00da ffff ffff
Description: The contents of register, ‘f’, are rotated
one bit to the right. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
placed back in register, ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank will be
selected, overriding the BSR value. If
‘a’ is ‘1’, then the bank will be selected
as per the BSR value (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: RRNCF REG, 1, 0
Before Instruction
REG = 1101 0111
After Instruction
REG = 1110 1011
Example 2: RRNCF REG, 0, 0
Before Instruction
W=?
REG = 1101 0111
After Instruction
W=1110 1011
REG = 1101 0111
register f
SETF Set f
Syntax: SETF f {,a}
Operands: 0 f 255
a [0,1]
Operation: FFh f
Status Affected: None
Encoding: 0110 100a ffff ffff
Description: The contents of the specified register
are set to FFh.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write
register ‘f
Example: SETF REG,1
Before Instruction
REG = 5Ah
After Instruction
REG = FFh
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SLEEP Enter Sleep Mo d e
Syntax: SLEEP
Operands: None
Operation: 00h WDT,
0 WDT postscaler,
1 TO,
0 PD
Status Affected: TO, PD
Encoding: 0000 0000 0000 0011
Description: The Power-Down status bit (PD) is
cleared. The Time-out status bit (TO)
is set. The Watchdog Timer and its
postscaler are cleared.
The processor is put into Sleep mode
with the oscillator stopped.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
Process
Data
Go to
Sleep
Example: SLEEP
Before Instruction
TO =?
PD =?
After Instruction
TO =1
PD =0
† If WDT causes wake-up, this bit is cleared.
SUBFWB Subtract f from W with Borro w
Syntax: SUBFWB f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) – (f) – (C) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0101 01da ffff ffff
Description: Subtract register, ‘f’, and Carry flag
(borrow) from W (2’s complement
method). If ‘d’ is ‘0’, the result is stored in
W. If ‘d’ is ‘1’, the result is stored in
register, ‘f’ (default).
If ‘a’ is0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: SUBFWB REG, 1, 0
Before Instruction
REG = 3
W=2
C=1
After Instruction
REG = FF
W=2
C=0
Z=0
N = 1 ; result is negative
Example 2: SUBFWB REG, 0, 0
Before Instruction
REG = 2
W=5
C=1
After Instruction
REG = 2
W=3
C=1
Z=0
N = 0 ; result is positive
Example 3: SUBFWB REG, 1, 0
Before Instruction
REG = 1
W=2
C=0
After Instruction
REG = 0
W=2
C=1
Z = 1 ; result is zero
N=0
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SUBLW Subtract W from Literal
Syntax: SUBLW k
Operands: 0 k 255
Operation: k – (W) W
Status Affected: N, OV, C, DC, Z
Encoding: 0000 1000 kkkk kkkk
Description: W is subtracted from the eight-bit
literal ‘k’. The result is placed in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example 1: SUBLW 0x02
Before Instruction
W = 01h
C=?
After Instruction
W = 01h
C = 1 ; result is positive
Z=0
N=0
Example 2: SUBLW 0x02
Before Instruction
W = 02h
C=?
After Instruction
W = 00h
C = 1 ; result is zero
Z=1
N=0
Example 3: SUBLW 0x02
Before Instruction
W = 03h
C=?
After Instruction
W = FFh ; (2’s complement)
C = 0 ; result is negative
Z=0
N=1
SUBWF Subtract W from f
Syntax: SUBWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – (W) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0101 11da ffff ffff
Description: Subtract W from register, ‘f’ (2’s
complement method). If ‘d’ is0’, the
result is stored in W. If ‘d’ is ‘1’, the result
is stored back in register, ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Liter a l Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: SUBWF REG, 1, 0
Before Instruction
REG = 3
W=2
C=?
After Instruction
REG = 1
W=2
C = 1 ; result is positive
Z=0
N=0
Example 2: SUBWF REG, 0, 0
Before Instruction
REG = 2
W=2
C=?
After Instruction
REG = 2
W=0
C = 1 ; result is zero
Z=1
N=0
Example 3: SUBWF REG, 1, 0
Before Instruction
REG = 1
W=2
C=?
After Instruction
REG = FFh ;(2’s complement)
W=2
C = 0 ; result is negative
Z=0
N=1
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SUBWFB Subtract W from f with Borrow
Syntax: SUBWFB f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f) – (W) – (C) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0101 10da ffff ffff
Description: Subtract W and the Carry flag (borrow)
from register, ‘f’ (2’s complement
method). If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register, ‘f’ (default).
If ‘a’ is ‘0, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example 1: SUBWFB REG, 1, 0
Before Instruction
REG = 19h (0001 1001)
W=0Dh(0000 1101)
C=1
After Instruction
REG = 0Ch (0000 1011)
W=0Dh(0000 1101)
C=1
Z=0
N = 0 ; result is positive
Example 2: SUBWFB REG, 0, 0
Before Instruction
REG = 1Bh (0001 1011)
W=1Ah(0001 1010)
C=0
After Instruction
REG = 1Bh (0001 1011)
W = 00h
C=1
Z = 1 ; result is zero
N=0
Example 3: SUBWFB REG, 1, 0
Before Instruction
REG = 03h (0000 0011)
W=0Eh(0000 1101)
C=1
After Instruction
REG = F5h (1111 0100)
; [2’s comp]
W=0Eh(0000 1101)
C=0
Z=0
N = 1 ; result is negative
SW APF Swap f
Syntax: SWAPF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (f<3:0>) dest<7:4>,
(f<7:4>) dest<3:0>
Status Affected: None
Encoding: 0011 10da ffff ffff
Description: The upper and lower nibbles of regis-
ter, ‘f’, are exchanged. If ‘d’ is ‘0’, the
result is placed in W. If ‘d’ is 1’, the
result is placed in register, ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orien ted and
Bit-Oriented Instructions in Index e d
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: SWAPF REG, 1, 0
Before Instruction
REG = 53h
After Instruction
REG = 35h
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TBLRD Table Read
Syntax: TBLRD ( *; *+; *-; +*)
Operands: None
Operation: if TBLRD *,
(Prog Mem (TBLPTR)) TABLAT,
TBLPTR – No Change;
if TBLRD *+,
(Prog Mem (TBLPTR)) TABLAT,
(TBLPTR) + 1 TBLPTR;
if TBLRD *-,
(Prog Mem (TBLPTR)) TABLAT,
(TBLPTR) – 1 TBLPTR;
if TBLRD +*,
(TBLPTR) + 1 TBLPTR,
(Prog Mem (TBLPTR)) TABLAT
Status Affected: None
Encoding: 0000 0000 0000 10nn
nn=0 *
=1 *+
=2 *-
=3 +*
Description: This instruction is used to read the contents
of Program Memory (P.M.). To address the
program memory, a pointer called Table
Pointer (TBLPTR) is used.
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory.
TBLPTR has a 2-Mbyte address range.
TBLPTR<0> = 0: Least Significant Byte of
Program Memory Word
TBLPTR<0> = 1: Most Significant Byte of
Program Memory Word
The TBLRD instruction can modify the
value of TBLPTR as follows:
no change
post-increment
post-decrement
pre-increment
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
No
operation
No
operation
No operation
(Read Program
Memory)
No
operation
No operation
(Write
TABLAT)
TBLRD Table Read (Continued)
Example 1: TBLRD *+
Before Instruction
TABLAT = 55h
TBLPTR = 00A356h
MEMORY(00A356h) = 34h
After Instruction
TABLAT = 34h
TBLPTR = 00A357h
Example 2: TBLRD +*
Before Instruction
TABLAT = AAh
TBLPTR = 01A357h
MEMORY(01A357h) = 12h
MEMORY(01A358h) = 34h
After Instruction
TABLAT = 34h
TBLPTR = 01A358h
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TBLWT Table Write
Syntax: TBLWT ( *; *+; *-; +*)
Operands: None
Operation: if TBLWT*,
(TABLAT) Holding Register,
TBLPTR – No Change;
if TBLWT*+,
(TABLAT) Holding Register,
(TBLPTR) + 1 TBLPTR;
if TBLWT*-,
(TABLAT) Holding Register,
(TBLPTR) – 1 TBLPTR;
if TBLWT+*,
(TBLPTR) + 1 TBLPTR,
(TABLAT) Holding Register
Status Affected: None
Encoding: 0000 0000 0000 11nn
nn=0 *
=1 *+
=2 *-
=3 +*
Description: This instruction uses the 3 LSBs of
TBLPTR to determine which of the
8 holding registers the TABLAT is written
to. The holding registers are used to
program the contents of Program Memory
(P.M.). (Refer to Section 6.0 “Memory
Organization” for additional details on
programming Flash memory.)
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory.
TBLPTR has a 2-Mbyte address range.
The LSb of the TBLPTR selects which
byte of the program memory location to
access.
TBLPTR<0> = 0: Least Significant Byte
of Program Memory
Word
TBLPTR<0> = 1: Most Significant Byte of
Program Memory Word
The TBLWT instruction can modify the
value of TBLPTR as follows:
no change
post-increment
post-decrement
pre-increment
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode No
operation
No
operation
No
operation
No
operation
No
operation
(Read
TABLAT)
No
operation
No
operation
(Write to
Holding
Register)
TBLWT Table Write (Continued)
Example 1: TBLWT *+
Before Instruction
TABLAT = 55h
TBLPTR = 00A356h
HOLDING REGISTER
(00A356h) = FFh
After Instructions (table write completion)
TABLAT = 55h
TBLPTR = 00A357h
HOLDING REGISTER
(00A356h) = 55h
Example 2: TBLWT +*
Before Instruction
TABLAT = 34h
TBLPTR = 01389Ah
HOLDING REGISTER
(01389Ah) = FFh
HOLDING REGISTER
(01389Bh) = FFh
After Instruction (table write completion)
TABLAT = 34h
TBLPTR = 01389Bh
HOLDING REGISTER
(01389Ah) = FFh
HOLDING REGISTER
(01389Bh) = 34h
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TST FSZ Test f, Skip if 0
Syntax: TSTFSZ f {,a}
Operands: 0 f 255
a [0,1]
Operation: skip if f = 0
Status Affected: None
Encoding: 0110 011a ffff ffff
Description: If ‘f’ = 0, the next instruction fetched
during the current instruction execution
is discarded and a NOP is executed,
making this a two-cycle instruction.
If ‘a’ is0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE TSTFSZ CNT, 1
NZERO :
ZERO :
Before Instruction
PC = Address (HERE)
After Instruction
If CNT = 00h,
PC = Address (ZERO)
If CNT 00h,
PC = Address (NZERO)
XORLW Exclu sive OR Literal with W
Syntax: XORLW k
Operands: 0 k 255
Operation: (W) .XOR. k W
Status Affected: N, Z
Encoding: 0000 1010 kkkk kkkk
Description: The contents of W are XORed with
the 8-bit literal, ‘k’. The result is placed
in W.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
W
Example: XORLW 0xAF
Before Instruction
W=B5h
After Instruction
W=1Ah
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XORWF Exclusive OR W with f
Syntax: XORWF f {,d {,a}}
Operands: 0 f 255
d [0,1]
a [0,1]
Operation: (W) .XOR. (f) dest
Status Affected: N, Z
Encoding: 0001 10da ffff ffff
Description: Exclusive OR the contents of W with
register, ‘f’. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in the register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f 95 (5Fh). See
Section 28.2.3 “Byte-Orient ed and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: XORWF REG, 1, 0
Before Instruction
REG = AFh
W=B5h
After Instruction
REG = 1Ah
W=B5h
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28.2 Extended Instruction Set
In addition to the standard 75 instructions of the PIC18
instruction set, the PIC18F46J50 family of devices also
provide an optional extension to the core CPU function-
ality. The added features include eight additional
instructions that augment Indirect and Indexed
Addressing operations and the implementation of
Indexed Literal Offset Addressing for many of the
standard PIC18 instructions.
The additional features of the extended instruction
set are enabled by default on unprogrammed
devices. Users must properly set or clear the XINST
Configuration bit during programming to enable or
disable these features.
The instructions in the extended set can all be
classified as literal operations, which either manipulate
the File Select Registers (FSR), or use them for
Indexed Addressing. Two of the instructions, ADDFSR
and SUBFSR, each have an additional special instanti-
ation for using FSR2. These versions (ADDULNK and
SUBULNK) allow for automatic return after execution.
The extended instructions are specifically implemented
to optimize re-entrant program code (that is, code that
is recursive or that uses a software stack) written in
high-level languages, particularly C. Among other
things, they allow users working in high-level
languages to perform certain operations on data
structures more efficiently. These include:
Dynamic allocation and deallocation of software
stack space when entering and leaving
subroutines
Function Pointer invocation
Software Stack Pointer manipulation
Manipulation of variables located in a software
stack
A summary of the instructions in the extended instruc-
tion set is provided in Tab l e 2 8 - 3 . Detailed descriptions
are provided in Section 28.2.2 “Extended Instruction
Set”. The opcode field descriptions in Table 28-1
(page 436) apply to both the standard and extended
PIC18 instruction sets.
28.2.1 EXTENDED INSTRUCTION SYNTAX
Most of the extended instructions use indexed argu-
ments, using one of the FSRs and some offset to specify
a source or destination register. When an argument for
an instruction serves as part of Indexed Addressing, it is
enclosed in square brackets (“[ ]”). This is done to indi-
cate that the argument is used as an index or offset. The
MPASM™ Assembler will flag an error if it determines
that an index or offset value is not bracketed.
When the extended instruction set is enabled, brackets
are also used to indicate index arguments in
byte-oriented and bit-oriented instructions. This is in
addition to other changes in their syntax. For more
details, see Section 28.2.3.1 “Extended Instruction
Syntax with Standard PIC18 Commands”.
TABLE 28-3: EXTENSIONS TO THE PIC18 INSTRUCTION SET
Note: The instruction set extension and the
Indexed Literal Offset Addressing mode
were designed for optimizing applications
written in C; the user may likely never use
these instructions directly in assembler.
The syntax for these commands is
provided as a reference for users who
may be reviewing code that has been
generated by a compiler.
Note: In the past, square brackets have been
used to denote optional arguments in the
PIC18 and earlier instruction sets. In this
text and going forward, optional
arguments are denoted by braces (“{ }”).
Mnemonic,
Operands Description Cycles 16-Bit Instruction Word Status
Affected
MSb LSb
ADDFSR
ADDULNK
CALLW
MOVSF
MOVSS
PUSHL
SUBFSR
SUBULNK
f, k
k
zs, fd
zs, zd
k
f, k
k
Add Literal to FSR
Add Literal to FSR2 and Return
Call Subroutine using WREG
Move zs (source) to 1st word
fd (destination) 2nd word
Move zs (source) to 1st word
zd (destination) 2nd word
Store Literal at FSR2,
Decrement FSR2
Subtract Literal from FSR
Subtract Literal from FSR2 and
Return
1
2
2
2
2
1
1
2
1110
1110
0000
1110
1111
1110
1111
1110
1110
1110
1000
1000
0000
1011
ffff
1011
xxxx
1010
1001
1001
ffkk
11kk
0001
0zzz
ffff
1zzz
xzzz
kkkk
ffkk
11kk
kkkk
kkkk
0100
zzzz
ffff
zzzz
zzzz
kkkk
kkkk
kkkk
None
None
None
None
None
None
None
None
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28.2.2 EXTENDED INSTRUCTION SET
ADDFSR Add Literal to FSR
Syntax: ADDFSR f, k
Operands: 0 k 63
f [ 0, 1, 2 ]
Operation: FSR(f) + k FSR(f)
Status Affected: None
Encoding: 1110 1000 ffkk kkkk
Description: The 6-bit literal, ‘k’, is added to the
contents of the FSR specified by ‘f’.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
FSR
Example: ADDFSR 2, 0x23
Before Instruction
FSR2 = 03FFh
After Instruction
FSR2 = 0422h
ADDULNK Add Literal to FSR2 and Return
Syntax: ADDULNK k
Operands: 0 k 63
Operation: FSR2 + k FSR2,
(TOS) PC
Status Affected: None
Encoding: 1110 1000 11kk kkkk
Description: The 6-bit literal, ‘k’, is added to the
contents of FSR2. A RETURN is then
executed by loading the PC with the
TOS.
The instruction takes two cycles to
execute; a NOP is performed during
the second cycle.
This may be thought of as a special
case of the ADDFSR instruction,
where f = 3 (binary ‘11’); it operates
only on FSR2.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
literal ‘k’
Process
Data
Write to
FSR
No
Operation
No
Operation
No
Operation
No
Operation
Example: ADDULNK 0x23
Before Instruction
FSR2 = 03FFh
PC = 0100h
After Instruction
FSR2 = 0422h
PC = (TOS)
Note: All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
2011 Microchip Technology Inc. DS39931D-page 479
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CALLW Subr o utine C all using WREG
Syntax: CALLW
Operands: None
Operation: (PC + 2) TOS,
(W) PCL,
(PCLATH) PCH,
(PCLATU) PCU
Status Affected: None
Encoding: 0000 0000 0001 0100
Description First, the return address (PC + 2) is
pushed onto the return stack. Next, the
contents of W are written to PCL; the
existing value is discarded. Then, the
contents of PCLATH and PCLATU are
latched into PCH and PCU, respec-
tively. The second cycle is executed as
a NOP instruction while the new next
instruction is fetched.
Unlike CALL, there is no option to
update W, STATUS or BSR.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
WREG
Push PC to
stack
No
operation
No
operation
No
operation
No
operation
No
operation
Example: HERE CALLW
Before Instruction
PC = address (HERE)
PCLATH = 10h
PCLATU = 00h
W = 06h
After Instruction
PC = 001006h
TOS = address (HERE + 2)
PCLATH = 10h
PCLATU = 00h
W = 06h
MOV S F Move Index e d t o f
Syntax: MOVSF [zs], fd
Operands: 0 zs 127
0 fd 4095
Operation: ((FSR2) + zs) fd
Status Affected: None
Encoding:
1st word (source)
2nd word (destin.)
1110
1111 1011
ffff 0zzz
ffff zzzzs
ffffd
Description: The contents of the source register are
moved to destination register, ‘fd’. The
actual address of the source register is
determined by adding the 7-bit literal
offset ‘zs’, in the first word, to the value
of FSR2. The address of the destina-
tion register is specified by the 12-bit lit-
eral ‘fd’ in the second word. Both
addresses can be anywhere in the
4096-byte data space (000h to FFFh).
The MOVSF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Determine
source addr
Determine
source addr
Read
source reg
Decode No
operation
No dummy
read
No
operation
Write
register ‘f
(dest)
Example: MOVSF [0x05], REG2
Before Instruction
FSR2 = 80h
Contents
of 85h = 33h
REG2 = 11h
After Instruction
FSR2 = 80h
Contents
of 85h = 33h
REG2 = 33h
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MOVSS Move Indexed to Indexed
Syntax: MOVSS [zs], [zd]
Operands: 0 zs 127
0 zd 127
Operation: ((FSR2) + zs) ((FSR2) + zd)
Status Affected: None
Encoding:
1st word (source)
2nd word (dest.)
1110
1111 1011
xxxx 1zzz
xzzz zzzzs
zzzzd
Description The contents of the source register are
moved to the destination register. The
addresses of the source and destina-
tion registers are determined by adding
the 7-bit literal offsets, ‘zs’ or ‘zd’,
respectively, to the value of FSR2. Both
registers can be located anywhere in
the 4096-byte data memory space
(000h to FFFh).
The MOVSS instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h. If the
resultant destination address points to
an Indirect Addressing register, the
instruction will execute as a NOP.
Words: 2
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Determine
source addr
Determine
source addr
Read
source reg
Decode Determine
dest addr
Determine
dest addr
Write
to dest reg
Example: MOVSS [0x05], [0x06]
Before Instruction
FSR2 = 80h
Contents
of 85h = 33h
Contents
of 86h = 11h
After Instruction
FSR2 = 80h
Contents
of 85h = 33h
Contents
of 86h = 33h
PUSHL Store Literal at FSR2, Decrement FSR2
Syntax: PUSHL k
Operands: 0k 255
Operation: k (FSR2),
FSR2 – 1 FSR2
Status Affected: None
Encoding: 1110 1010 kkkk kkkk
Description: The 8-bit literal, ‘k’, is written to the data
memory address specified by FSR2.
FSR2 is decremented by 1 after the
operation.
This instruction allows users to push
values onto a software stack.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read ‘k’ Process
data
Write to
destination
Example: PUSHL 0x08
Before Instruction
FSR2H:FSR2L = 01ECh
Memory (01ECh) = 00h
After Instruction
FSR2H:FSR2L = 01EBh
Memory (01ECh) = 08h
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SUBFSR Subtract Literal from FSR
Syntax: SUBFSR f, k
Operands: 0 k 63
f [ 0, 1, 2 ]
Operation: FSRf – k FSRf
Status Affected: None
Encoding: 1110 1001 ffkk kkkk
Description: The 6-bit literal, ‘k’, is subtracted
from the contents of the FSR
specified
by ‘f’.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: SUBFSR 2, 0x23
Before Instruction
FSR2 = 03FFh
After Instruction
FSR2 = 03DCh
SUBULNK Subtr act Literal from FSR2 a nd Return
Syntax: SUBULNK k
Operands: 0 k 63
Operation: FSR2 – k FSR2,
(TOS) PC
Status Affected: None
Encoding: 1110 1001 11kk kkkk
Description: The 6-bit literal, ‘k’, is subtracted from
the contents of the FSR2. A RETURN is
then executed by loading the PC with
the TOS.
The instruction takes two cycles to
execute; a NOP is performed during the
second cycle.
This may be thought of as a special case
of the SUBFSR instruction, where f = 3
(binary ‘11’); it operates only on FSR2.
Words: 1
Cycles: 2
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
No
Operation
No
Operation
No
Operation
No
Operation
Example: SUBULNK 0x23
Before Instruction
FSR2 = 03FFh
PC = 0100h
After Instruction
FSR2 = 03DCh
PC = (TOS)
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28.2.3 BYTE-ORIENTED AND
BIT-ORIENTED INSTRUCTIONS IN
INDEXED LITERAL OFFSET MODE
In addition to eight new commands in the extended set,
enabling the extended instruction set also enables
Indexed Literal Offset Addressing (Section 6.6.1
“Indexed Addressing with Literal Offset”). This has
a significant impact on the way that many commands of
the standard PIC18 instruction set are interpreted.
When the extended set is disabled, addresses embed-
ded in opcodes are treated as literal memory locations:
either as a location in the Access Bank (a = 0) or in a
GPR bank designated by the BSR (a = 1). When the
extended instruction set is enabled and a = 0, however,
a file register argument of 5Fh or less is interpreted as
an offset from the pointer value in FSR2 and not as a
literal address. For practical purposes, this means that
all instructions that use the Access RAM bit as an
argument – that is, all byte-oriented and bit-oriented
instructions, or almost half of the core PIC18 instruc-
tions – may behave differently when the extended
instruction set is enabled.
When the content of FSR2 is 00h, the boundaries of the
Access RAM are essentially remapped to their original
values. This may be useful in creating
backward-compatible code. If this technique is used, it
may be necessary to save the value of FSR2 and
restore it when moving back and forth between C and
assembly routines in order to preserve the Stack
Pointer. Users must also keep in mind the syntax
requirements of the extended instruction set (see
Section 28.2.3.1 “Extended Instruction Syntax with
Standard PIC18 Commands”).
Although the Indexed Literal Offset mode can be very
useful for dynamic stack and pointer manipulation, it
can also be very annoying if a simple arithmetic opera-
tion is carried out on the wrong register. Users who are
accustomed to the PIC18 programming must keep in
mind that, when the extended instruction set is
enabled, register addresses of 5Fh or less are used for
Indexed Literal Offset Addressing.
Representative examples of typical byte-oriented and
bit-oriented instructions in the Indexed Literal Offset
mode are provided on the following page to show how
execution is affected. The operand conditions provided
in the examples are applicable to all instructions of
these types.
28.2.3.1 Extended Instruction Syntax with
Standard PIC18 Commands
When the extended instruction set is enabled, the file
register argument ‘f’ in the standard byte-oriented and
bit-oriented commands is replaced with the literal offset
value ‘k’. As already noted, this occurs only when ‘f’ is
less than or equal to 5Fh. When an offset value is used,
it must be indicated by square brackets (“[ ]”). As with
the extended instructions, the use of brackets indicates
to the compiler that the value is to be interpreted as an
index or an offset. Omitting the brackets, or using a
value greater than 5Fh within the brackets, will
generate an error in the MPASM Assembler.
If the index argument is properly bracketed for Indexed
Literal Offset Addressing, the Access RAM argument is
never specified; it will automatically be assumed to be
0’. This is in contrast to standard operation (extended
instruction set disabled) when ‘a’ is set on the basis of
the target address. Declaring the Access RAM bit in
this mode will also generate an error in the MPASM
Assembler.
The destination argument ‘d’ functions as before.
In the latest versions of the MPASM Assembler,
language support for the extended instruction set must
be explicitly invoked. This is done with either the
command line option, /y, or the PE directive in the
source listing.
28.2.4 CONSIDERATIONS WHEN
ENABLING THE EXTENDED
INSTRUCTION SET
It is important to note that the extensions to the instruc-
tion set may not be beneficial to all users. In particular,
users who are not writing code that uses a software
stack may not benefit from using the extensions to the
instruction set.
Additionally, the Indexed Literal Offset Addressing
mode may create issues with legacy applications
written to the PIC18 assembler. This is because
instructions in the legacy code may attempt to address
registers in the Access Bank below 5Fh. Since these
addresses are interpreted as literal offsets to FSR2
when the instruction set extension is enabled, the
application may read or write to the wrong data
addresses.
When porting an application to the PIC18F46J50 fam-
ily, it is very important to consider the type of code. A
large, re-entrant application that is written in C, and
would benefit from efficient compilation, will do well
when using the instruction set extensions. Legacy
applications that heavily use the Access Bank will most
likely not benefit from using the extended instruction
set.
Note: Enabling the PIC18 instruction set exten-
sion may cause legacy applications to
behave erratically or fail entirely
2011 Microchip Technology Inc. DS39931D-page 483
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ADDWF ADD W to Indexed
(Indexed Literal Offset mode)
Syntax: ADDWF [k] {,d}
Operands: 0 k 95
d [0,1]
Operation: (W) + ((FSR2) + k) dest
Status Affected: N, OV, C, DC, Z
Encoding: 0010 01d0 kkkk kkkk
Description: The contents of W are added to the
contents of the register indicated by
FSR2, offset by the value, ‘k’.
If ‘d’ is ‘0’, the result is stored in W. If ‘d’
is ‘1’, the result is stored back in
register ‘f’ (default).
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read ‘k’ Process
Data
Write to
destination
Example: ADDWF [OFST] ,0
Before Instruction
W = 17h
OFST = 2Ch
FSR2 = 0A00h
Contents
of 0A2Ch = 20h
After Instruction
W = 37h
Contents
of 0A2Ch = 20h
BSF Bit Set Indexed
(Indexed Literal Offset mode)
Syntax: BSF [k], b
Operands: 0 f 95
0 b 7
Operation: 1 ((FSR2) + k)<b>
Status Affected: None
Encoding: 1000 bbb0 kkkk kkkk
Description: Bit ‘b’ of the register indicated by
FSR2, offset by the value, ‘k’, is set.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example: BSF [FLAG_OFST], 7
Before Instruction
FLAG_OFST = 0Ah
FSR2 = 0A00h
Contents
of 0A0Ah = 55h
After Instruction
Contents
of 0A0Ah = D5h
SETF Set Indexed
(Indexed Literal Offset mode)
Syntax: SETF [k]
Operands: 0 k 95
Operation: FFh ((FSR2) + k)
Status Affected: None
Encoding: 0110 1000 kkkk kkkk
Description: The contents of the register indicated
by FSR2, offset by, ‘k’, are set to FFh.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read ‘k’ Process
Data
Write
register
Example: SETF [OFST]
Before Instruction
OFST = 2Ch
FSR2 = 0A00h
Contents
of 0A2Ch = 00h
After Instruction
Contents
of 0A2Ch = FFh
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DS39931D-page 484 2011 Microchip Technology Inc.
28.2.5 SPECIAL CONSIDERATIONS WITH
MICROCHIP MPLAB® IDE TOOLS
The latest versions of Microchip’s software tools have
been designed to fully support the extended instruction
set for the PIC18F46J50 family. This includes the
MPLAB C18 C Compiler, MPASM assembly language
and MPLAB Integrated Development Environment
(IDE).
When selecting a target device for software
development, MPLAB IDE will automatically set default
Configuration bits for that device. The default setting for
the XINST Configuration bit is ‘1’, enabling the
extended instruction set and Indexed Literal Offset
Addressing. For proper execution of applications
developed to take advantage of the extended
instruction set, XINST must be set during
programming.
To develop software for the extended instruction set,
the user must enable support for the instructions and
the Indexed Addressing mode in their language tool(s).
Depending on the environment being used, this may be
done in several ways:
A menu option or dialog box within the environ-
ment that allows the user to configure the
language tool and its settings for the project
A command line option
A directive in the source code
These options vary between different compilers,
assemblers and development environments. Users are
encouraged to review the documentation accompany-
ing their development systems for the appropriate
information.
2011 Microchip Technology Inc. DS39931D-page 485
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29.0 DEVELOPMENT SUPPORT
The PIC® microcontrollers and dsPIC® digital signal
controllers are supported with a full range of software
and hardware development tools:
Integrated Development Environment
- MPLAB® IDE Software
Compilers/Assemblers/Linkers
- MPLAB C Compiler for Various Device
Families
- HI-TECH C for Various Device Families
- MPASMTM Assembler
-MPLINK
TM Object Linker/
MPLIBTM Object Librarian
- MPLAB Assembler/Linker/Librarian for
Various Device Families
Simulators
- MPLAB SIM Software Simulator
•Emulators
- MPLAB REAL ICE™ In-Circuit Emulator
In-Circuit Debuggers
- MPLAB ICD 3
- PICkit™ 3 Debug Express
Device Programmers
- PICkit™ 2 Programmer
- MPLAB PM3 Device Programmer
Low-Cost Demonstration/Development Boards,
Evaluation Kits, and Starter Kits
29.1 MPLAB Integrated Development
Environment Software
The MPLAB IDE software brings an ease of software
development previously unseen in the 8/16/32-bit
microcontroller market. The MPLAB IDE is a Windows®
operating system-based application that contains:
A single graphical interface to all debugging tools
- Simulator
- Programmer (sold separately)
- In-Circuit Emulator (sold separately)
- In-Circuit Debugger (sold separately)
A full-featured editor with color-coded context
A multiple project manager
Customizable data windows with direct edit of
contents
High-level source code debugging
Mouse over variable inspection
Drag and drop variables from source to watch
windows
Extensive on-line help
Integration of select third party tools, such as
IAR C Compilers
The MPLAB IDE allows you to:
Edit your source files (either C or assembly)
One-touch compile or assemble, and download to
emulator and simulator tools (automatically
updates all project information)
Debug using:
- Source files (C or assembly)
- Mixed C and assembly
- Machine code
MPLAB IDE supports multiple debugging tools in a
single development paradigm, from the cost-effective
simulators, through low-cost in-circuit debuggers, to
full-featured emulators. This eliminates the learning
curve when upgrading to tools with increased flexibility
and power.
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DS39931D-page 486 2011 Microchip Technology Inc.
29.2 MPLAB C Compilers for Various
Device Families
The MPLAB C Compiler code development systems
are complete ANSI C compilers for Microchip’s PIC18,
PIC24 and PIC32 families of microcontrollers and the
dsPIC30 and dsPIC33 families of digital signal control-
lers. These compilers provide powerful integration
capabilities, superior code optimization and ease of
use.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
29.3 HI-TECH C for Various Device
Families
The HI-TECH C Compiler code development systems
are complete ANSI C compilers for Microchip’s PIC
family of microcontrollers and the dsPIC family of digital
signal controllers. These compilers provide powerful
integration capabilities, omniscient code generation
and ease of use.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
The compilers include a macro assembler, linker, pre-
processor, and one-step driver, and can run on multiple
platforms.
29.4 MPASM Assembler
The MPASM Assembler is a full-featured, universal
macro assembler for PIC10/12/16/18 MCUs.
The MPASM Assembler generates relocatable object
files for the MPLINK Object Linker, Intel® standard HEX
files, MAP files to detail memory usage and symbol
reference, absolute LST files that contain source lines
and generated machine code and COFF files for
debugging.
The MPASM Assembler features include:
Integration into MPLAB IDE projects
User-defined macros to streamline
assembly code
Conditional assembly for multi-purpose
source files
Directives that allow complete control over the
assembly process
29.5 MPLINK Object Linker/
MPLIB Object Librarian
The MPLINK Object Linker combines relocatable
objects created by the MPASM Assembler and the
MPLAB C18 C Compiler. It can link relocatable objects
from precompiled libraries, using directives from a
linker script.
The MPLIB Object Librarian manages the creation and
modification of library files of precompiled code. When
a routine from a library is called from a source file, only
the modules that contain that routine will be linked in
with the application. This allows large libraries to be
used efficiently in many different applications.
The object linker/library features include:
Efficient linking of single libraries instead of many
smaller files
Enhanced code maintainability by grouping
related modules together
Flexible creation of libraries with easy module
listing, replacement, deletion and extraction
29.6 MPLAB Assembler, Linker and
Librarian for Various Device
Families
MPLAB Assembler produces relocatable machine
code from symbolic assembly language for PIC24,
PIC32 and dsPIC devices. MPLAB C Compiler uses
the assembler to produce its object file. The assembler
generates relocatable object files that can then be
archived or linked with other relocatable object files and
archives to create an executable file. Notable features
of the assembler include:
Support for the entire device instruction set
Support for fixed-point and floating-point data
Command line interface
Rich directive set
Flexible macro language
MPLAB IDE compatibility
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29.7 MPLAB SIM Software Simulator
The MPLAB SIM Software Simulator allows code
development in a PC-hosted environment by simulat-
ing the PIC MCUs and dsPIC® DSCs on an instruction
level. On any given instruction, the data areas can be
examined or modified and stimuli can be applied from
a comprehensive stimulus controller. Registers can be
logged to files for further run-time analysis. The trace
buffer and logic analyzer display extend the power of
the simulator to record and track program execution,
actions on I/O, most peripherals and internal registers.
The MPLAB SIM Software Simulator fully supports
symbolic debugging using the MPLAB C Compilers,
and the MPASM and MPLAB Assemblers. The soft-
ware simulator offers the flexibility to develop and
debug code outside of the hardware laboratory envi-
ronment, making it an excellent, economical software
development tool.
29.8 MPLAB REAL ICE In-Circuit
Emulator System
MPLAB REAL ICE In-Circuit Emulator System is
Microchip’s next generation high-speed emulator for
Microchip Flash DSC and MCU devices. It debugs and
programs PIC® Flash MCUs and dsPIC® Flash DSCs
with the easy-to-use, powerful graphical user interface of
the MPLAB Integrated Development Environment (IDE),
included with each kit.
The emulator is connected to the design engineer’s PC
using a high-speed USB 2.0 interface and is connected
to the target with either a connector compatible with in-
circuit debugger systems (RJ11) or with the new high-
speed, noise tolerant, Low-Voltage Differential Signal
(LVDS) interconnection (CAT5).
The emulator is field upgradable through future firmware
downloads in MPLAB IDE. In upcoming releases of
MPLAB IDE, new devices will be supported, and new
features will be added. MPLAB REAL ICE offers
significant advantages over competitive emulators
including low-cost, full-speed emulation, run-time
variable watches, trace analysis, complex breakpoints, a
ruggedized probe interface and long (up to three meters)
interconnection cables.
29.9 MPLAB ICD 3 In-Circuit Debugger
System
MPLAB ICD 3 In-Circuit Debugger System is Micro-
chip’s most cost effective high-speed hardware
debugger/programmer for Microchip Flash Digital Sig-
nal Controller (DSC) and microcontroller (MCU)
devices. It debugs and programs PIC® Flash microcon-
trollers and dsPIC® DSCs with the powerful, yet easy-
to-use graphical user interface of MPLAB Integrated
Development Environment (IDE).
The MPLAB ICD 3 In-Circuit Debugger probe is con-
nected to the design engineer’s PC using a high-speed
USB 2.0 interface and is connected to the target with a
connector compatible with the MPLAB ICD 2 or MPLAB
REAL ICE systems (RJ-11). MPLAB ICD 3 supports all
MPLAB ICD 2 headers.
29.10 PICkit 3 In-Circuit Debugger/
Programmer and
PICkit 3 Debug Express
The MPLAB PICkit 3 allows debugging and program-
ming of PIC® and dsPIC® Flash microcontrollers at a
most affordable price point using the powerful graphical
user interface of the MPLAB Integrated Development
Environment (IDE). The MPLAB PICkit 3 is connected
to the design engineer’s PC using a full speed USB
interface and can be connected to the target via an
Microchip debug (RJ-11) connector (compatible with
MPLAB ICD 3 and MPLAB REAL ICE). The connector
uses two device I/O pins and the reset line to imple-
ment in-circuit debugging and In-Circuit Serial Pro-
gramming™.
The PICkit 3 Debug Express include the PICkit 3, demo
board and microcontroller, hookup cables and CDROM
with user’s guide, lessons, tutorial, compiler and
MPLAB IDE software.
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DS39931D-page 488 2011 Microchip Technology Inc.
29.11 PICkit 2 Development
Programmer/Debugger and
PICkit 2 Debug Express
The PICkit™ 2 Development Programmer/Debugger is
a low-cost development tool with an easy to use inter-
face for programming and debugging Microchip’s Flash
families of microcontrollers. The full featured
Windows® programming interface supports baseline
(PIC10F, PIC12F5xx, PIC16F5xx), midrange
(PIC12F6xx, PIC16F), PIC18F, PIC24, dsPIC30,
dsPIC33, and PIC32 families of 8-bit, 16-bit, and 32-bit
microcontrollers, and many Microchip Serial EEPROM
products. With Microchip’s powerful MPLAB Integrated
Development Environment (IDE) the PICkit™ 2
enables in-circuit debugging on most PIC® microcon-
trollers. In-Circuit-Debugging runs, halts and single
steps the program while the PIC microcontroller is
embedded in the application. When halted at a break-
point, the file registers can be examined and modified.
The PICkit 2 Debug Express include the PICkit 2, demo
board and microcontroller, hookup cables and CDROM
with user’s guide, lessons, tutorial, compiler and
MPLAB IDE software.
29.12 MPLAB PM3 Device Programmer
The MPLAB PM3 Device Programmer is a universal,
CE compliant device programmer with programmable
voltage verification at VDDMIN and VDDMAX for
maximum reliability. It features a large LCD display
(128 x 64) for menus and error messages and a modu-
lar, detachable socket assembly to support various
package types. The ICSP™ cable assembly is included
as a standard item. In Stand-Alone mode, the MPLAB
PM3 Device Programmer can read, verify and program
PIC devices without a PC connection. It can also set
code protection in this mode. The MPLAB PM3
connects to the host PC via an RS-232 or USB cable.
The MPLAB PM3 has high-speed communications and
optimized algorithms for quick programming of large
memory devices and incorporates an MMC card for file
storage and data applications.
29.13 Demonstration/Development
Boards, Evaluation Kits, and
Starter Kits
A wide variety of demonstration, development and
evaluation boards for various PIC MCUs and dsPIC
DSCs allows quick application development on fully func-
tional systems. Most boards include prototyping areas for
adding custom circuitry and provide application firmware
and source code for examination and modification.
The boards support a variety of features, including LEDs,
temperature sensors, switches, speakers, RS-232
interfaces, LCD displays, potentiometers and additional
EEPROM memory.
The demonstration and development boards can be
used in teaching environments, for prototyping custom
circuits and for learning about various microcontroller
applications.
In addition to the PICDEM™ and dsPICDEM™ demon-
stration/development board series of circuits, Microchip
has a line of evaluation kits and demonstration software
for analog filter design, KEELOQ® security ICs, CAN,
IrDA®, PowerSmart battery management, SEEVAL®
evaluation system, Sigma-Delta ADC, flow rate
sensing, plus many more.
Also available are starter kits that contain everything
needed to experience the specified device. This usually
includes a single application and debug capability, all
on one board.
Check the Microchip web page (www.microchip.com)
for the complete list of demonstration, development
and evaluation kits.
2011 Microchip Technology Inc. DS39931D-page 489
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30.0 ELECTR ICAL CHARACTERISTICS
Absolute Maximum Ratings(†)
Ambient temperature under bias.............................................................................................................-40°C to +125°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on any digital only I/O pin or MCLR with respect to VSS (when VDD 2.0V) .................................. -0.3V to 6.0V
Voltage on any digital only I/O pin or MCLR with respect to VSS (when VDD < 2.0V) ..................... -0.3V to (VDD + 4.0V)
Voltage on any combined digital and analog pin with respect to VSS (except VDD)........................ -0.3V to (VDD + 0.3V)
Voltage on VDDCORE with respect to VSS................................................................................................... -0.3V to 2.75V
Voltage on VDD with respect to VSS ........................................................................................................... -0.3V to 4.0V
Voltage on VUSB with respect to VSS................................................................................................ (VDD – 0.3V) to 4.0V
Total power dissipation (Note 1) ...............................................................................................................................1.0W
Maximum current out of VSS pin ...........................................................................................................................300 mA
Maximum current into VDD pin ..............................................................................................................................250 mA
Maximum output current sunk by any PORTB, PORTC and RA6 I/O pin...............................................................25mA
Maximum output current sunk by any PORTA (except RA6), PORTD and PORTE I/O pin......................................4 mA
Maximum output current sourced by any PORTB, PORTC and RA6 I/O pin .........................................................25 mA
Maximum output current sourced by any PORTA (except RA6), PORTD and PORTE I/O pin ................................4 mA
Maximum current sunk byall ports .......................................................................................................................200 mA
Maximum current sourced by all ports ..................................................................................................................200 mA
Note 1: Power dissipation is calculated as follows:
PDIS = VDD x {IDD IOH} + {(VDD – VOH) x IOH} + (VOL x IOL)
NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.
PIC18F46J50 FAMILY
DS39931D-page 490 2011 Microchip Technology Inc.
FIGURE 30-1: PIC18F46J50 FAMILY VDD FREQU ENC Y GR AP H ( I ND US TR IA L )
FIGURE 30 - 2: PI C1 8LF 46J 50 FAMI L Y VDDCORE FREQUENCY GRAPH (INDUSTRIAL)(1)
0
Note 1: When the USB module is enabled, VUSB should be provided 3.0V-3.6V while VDD must be 2.35V. When the USB
module is not enabled, the wider limits shaded in grey apply. VUSB should be maintained VDD, but may optionally
be high-impedance (without external pull-down) when the USB module is not in use.
Frequency
Voltage (VDD)
4.0V
2.15V
48 MHz
3.5V
3.0V
2.5V
3.6V
8 MHz
PIC18F46J 50 Fam ily Valid Operating Range
2.35V(1)
Frequency
Voltage (VDDCORE)
3.00V
2.00V
48 MHz
2.75V
2.50V
2.25V
2.75V
8 MHz
2.35V(2)
Note 1: VDD and VDDCORE must be maintained so that VDDCORE VDD.
2: When the USB module is enabled, VUSB should be provided 3.0V-3.6V while VDDCORE must be 2.35V. When
the USB module is not enabled, the wider limits shaded in grey apply. VUSB should be maintained VDD, but
may optionally be high-impedance (without external pull-down) when the USB module is not in use.
0
PIC18LF46J50 Family Valid Operating Range
2011 Microchip Technology Inc. DS39931D-page 491
PIC18F46J50 FAMILY
30.1 DC Characteristics: Supply Voltage PIC18F46J50 Family (Industri al)
PIC18F46J 50 Fam ily Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
Param
No. Symbol Characteristic Min Typ Max Units Conditions
D001 VDD Supply Voltage 2.15 3.6 V PIC18F4XJ50, PIC18F2XJ50
D001A VDD Supply Voltage 2.0 3.6 V PIC18LF4XJ50, PIC18LF2XJ50
D001B VDDCORE External Supply for
Microcontroller Core 2.0 2.75 V PIC18LF4XJ50, PIC18LF2XJ50
D001C AVDD Analog Supply Voltage VDD – 0.3 VDD + 0.3 V
D001D AVSS Analog Ground Potential VSS – 0.3 VSS + 0.3 V
D001E VUSB USB Supply Voltage 3.0 3.3 3.6 V USB module enabled(2)
D002 VDR RAM Data Retention
Voltage(1) 1.5 V
D003 VPOR VDD Star t Volt age
to Ensure Internal
Power-on Reset Signal
0.7 V See Section 5.3 “Power-on
Reset (POR)” for details
D004 SVDD VDD Rise Rate
to Ensure Internal
Power-on Reset Signal
0.05 V/ms See Section 5.3 “Power-on
Reset (POR)” for details
D005 VBOR(3) VDDCORE Brown-out
Reset Voltage 1.9 2.0 2.2 V PIC18F4XJ50, PIC18F2XJ50
only
D006 VDSBOR VDD Brown-out Reset
Voltage 1.8 V DSBOREN = 1 on “LF” device or
“F” device in Deep Sleep
Note 1: This is the limit to which VDDCORE can be lowered in Sleep mode, or during a device Reset, without losing RAM
data.
2: VUSB should always be maintained VDD, but may be left floating (high impedance, without external
pull-down) when the USB module is disabled and RC4/RC5 will not be used as general purpose inputs.
3: The device will operate normally until Brown-out Reset occurs, even though VDD may be below VDDMIN.
PIC18F46J50 FAMILY
DS39931D-page 492 2011 Microchip Technology Inc.
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial)
PIC18LF46J50 Family Standard Operating Condition s (unle ss otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Power-Down Current (IPD)(1) – Sleep mode
PIC18LFXXJ50 0.01 1.4 A -40°C
VDD = 2.0V,
VDDCORE = 2.0V
Sleep mode,
REGSLP = 1
0.06 1.4 A +25°C
0.52 6.0 A +60°C
1.8 10.2 A +85°C
PIC18LFXXJ50 0.035 1.5 A -40°C
VDD = 2.5V,
VDDCORE = 2.5V
0.13 1.5 A +25°C
0.63 8.0 A +60°C
2.2 12.6 A +85°C
PIC18FXXJ50 2.4 6.0 A -40°C
VDD = 2.15V
Vddcore = 10 F
Capacitor
3.0 6.0 A+25°C
3.8 8.0 A+60°C
5.6 16 A+85°C
PIC18FXXJ50 3.5 7.0 A -40°C
VDD = 3.3V
Vddcore = 10 F
Capacitor
3.2 7.0 A+25°C
4.2 10 A+60°C
6.4 19 A+85°C
Power-Down Current (IPD)(1) – Deep Sleep mode
PIC18FXXJ50 125 nA -40°C
VDD = 2.15V,
VDDCORE = 10 F
Capacitor
Deep Sleep mode
15 100 nA +25°C
115 250 nA +60°C
0.46 1.0 A+85°C
PIC18FXXJ50 350 nA -40°C
VDD = 3.3V,
VDDCORE = 10 F
Capacitor
33 150 nA +25°C
191 389 nA +60°C
0.65 2.0 A+85°C
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Specifications”, and therefore, may be as low as 900 during Idle conditions.
2011 Microchip Technology Inc. DS39931D-page 493
PIC18F46J50 FAMILY
Supply Current (IDD)(2)
PIC18LFXXJ50 5.3 14.2 A -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 31 kHz
(RC_RUN mode,
Internal RC Oscillator,
INTSRC = 0)
6.2 14.2 A +25°C
8.5 19.0 A +85°C
PIC18LFXXJ50 8.0 16.5 A -40°C
VDD = 2.5V,
VDDCORE = 2.5V
8.7 16.5 A +25°C
11.3 22.4 A +85°C
PIC18FXXJ50 37 77 A-40°C VDD = 2.15V
VDDCORE = 10 F
Capacitor
48 77 A+25°C
60 93 A+85°C
PIC18FXXJ50 45 84 A-40°C VDD = 3.3V
VDDCORE = 10 F
Capacitor
54 84 A+25°C
65 108 A+85°C
PIC18LFXXJ50 1.1 1.5 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0
FOSC = 4 MHz,
RC_RUN mode,
Internal RC Oscillator
1.1 1.5 mA +25°C
1.2 1.6 mA +85°C
PIC18LFXXJ50 1.5 1.7 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V
1.6 1.7 mA +25°C
1.6 1.9 mA +85°C
PIC18FXXJ50 1.3 2.6 mA -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
1.4 2.6 mA +25°C
1.4 2.8 mA +85°C
PIC18FXXJ50 1.6 2.9 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
1.6 2.9 mA +25°C
1.6 3.0 mA +85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Conditions (u nless othe rwise stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Speci fic at ions, and therefore, may be as low as 900 during Idle conditions.
PIC18F46J50 FAMILY
DS39931D-page 494 2011 Microchip Technology Inc.
Supply Current (IDD)(2)
PIC18LFXXJ50 1.9 3.6 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 8 MHz,
RC_RUN mode,
Internal RC Oscillator
2.0 3.8 mA +25°C
2.0 3.8 mA +85°C
PIC18LFXXJ50 2.8 4.8 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V
2.8 4.8 mA +25°C
2.8 4.9 mA +85°C
PIC18FXXJ50 2.3 4.2 mA -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
2.3 4.2 mA +25°C
2.4 4.5 mA +85°C
PIC18FXXJ50 2.8 5.1 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
2.8 5.1 mA +25°C
2.8 5.4 mA +85°C
PIC18LFXXJ50 1.9 9.4 A -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 31 kHz,
RC_IDLE mode,
Internal RC Oscillator,
INTSRC = 0
2.3 9.4 A +25°C
4.5 17.2 A +85°C
PIC18LFXXJ50 2.4 10.5 A -40°C
VDD = 2.5V,
VDDCORE = 2.5V
2.8 10.5 A +25°C
5.4 19.5 A +85°C
PIC18FXXJ50 33.3 75 A-40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
43.8 75 A+25°C
55.3 92 A+85°C
PIC18FXXJ50 36.1 82 A-40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
44.5 82 A+25°C
56.3 105 A+85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Condition s (unle ss otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Specifications”, and therefore, may be as low as 900 during Idle conditions.
2011 Microchip Technology Inc. DS39931D-page 495
PIC18F46J50 FAMILY
Supply Current (IDD)(2)
PIC18LFXXJ50 0.531 0.980 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 4 MHz,
RC_IDLE mode,
Internal RC Oscillator
0.571 0.980 mA +25°C
0.608 1.12 mA +85°C
PIC18LFXXJ50 0.625 1.14 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V
0.681 1.14 mA +25°C
0.725 1.25 mA +85°C
PIC18FXXJ50 0.613 1.21 mA -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
0.680 1.21 mA +25°C
0.730 1.30 mA +85°C
PIC18FXXJ50 0.673 1.27 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
0.728 1.27 mA +25°C
0.779 1.45 mA +85°C
PIC18LFXXJ50 0.750 1.4 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 8 MHz,
RC_IDLE mode,
Internal RC Oscillator
0.797 1.5 mA +25°C
0.839 1.6 mA +85°C
PIC18LFXXJ50 0.91 2.4 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V
0.96 2.4 mA +25°C
1.01 2.5 mA +85°C
PIC18FXXJ50 0.87 2.1 mA -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
0.93 2.1 mA +25°C
0.98 2.3 mA +85°C
PIC18FXXJ50 0.95 2.6 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
1.01 2.6 mA +25°C
1.06 2.7 mA +85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Conditions (u nless othe rwise stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Speci fic at ions, and therefore, may be as low as 900 during Idle conditions.
PIC18F46J50 FAMILY
DS39931D-page 496 2011 Microchip Technology Inc.
Supply Current (IDD)(2)
PIC18LFXXJ50 0.879 1.25 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 4 MHz,
PRI_RUN mode,
EC Oscillator
0.881 1.25 mA +25°C
0.891 1.36 mA +85°C
PIC18LFXXJ50 1.35 1.70 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V
1.30 1.70 mA +25°C
1.27 1.82 mA +85°C
PIC18FXXJ50 1.09 1.60 mA -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
1.09 1.60 mA +25°C
1.11 1.70 mA +85°C
PIC18FXXJ50 1.36 1.95 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
1.36 1.89 mA +25°C
1.41 1.92 mA +85°C
PIC18LFXXJ50 10.9 14.8 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V FOSC = 48 MHz,
PRI_RUN mode,
EC Oscillator
10.6 14.8 mA +25°C
10.6 15.2 mA +85°C
PIC18FXXJ50 12.9 23.2 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
12.8 22.7 mA +25°C
12.7 22.7 mA +85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Condition s (unle ss otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Specifications”, and therefore, may be as low as 900 during Idle conditions.
2011 Microchip Technology Inc. DS39931D-page 497
PIC18F46J50 FAMILY
Supply Current (IDD)(2)
PIC18LFXXJ50 0.28 0.70 mA -40°C
VDD = 2.0V,
VDDCORE = 2.0V
FOSC = 4 MHz
PRI_IDLE mode,
EC Oscillator
0.30 0.70 mA +25°C
0.34 0.75 mA +85°C
PIC18LFXXJ50 0.37 1.0 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V
0.40 1.0 mA +25°C
0.50 1.1 mA +85°C
PIC18FXXJ50 0.36 0.85 mA -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
0.38 0.85 mA +25°C
0.41 0.90 mA +85°C
PIC18FXXJ50 0.45 1.3 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
0.48 1.2 mA +25°C
0.55 1.2 mA +85°C
PIC18LFXXJ50 4.5 6.5 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V FOSC = 48 MHz
PRI_IDLE mode,
EC Oscillator
4.5 6.5 mA +25°C
4.6 6.5 mA +85°C
PIC18FXXJ50 4.8 12.4 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
4.9 11.5 mA +25°C
5.1 11.5 mA +85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Conditions (u nless othe rwise stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Speci fic at ions, and therefore, may be as low as 900 during Idle conditions.
PIC18F46J50 FAMILY
DS39931D-page 498 2011 Microchip Technology Inc.
Supply Current (IDD)(2)
PIC18LFXXJ50 8.2 11 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V FOSC = 24 MHz
PRI_RUN mode,
ECPLL Oscillator
(4 MHz Input)
8.1 11 mA +25°C
8.0 10 mA +85°C
PIC18FXXJ50 8.1 15 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
8.1 14 mA +25°C
8.1 14 mA +85°C
PIC18LFXXJ50 12 14 mA -40°C
VDD = 2.5V,
VDDCORE = 2.5V FOSC = 48 MHz
PRI_RUN mode,
ECPLL Oscillator
(4 MHz Input)
12 14 mA +25°C
11 14 mA +85°C
PIC18FXXJ50 14 24 mA -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
14 23 mA +25°C
14 23 mA +85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Condition s (unle ss otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Specifications”, and therefore, may be as low as 900 during Idle conditions.
2011 Microchip Technology Inc. DS39931D-page 499
PIC18F46J50 FAMILY
Supply Current (IDD)(2)
PIC18LFXXJ50 9.9 45 A -40°C
VDD = 2.5V,
VDDCORE = 2.5V
FOSC = 32 kHz(3)
SEC_RUN mode,
LPT1OSC = 0
11 45 A +25°C
13 61 A +85°C
PIC18FXXJ50 39 95 A-40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
50 95 A+25°C
57 105 A+85°C
PIC18FXXJ50 42 110 A-40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
54 110 A+25°C
57 150 A+85°C
PIC18LFXXJ50 3.5 31 A -40°C
VDD = 2.5V,
VDDCORE = 2.5V
FOSC = 32 kHz(3)
SEC_IDLE mode,
LPT1OSC = 0
3.8 31 A +25°C
4.3 50 A +85°C
PIC18FXXJ50 34 87 A-40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
45 89 A+25°C
56 97 A+85°C
PIC18FXXJ50 35 100 A-40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
46 100 A+25°C
56 140 A+85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Conditions (u nless othe rwise stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Speci fic at ions, and therefore, may be as low as 900 during Idle conditions.
PIC18F46J50 FAMILY
DS39931D-page 500 2011 Microchip Technology Inc.
Modul e Di ffer ential Cur rents (IWDT, IHLVD, IOSCB, IAD, IUSB)
W atchdog Timer 0.84 8.0 A -40°C VDD = 2.5V,
VDDCORE = 2.5V PIC18LFXXJ50
0.96 8.0 A +25°C
0.97 10.4 A +85°C
0.65 7.0 A-40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor PIC18FXXJ50
0.78 7.0 A+25°C
0.77 10 A+85°C
1.3 12.1 A-40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
1.3 12.1 A+25°C
1.3 13.6 A+85°C
D022B
(IHLVD)
High/Lo w -Voltage Detect 3.9 8.0 A -40°C VDD = 2.5V,
VDDCORE = 2.5V PIC18LFXXJ50
4.7 8.0 A +25°C
5.4 9.0 A +85°C
2.6 6.0 A-40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor PIC18FXXJ50
3.1 6.0 A+25°C
3.5 8.0 A+85°C
3.5 9.0 A-40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
4.1 9.0 A+25°C
4.5 12 A+85°C
D025
(IOSCB)
Real-Time Clock/Calendar
with Low-Power Timer1
Oscillator
0.80 4.0 A-40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor
PIC18FXXJ50
32.768 kHz(3), T1OSCEN = 1,
LPT1OSC = 0
0.83 4.5 A+25°C
0.95 4.5 A+60°C
1.2 4.5 A+85°C
0.75 4.5 A-40°C VDD = 2.5V,
VDDCORE = 10 F
Capacitor
0.92 5.0 A+25°C
1.1 5.0 A+60°C
1.1 5.0 A+85°C
0.95 6.5 A-40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
1.1 6.5 A+25°C
1.2 8.0 A+60°C
1.4 8.0 A+85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Condition s (unle ss otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwis e stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Specifications”, and therefore, may be as low as 900 during Idle conditions.
2011 Microchip Technology Inc. DS39931D-page 501
PIC18F46J50 FAMILY
D026
(IAD)
Modul e Di ffer ential Cur rents (IWDT, IHLVD, IOSCB, IAD, IUSB)
A/D Converter 3.0 10 A -40°C VDD = 2.5V,
VDDCORE = 2.5V
PIC18LFXXJ50
A/D on, not converting
3.0 10 A +25°C
3.0 10 A +85°C
3.0 10 A -40°C VDD = 2.15V,
VDDCORE = 10 F
Capacitor PIC18FXXJ50
A/D on, not converting
3.0 10 A+25°C
3.0 10 A+85°C
3.2 11 A -40°C VDD = 3.3V,
VDDCORE = 10 F
Capacitor
3.2 11 A+25°C
3.2 11 A+85°C
D027
(IUSB)
USB Module 1.6 3.2 mA -40°C
VDD and
VUSB = 3.3V,
VDDCORE = 10 F
Capacitor
PIC18FXXJ50
USB enabled, no cable
connected.(4) Traffic makes a
difference, see Section 22.6.4
“USB T ransceiver Current
Consumption”
1.6 3.2 mA +25°C
1.5 3.2 mA +85°C
30.2 DC Characteristics: Power-Down and Supply Current
PIC18F46J50 Family (Industrial) (Continued)
PIC18LF46J50 Family Standard Operating Conditions (u nless othe rwise stated)
Operating temperature -40°C T
A +85°C for industrial
PIC18F46J50 Family Standard Opera ting Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Device Typ Max Units Conditions
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured
with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features
that add delta current are disabled (such as WDT, Timer1 oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as
I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature,
also have an impact on the current consumption. All features that add delta current are disabled (USB module,
WDT, etc.). The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD/VSS;
MCLR = VDD; WDT disabled unless otherwise specified.
3: Low-power Timer1 with standard, low-cost 32 kHz crystals has an operating temperature range of -10°C to
+70°C. Extended temperature crystals are available at a much higher cost.
4: This is the module differential current when the USB module is enabled and clocked at 48 MHz, but with no USB
cable attached. When the USB cable is attached, or data is being transmitted, the current consumption may be
much higher (see Section 22.6.4 “USB Transceiver Current Consumption”). During USB Suspend mode
(USBEN = 1, SUSPND = 1, bus in Idle state), the USB module current will be dominated by the D+ or D- pull-up
resistor. The integrated pull-up resistors use “resistor switching” according to the resistor_ecn supplement to
the “USB 2.0 Speci fic at ions, and therefore, may be as low as 900 during Idle conditions.
PIC18F46J50 FAMILY
DS39931D-page 502 2011 Microchip Technology Inc.
30.3 DC Characteristics:PIC18F46J50 Family (Industrial)
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
Param
No. Symbol Characteristic Min Max Units Conditions
VIL Input Low Volta ge
All I/O ports:
D030 with TTL Buffer(4) VSS 0.15 VDD VVDD < 3.3V
D030A with TTL Buffer(4) VSS 0.8 V 3.3V < VDD <3.6V
D031 with Schmitt Trigger Buffer VSS 0.2 VDD V
D031A SDAx/SCLx VSS 0.3 VDD VI
2C™ enabled
D031B SDAx/SCLx VSS 0.8 V SMBus enabled
D032 MCLR VSS 0.2 VDD V
D033 OSC1 VSS 0.3 VDD V HS, HSPLL modes
D033A
D034
OSC1
T1OSI
VSS
VSS
0.2 VDD
0.3
V
V
EC, ECPLL modes
T1OSCEN = 1
VIH Input High Voltage
I/O Ports without 5.5V
Toleran ce:
D040 with TTL Buffer(4) 0.25 VDD + 0.8V VDD VVDD < 3.3V
D040A with TTL Buffer(4) 2.0 VDD V3.3V < VDD <3.6V
D041 with Schmitt Trigger Buffer 0.8 VDD VDD V
I/O Ports with 5.5V Tolerance:(5)
Dxxx with TTL Buffer 0.25 VDD + 0.8V 5.5 V VDD < 3.3V
DxxxA 2.0 5.5 V 3.3V VDD 3.6V
Dxxx with Schmitt Trigger Buffer 0.8 VDD 5.5 V
D041A SDAx/SCLx 0.7 VDD 5.5 V I2C™ enabled
D041B SDAx/SCLx 2.1 5.5 V SMBus enabled, VDD > 3V
D042 MCLR 0.8 VDD 5.5 V
D043 OSC1 0.7 VDD VDD V HS, HSPLL modes
D043A
D044
OSC1
T1OSI
0.8 VDD
1.6
VDD
VDD
V
V
EC, ECPLL modes
T1OSCEN = 1
IIL Input Leakage Current (1,2)
D060 I/O Ports ±0.2 AV
SS VPIN VDD,
Pin at high-impedance
D061 MCLR —±0.2A Vss VPIN VDD
D063 OSC1 ±0.2 A Vss VPIN VDD
IPU Weak Pull-up Current
D070 IPURB PORTB, PORTD(3) and
PORTE(3) Weak Pull-up Current
80 400 AV
DD = 3.3V, VPIN = VSS
Note 1: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels
represent normal operating conditions. Higher leakage current may be measured at different input voltages.
2: Negative current is defined as current sourced by the pin.
3: Only available on 44-pin devices.
4: When used as general purpose inputs, the RC4 and RC5 thresholds are referenced to VUSB instead of VDD.
5: Refer to Ta b le 1 0 - 2 for pin tolerance levels.
2011 Microchip Technology Inc. DS39931D-page 503
PIC18F46J50 FAMILY
VOL Output Low Voltage
D080 I/O Ports:
PORTA (except RA6),
PORTD, PORTE
—0.4VI
OL = 2 mA, VDD = 3.3V,
-40C to +85C
PORTB, PORTC, RA6 0.4 V IOL = 8.5 mA, VDD = 3.3V,
-40C to +85C
VOH Output High Voltage
D090 I/O Ports: V
PORTA (except RA6),
PORTD, PORTE
2.4 V IOH = -2 mA, VDD = 3.3V,
-40C to +85C
PORTB, PORTC, RA6 2.4 V IOH = -6 mA, VDD = 3.3V,
-40C to +85C
Capacitive Loading Specs
on Output Pins
D101 CIO All I/O Pins and OSC2 50 pF To meet the AC Timing
Specifications
D102 CBSCLx, SDAx 400 pF I2C™ Specification
30.3 DC Characteristics:PIC18F46J50 Family (Industrial) (Continued)
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
Param
No. Symbol Characteristic Min Max Units Conditions
Note 1: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels
represent normal operating conditions. Higher leakage current may be measured at different input voltages.
2: Negative current is defined as current sourced by the pin.
3: Only available on 44-pin devices.
4: When used as general purpose inputs, the RC4 and RC5 thresholds are referenced to VUSB instead of VDD.
5: Refer to Table 10-2 for pin tolerance levels.
PIC18F46J50 FAMILY
DS39931D-page 504 2011 Microchip Technology Inc.
TABLE 30-1: MEMORY PROGRAMMING REQUIREMENTS
TABLE 30-2: COMPARATOR SPECIFICATIONS
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Sym Characteristic Min Typ† Max Units Conditions
Program Flash Memory
D130 EPCell Endurance 10K E/W -40C to +85C
D131 VPR VDDcore for Read VMIN —2.75VVMIN = Minimum operating
voltage
D132B VPEW VDDCORE for Self-Timed Erase or
Write
2.25 2.75 V
D133A TIW Self-Timed Write Cycle Time 2.8 ms 64 bytes
D133B TIE Self-Timed Block Erase Cycle
Time
—33.0—ms
D134 TRETD Characteristic Retention 20 Year Provided no other
specifications are violated
D135 IDDP Supply Current during
Programming
—3—mA
Data in “Typ” column is at 3.3V, 25°C unless otherwise stated.
Operating Conditions: 3.0V < VDD < 3.6V, -40°C < TA < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
D300 VIOFF Input Offset Voltage +/-5 +/-25 mV
D301 VICM Input Common Mode Voltage 0 VDD V
VIRV Internal Reference Voltage 0.57 0.60 0.63 V
D302 CMRR Common Mode Rejection Ratio 55 dB
D303 TRESP Response Time(1) —150400 ns
D304 TMC2OV Comparator Mode Change to
Output Valid
—— 10 s
Note 1: Response time measured with one comparator input at VDD/2, while the other input transitions from VSS to
VDD.
2011 Microchip Technology Inc. DS39931D-page 505
PIC18F46J50 FAMILY
TABLE 30-3: VOLTAGE REFERENCE SPECIFICATIONS
TABLE 30-4: INTERNAL VOLTAGE REGULATOR SPECIFICATIONS
TABLE 30-5: ULPWU SPECIFICATIONS
TABLE 30-6: CTMU CURRENT SOURCE SPECIFICATIONS
Operating Condit ions : 3.0V < VDD < 3.6V, -40°C < TA < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
D310 VRES Resolution VDD/24 VDD/32 LSb
D311 VRAA Absolute Accuracy 1/2 LSb
D312 VRUR Unit Resistor Value (R) 2k
D313 TSET Settling Time(1) — — 10 s
Note 1: Settling time measured while CVRR = 1 and CVR<3:0> bits transition from ‘0000’ to1111’.
Operating Condit ions : -40°C < T
A < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
VRGOUT Regulator Output Voltage 2.35 2.5 2.7 V Regulator enabled, VDD = 3.0V
CEFC External Filter Capacitor
Value(1) 5.4 10 18 F ESR < 3 recommended
ESR < 5 required
Note 1: CEFC applies for PIC18F devices in the family. For PIC18LF devices in the family, there is no specific
minimum or maximum capacitance for VDDCORE, although proper supply rail bypassing should still be
used.
DC CHARACTERISTICS Standard Operating Conditions (unless ot he rwise stated)
Operating temperature -40°C T
A +85°C for industrial
Param
No. Sym Characteristic Min Typ† Max Units Conditions
D100 IULP Ultra Low-Power Wake-up Current —60 nA
Net of I/O leakage and current sink
at 1.6V on pin,
VDD = 3.3V
See Application Note AN879,
Usi ng the Mi crochi p Ultra
Low-Power Wake-up Module
(DS00879)
Data in “Typ” column is at 3.3V, 25°C unless otherwise stated.
DC CHARACTERISTICS Standard Operating Condi tions: 2. 0V to 3.6V (u nles s otherwi se stated)
Operating temperature -40°C TA +85°C for Industrial
Param
No. Sym Characteristic Min Typ(1) Max Units Conditions
IOUT1 CTMU Current Source, Base Range 550 nA CTMUICON<1:0> = 01
IOUT2 CTMU Current Source, 10x Range 5.5 A CTMUICON<1:0> = 10
IOUT3 CTMU Current Source, 100x Range 55 A CTMUICON<1:0> = 11
Note 1: Nominal value at center point of current trim range (CTMUICON<7:2> = 000000).
PIC18F46J50 FAMILY
DS39931D-page 506 2011 Microchip Technology Inc.
TABLE 30-7: USB MODULE SPECIFICATIONS
Operating Conditions: -40°C < TA < +85°C (unless otherwise stated)
Param
No. Sym Characteristics Min Typ Max Units Comments
D313 VUSB USB Voltage 3.0 3.6 V Voltage on VUSB pin must
be in this range for proper
USB operation
D314 IIL Input Leakage on D+ or D- +/-0.5 AVSS < VPIN < VUSB
D315 VILUSB Input Low Voltage for
USB Buffer
——0.8 VFor VUSB range
D316 VIHUSB Input High Voltage for
USB Buffer
2.0 V For VUSB range
D318 VDIFS Differential Input Sensitivity 0.2 V The difference between D+
and D- must exceed this
value while VCM is met
D319 VCM Differential Common Mode
Range
0.8 2.5 V
D320 ZOUT Driver Output Impedance(1) 28 44
D321 VOL Voltage Output Low 0.0 0.3 V 1.5 kload connected to
3.6V
D322 VOH Voltage Output High 2.8 3.6 V 1.5 kload connected to
ground
Note 1: The D+ and D- signal lines have built-in impedance matching resistors. No external resistors, capacitors or
magnetic components are necessary on the D+/D- signal paths between the PIC18F46J50 family device
and a USB cable.
2011 Microchip Technology Inc. DS39931D-page 507
PIC18F46J50 FAMILY
FIGURE 30-3: HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
TABLE 30-8: HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C TA +85°C for industrial
Param
No. Symbol Characteristic Min Typ Max Units Conditions
D420 HLVD Voltage on VDD
Transition High-to-Low
HLVDL<3:0> = 1000 2.33 2.45 2.57 V
HLVDL<3:0> = 1001 2.47 2.60 2.73 V
HLVDL<3:0> = 1010 2.66 2.80 2.94 V
HLVDL<3:0> = 1011 2.76 2.90 3.05 V
HLVDL<3:0> = 1100 2.85 3.00 3.15 V
HLVDL<3:0> = 1101 2.97 3.13 3.29 V
HLVDL<3:0> = 1110 3.23 3.40 3.57 V
D421 TIRVST Time for Internal Reference Voltage to
become Stable
—20—s
D422 TLVD High/Low-Voltage Detect Pulse Width 200 s
VHLVD
HLVDIF
VDD
(HLVDIF set by hardware) (HLVDIF can be
cleared in software)
VHLVD
For VDIRMAG = 1:
For VDIRMAG = 0:VDD
PIC18F46J50 FAMILY
DS39931D-page 508 2011 Microchip Technology Inc.
30.4 AC (Timing) Characteristics
30.4.1 TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created
following one of the following formats:
1. TppS2ppS 3. TCC:ST (I2C specifications only)
2. TppS 4. Ts (I2C specifications only)
T
F Frequency T Time
Lowercase letters (pp) and their meanings:
pp
cc CCP1 osc OSC1
ck CLKO rd RD
cs CS rw RD or WR
di SDI sc SCK
do SDO ss SS
dt Data in t0 T0CKI
io I/O port t1 T13CKI
mc MCLR wr WR
Uppercase letters and their meanings:
S
F Fall P Period
HHigh RRise
I Invalid (High-impedance) V Valid
L Low Z High-impedance
I2C only
AA output access High High
BUF Bus free Low Low
T
CC:ST (I2C specifications only)
CC
HD Hold SU Setup
ST
DAT DATA input hold STO Stop condition
STA Start condition
2011 Microchip Technology Inc. DS39931D-page 509
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30.4.2 TIMING CONDITIONS
The temperature and voltages specified in Table 30-9
apply to all timing specifications unless otherwise
noted. Figure 30-4 specifies the load conditions for the
timing specifications.
TABLE 30-9: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC
FIGU RE 30-4: LO AD C OND IT I ONS FOR D EV I CE TIMING S P EC IF IC ATI O NS
AC CHARACTERISTICS St anda rd Operat ing Conditi ons (unle ss otherw is e stated)
Operating temperature -40°C TA +85°C for industrial
Operating voltage VDD range as described in Section 30.1 and Section 30.3.
VDD/2
CL
RL
Pin
Pin
VSS
VSS
CL
RL=464
CL= 50 pF for all pins except OSC2/CLKO/RA6
and including D and E outputs as ports
CL= 15 pF for OSC2/CLKO/RA6
Load Condition 1 Load Condition 2
PIC18F46J50 FAMILY
DS39931D-page 510 2011 Microchip Technology Inc.
30.4.3 TIMING DIAGRAMS AND SPECIFICATIONS
FIGU RE 30-5: EXT ER NA L C LOC K TIMI NG
TABLE 30-10: EXTERNAL CLOCK TIMING REQUIREMENTS
Param.
No. Symbol Characteristic Min Max Units Conditions
1A FOSC External CLKI Frequency(1) DC 48 MHz EC Oscillator mode
DC 48 ECPLL Oscillator mode(2)
Oscillator Frequency(1) 4 16 MHz HS Oscillator mode
416
(4) HSPLL Oscillator mode(3)
1TOSC External CLKI Period(1) 20.8 ns EC Oscillator mode
20.8 ECPLL Oscillator mode(2)
Oscillator Period(1) 62.5 250 ns HS Oscillator mode
62.5(4) 250 HSPLL Oscillator mode(3)
2TCY Instruction Cycle Time(1) 83.3 DC ns TCY = 4/FOSC, Industrial
3TOSL,
TOSH
External Clock in (OSC1)
High or Low Time
10 ns EC Oscillator mode
4TOSR,
TOSF
External Clock in (OSC1)
Rise or Fall Time
7.5 ns EC Oscillator mode
Note 1: The instruction cycle period (T
CY) equals four times the input oscillator time base period for all configura-
tions except PLL. All specified values are based on characterization data for that particular oscillator type
under standard operating conditions, with the device executing code. Exceeding these specified limits may
result in an unstable oscillator operation and/or higher than expected current consumption. All devices are
tested to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external
clock input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.
2: In order to use the PLL, the external clock frequency must be either 4, 8, 12, 16, 20, 24, 40 or 48 MHz.
3: In order to use the PLL, the crystal/resonator must produce a frequency of either 4, 8, 12 or 16 MHz.
4: This is the maximum crystal/resonator driver frequency. The internal FOSC frequency when running from
the PLL can be up to 48 MHz.
OSC1
CLKO
Q4 Q1 Q2 Q3 Q4 Q1
1
2
3344
2011 Microchip Technology Inc. DS39931D-page 511
PIC18F46J50 FAMILY
TABLE 30-11: PLL CLOCK TIMING SPECIFICATIONS (VDDCORE = 2.35V TO 2.75V)
TABLE 30-12: INTERNAL RC ACCURACY (INTOSC AND INTRC SOURCES)
Param
No. Sym Characteristic Min Typ Max Units Conditions
F10 FPLLIN PLL Input Frequency Range 4(1) —MHz
F11 FPLLO PLL Output Frequency (24x FPLLIN)—96MHz
F12 trc PLL Start-up Time (lock time) 2 ms
Note 1: PLL is designed for 4 MHz input frequency, but can accept 4 MHz to 48 MHz inputs using the PLL input prescaler.
Param
No. Device Min Typ Max Units Conditions
INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz, 31 kHz(1)
All Devices -1 +/-0.15 +1 % 0°C to +85°C VDD = 2.4V-3.6V
VDDCORE = 2.3V-2.7V
-1 +/-0.25 +1 % -40°C to +85°C VDD = 2.0V-3.6V
VDDCORE = 2.0V-2.7V
INTRC Accuracy @ Freq = 31 kHz(1)
All Devices 20.3 42.2 kHz -40°C to +85°C VDD = 2.0V-3.6V
VDDCORE = 2.0V-2.7V
Note 1: The accuracy specification of the 31 kHz clock is determined by which source is providing it at a given time.
When INTSRC (OSCTUNE<7>) is 1’, use the INTOSC accuracy specification. When INTSRC is ‘0’, use
the INTRC accuracy specification.
PIC18F46J50 FAMILY
DS39931D-page 512 2011 Microchip Technology Inc.
FIGURE 30-6: CLKO AND I/O TIMING
TABLE 30-13: CLKO AND I/O TIMING REQUIREMENTS
Param
No. Symbol Characteristic Min Typ Max Units Conditions
10 TOSH2CKLOSC1 to CLKO 75 200 ns (Note 1)
11 TOSH2CKHOSC1 to CLKO 75 200 ns (Note 1)
12 TCKRCLKO Rise Time 15 30 ns(Note 1)
13 TCKFCLKO Fall Time 15 30 ns(Note 1)
14 TCKL2IOVCLKO to Port Out Valid 0.5 TCY + 20 ns
15 TIOV2CKH Port In Valid before CLKO 0.25 TCY + 25 ns
16 TCKH2IOI Port In Hold after CLKO 0—ns
17 TOSH2IOVOSC1 (Q1 cycle) to Port Out Valid 50 150 ns
18 TOSH2IOIOSC1 (Q2 cycle) to Port Input Invalid
(I/O in hold time)
100 ns
19 TIOV2OSH Port Input Valid to OSC1 
(I/O in setup time)
0—ns
20 TIOR Port Output Rise Time 6 ns
21 TIOF Port Output Fall Time 5 ns
22† TINP INTx pin High or Low Time TCY ——ns
23† TRBP RB<7:4> Change INTx High or Low
Time
TCY ——ns
These parameters are asynchronous events not related to any internal clock edges.
Note 1: Measurements are taken in EC mode, where CLKO output is 4 x TOSC.
Note: Refer to Figure 30-4 for load conditions.
OSC1
CLKO
I/O pin
(Input)
I/O pin
(Output)
Q4 Q1 Q2 Q3
10
13
14
17
20, 21
19 18
15
11
12
16
Old Value New Value
2011 Microchip Technology Inc. DS39931D-page 513
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FIGURE 30-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
TABLE 30-14: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
No. Symbol Characteristic Min Typ Max Units Conditions
30 TMCLMCLR Pulse Width (low) 2 s(Note 3)
31 TWDT Watchdog Timer Time-out Period
(no postscaler)
2.67 4.0 5.53 ms
32 TOST Oscillator Start-up Timer Period 1024 TOSC 1024 TOSC —TOSC = OSC1 period
33 TPWRT Power-up Timer Period 1.0 ms
34 TIOZ I/O High-Impedance from MCLR
Low or Watchdog Timer Reset
——3 TCY + 2 s(Note 1)
36 TIRVST Time for Internal Reference
Voltage to become Stable
—20 s
37 TLVD High/Low-Voltage Detect
Pulse Width
—200 s
38 TCSD CPU Start-up Time 200 s(Note 2)
Note 1: The maximum TIOZ is the lesser of (3 TCY + 2 s) or 700 s.
2: MCLR rising edge to code execution, assuming TPWRT (and TOST, if applicable) has already expired.
3: The MCLR input has an internal noise filter to avoid nuisance Resets. When deliberately trying to reset the
microcontroller, MCLR must be held low for at least this amount of time to ensure a Reset sequence is
triggered.
VDD
MCLR
Internal
POR
PWRT
Time-out
Oscillator
Time-out
Internal
Reset
Watchdog
Timer
Reset
33
32
30
31
34
I/O pins
34
Note: Refer to Figure 30-4 for load conditions.
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DS39931D-page 514 2011 Microchip Technology Inc.
TABLE 30-15: LOW-POWER WAKE-UP TIME
Param.
No. Symbol Characteristic Min Typ Max Units Conditions
W1 WDS Deep Sleep 1.5 ms ms REGSLP = 1
W2 WSLEEP Sleep 300 µs µs REGSLP = 1, PLLEN = 0,
FOSC = 8 MHz INTOSC
W3 WDOZE1 Sleep 12 µs µs REGSLP = 0, PLLEN = 0,
FOSC = 8 MHz INTOSC
W4 WDOZE2 Sleep 1.1 µs µs REGSLP = 0, PLLEN = 0,
FOSC = 8 MHz EC
W5 WDOZE3 Sleep 250 ns ns REGSLP = 0, PLLEN = 0,
FOSC = 48 MHz EC
W6 WIDLE Idle 300 ns ns FOSC = 48 MHz EC
2011 Microchip Technology Inc. DS39931D-page 515
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FIGU RE 30-8: T I ME R 0 AN D TIMER1 E XTE RN AL C LO CK TIMI NGS
TABLE 30-16: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No. Symbol Characteristic Min Max Units Conditions
40 TT0H T0CKI High Pulse Width No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
41 TT0L T0CKI Low Pulse Width No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
42 TT0P T0CKI Period No prescaler TCY + 10 ns
With prescaler Greater of:
20 ns or
(TCY + 40)/N
—nsN = prescale
value
(1, 2, 4,..., 256)
45 TT1H T1CKI/T3CKI
High Time
Synchronous, no prescaler 0.5 TCY + 20 ns
Synchronous, with prescaler 10 ns
Asynchronous 30 ns
46 TT1L T1CKI/T3CKI
Low Time
Synchronous, no prescaler 0.5 TCY + 5 ns
Synchronous, with prescaler 10 ns
Asynchronous 30 ns
47 TT1P T1CKI/T3CKI
Input Period
Synchronous Greater of:
20 ns or
(TCY + 40)/N
—nsN = prescale
value
(1, 2, 4, 8)
Asynchronous 83 ns
FT1 T1CKI Input Frequency Range(1) DC 12 MHz
48 T
CKE2TMRI Delay from External T1CKI Clock Edge to
Timer Increment
2 TOSC 7 TOSC
Note 1: The Timer1 oscillator is designed to drive 32.768 kHz crystals. When T1CKI is used as a digital input,
frequencies up to 12 MHz are supported.
Note: Refer to Figure 30-4 for load conditions.
46
47
45
48
41
42
40
T0CKI
T1OSO/T1CKI
TMR0 or
TMR1
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DS39931D-page 516 2011 Microchip Technology Inc.
FIGURE 30-9: ENHANCED CAPTURE/COMPARE/PWM TIMINGS
TABLE 30-17: ENHANCED CAPTURE/COMPARE/PWM REQUIREMENTS
Param
No. Symbol Characteristic Min Max Units Conditions
50 TCCL ECCPx Input Low Time No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
51 TCCH ECCPx Input High Time No prescaler 0.5 TCY + 20 ns
With prescaler 10 ns
52 TCCP ECCPx Input Period 3 TCY + 40
N
—nsN = prescale
value (1, 4 or 16)
53 TCCR ECCPx Output Rise Time 25 ns
54 TCCF ECCPx Output Fall Time 25 ns
Note: Refer to Figure 30-4 for load conditions.
ECCPx
(Capture Mode)
50 51
52
ECCPx
53 54
(Compare or PWM Mode)
2011 Microchip Technology Inc. DS39931D-page 517
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FIGURE 30-10: PARALLEL MASTER PORT READ TIMING DIAGRAM
TABLE 30-18: PARALLEL MASTER PORT READ TIMING REQUIREMENTS
Param.
No Symbol Characteristics Min Typ Max Units
PM1 PMALL/PMALH Pulse Width 0.5 T
CY —ns
PM2 Address Out Valid to PMALL/PMALH
Invalid (address setup time)
0.75 TCY —ns
PM3 PMALL/PMALH Invalid to Address Out
Invalid (address hold time)
0.25 TCY —ns
PM5 PMRD Pulse Width 0.5 TCY —ns
PM6 Data in Valid to PMRD or PMENB Invalid
(data setup time)
———ns
PM7 PMRD or PMENB Inactive to Data In Invalid
(data hold time)
—— 5ns
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2
System
PMALL/PMALH
PMD<7:0>
Address
PMA<13:18>
Operating Conditions: 2.0V < VDD < 3.6V, -40°C < TA < +85°C unless otherwise stated.
PMWR
PMCS
PMRD
Clock
PM2
PM3
PM6
PM7
PM5
PM1
Data
Address<7:0>
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DS39931D-page 518 2011 Microchip Technology Inc.
FIGURE 30-11: PARALLEL MASTER PORT W RITE TIMING DIAGRAM
TABLE 30-19: PARALLEL MASTER PORT WRITE TIMING REQUIREMENTS
Param.
No Symbol Characteristics Min Typ Max Units
PM11 PMWR Pulse Width 0.5 T
CY —ns
PM12 Data Out Valid before PMWR or PMENB
goes Inactive (data setup time)
0.75 TCY —ns
PM13 PMWR or PMEMB Invalid to Data Out
Invalid (data hold time)
0.25 TCY —ns
PM16 PMCS Pulse Width T
CY – 5 ns
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2
System
PMALL/
PMD<7:0>
Address
PMA<13:18>
PMWR
PMCS<2:1>
PMRD
Clock
PM12 PM13
PM11
PM16
Data
Address<7:0>
PMALH
Note: Operating Conditions: 2.0V < VDD < 3.6V, -40°C < TA < +85°C unless otherwise stated.
2011 Microchip Technology Inc. DS39931D-page 519
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FIGURE 30-12: PARALLEL SLAVE PORT TIMING
TABLE 30-20: PARALLE L SLAVE PORT REQUIREMENTS
AC CHARACTERISTICS Standard Operating Conditions: 2.0V to 3.6V
(unless otherwise stated)
Operating temperature -40°C TA +85°C for Industrial
Param.
No. Symbol Characteristic Min Typ Max Units Conditions
PS1 TdtV2wrH Data In Valid before PMWR or PMCS
Inactive (setup time)
20 ns
PS2 TwrH2dtI PMWR or PMCS Inactive to Data–In
Invalid (hold time)
20 ns
PS3 TrdL2dtV PMRD and PMCS Active to Data–Out
Valid
80 ns
PS4 TrdH2dtI PMRD Inactiveor PMCS Inactive to
Data–Out Invalid
10 30 ns
PMCS
PMRD
PMWR
PMD<7:0>
PS1
PS2
PS3
PS4
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DS39931D-page 520 2011 Microchip Technology Inc.
FIGURE 30-13: EXAMPLE SPI MASTER MODE TIMI NG (CKE = 0)
TABLE 30-21: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Param
No. Symbol Characteristic Min Max Units Conditions
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 35 ns VDD = 3.3V,
VDDCORE = 2.5V
100 ns VDD = 2.15V,
VDDCORE = 2.15V
74 TSCH2DIL,
TSCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 30 ns VDD = 3.3V,
VDDCORE = 2.5V
83 ns VDD = 2.15V
75 TDOR SDOx Data Output Rise Time 25 ns PORTB or PORTC
76 TDOF SDOx Data Output Fall Time 25 ns PORTB or PORTC
78 TSCR SCKx Output Rise Time (Master mode) 25 ns PORTB or PORTC
79 TSCF SCKx Output Fall Time (Master mode) 25 ns PORTB or PORTC
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDIx
73
74
75, 76
78
79
79
78
MSb LSb
bit 6 - - - - - - 1
MSb In LSb In
bit 6 - - - - 1
Note: Refer to Figure 30-4 for load conditions.
2011 Microchip Technology Inc. DS39931D-page 521
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FIGURE 30-14: EXAMPLE SPI MASTER MODE TIMI NG (CKE = 1)
TABLE 30-22: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Param.
No. Symbol Characteristic Min Max Units Conditions
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 35 ns VDD = 3.3V,
VDDCORE = 2.5V
100 ns VDD = 2.15V,
VDDCORE = 2.15V
74 TSCH2DIL,
T
SCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 30 ns VDD = 3.3V,
VDDCORE = 2.5V
83 ns VDD = 2.15V
75 TDOR SDOx Data Output Rise Time 25 ns PORTB or PORTC
76 TDOF SDOx Data Output Fall Time 25 ns PORTB or PORTC
78 T
SCR SCKx Output Rise Time (Master mode) 25 ns PORTB or PORTC
79 T
SCF SCKx Output Fall Time (Master mode) 25 ns PORTB or PORTC
81 TDOV2SCH,
TDOV2SCL
SDOx Data Output Setup to SCKx Edge TCY —ns
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDIx
81
74
75, 76
78
MSb
79
73
MSb In
bit 6 - - - - - - 1
LSb In
bit 6 - - - - 1
LSb
Note: Refer to Figure 30-4 for load conditions.
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DS39931D-page 522 2011 Microchip Technology Inc.
FIGURE 30-15: EXAMPLE SPI SLAVE MOD E TIMING (CKE = 0)
TABLE 30-23: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0)
Param
No. Symbol Characteristic Min Max Units Conditions
70 T
SSL2SCH,
T
SSL2SCL
SSx to SCKx or SCKx Input 3 TCY —ns
70A TSSL2WB SSx to Write to SSPxBUF 3 TCY —ns
71 TSCH SCKx Input High Time
(Slave mode)
Continuous 1.25 TCY + 30 ns
71A Single byte 40 ns (Note 1)
72 T
SCL SCKx Input Low Time
(Slave mode)
Continuous 1.25 TCY + 30 ns
72A Single byte 40 ns (Note 1)
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 25 ns
73A TB2BLast Clock Edge of Byte 1 to the First Clock Edge of
Byte 2
1.5 TCY + 40 ns (Note 2)
74 T
SCH2DIL,
T
SCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 35 ns VDD = 3.3V,
VDDCORE = 2.5V
100 ns VDD = 2.15V
75 TDOR SDOx Data Output Rise Time 25 ns PORTB or PORTC
76 TDOF SDOx Data Output Fall Time 25 ns PORTB or PORTC
77 T
SSH2DOZ SSx to SDOx Output High-Impedance 10 70 ns
80 T
SCH2DOV,
T
SCL2DOV
SDOx Data Output Valid after SCKx Edge 50 ns VDD = 3.3V,
VDDCORE = 2.5V
100 ns VDD = 2.15V
83 T
SCH2SSH,
T
SCL2SSH
SSx after SCKx Edge 1.5 TCY + 40 ns
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
SSx
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDI
70
71 72
73
74
75, 76 77
80
SDIx
MSb LSb
bit 6 - - - - - - 1
bit 6 - - - - 1 LSb In
83
Note: Refer to Figure 30-4 for load conditions.
MSb In
2011 Microchip Technology Inc. DS39931D-page 523
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FIGURE 30-16: EXAMPLE SPI SLAV E MODE TIMING (CKE = 1)
TABLE 30-24: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param
No. Symbol Characteristic Min Max Units Conditions
70 TSSL2SCH,
TSSL2SCL
SSx to SCKx or SCKx Input 3 TCY —ns
70A TSSL2WB SSx to Write to SSPxBUF 3 TCY —ns
71 TSCH SCKx Input High Time
(Slave mode)
Continuous 1.25 TCY + 30 ns
71A Single byte 40 ns (Note 1)
72 TSCL SCKx Input Low Time
(Slave mode)
Continuous 1.25 TCY + 30 ns
72A Single byte 40 ns (Note 1)
73 TDIV2SCH,
TDIV2SCL
Setup Time of SDIx Data Input to SCKx Edge 25 ns
73A TB2BLast Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 ns (Note 2)
74 TSCH2DIL,
TSCL2DIL
Hold Time of SDIx Data Input to SCKx Edge 35 ns VDD = 3.3V,
VDDCORE = 2.5V
100 ns VDD = 2.15V
75 TDOR SDOx Data Output Rise Time 25 ns
76 TDOF SDOx Data Output Fall Time 25 ns
77 TSSH2DOZ SSx to SDOx Output High-Impedance 10 70 ns
80 T
SCH2DOV,
T
SCL2DOV
SDOx Data Output Valid after SCKx Edge 50 ns VDD = 3.3V,
VDDCORE = 2.5V
—100nsV
DD = 2.15V
81 TDOV2SCH,
TDOV2SCL
SDOx Data Output Setup to SCKx Edge T
CY —ns
82 T
SSL2DOV SDOx Data Output Valid after SSx Edge 50 ns
83 T
SCH2SSH,
T
SCL2SSH
SSx after SCKx Edge 1.5 TCY + 40 ns
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
SSx
SCKx
(CKP = 0)
SCKx
(CKP = 1)
SDOx
SDI
70
71 72
82
SDIx
74
75, 76
MSb bit 6 - - - - - - 1 LSb
77
bit 6 - - - - 1 LSb In
80
83
Note: Refer to Figure 30-4 for load conditions.
73
MSb In
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DS39931D-page 524 2011 Microchip Technology Inc.
FIGURE 30 - 17: I2C™ BUS ST ART/STOP BITS T IMING
TABLE 30-25: I2C™ BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
FIGURE 30 - 18: I2C™ BUS DATA TIMING
Param.
No. Symbol Characteristic Min Max Units Conditions
90 TSU:STA Start Condition 100 kHz mode 4700 ns Only relevant for Repeated
Start condition
Setup Time 400 kHz mode 600
91 THD:STA Start Condition 100 kHz mode 4000 ns After this period, the first
clock pulse is generated
Hold Time 400 kHz mode 600
92 TSU:STO Stop Condition 100 kHz mode 4700 ns
Setup Time 400 kHz mode 600
93 THD:STO Stop Condition 100 kHz mode 4000 ns
Hold Time 400 kHz mode 600
Note: Refer to Figure 30-4 for load conditions.
91
92
93
SCLx
SDAx
Start
Condition
Stop
Condition
90
Note: Refer to Figure 30-4 for load conditions.
90
91 92
100
101
103
106 107
109 109
110
102
SCLx
SDAx
In
SDAx
Out
2011 Microchip Technology Inc. DS39931D-page 525
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TABLE 30-26: I2C™ BUS DATA REQUIREMENTS (SLAVE MODE)
Param.
No. Symbol Characteristic Min Max Units Conditions
100 THIGH Clock High Time 100 kHz mode 4.0 s
400 kHz mode 0.6 s
MSSP modules 1.5 TCY
101 TLOW Clock Low Time 100 kHz mode 4.7 s
400 kHz mode 1.3 s
MSSP modules 1.5 TCY
102 TRSDAx and SCLx Rise Time 100 kHz mode 1000 ns
400 kHz mode 20 + 0.1 CB300 ns CB is specified to be from
10 to 400 pF
103 TFSDAx and SCLx Fall Time 100 kHz mode 300 ns
400 kHz mode 20 + 0.1 CB300 ns CB is specified to be from
10 to 400 pF
90 TSU:STA Start Condition Setup Time 100 kHz mode 4.7 s Only relevant for Repeated
Start condition
400 kHz mode 0.6 s
91 THD:STA Start Condition Hold Time 100 kHz mode 4.0 s After this period, the first clock
pulse is generated
400 kHz mode 0.6 s
106 THD:DAT Data Input Hold Time 100 kHz mode 0 ns
400 kHz mode 0 0.9 s
107 TSU:DAT Data Input Setup Time 100 kHz mode 250 ns (Note 2)
400 kHz mode 100 ns
92 TSU:STO Stop Condition Setup Time 100 kHz mode 4.7 s
400 kHz mode 0.6 s
109 TAA Output Valid from Clock 100 kHz mode 3500 ns (Note 1)
400 kHz mode ns
110 TBUF Bus Free Time 100 kHz mode 4.7 s Time the bus must be free
before a new transmission can
start
400 kHz mode 1.3 s
D102 CBBus Capacitive Loading 400 pF
Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns)
of the falling edge of SCLx to avoid unintended generation of Start or Stop conditions.
2: A Fast mode I2C™ bus device can be used in a Standard mode I2C bus system, but the requirement, TSU:DAT 250 ns,
must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCLx signal.
If such a device does stretch the LOW period of the SCLx signal, it must output the next data bit to the SDAx line,
TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification), before the SCLx
line is released.
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FIGURE 30 - 19: MSSPx I2C™ BUS START/STOP BITS TIMING W AVEFORMS
TABLE 30-27: MSSPx I2C™ BUS START/STOP BITS REQUIREMENTS
FIGURE 30 - 20: MSSPx I2C™ BUS DA T A T IMIN G
Param.
No. Symbol Characteristic Min Max Units Conditions
90 TSU:STA Start Condition 100 kHz mode 2(TOSC)(BRG + 1) ns Only relevant for
Repeated Start condition
Setup Time 400 kHz mode 2(TOSC)(BRG + 1)
91 THD:STA Start Condition 100 kHz mode 2(TOSC)(BRG + 1) ns After this period, the first
clock pulse is generated
Hold Time 400 kHz mode 2(TOSC)(BRG + 1)
92 TSU:STO Stop Condition 100 kHz mode 2(TOSC)(BRG + 1) ns
Setup Time 400 kHz mode 2(TOSC)(BRG + 1)
93 THD:STO Stop Condition 100 kHz mode 2(TOSC)(BRG + 1) ns
Hold Time 400 kHz mode 2(TOSC)(BRG + 1)
Note: Refer to Figure 30-4 for load conditions.
91 93
SCLx
SDAx
Start
Condition
Stop
Condition
90 92
Note: Refer to Figure 30-4 for load conditions.
90 91 92
100
101
103
106 107
109 109 110
102
SCLx
SDAx
In
SDAx
Out
2011 Microchip Technology Inc. DS39931D-page 527
PIC18F46J50 FAMILY
TABLE 30-28: MSSPx I2C™ BUS DATA REQUIREMENTS
Param.
No. Symbol Characteristic Min Max Units Conditions
100 THIGH Clock High Time 100 kHz mode 2(TOSC)(BRG + 1) s
400 kHz mode 2(TOSC)(BRG + 1) s
101 TLOW Clock Low Time 100 kHz mode 2(TOSC)(BRG + 1) s
400 kHz mode 2(TOSC)(BRG + 1) s
102 TRSDAx and SCLx
Rise Time
100 kHz mode 1000 ns CB is specified to be
from 10 to 400 pF
400 kHz mode 20 + 0.1 CB300 ns
103 TFSDAx and SCLx
Fall Time
100 kHz mode 300 ns CB is specified to be
from 10 to 400 pF
400 kHz mode 20 + 0.1 CB 300 ns
90 T
SU:STA Start Condition
Setup Time
100 kHz mode 2(TOSC)(BRG + 1) s Only relevant for
Repeated Start condition
400 kHz mode 2(TOSC)(BRG + 1) s
91 THD:STA Start Condition
Hold Time
100 kHz mode 2(TOSC)(BRG + 1) s After this period, the first
clock pulse is generated
400 kHz mode 2(TOSC)(BRG + 1) s
106 THD:DAT Data Input
Hold Time
100 kHz mode 0 ns
400 kHz mode 0 0.9 s
107 T
SU:DAT Data Input
Setup Time
100 kHz mode 250 ns (Note 1)
400 kHz mode 100 ns
92 TSU:STO Stop Condition
Setup Time
100 kHz mode 2(TOSC)(BRG + 1) s
400 kHz mode 2(TOSC)(BRG + 1) s
109 TAA Output Valid
from Clock
100 kHz mode 3500 ns
400 kHz mode 1000 ns
110 TBUF Bus Free Time 100 kHz mode 4.7 s Time the bus must be
free before a new
transmission can start
400 kHz mode 1.3 s
D102 CBBus Capacitive Loading 400 pF
Note 1: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but Parameter #107 250 ns
must then be met. This will automatically be the case if the device does not stretch the LOW period of the
SCLx signal. If such a device does stretch the LOW period of the SCLx signal, it must output the next data bit
to the SDAx line, Parameter #102 + Parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode), before the
SCLx line is released.
PIC18F46J50 FAMILY
DS39931D-page 528 2011 Microchip Technology Inc.
FIGURE 30-21: EUSARTx SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) T IMING
TABLE 30-29: EUSARTx SYNCHRONOUS TRANSMISSION REQUIREMENTS
FIGURE 30-22: EUSARTx SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
TABLE 30-30: EUSARTx SYNCHRONOUS RECEIVE REQUIREMENTS
Param
No. Symbol Characteristic Min Max Units Conditions
120 T
CKH2DTV Sync XMIT (Master and Slave)
Clock High to Data Out Valid 40 ns
121 TCKRF Clock Out Rise Time and Fall Time (Master mode) 20 ns
122 TDTRF Data Out Rise Time and Fall Time 20 ns
Param.
No. Symbol Characteristic Min Max Units Conditions
125 TDTV2CKL Sync RCV (Master and Slave)
Data Hold before CKx (DTx hold time) 10 ns
126 TCKL2DTL Data Hold after CKx (DTx hold time) 15 ns
121 121
120 122
TXx/CKx
RXx/DTx
pin
pin
Note: Refer to Figure 30-4 for load conditions.
125
126
TXx/CKx
RXx/DTx
pin
pin
Note: Refer to Figure 30-4 for load conditions.
2011 Microchip Technology Inc. DS39931D-page 529
PIC18F46J50 FAMILY
TABLE 30-31: A/D CONVERTER CHARACTERISTICS: PIC18F46J50 FAMILY (INDUSTRIAL)
FIGURE 30-23: A/D CONVERSION TIMING
Param
No. Symbol Characteristic Min Typ Max Units Conditions
A01 NRResolution 10 bit VREF 3.0V
A03 EIL Integral Linearity Error <±1 LSb VREF 3.0V
A04 EDL Differential Linearity Error <±1 LSb VREF 3.0V
A06 EOFF Offset Error <±3 LSb VREF 3.0V
A07 EGN Gain Error <±3.5 LSb VREF 3.0V
A10 Monotonicity Guaranteed(1) —VSS VAIN VREF
A20 VREF Reference Voltage Range
(VREFH – VREFL)
2.0
3
V
V
VDD 3.0V
VDD 3.0V
A21 VREFH Reference Voltage High VREFL —VDD + 0.3V V
A22 VREFL Reference Voltage Low VSS – 0.3V VREFH V
A25 VAIN Analog Input Voltage VREFL —VREFH V
A30 ZAIN Recommended Impedance of
Analog Voltage Source
——2.5k
A50 IREF VREF Input Current(2)
5
150
A
A
During VAIN acquisition.
During A/D conversion
cycle.
Note 1: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes.
2: VREFH current is from RA3/AN3/VREF+/C1INB pin or VDD, whichever is selected as the VREFH source.
VREFL current is from the RA2/AN2/VREF-/CVREF/C2INB pin or VSS, whichever is selected as the VREFL source.
131
130
132
BSF ADCON0, GO
Q4
A/D CLK
A/D DATA
ADRES
ADIF
GO
SAMPLE
OLD_DATA
SAMPLING STOPPED
DONE
NEW_DATA
(Note 2)
987 21 0
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the
SLEEP instruction to be executed.
2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.
. . . . . .
TCY (Note 1)
PIC18F46J50 FAMILY
DS39931D-page 530 2011 Microchip Technology Inc.
TABLE 30-32: A/D CONVERSION REQUIREMENTS
FIGU RE 30-24: USB SI GNAL T IMIN G
TABLE 30-33: USB LOW-SPEED TIMING REQUIREMENTS
TABLE 30-34: USB FULL- SPEED REQUIREMENTS
Param
No. Symbol Characteristic Min Max Units Conditions
130 TAD A/D Clock Period 0.7 25.0(1) sTOSC based, VREF 3.0V
131 TCNV Conversion Time
(not including acquisition time)(2) 11 12 TAD
132 TACQ Acquisition Time(3) 1.4 s-40C to +85C
135 TSWC Switching Time from Convert Sample (Note 4)
137 TDIS Discharge Time 0.2 s
Note 1: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
2: ADRES registers may be read on the following TCY cycle.
3: The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale
after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50.
4: On the following cycle of the device clock.
Param
No. Symbol Characteristic Min Typ Max Units Conditions
TLR Transition Rise Time 75 300 ns CL = 200 to 600 pF
TLF Transition Fall Time 75 300 ns CL = 200 to 600 pF
TLRFM Rise/Fall Time Matching 80 125 %
Param
No. Symbol Characteristic Min Typ Max Units Conditions
TFR Transition Rise Time 4 20 ns CL = 50 pF
TFF Transition Fall Time 4 20 ns CL = 50 pF
TFRFM Rise/Fall Time Matching 90 111.1 %
VCRS
USB Data Differential Lines
90%
10%
TLR, TFR TLF, TFF
2011 Microchip Technology Inc. DS39931D-page 531
PIC18F46J50 FAMILY
31.0 PACKAGING INFORMATION
31.1 Package Marking Information
Legend: XX...X Customer-specific information
Y Year code (last digit of calendar year)
YY Year code (last 2 digits of calendar year)
WW Week code (week of January 1 is week ‘01’)
NNN Alphanumeric traceability code
Pb-free JEDEC designator for Matte Tin (Sn)
*This package is Pb-free. The Pb-free JEDEC designator ( )
can be found on the outer packaging for this package.
Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
3
e
28-Lead SOIC (.300”)
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
YYWWNNN
Example
PIC18F26J50/SO
1110017
28-Lead QFN
XXXXXXXX
XXXXXXXX
YYWWNNN
Example
18F26J50
/ML
1110017
3
e
3
e
28-Lead SPDIP
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
YYWWNNN
Example
-I/SP
PIC18F26J50
1110017
3
e
28-Lead SSOP
XXXXXXXXXXXX
XXXXXXXXXXXX
YYWWNNN
Example
18F26J50
/SS
1110017
3
e
PIC18F46J50 FAMILY
DS39931D-page 532 2011 Microchip Technology Inc.
XXXXXXXXXX
44-Lead QFN
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
18F46J50
Example
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1110017
44-Lead TQFP
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
Example
18F46J50
-I/PT
1110017
3
e
3
e
2011 Microchip Technology Inc. DS39931D-page 533
PIC18F46J50 FAMILY
31.2 Package Details
The following sections give the technical details of the packages.
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2011 Microchip Technology Inc. DS39931D-page 535
PIC18F46J50 FAMILY
Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
PIC18F46J50 FAMILY
DS39931D-page 536 2011 Microchip Technology Inc.
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2011 Microchip Technology Inc. DS39931D-page 537
PIC18F46J50 FAMILY
Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
PIC18F46J50 FAMILY
DS39931D-page 538 2011 Microchip Technology Inc.
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DS39931D-page 544 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 545
PIC18F46J50 FAMILY
APPENDIX A: REVISION HISTORY
Revision A (September 2008)
Original data sheet for the PIC18F46J50 family of
devices.
Revision B (March 2009)
Changes to the Electrical Characteristics and minor
text edits throughout the document.
Revision C (October 2009)
Removed “Preliminary” marking.
Revisi on D (Mar ch 2011)
Added Section 2.0, Guidelines for Getting Started
with PIC18FJ Microcontrollers. Renamed CTEDG1
and CTEDG2 pin functions to CTED1 and CTED2,
respectively. Clarifications and minor text edits
throughout the document.
APPENDIX B: DEVICE
DIFFERENCES
The differences between the devices listed in this data
sheet are shown in Table B-1,
TABLE B-1: DEVICE DIFFERENCES BETWEEN PIC18F46J50 FAMILY MEMBERS
Features PIC18F24J50 PIC18F25J50 PIC18F26J50 PIC18F44J50 PIC18F45J50 PIC18F46J50
Program Memory 16K 32K 64K 16K 32K 64K
Program Memory
(Instructions)
8,192 16,384 32,768 8,192 16,384 32,768
I/O Ports (Pins) Ports A, B, C Ports A, B, C, D, E
10-Bit ADC Module 10 Input Channels 13 Input Channels
Packages 28-Pin QFN, SOIC, SSOP and SPDIP (300 mil) 44-Pin QFN and TQFP
PIC18F46J50 FAMILY
DS39931D-page 546 2011 Microchip Technology Inc.
NOTES:
2011 Microchip Technology Inc. DS39931D-page 547
PIC18F46J50 FAMILY
INDEX
A
A/D ................................................................................... 347
A/D Converter Interrupt, Configuring ....................... 351
Acquisition Requirements ........................................ 352
ADCAL Bit ................................................................ 355
ADRESH Register .................................................... 350
Analog Port Pins, Configuring .................................. 353
Associated Registers ............................................... 356
Automatic Acquisition Time ...................................... 353
Calibration ................................................................ 355
Configuring the Module ............................................ 351
Conversion Clock (TAD) ........................................... 353
Conversion Requirements ....................................... 530
Conversion Status (GO/DONE Bit) .......................... 350
Conversions ............................................................. 354
Converter Characteristics ........................................ 529
Operation in Power-Managed Modes ...................... 355
Special Event Trigger (ECCPx) ............................... 354
Use of the ECCP2 Trigger ....................................... 354
Absolute Maximum Ratings ............................................. 489
AC (Timing) Characteristics ............................................. 508
Load Conditions for Device Timing
Specifications ................................................... 509
Parameter Symbology ............................................. 508
Temperature and Voltage Specifications ................. 509
Timing Conditions .................................................... 509
ACKSTAT ........................................................................ 313
ACKSTAT Status Flag ..................................................... 313
ADCAL Bit ........................................................................ 355
ADCON0 Register
GO/DONE Bit ........................................................... 350
ADDFSR .......................................................................... 478
ADDLW ............................................................................ 441
ADDULNK ........................................................................ 478
ADDWF ............................................................................ 441
ADDWFC ......................................................................... 442
ADRESL Register ............................................................ 350
Analog-to-Digital Converter. See A/D.
ANDLW ............................................................................ 442
ANDWF ............................................................................ 443
Assembler
MPASM Assembler .................................................. 486
Auto-Wake-up on Sync Break Character ......................... 338
B
Baud Rate Generator ....................................................... 309
BC .................................................................................... 443
BCF .................................................................................. 444
BF .................................................................................... 313
BF Status Flag ................................................................. 313
Block Diagrams
+5V System Hardware Interface .............................. 133
8-Bit Multiplexed Address and Data Application ...... 191
A/D ........................................................................... 350
Analog Input Model .................................................. 351
Baud Rate Generator ............................................... 310
Capture Mode Operation ......................................... 248
Clock Source Multiplexing ........................................ 238
Comparator Analog Input Model .............................. 387
Comparator Output .................................................. 385
Comparator Voltage Reference ............................... 391
Comparator Voltage Reference Output
Buffer Example ................................................ 393
Compare Mode Operation ....................................... 249
CTMU ...................................................................... 401
CTMU Current Source Calibration Circuit ............... 404
CTMU Typical Connections and Internal
Configuration for Pulse Delay Generation ....... 412
CTMU Typical Connections and Internal
Configuration for Time Measurement .............. 411
Demultiplexed Addressing Mode with
Chip Select ...................................................... 184
Device Clock .............................................................. 36
Enhanced PWM Mode ............................................. 253
EUSART Transmit ................................................... 334
EUSARTx Receive .................................................. 337
Fail-Safe Clock Monitor ........................................... 432
Fully Multiplexed Addressing Mode with
Chip Select ...................................................... 184
Generic I/O Port Operation ...................................... 131
High/Low-Voltage Detect with External Input .......... 396
Interrupt Logic .......................................................... 116
LCD Control, Byte Mode .......................................... 192
Legacy Parallel Slave Port ...................................... 178
MSSPx (I2C Master Mode) ...................................... 308
MSSPx (I2C Mode) .................................................. 288
MSSPx (SPI Mode) ................................................. 270
Multiplexed Addressing Application ......................... 191
On-Chip Reset Circuit ................................................ 63
Parallel EEPROM (Up to 15-Bit Address,
16-Bit Data) ..................................................... 192
Parallel EEPROM (Up to 15-Bit Address,
8-Bit Data) ....................................................... 192
Parallel Master/Slave Connection
Addressed Buffer ............................................. 181
Parallel Master/Slave Connection Buffered ............. 180
Partially Multiplexed Addressing Application ........... 191
Partially Multiplexed Addressing Mode with
Chip Select ...................................................... 184
PIC18F2XJ50 (28-Pin) .............................................. 14
PIC18F4XJ50 (44-Pin) .............................................. 15
PMP Module ............................................................ 169
PWM Operation (Simplified) .................................... 250
Reads From Flash Program Memory ...................... 107
RTCC ....................................................................... 225
Simplified Steering ................................................... 266
Single Comparator ................................................... 387
Table Read Operation ............................................. 103
Table Write Operation ............................................. 104
Table Writes to Flash Program Memory .................. 109
Timer0 in 16-Bit Mode ............................................. 196
Timer0 in 8-Bit Mode ............................................... 196
Timer1 ..................................................................... 204
Timer2 ..................................................................... 212
Timer3 ..................................................................... 216
Timer4 ..................................................................... 224
USB External Circuitry ............................................. 362
USB Interrupt Logic ................................................. 372
USB Peripheral and Options ................................... 357
Using the Open-Drain Output .................................. 133
USTAT FIFO ............................................................ 363
Watchdog Timer ...................................................... 427
BN .................................................................................... 444
BNC ................................................................................. 445
BNN ................................................................................. 445
BNOV .............................................................................. 446
BNZ ................................................................................. 446
BOR. See Brown-out Reset.
PIC18F46J50 FAMILY
DS39931D-page 548 2011 Microchip Technology Inc.
BOV .................................................................................. 449
BRA .................................................................................. 447
Break Character (12-Bit) Transmit and Receive .............. 340
Brown-out Reset (BOR) ..................................................... 65
and On-Chip Voltage Regulator ............................... 430
Detecting .................................................................... 65
Disabling in Sleep Mode ............................................ 65
BSF .................................................................................. 447
BTFSC .............................................................................448
BTFSS .............................................................................. 448
BTG .................................................................................. 449
BZ ..................................................................................... 450
C
C Compilers
MPLAB C18 .............................................................486
Calibration (A/D Converter) .............................................. 355
CALL ................................................................................ 450
CALLW .............................................................................479
Capture (ECCP Module) .................................................. 248
CCPRxH:CCPRxL Registers ................................... 248
ECCP Pin Configuration .......................................... 248
Prescaler ..................................................................248
Software Interrupt .................................................... 248
Timer1/Timer3 Mode Selection ................................ 248
Clock Sources .................................................................... 42
Effects of Power-Managed Modes ............................. 45
Selecting the 31 kHz Source ......................................42
Selection Using OSCCON Register ........................... 42
CLRF ................................................................................451
CLRWDT ..........................................................................451
Code Examples
16 x 16 Signed Multiply Routine .............................. 114
16 x 16 Unsigned Multiply Routine .......................... 114
512-Byte SPI Master Mode Init and Transfer ........... 286
8 x 8 Signed Multiply Routine .................................. 113
8 x 8 Unsigned Multiply Routine .............................. 113
A/D Calibration Routine ...........................................355
Calculating Baud Rate Error .................................... 328
Capacitance Calibration Routine ............................. 408
Capacitive Touch Switch Routine ............................ 410
Changing Between Capture Prescalers ................... 248
Clearing ACTVIF Bit .................................................374
Communicating with the +5V System ...................... 133
Computed GOTO Using an Offset Value ................... 81
Configuring EUSART2 Input and Output Functions .... 154
Current Calibration Routine ..................................... 406
Erasing Flash Program Memory .............................. 108
Fast Register Stack .................................................... 81
How to Clear RAM (Bank 1) Using
Indirect Addressing ............................................ 97
Initializing PORTA .................................................... 136
Initializing PORTB .................................................... 139
Initializing PORTC .................................................... 143
Initializing PORTD .................................................... 146
Initializing PORTE .................................................... 148
Loading the SSP1BUF (SSP1SR) Register ............. 273
Reading a Flash Program Memory Word ................ 107
Saving STATUS, WREG and BSR
Registers in RAM ............................................. 130
Setting the RTCWREN Bit ....................................... 239
Setup for CTMU Calibration Routines ...................... 405
Single-Word Write to Flash Program Memory ......... 111
Two-Word Instructions ............................................... 83
Ultra Low-Power Wake-up Initialization ..................... 61
Writing to Flash Program Memory ........................... 110
Code Protection ............................................................... 417
COMF .............................................................................. 452
Comparator ...................................................................... 385
Analog Input Connection Considerations ................ 387
Associated Registers ............................................... 390
Configuration, Control .............................................. 388
Effects of a Reset .................................................... 390
Enable and Input Selection ...................................... 388
Enable and Output Selection ................................... 388
Interrupts ................................................................. 389
Operation ................................................................. 387
Operation During Sleep ........................................... 390
Registers ................................................................. 385
Response Time ........................................................ 387
Comparator Specifications ............................................... 504
Comparator Voltage Reference ....................................... 391
Accuracy and Error .................................................. 393
Associated Registers ............................................... 393
Configuring .............................................................. 392
Connection Considerations ...................................... 393
Effects of a Reset .................................................... 393
Operation During Sleep ........................................... 393
Compare (ECCP Module) ................................................ 249
CCPRx Register ...................................................... 249
Pin Configuration ..................................................... 249
Software Interrupt .................................................... 249
Special Event Trigger ...................................... 221, 249
Timer1/Timer3 Mode Selection ................................ 249
Compare (ECCPx Module)
Special Event Trigger .............................................. 354
Computed GOTO ............................................................... 81
Configuration Bits ............................................................ 417
Configuration Mismatch (CM) Reset .................................. 66
Configuration Register Protection .................................... 433
Configuration Registers
Bits and Device IDs ................................................. 418
Mapping Flash Configuration Words ....................... 418
Core Features
Easy Migration ........................................................... 12
Expanded Memory ..................................................... 11
Extended Instruction Set ........................................... 12
nanoWatt Technology ................................................ 11
Oscillator Options and Features ................................ 11
Universal Serial Bus (USB) ........................................ 11
CPFSEQ .......................................................................... 452
CPFSGT .......................................................................... 453
CPFSLT ........................................................................... 453
Crystal Oscillator/Ceramic Resonators .............................. 37
CTMU
Associated Registers ............................................... 415
Calibration ............................................................... 403
Creating a Delay ...................................................... 412
Effects of a Reset .................................................... 412
Initialization .............................................................. 403
Measuring Capacitance ........................................... 409
Measuring Time ....................................................... 411
Operation ................................................................. 402
Operation During Idle Mode ..................................... 412
Operation During Sleep Mode ................................. 412
CTMU Current Source Specifications .............................. 505
Customer Change Notification Service ............................ 559
Customer Notification Service ......................................... 559
Customer Support ............................................................ 559
2011 Microchip Technology Inc. DS39931D-page 549
PIC18F46J50 FAMILY
D
Data Addressing Modes ..................................................... 97
Comparing Addressing Modes with the
Extended Instruction Set Enabled ................... 101
Direct .......................................................................... 97
Indexed Literal Offset ............................................... 100
BSR ................................................................. 102
Instructions Affected ........................................ 100
Mapping Access Bank ..................................... 102
Indirect ....................................................................... 97
Inherent and Literal .................................................... 97
Data Memory ..................................................................... 84
Access Bank .............................................................. 86
Bank Select Register (BSR) ....................................... 84
Extended Instruction Set ............................................ 99
General Purpose Registers ........................................ 86
Memory Maps
Access Bank Special Function Registers .......... 87
Non-Access Bank Special
Function Registers ..................................... 88
PIC18F46J50 Family Devices ........................... 85
Special Function Registers ........................................ 87
Context Defined SFRs ....................................... 89
USB RAM ................................................................... 84
DAW ................................................................................. 454
DC Characteristics ........................................................... 502
Power-Down and Supply Current ............................ 492
Supply Voltage ......................................................... 491
DCFSNZ .......................................................................... 455
DECF ............................................................................... 454
DECFSZ ........................................................................... 455
Development Support ...................................................... 485
Device Differences ........................................................... 545
Device Overview ................................................................ 11
Details on Individual Family Members ....................... 12
Features (28-Pin Devices) ......................................... 13
Features (44-Pin Devices) ......................................... 13
Other Special Features .............................................. 12
Direct Addressing ............................................................... 98
E
Effect on Standard PICMCU Instructions ......................... 482
Electrical Characteristics .................................................. 489
Absolute Maximum Ratings ..................................... 489
DC Characteristics ........................................... 491–502
Enhanced Capture/Compare/PWM (ECCP) .................... 245
Associated Registers ............................................... 267
Capture Mode. See Capture.
Compare Mode. See Compare.
ECCP Mode and Timer Resources .......................... 247
Enhanced PWM Mode ............................................. 253
Auto-Restart ..................................................... 262
Auto-Shutdown ................................................ 261
Direction Change in Full-Bridge
Output Mode ............................................ 259
Full-Bridge Application ..................................... 257
Full-Bridge Mode ............................................. 257
Half-Bridge Application .................................... 256
Half-Bridge Application Examples ................... 263
Half-Bridge Mode ............................................. 256
Output Relationships (Active-High
and Active-Low) ....................................... 254
Output Relationships Diagram ......................... 255
Programmable Dead-Band Delay .................... 263
Shoot-Through Current .................................... 263
Start-up Considerations ................................... 260
Outputs and Configuration ....................................... 247
Enhanced Universal Synchronous Asynchronous Receiver
Transmitter (EUSART). See EUSART.
Equations
A/D Acquisition Time ............................................... 352
A/D Minimum Charging Time .................................. 352
Bytes Transmitted for a Given DMABC ................... 284
Calculating Output of Comparator
Voltage Reference ........................................... 392
Calculating the Minimum Required
Acquisition Time .............................................. 352
Calculating USB Transceiver Current ...................... 380
Estimating USB Transceiver Current
Consumption ................................................... 379
Errata ................................................................................... 9
EUSART .......................................................................... 323
Asynchronous Mode ................................................ 333
12-Bit Break Transmit and Receive ................. 340
Associated Registers, Reception ..................... 338
Associated Registers, Transmission ............... 335
Auto-Wake-up on Sync Break ......................... 338
Receiver .......................................................... 336
Setting Up 9-Bit Mode with Address Detect .... 336
Setting Up Asynchronous Receive .................. 336
Transmitter ...................................................... 333
Baud Rate Generator
Operation in Power-Managed Mode ................ 327
Baud Rate Generator (BRG) ................................... 327
Associated Registers ....................................... 328
Auto-Baud Rate Detect .................................... 331
Baud Rates, Asynchronous Modes ................. 329
Formulas .......................................................... 327
High Baud Rate Select (BRGH Bit) ................. 327
Sampling ......................................................... 327
Synchronous Master Mode ...................................... 341
Associated Registers, Reception ..................... 344
Associated Registers, Transmission ............... 342
Reception ........................................................ 343
Transmission ................................................... 341
Synchronous Slave Mode ........................................ 345
Associated Registers, Reception ..................... 346
Associated Registers, Transmission ............... 345
Reception ........................................................ 346
Transmission ................................................... 345
Extended Instruction Set
ADDFSR .................................................................. 478
ADDULNK ............................................................... 478
CALLW .................................................................... 479
MOVSF .................................................................... 479
MOVSS .................................................................... 480
PUSHL ..................................................................... 480
SUBFSR .................................................................. 481
SUBULNK ................................................................ 481
Extended Instructions
Considerations when Enabling ................................ 482
External Clock Input ........................................................... 38
F
Fail-Safe Clock Monitor ........................................... 417, 431
Interrupts in Power-Managed Modes ...................... 433
POR or Wake-up From Sleep .................................. 433
WDT During Oscillator Failure ................................. 432
Fast Register Stack ........................................................... 81
Features Overview ............................................................... 3
Comparative Table ...................................................... 4
Firmware Instructions ...................................................... 435
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DS39931D-page 550 2011 Microchip Technology Inc.
Flash Program Memory ....................................................103
Associated Registers ...............................................112
Control Registers ..................................................... 104
EECON1 and EECON2 ................................... 104
TABLAT (Table Latch) Register ....................... 106
TBLPTR (Table Pointer) Register .................... 106
Erase Sequence ...................................................... 108
Erasing .....................................................................108
Memory Write Sequence ......................................... 111
Operation During Code-Protect ............................... 112
Reading ....................................................................107
Table Pointer
Boundaries Based on Operation ...................... 106
Table Pointer Boundaries ........................................ 106
Table Reads and Table Writes ................................ 103
Write Sequence ....................................................... 109
Writing ......................................................................109
Unexpected Termination .................................. 112
Write Verify ...................................................... 112
FSCM. See Fail-Safe Clock Monitor.
G
Getting Started Guidelines ........................................... 29, 30
Connection Requirements ......................................... 29
External Oscillator Pins .............................................. 33
ICSP Pins ................................................................... 32
Power Supply Pins ..................................................... 30
Unused I/Os ...............................................................33
Voltage Regulator Pins (VCAP/VDDCORE) ................... 31
GOTO ............................................................................... 456
H
Hardware Multiplier ..........................................................113
8 x 8 Multiplication Algorithms ................................. 113
Operation .................................................................113
Performance Comparison (table) .............................113
High/Low-Voltage Detect ................................................. 395
Applications .............................................................. 399
Associated Registers ...............................................400
Characteristics ......................................................... 507
Current Consumption ............................................... 397
Effects of a Reset ..................................................... 400
Operation .................................................................396
During Sleep .................................................... 400
Setup ........................................................................ 397
Start-up Time ........................................................... 397
Typical Application ...................................................399
I
I/O Ports ...........................................................................131
Open-Drain Outputs ................................................. 133
Pin Capabilities ........................................................ 132
TTL Input Buffer Option ........................................... 133
I2C Mode .......................................................................... 288
I2C Mode (MSSP)
Acknowledge Sequence Timing ............................... 316
Associated Registers ...............................................322
Baud Rate Generator ............................................... 309
Bus Collision
During a Repeated Start Condition .................. 320
During a Stop Condition ................................... 321
Clock Arbitration .......................................................311
Clock Stretching ....................................................... 303
10-Bit Slave Receive Mode (SEN = 1) ............ 303
10-Bit Slave Transmit Mode ............................ 303
7-Bit Slave Receive Mode (SEN = 1) .............. 303
7-Bit Slave Transmit Mode .............................. 303
Clock Synchronization and CKP bit ......................... 304
Effects of a Reset .................................................... 317
General Call Address Support ................................. 307
I2C Clock Rate w/BRG ............................................. 310
Master Mode ............................................................ 308
Operation ......................................................... 309
Reception ........................................................ 313
Repeated Start Condition Timing .................... 312
Start Condition Timing ..................................... 311
Transmission ................................................... 313
Multi-Master Communication, Bus Collision
and Arbitration ................................................. 317
Multi-Master Mode ................................................... 317
Operation ................................................................. 293
Read/Write Bit Information (R/W Bit) ............... 293, 296
Registers ................................................................. 288
Serial Clock (SCLx Pin) ........................................... 296
Slave Mode .............................................................. 293
Addressing ....................................................... 293
Addressing Masking Modes
5-Bit ......................................................... 294
7-Bit ......................................................... 295
Reception ........................................................ 296
Transmission ................................................... 296
Sleep Operation ....................................................... 317
Stop Condition Timing ............................................. 316
INCF ................................................................................ 456
INCFSZ ............................................................................ 457
In-Circuit Debugger .......................................................... 434
In-Circuit Serial Programming (ICSP) ...................... 417, 434
Indexed Literal Offset Addressing
and Standard PIC18 Instructions ............................. 482
Indexed Literal Offset Mode ............................................. 482
Indirect Addressing ............................................................ 98
INFSNZ ............................................................................ 457
Initialization Conditions for All Registers ...................... 69–76
Instruction Cycle ................................................................ 82
Clocking Scheme ....................................................... 82
Flow/Pipelining ........................................................... 82
Instruction Set .................................................................. 435
ADDLW .................................................................... 441
ADDWF .................................................................... 441
ADDWF (Indexed Literal Offset Mode) .................... 483
ADDWFC ................................................................. 442
ANDLW .................................................................... 442
ANDWF .................................................................... 443
BC ............................................................................ 443
BCF ......................................................................... 444
BN ............................................................................ 444
BNC ......................................................................... 445
BNN ......................................................................... 445
BNOV ...................................................................... 446
BNZ ......................................................................... 446
BOV ......................................................................... 449
BRA ......................................................................... 447
BSF .......................................................................... 447
BSF (Indexed Literal Offset Mode) .......................... 483
BTFSC ..................................................................... 448
BTFSS ..................................................................... 448
BTG ......................................................................... 449
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BZ ............................................................................ 450
CALL ........................................................................ 450
CLRF ........................................................................ 451
CLRWDT .................................................................. 451
COMF ...................................................................... 452
CPFSEQ .................................................................. 452
CPFSGT .................................................................. 453
CPFSLT ................................................................... 453
DAW ......................................................................... 454
DCFSNZ .................................................................. 455
DECF ....................................................................... 454
DECFSZ ................................................................... 455
Extended Instructions .............................................. 477
Considerations when Enabling ........................ 482
Syntax .............................................................. 477
Use with MPLAB IDE Tools ............................. 484
General Format ........................................................ 437
GOTO ...................................................................... 456
INCF ......................................................................... 456
INCFSZ .................................................................... 457
INFSNZ .................................................................... 457
IORLW ..................................................................... 458
IORWF ..................................................................... 458
LFSR ........................................................................ 459
MOVF ....................................................................... 459
MOVFF .................................................................... 460
MOVLB .................................................................... 460
MOVLW ................................................................... 461
MOVWF ................................................................... 461
MULLW .................................................................... 462
MULWF .................................................................... 462
NEGF ....................................................................... 463
NOP ......................................................................... 463
Opcode Field Descriptions ....................................... 436
POP ......................................................................... 464
PUSH ....................................................................... 464
RCALL ..................................................................... 465
RESET ..................................................................... 465
RETFIE .................................................................... 466
RETLW .................................................................... 466
RETURN .................................................................. 467
RLCF ........................................................................ 467
RLNCF ..................................................................... 468
RRCF ....................................................................... 468
RRNCF .................................................................... 469
SETF ........................................................................ 469
SETF (Indexed Literal Offset Mode) ........................ 483
SLEEP ..................................................................... 470
Standard Instructions ............................................... 435
SUBFWB .................................................................. 470
SUBLW .................................................................... 471
SUBWF .................................................................... 471
SUBWFB .................................................................. 472
SWAPF .................................................................... 472
TBLRD ..................................................................... 473
TBLWT ..................................................................... 474
TSTFSZ ................................................................... 475
XORLW .................................................................... 475
XORWF .................................................................... 476
INTCON Registers ................................................... 117–119
Inter-Integrated Circuit. See I2C.
Frequency Drift. See INTOSC Frequency Drift.
Internal Oscillator
Internal Oscillator Block ..................................................... 38
Adjustment ................................................................. 39
OSCTUNE Register ................................................... 39
Internal RC Oscillator
Use with WDT .......................................................... 427
Internal Voltage Reference Specifications ....................... 505
Internet Address .............................................................. 559
Interrupt Sources ............................................................. 417
A/D Conversion Complete ....................................... 351
Capture Complete (ECCP) ...................................... 248
Compare Complete (ECCP) .................................... 249
Interrupt-on-Change (RB7:RB4) .............................. 139
TMR0 Overflow ........................................................ 197
TMR1 Overflow ........................................................ 206
TMR3 Overflow ................................................ 213, 221
TMR4 to PR4 Match ................................................ 224
TMR4 to PR4 Match (PWM) .................................... 223
Interrupts ......................................................................... 115
Control Bits .............................................................. 115
Control Registers. See INTCON Registers.
During, Context Saving ............................................ 130
INTx Pin ................................................................... 130
PORTB, Interrupt-on-Change .................................. 130
RCON Register ........................................................ 129
TMR0 ....................................................................... 130
Interrupts, Flag Bits
Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ..... 139
INTOSC Frequency Drift .................................................... 39
INTOSC, INTRC. See Internal Oscillator Block.
IORLW ............................................................................. 458
IORWF ............................................................................. 458
IPR Registers ........................................................... 126–128
L
LFSR ............................................................................... 459
Low-Power Modes ............................................................. 47
Clock Transitions and Status Indicators .................... 48
Deep Sleep Mode ...................................................... 54
and RTCC Peripheral ........................................ 56
Brown-out Reset (DSBOR) ................................ 56
Fault Detection .................................................. 56
Preparing for ...................................................... 54
Registers ........................................................... 57
Typical Sequence .............................................. 56
Wake-up Sources .............................................. 55
Watchdog Timer (DSWDT) ................................ 55
Exiting Idle and Sleep Modes .................................... 53
By Interrupt ........................................................ 53
By Reset ............................................................ 53
By WDT Time-out .............................................. 53
Without an Oscillator Start-up Delay ................. 54
Idle Modes ................................................................. 52
PRI_IDLE .......................................................... 52
RC_IDLE ........................................................... 53
SEC_IDLE ......................................................... 52
Multiple Sleep Commands ......................................... 48
Run Modes ................................................................ 48
PRI_RUN ........................................................... 48
RC_RUN ............................................................ 50
SEC_RUN ......................................................... 48
Sleep Mode ............................................................... 51
Summary (table) ........................................................ 48
Ultra Low-Power Wake-up ......................................... 60
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DS39931D-page 552 2011 Microchip Technology Inc.
M
Master Clear (MCLR) ......................................................... 65
Master Synchronous Serial Port (MSSP). See MSSP.
Memory Organization ......................................................... 77
Data Memory ............................................................. 84
Program Memory ....................................................... 77
Return Address Stack ................................................79
Memory Programming Requirements ..............................504
Microchip Internet Web Site ............................................. 559
MOVF ............................................................................... 459
MOVFF ............................................................................. 460
MOVLB ............................................................................. 460
MOVLW ............................................................................ 461
MOVSF ............................................................................479
MOVSS ............................................................................ 480
MOVWF ...........................................................................461
MPLAB MPASM Assembler, Linker, Librarian ................. 486
MPLAB Integrated Development Environment
Software ................................................................... 485
MPLAB PM3 Device Programmer .................................... 488
MPLAB REAL ICE In-Circuit Emulator System ................ 487
MPLINK Object Linker/MPLIB Object Librarian ............... 486
MSSP
ACK Pulse ........................................................ 293, 296
I2C Mode. See I2C Mode.
Module Overview ..................................................... 269
SPI Master/Slave Connection .................................. 274
TMR4 Output for Clock Shift .................................... 224
MULLW ............................................................................462
MULWF ............................................................................ 462
N
NEGF ............................................................................... 463
NOP ................................................................................. 463
O
Oscillator Configurations ....................................................35
Internal Oscillator Block ............................................. 38
Oscillator Control .......................................................35
Oscillator Modes ........................................................ 35
Oscillator Modes and USB Operation ........................ 36
Oscillator Types .........................................................35
Transitions ................................................................. 43
Oscillator Selection ..........................................................417
Oscillator Settings for USB .................................................40
Configuration Options ................................................ 41
Oscillator Start-up Timer (OST) ......................................... 45
Oscillator Switching ............................................................42
Oscillator, Timer1 ............................................. 199, 205, 217
Oscillator, Timer3 ............................................................. 213
P
P1A/P1B/P1C/P1D.See Enhanced
Capture/Compare/PWM (ECCP). ............................253
Packaging
Details ...................................................................... 533
Marking ....................................................................531
Parallel Master Port (PMP) .............................................. 169
Application Examples ...............................................191
Associated Registers ...............................................193
Data Registers ......................................................... 176
Master Port Modes ...................................................183
Module Registers ..................................................... 170
Slave Port Modes ..................................................... 178
Peripheral Pin Select (PPS) ............................................. 150
Peripheral Pin Select Registers ............................... 155–168
PIE Registers ........................................................... 123–125
Pin Diagrams ................................................................... 5–7
Pin Functions
AVDD1 ........................................................................ 28
AVDD2 ........................................................................ 28
AVSS1 ........................................................................ 28
MCLR .................................................................. 16, 22
OSC1/CLKI/RA7 .................................................. 16, 22
OSC2/CLKO/RA6 ................................................ 16, 22
RA0/AN0/C1INA/ULPWU/PMA6/RP0 ....................... 23
RA0/AN0/C1INA/ULPWU/RP0 .................................. 17
RA1/AN1/C2INA/PMA7/RP1 ..................................... 23
RA1/AN1/C2INA/RP1 ................................................ 17
RA2/AN2/VREF-/CVREF/C2INB ............................ 17, 23
RA3/AN3/VREF+/C1INB ....................................... 17, 23
RA5/AN4/SS1/HLVDIN/RCV/RP2 ....................... 17, 23
RA6 ...................................................................... 17, 23
RA7 ...................................................................... 17, 23
RB0/AN12/INT0/RP3 ........................................... 18, 24
RB1/AN10/PMBE/RTCCS/RP4 ................................. 24
RB1/AN10/RTCC/RP4 ............................................... 18
RB2/AN8/CTED1/PMA3/VMO/REFO/RP5 ................ 24
RB2/AN8/CTED1/VMO/REFO/RP5 ........................... 18
RB3/AN9/CTED2/PMA2/VPO/RP6 ............................ 24
RB3/AN9/CTED2/VPO/RP6 ...................................... 18
RB4/KBI0/SCK1/SCL1/RP7 ....................................... 19
RB4/PMA1/KBI0/SCK1/SCL1/RP7 ............................ 25
RB5/KBI1/SDI1/SDA1/RP8 ........................................ 19
RB5/PMA0/KBI1/SDI1/SDA1/RP8 ............................. 25
RB6/KBI2/PGC/RP9 ............................................ 19, 25
RB7/KBI3/PGD/RP10 .......................................... 19, 25
RC0/T1OSO/T1CKI/RP11 ................................... 20, 26
RC1/T1OSI/UOE/RP12 ....................................... 20, 26
RC2/AN11/CTPLS/RP13 ..................................... 20, 26
RC4/D-/VM .......................................................... 20, 26
RC5/D+/VP .......................................................... 20, 26
RC6/PMA5/TX1/CK1/RP17 ....................................... 26
RC6/TX1/CK1/RP17 .................................................. 20
RC7/PMA4/RX1/DT1/SDO1/RP18 ............................ 26
RC7/RX1/DT1/SDO1/RP18 ....................................... 20
RD0/PMD0/SCL2 ....................................................... 27
RD1/PMD1/SDA2 ...................................................... 27
RD2/PMD2/RP19 ....................................................... 27
RD3/PMD3/RP20 ....................................................... 27
RD4/PMD4/RP21 ....................................................... 27
RD5/PMD5/RP22 ....................................................... 27
RD6/PMD6/RP23 ....................................................... 27
RD7/PMD7/RP24 ....................................................... 27
RE0/AN5/PMRD ........................................................ 28
RE1/AN6/PMWR ....................................................... 28
RE2/AN7/PMCS ........................................................ 28
VDD ............................................................................ 21
VDD1 .......................................................................... 28
VDD2 .......................................................................... 28
VDDCORE/VCAP ..................................................... 21, 28
VSS1 .................................................................... 21, 28
VSS2 .................................................................... 21, 28
VUSB .................................................................... 21, 28
Pinout I/O Descriptions
PIC18F2XJ50 (28-Pin) ............................................... 16
PIC18F4XJ50 (44-Pin) ............................................... 22
PIR Registers ................................................................... 120
PLL Frequency Multiplier ................................................... 38
POP ................................................................................. 464
2011 Microchip Technology Inc. DS39931D-page 553
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POR. See Power-on Reset.
PORTA
Additional Pin Functions
Ultra Low-Power Wake-up ................................. 60
Associated Registers ............................................... 138
LATA Register .......................................................... 136
PORTA Register ...................................................... 136
TRISA Register ........................................................ 136
PORTB
Associated Registers ............................................... 142
LATB Register .......................................................... 139
PORTB Register ...................................................... 139
RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) ........ 139
TRISB Register ........................................................ 139
PORTC
Associated Registers ............................................... 145
LATC Register ......................................................... 143
PORTC Register ...................................................... 143
TRISC Register ........................................................ 143
PORTD
Associated Registers ............................................... 147
LATD Register ......................................................... 146
PORTD Register ...................................................... 146
TRISD Register ........................................................ 146
PORTE
Associated Registers ............................................... 149
LATE Register .......................................................... 148
PORTE Register ...................................................... 148
TRISE Register ........................................................ 148
Power-Managed Modes
and EUSART Operation ........................................... 327
and PWM Operation ................................................ 267
and SPI Operation ................................................... 278
Clock Sources ............................................................ 47
Entering ...................................................................... 47
Selecting .................................................................... 47
Power-on Reset (POR) ...................................................... 65
Power-up Delays ................................................................ 45
Power-up Timer (PWRT) ............................................. 45, 66
Time-out Sequence .................................................... 66
Prescaler, Timer0 ............................................................. 197
Prescaler, Timer2 (Timer4) .............................................. 251
PRI_IDLE Mode ................................................................. 52
PRI_RUN Mode ................................................................. 48
Product Identification System .......................................... 561
Program Counter ............................................................... 79
PCL, PCH and PCU Registers ................................... 79
PCLATH and PCLATU Registers .............................. 79
Program Memory
ALU
STATUS ............................................................. 96
Extended Instruction Set ............................................ 99
Flash Configuration Words ........................................ 78
Hard Memory Vectors ................................................ 78
Instructions ................................................................. 83
Two-Word .......................................................... 83
Interrupt Vector .......................................................... 78
Look-up Tables .......................................................... 81
Memory Maps ............................................................ 77
Hard Vectors and Configuration Words ............. 78
Reset Vector .............................................................. 78
Program Verification and Code Protection ....................... 433
Programming, Device Instructions ................................... 435
Pulse Steering .................................................................. 264
PUSH ............................................................................... 464
PUSH and POP Instructions .............................................. 80
PUSHL ............................................................................. 480
PWM (CCP Module) ........................................................ 250
Associated Registers ............................................... 252
Duty Cycle ............................................................... 250
Example Frequencies/Resolutions .......................... 251
Operation Setup ...................................................... 251
Period ...................................................................... 250
PR2/PR4 Registers ................................................. 250
TMR2 (TMR4) to PR2 (PR4) Match ........................ 250
TMR4 to PR4 Match ................................................ 223
PWM (ECCP Module)
Effects of a Reset .................................................... 267
Operation in Power-Managed Modes ...................... 267
Operation with Fail-Safe Clock Monitor ................... 267
Pulse Steering ......................................................... 264
Steering Synchronization ......................................... 266
PWM Mode. See Enhanced Capture/Compare/PWM ....... 253
Q
Q Clock ............................................................................ 251
R
RAM. See Data Memory.
RBIF Bit ........................................................................... 139
RC_IDLE Mode .................................................................. 53
RC_RUN Mode .................................................................. 50
RCALL ............................................................................. 465
RCON Register
Bit Status During Initialization .................................... 68
Reader Response ............................................................ 560
Real-Time Clock and Calendar (RTCC) .......................... 225
Operation ................................................................. 237
Registers ................................................................. 226
Reference Clock Output .................................................... 44
Register File ....................................................................... 86
Register File Summary ................................................. 89,95
Registers
ADCON0 (A/D Control 0) ......................................... 347
ADCON1 (A/D Control 1) ......................................... 348
ALRMCFG (Alarm Configuration) ............................ 229
ALRMDAY (Alarm Day Value) ................................. 234
ALRMHR (Alarm Hours Value) ................................ 235
ALRMMIN (Alarm Minutes Value) ........................... 236
ALRMMNTH (Alarm Month Value) .......................... 234
ALRMRPT (Alarm Repeat Counter) ........................ 230
ALRMSEC (Alarm Seconds Value) ......................... 236
ALRMWD (Alarm Weekday Value) .......................... 235
ANCON0 (A/D Port Configuration 2) ....................... 349
ANCON1 (A/D Port Configuration 1) ....................... 349
Associated with Comparator .................................... 385
Associated with Program Flash Memory ................. 112
BAUDCONx (Baud Rate Control) ............................ 326
BDnSTAT ................................................................ 367
BDnSTAT (Buffer Descriptor n Status,
CPU Mode) ...................................................... 368
BDnSTAT (Buffer Descriptor n Status,
SIE Mode) ....................................................... 369
BDnSTAT (SIE Mode) ............................................. 369
Buffer Descriptors, Summary .................................. 371
CCPxCON (Enhanced Capture/Compare/PWM x
Control) ............................................................ 246
CMSTAT (Comparator Status) ................................ 386
CMxCON (Comparator Control x) ........................... 386
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DS39931D-page 554 2011 Microchip Technology Inc.
CONFIG1H (Configuration 1 High) ..........................420
CONFIG1L (Configuration 1 Low) ............................ 419
CONFIG2H (Configuration 2 High) ..........................422
CONFIG2L (Configuration 2 Low) ............................ 421
CONFIG3H (Configuration 3 High) ..........................424
CONFIG3L (Configuration 3 Low) ............................ 423
CONFIG4H (Configuration 4 High) ..........................425
CONFIG4L (Configuration 4 Low) ............................ 424
CTMUCONH (CTMU Control High) ......................... 413
CTMUCONL (CTMU Control Low) ...........................414
CTMUICON (CTMU Current Control) ...................... 415
CVRCON (Comparator Voltage Reference
Control) ............................................................ 392
DAY (Day Value) ......................................................232
DEVID1 (Device ID 1) .............................................. 425
DEVID2 (Device ID 2) .............................................. 426
DMACON1 (DMA Control 1) .................................... 282
DMACON2 (DMA Control 2) .................................... 283
DSCONH (Deep Sleep Control High Byte) ................ 57
DSCONL (Deep Sleep Control Low Byte) ................. 57
DSGPR0 (Deep Sleep Persistent General
Purpose 0) .........................................................58
DSGPR1 (Deep Sleep Persistent General
Purpose 1) .........................................................58
DSWAKEH (Deep Sleep Wake High Byte) ................ 59
DSWAKEL (Deep Sleep Wake Low Byte) ................. 59
ECCPxAS (ECCPx Auto-Shutdown Control) ........... 261
ECCPxDEL (Enhanced PWM Control) .................... 264
EECON1 (EEPROM Control 1) ................................105
HLVDCON (High/Low-Voltage Detect Control) ........ 395
HOURS (Hours Value) ............................................. 233
I2C Mode (MSSP) .................................................... 288
INTCON (Interrupt Control) ......................................117
INTCON2 (Interrupt Control 2) ................................. 118
INTCON3 (Interrupt Control 3) ................................. 119
IPR1 (Peripheral Interrupt Priority 1) ........................ 126
IPR2 (Peripheral Interrupt Priority 2) ........................ 127
IPR3 (Peripheral Interrupt Priority 3) ........................ 128
MINUTES (Minutes Value) .......................................233
MONTH (Month Value) ............................................ 231
ODCON1 (Peripheral Open-Drain Control 1) ........... 134
ODCON2 (Peripheral Open-Drain Control 2) ........... 134
ODCON3 (Peripheral Open-Drain Control 3) ........... 135
OSCCON (Oscillator Control) .................................... 43
OSCTUNE (Oscillator Tuning) ................................... 40
PADCFG1 (Pad Configuration Control 1) ................ 135
PADCFG1 (Pad Configuration) ................................ 228
Parallel Master Port .................................................170
PIE1 (Peripheral Interrupt Enable 1) ........................ 123
PIE2 (Peripheral Interrupt Enable 2) ........................ 124
PIE3 (Peripheral Interrupt Enable 3) ........................ 125
PIR1 (Peripheral Interrupt Request (Flag) 1) ........... 120
PIR2 (Peripheral Interrupt Request (Flag) 2) ........... 121
PIR3 (Peripheral Interrupt Request (Flag) 3) ........... 122
PMADDRH (Parallel Port Address High Byte,
Master Modes) ................................................. 177
PMADDRL (Parallel Port Address Low Byte,
Master Modes) ................................................. 177
PMCONH (Parallel Port Control High Byte) ............. 170
PMCONL (Parallel Port Control Low Byte) .............. 171
PMEH (Parallel Port Enable High Byte) ................... 174
PMEL (Parallel Port Enable Low Byte) .................... 174
PMMODEH (Parallel Port Mode High Byte) .............172
PMMODEL (Parallel Port Mode Low Byte) .............. 173
PMSTATH (Parallel Port Status High Byte) .............175
PMSTATL (Parallel Port Status Low Byte) .............. 175
PORTE .................................................................... 148
PPSCON (Peripheral Pin Select Input 0) ................. 155
PSTRxCON (Pulse Steering Control) ...................... 265
RCON (Reset Control) ....................................... 64, 129
RCSTAx (Receive Status and Control) .................... 325
REFOCON (Reference Oscillator Control) ................ 44
Reserved ................................................................. 231
RPINR1 (Peripheral Pin Select Input 1) ................... 156
RPINR12 (Peripheral Pin Select Input 12) ............... 158
RPINR13 (Peripheral Pin Select Input 13) ............... 158
RPINR16 (Peripheral Pin Select Input 16) ............... 159
RPINR17 (Peripheral Pin Select Input 17) ............... 159
RPINR2 (Peripheral Pin Select Input 2) ................... 156
RPINR21 (Peripheral Pin Select Input 21) ............... 159
RPINR22 (Peripheral Pin Select Input 22) ............... 160
RPINR23 (Peripheral Pin Select Input 23) ............... 160
RPINR24 (Peripheral Pin Select Input 24) ............... 160
RPINR3 (Peripheral Pin Select Input 3) ................... 156
RPINR4 (Peripheral Pin Select Input 4) ................... 157
RPINR6 (Peripheral Pin Select Input 6) ................... 157
RPINR7 (Peripheral Pin Select Input 7) ................... 157
RPINR8 (Peripheral Pin Select Input 8) ................... 158
RPOR0 (Peripheral Pin Select Output 0) ................. 161
RPOR1 (Peripheral Pin Select Output 1) ................. 161
RPOR10 (Peripheral Pin Select Output 10) ............. 164
RPOR11 (Peripheral Pin Select Output 11) ............. 164
RPOR12 (Peripheral Pin Select Output 12) ............. 165
RPOR13 (Peripheral Pin Select Output 13) ............. 165
RPOR17 (Peripheral Pin Select Output 17) ............. 165
RPOR18 (Peripheral Pin Select Output 18) ............. 166
RPOR19 (Peripheral Pin Select Output 19) ............. 166
RPOR2 (Peripheral Pin Select Output 2) ................. 161
RPOR20 (Peripheral Pin Select Output 20) ............. 166
RPOR21 (Peripheral Pin Select Output 21) ............. 167
RPOR22 (Peripheral Pin Select Output 22) ............. 167
RPOR23 (Peripheral Pin Select Output 23) ............. 167
RPOR24 (Peripheral Pin Select Output 24) ............. 168
RPOR3 (Peripheral Pin Select Output 3) ................. 162
RPOR4 (Peripheral Pin Select Output 4) ................. 162
RPOR5 (Peripheral Pin Select Output 5) ................. 162
RPOR6 (Peripheral Pin Select Output 6) ................. 163
RPOR7 (Peripheral Pin Select Output 7) ................. 163
RPOR8 (Peripheral Pin Select Output 8) ................. 163
RPOR9 (Peripheral Pin Select Output 9) ................. 164
RTCCAL (RTCC Calibration) ................................... 228
RTCCFG (RTCC Configuration) .............................. 227
SECONDS (Seconds Value) ................................... 233
SPI Mode (MSSP) ................................................... 271
SSPxCON1 (MSSPx Control 1, I2C Mode) .............. 290
SSPxCON1 (MSSPx Control 1, SPI Mode) ............. 272
SSPxCON2 (MSSPx Control 2,
I2C Master Mode) ............................................ 291
SSPxCON2 (MSSPx Control 2, I2C Slave Mode) .... 292
SSPxMSK (I2C Slave Address Mask) ...................... 292
SSPxSTAT (MSSPx Status, I2C Mode) ................... 289
SSPxSTAT (MSSPx Status, SPI Mode) .................. 271
STATUS .................................................................... 96
STKPTR (Stack Pointer) ............................................ 80
T0CON (Timer0 Control) ......................................... 195
T1CON (Timer1 Control) ......................................... 199
T1GCON (Timer1 Gate Control) .............................. 201
T2CON (Timer2 Control) ......................................... 211
T3CON (Timer3 Control) ......................................... 213
T3GCON (Timer3 Gate Control) .............................. 214
2011 Microchip Technology Inc. DS39931D-page 555
PIC18F46J50 FAMILY
T4CON (Timer4 Control) .......................................... 223
TCLKCON (Timer Clock Control) ..................... 202, 215
TXSTAx (Transmit Status and Control) ................... 324
UADDR .................................................................... 365
UCFG (USB Configuration) ...................................... 361
UCON (USB Control) ............................................... 359
UEIE (USB Error Interrupt Enable) .......................... 377
UEIR (USB Error Interrupt Status) ........................... 376
UEPn (USB Endpoint n Control) .............................. 364
UFRMH:UFRML ....................................................... 365
UIE (USB Interrupt Enable) ...................................... 375
UIR (USB Interrupt Status) ...................................... 373
USTAT (USB Status) ............................................... 363
WDTCON (Watchdog Timer Control) ...................... 428
WKDY (Weekday Value) .......................................... 232
YEAR (Year Value) .................................................. 231
RESET ............................................................................. 465
Reset .................................................................................. 63
Brown-out Reset ........................................................ 65
Brown-out Reset (BOR) ............................................. 63
Configuration Mismatch (CM) .................................... 63
Configuration Mismatch Reset ................................... 66
Deep Sleep ................................................................ 63
Fast Register Stack .................................................... 81
MCLR ......................................................................... 65
MCLR Reset, During Power-Managed Modes ........... 63
MCLR Reset, Normal Operation ................................ 63
Power-on Reset ......................................................... 65
Power-on Reset (POR) .............................................. 63
Power-up Timer ......................................................... 66
RESET Instruction ..................................................... 63
Stack Full Reset ......................................................... 63
Stack Underflow Reset .............................................. 63
State of Registers ...................................................... 68
Watchdog Timer (WDT) Reset ................................... 63
Resets .............................................................................. 417
Brown-out Reset (BOR) ........................................... 417
Oscillator Start-up Timer (OST) ............................... 417
Power-on Reset (POR) ............................................ 417
Power-up Timer (PWRT) ......................................... 417
RETFIE ............................................................................ 466
RETLW ............................................................................ 466
RETURN .......................................................................... 467
Return Address Stack ........................................................ 79
Associated Registers ................................................. 79
Revision History ............................................................... 545
RLCF ................................................................................ 467
RLNCF ............................................................................. 468
RRCF ............................................................................... 468
RRNCF ............................................................................ 469
RTCC
Alarm ........................................................................ 241
Configuring ...................................................... 241
Interrupt ........................................................... 242
Mask Settings .................................................. 241
Alarm Value Registers (ALRMVAL) ......................... 234
Control Registers ..................................................... 227
Low-Power Modes ................................................... 242
Operation
Calibration ....................................................... 240
Clock Source ................................................... 238
Digit Carry Rules ............................................. 238
General Functionality ....................................... 239
Leap Year ........................................................ 239
Register Mapping ............................................ 239
ALRMVAL ................................................ 240
RTCVAL .................................................. 240
Safety Window for Register Reads
and Writes ............................................... 239
Write Lock ........................................................ 239
Register Interface .................................................... 237
Register Maps ......................................................... 243
Alarm Value ..................................................... 243
RTCC Control .................................................. 243
RTCC Value .................................................... 243
Reset ....................................................................... 242
Device ............................................................. 242
Power-on Reset (POR) .................................... 242
Value Registers (RTCVAL) ...................................... 231
RTCEN Bit Write .............................................................. 237
S
SCKx ............................................................................... 270
SDIx ................................................................................. 270
SDOx ............................................................................... 270
SEC_IDLE Mode ............................................................... 52
SEC_RUN Mode ................................................................ 48
Serial Clock, SCKx .......................................................... 270
Serial Data In (SDIx) ........................................................ 270
Serial Data Out (SDOx) ................................................... 270
Serial Peripheral Interface. See SPI Mode.
SETF ............................................................................... 469
Shoot-Through Current .................................................... 263
Slave Select (SSx) ........................................................... 270
SLEEP ............................................................................. 470
Software Simulator (MPLAB SIM) ................................... 487
Special Event Trigger. See Compare (ECCP Mode).
Special Features of the CPU ........................................... 417
SPI Mode (MSSP) ........................................................... 270
Associated Registers ............................................... 279
Bus Mode Compatibility ........................................... 278
Clock Speed, Interactions ........................................ 278
DMA Module ............................................................ 280
I/O Pin Considerations ..................................... 280
Idle and Sleep ................................................. 280
RAM to RAM Copy .......................................... 280
Registers ......................................................... 280
Effects of a Reset .................................................... 278
Enabling SPI I/O ...................................................... 274
Master Mode ............................................................ 275
Master/Slave Connection ........................................ 274
Operation ................................................................. 273
Open-Drain Output Option ............................... 273
Operation in Power-Managed Modes ...................... 278
Registers ................................................................. 271
Serial Clock ............................................................. 270
Serial Data In ........................................................... 270
Serial Data Out ........................................................ 270
Slave Mode .............................................................. 276
Slave Select ............................................................. 270
Slave Select Synchronization .................................. 276
PIC18F46J50 FAMILY
DS39931D-page 556 2011 Microchip Technology Inc.
SPI Clock ................................................................. 275
SSPxBUF Register .................................................. 275
SSPxSR Register ..................................................... 275
Typical Connection .................................................. 274
SSPOV ............................................................................. 313
SSPOV Status Flag .......................................................... 313
SSPxSTAT Register
R/W Bit ............................................................. 293, 296
SSx ................................................................................... 270
Stack Full/Underflow Resets .............................................. 81
SUBFSR ........................................................................... 481
SUBFWB ..........................................................................470
SUBLW ............................................................................471
SUBULNK ........................................................................481
SUBWF ............................................................................ 471
SUBWFB .......................................................................... 472
SWAPF ............................................................................472
T
Table Pointer Operations (table) ...................................... 106
Table Reads/Table Writes .................................................. 81
TAD ................................................................................... 353
TBLRD .............................................................................473
TBLWT .............................................................................474
Timer0 .............................................................................. 195
Associated Registers ...............................................197
Operation .................................................................196
Overflow Interrupt .................................................... 197
Prescaler ..................................................................197
Switching Assignment ...................................... 197
Prescaler Assignment (PSA Bit) ..............................197
Prescaler Select (T0PS2:T0PS0 Bits) .....................197
Reads and Writes in 16-Bit Mode ............................ 196
Source Edge Select (T0SE Bit) ................................ 196
Source Select (T0CS Bit) ......................................... 196
Timer1 .............................................................................. 199
16-Bit Read/Write Mode ........................................... 205
Associated Registers ...............................................210
Clock Source Selection ............................................ 203
Gate ......................................................................... 207
Interrupt .................................................................... 206
Operation .................................................................203
Oscillator .......................................................... 199, 205
Layout Considerations ..................................... 206
Resetting, Using the ECCP Special
Event Trigger ................................................... 207
TMR1H Register ...................................................... 199
TMR1L Register .......................................................199
Use as a Clock Source ............................................ 206
Timer2 .............................................................................. 211
Associated Registers ...............................................212
Interrupt .................................................................... 212
Operation .................................................................211
Output ...................................................................... 212
Timer3 .............................................................................. 213
16-Bit Read/Write Mode ........................................... 217
Associated Registers ...............................................221
Gate ......................................................................... 217
Operation .................................................................216
Oscillator .......................................................... 213, 217
Overflow Interrupt ............................................ 213, 221
Special Event Trigger (ECCP) ................................. 221
TMR3H Register ...................................................... 213
TMR3L Register .......................................................213
Timer4 .............................................................................. 223
Associated Registers ............................................... 224
Interrupt ................................................................... 224
MSSP Clock Shift .................................................... 224
Operation ................................................................. 223
Output ...................................................................... 224
Postscaler. See Postscaler, Timer4.
PR4 Register ........................................................... 223
Prescaler. See Prescaler, Timer4.
TMR4 Register ......................................................... 223
TMR4 to PR4 Match Interrupt .......................... 223, 224
Timing Diagrams
A/D Conversion ........................................................ 529
Asynchronous Reception ......................................... 337
Asynchronous Transmission .................................... 334
Asynchronous Transmission (Back-to-Back) ........... 334
Automatic Baud Rate Calculation ............................ 332
Auto-Wake-up Bit (WUE) During Normal
Operation ......................................................... 339
Auto-Wake-up Bit (WUE) During Sleep ................... 339
Baud Rate Generator with Clock Arbitration ............ 311
BRG Overflow Sequence ......................................... 332
BRG Reset Due to SDAx Arbitration During
Start Condition ................................................. 319
Bus Collision During a Repeated Start
Condition (Case 1) ........................................... 320
Bus Collision During a Repeated Start
Condition (Case 2) ........................................... 320
Bus Collision During a Start Condition
(SCLx = 0) ....................................................... 319
Bus Collision During a Stop Condition (Case 1) ...... 321
Bus Collision During a Stop Condition (Case 2) ...... 321
Bus Collision During Start Condition
(SDAx Only) ..................................................... 318
Bus Collision for Transmit and Acknowledge .......... 317
CLKO and I/O .......................................................... 512
Clock Synchronization ............................................. 304
Clock/Instruction Cycle .............................................. 82
Enhanced Capture/Compare/PWM ......................... 516
EUSARTx Synchronous Receive
(Master/Slave) ................................................. 528
EUSARTx Synchronous Transmission
(Master/Slave) ................................................. 528
Example SPI Master Mode (CKE = 0) ..................... 520
Example SPI Master Mode (CKE = 1) ..................... 521
Example SPI Slave Mode (CKE = 0) ....................... 522
Example SPI Slave Mode (CKE = 1) ....................... 523
External Clock .......................................................... 510
Fail-Safe Clock Monitor ........................................... 432
First Start Bit ............................................................ 311
Full-Bridge PWM Output .......................................... 258
Half-Bridge PWM Output ................................. 256, 263
High/Low-Voltage Detect Characteristics ................ 507
High-Voltage Detect (VDIRMAG = 1) ...................... 399
I22C Bus Data .......................................................... 524
I2C Acknowledge Sequence .................................... 316
I2C Bus Start/Stop Bits ............................................ 524
I2C Master Mode (7 or 10-Bit Transmission) ........... 314
I2C Master Mode (7-Bit Reception) .......................... 315
I2C Slave Mode (10-Bit Reception, SEN = 0,
ADMSK = 01001) ............................................ 300
I2C Slave Mode (10-Bit Reception, SEN = 0) .......... 301
I2C Slave Mode (10-Bit Reception, SEN = 1) .......... 306
I2C Slave Mode (10-Bit Transmission) .................... 302
2011 Microchip Technology Inc. DS39931D-page 557
PIC18F46J50 FAMILY
I2C Slave Mode (7-Bit Reception, SEN = 0,
ADMSK = 01011) ............................................. 298
I2C Slave Mode (7-Bit Reception, SEN = 0) ............ 297
I2C Slave Mode (7-Bit Reception, SEN = 1) ............ 305
I2C Slave Mode (7-Bit Transmission) ....................... 299
I2C Slave Mode General Call Address
Sequence (7 or 10-Bit Addressing Mode) ........ 307
I2C Stop Condition Receive or Transmit Mode ........ 316
Low-Voltage Detect (VDIRMAG = 0) ....................... 398
MSSPx I2C Bus Data ............................................... 526
MSSPx I2C Bus Start/Stop Bits ................................ 526
Parallel Master Port Read ........................................ 517
Parallel Master Port Write ........................................ 518
Parallel Slave Port ................................................... 519
Parallel Slave Port Read .................................. 179, 181
Parallel Slave Port Write .................................. 179, 182
PWM Auto-Shutdown with Auto-Restart Enabled .... 262
PWM Auto-Shutdown with Firmware Restart ........... 262
PWM Direction Change ........................................... 259
PWM Direction Change at Near 100% Duty Cycle .. 260
PWM Output ............................................................ 250
PWM Output (Active-High) ....................................... 254
PWM Output (Active-Low) ....................................... 255
Read and Write, 8-Bit Data, Demultiplexed
Address ............................................................ 186
Read, 16-Bit Data, Demultiplexed Address ............. 189
Read, 16-Bit Multiplexed Data, Fully
Multiplexed 16-Bit Address .............................. 190
Read, 16-Bit Multiplexed Data, Partially
Multiplexed Address ........................................ 189
Read, 8-Bit Data, Fully Multiplexed
16-Bit Address ................................................. 188
Read, 8-Bit Data, Partially Multiplexed Address ...... 186
Read, 8-Bit Data, Partially Multiplexed
Address, Enable Strobe ................................... 187
Read, 8-Bit Data, Wait States Enabled,
Partially Multiplexed Address ........................... 186
Repeated Start Condition ......................................... 312
Reset, Watchdog Timer (WDT), Oscillator Start-up
Timer (OST) and Power-up Timer (PWRT) ..... 513
Send Break Character Sequence ............................ 340
Slave Synchronization ............................................. 276
Slow Rise Time (MCLR Tied to VDD,
VDD Rise > TPWRT) ............................................ 67
SPI Mode (Master Mode) ......................................... 275
SPI Mode (Slave Mode, CKE = 0) ........................... 277
SPI Mode (Slave Mode, CKE = 1) ........................... 277
Steering Event at Beginning of Instruction
(STRSYNC = 1) ............................................... 266
Steering Event at End of Instruction
(STRSYNC = 0) ............................................... 266
Synchronous Reception (Master Mode, SREN) ...... 343
Synchronous Transmission ...................................... 341
Synchronous Transmission (Through TXEN) .......... 342
Time-out Sequence on Power-up
(MCLR Not Tied to VDD), Case 1 ....................... 67
Time-out Sequence on Power-up
(MCLR Not Tied to VDD), Case 2 ....................... 67
Time-out Sequence on Power-up
(MCLR Tied to VDD, VDD Rise < TPWRT) ........... 66
Timer Pulse Generation ........................................... 242
Timer0 and Timer1 External Clock .......................... 515
Timer1 Gate Count Enable Mode ............................ 207
Timer1 Gate Single Pulse Mode .............................. 209
Timer1 Gate Single Pulse/Toggle
Combined Mode .............................................. 210
Timer1 Gate Toggle Mode ....................................... 208
Timer3 Gate Count Enable Mode ............................ 217
Timer3 Gate Single Pulse Mode .............................. 219
Timer3 Gate Single Pulse/Toggle
Combined Mode .............................................. 220
Timer3 Gate Toggle Mode ....................................... 218
Transition for Entry to Idle Mode ............................... 52
Transition for Entry to SEC_RUN Mode .................... 49
Transition for Entry to Sleep Mode ............................ 51
Transition for Two-Speed Start-up
(INTRC to HSPLL) ........................................... 431
Transition for Wake From Idle to Run Mode .............. 53
Transition for Wake From Sleep (HSPLL) ................. 51
Transition From RC_RUN Mode to
PRI_RUN Mode ................................................. 50
Transition From SEC_RUN Mode to
PRI_RUN Mode (HSPLL) .................................. 49
Transition to RC_RUN Mode ..................................... 50
USB Signal .............................................................. 530
Write, 16-Bit Data, Demultiplexed Address ............. 189
Write, 16-Bit Multiplexed Data, Fully
Multiplexed 16-Bit Address .............................. 190
Write, 16-Bit Multiplexed Data, Partially
Multiplexed Address ........................................ 190
Write, 8-Bit Data, Fully Multiplexed
16-Bit Address ................................................. 188
Write, 8-Bit Data, Partially Multiplexed Address ...... 187
Write, 8-Bit Data, Partially Multiplexed
Address, Enable Strobe ................................... 188
Write, 8-Bit Data, Wait States Enabled,
Partially Multiplexed Address .......................... 187
Timing Diagrams and Specifications
AC Characteristics
Internal RC Accuracy ....................................... 511
CLKO and I/O Requirements ................................... 512
Enhanced Capture/Compare/PWM
Requirements .................................................. 516
EUSARTx Synchronous Receive Requirements ..... 528
EUSARTx Synchronous Transmission
Requirements .................................................. 528
Example SPI Mode Requirements
(Master Mode, CKE = 0) .................................. 520
Example SPI Mode Requirements
(Master Mode, CKE = 1) .................................. 521
Example SPI Mode Requirements
(Slave Mode, CKE = 0) .................................... 522
Example SPI Slave Mode Requirements
(CKE = 1) ......................................................... 523
External Clock Requirements .................................. 510
I2C Bus Data Requirements (Slave Mode) .............. 525
I2C Bus Start/Stop Bits Requirements
(Slave Mode) ................................................... 524
Low-Power Wake-up Time ...................................... 514
MSSPx I2C Bus Data Requirements ....................... 527
MSSPx I2C Bus Start/Stop Bits Requirements ........ 526
Parallel Master Port Read Requirements ................ 517
Parallel Master Port Write Requirements ................ 518
Parallel Slave Port Requirements ............................ 519
PLL Clock ................................................................ 511
Reset, Watchdog Timer, Oscillator Start-up
Timer, Power-up Timer and Brown-out
Reset Requirements ........................................ 513
Timer0 and Timer1 External Clock Requirements ... 515
PIC18F46J50 FAMILY
DS39931D-page 558 2011 Microchip Technology Inc.
USB Full-Speed Requirements ................................ 530
USB Low-Speed Requirements ............................... 530
TSTFSZ ............................................................................475
Two-Speed Start-up ................................................. 417, 431
Two-Word Instructions
Example Cases .......................................................... 83
TXSTAx Register
BRGH Bit ................................................................. 327
U
ULPWU Specifications ..................................................... 505
Ultra Low-Power Wake-up .................................................60
Universal Serial Bus .........................................................357
Address Register (UADDR) ..................................... 365
Associated Registers ...............................................381
Buffer Descriptor Table ............................................ 366
Buffer Descriptors .................................................... 366
Address Validation ...........................................369
Assignment in Different Buffering Modes ......... 371
BDnSTAT Register (CPU Mode) ..................... 367
BDnSTAT Register (SIE Mode) ....................... 369
Byte Count ....................................................... 369
Example ........................................................... 366
Memory Map .................................................... 370
Ownership ........................................................ 366
Ping-Pong Buffering ......................................... 370
Register Summary ........................................... 371
Status and Configuration ................................. 366
Endpoint Control ...................................................... 364
External Pull-up Resistors ........................................ 362
Eye Pattern Test Enable .......................................... 362
Firmware and Drivers ...............................................381
Frame Number Registers ......................................... 365
Internal Pull-up Resistors ......................................... 362
Internal Transceiver ................................................. 360
Interrupts .................................................................. 372
and USB Transactions ..................................... 372
Oscillator Requirements ........................................... 381
Overview .......................................................... 357, 382
Class Specifications and Drivers .....................383
Descriptors ....................................................... 383
Enumeration .....................................................383
Frames ............................................................. 382
Layered Framework ......................................... 382
Power ............................................................... 382
Speed ............................................................... 383
Transfer Types ................................................. 382
Ping-Pong Buffer Configuration ............................... 362
Power Modes ........................................................... 378
Bus Power Only ............................................... 378
Dual Power with Self-Power Dominance ......... 378
Self-Power Only ............................................... 378
Transceiver Current Consumption ................... 379
RAM ......................................................................... 365
Memory Map .................................................... 365
Status and Control ................................................... 358
UFRMH:UFRML Registers ...................................... 365
USB Specifications .......................................................... 506
USB. See Universal Serial Bus.
V
Voltage Reference Specifications .................................... 505
Voltage Regulator (On-Chip) ........................................... 429
Operation in Sleep Mode ......................................... 430
W
Watchdog Timer (WDT) ........................................... 417, 427
Associated Registers ............................................... 428
Control Register ....................................................... 427
During Oscillator Failure .......................................... 432
Programming Considerations .................................. 427
WCOL ...................................................... 311, 312, 313, 316
WCOL Status Flag ................................... 311, 312, 313, 316
WWW Address ................................................................ 559
WWW, On-Line Support ...................................................... 9
X
XORLW ............................................................................ 475
XORWF ........................................................................... 476
2011 Microchip Technology Inc. DS39931D-page 559
PIC18F46J50 FAMILY
THE MICROCHIP WEB SITE
Microchip provides online support via our WWW site at
www.microchip.com. This web site is used as a means
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Technical support is avail able throug h the web si te
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DS39931D-page 560 2011 Microchip Technology Inc.
READER RESP ONSE
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DS39931DPIC18F46J50 Family
1. What are the best features of this document?
2. How does this document meet your hardware and software development needs?
3. Do you find the organization of this document easy to follow? If not, why?
4. What additions to the document do you think would enhance the structure and subject?
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2011 Microchip Technology Inc. DS39931D-page 561
PIC18F46J50 FAMILY
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO. X/XX XXX
PatternPackageTemperature
Range
Device
Device PIC18F24J50
PIC18F25J50
PIC18F26J50
PIC18F44J50
PIC18F45J50
PIC18F46J50
PIC18LF24J50
PIC18LF25J50
PIC18LF26J50
PIC18LF44J50
PIC18LF45J50
PIC18LF46J50
Temperature Range I = -40C to +85C (Industrial)
Package SP = Skinny PDIP
SS = SSOP
SO = SOIC
ML = QFN
PT = TQFP (Thin Quad Flatpack)
Pattern QTP, SQTP, Code or Special Requirements
(blank otherwise)
Examples:
a) PIC18F46J50-I/PT 301 = Industrial temp.,
TQFP package, QTP pattern #301.
b) PIC18F46J50T-I/PT = Tape and reel, Industrial
temp., TQFP package.
DS39931D-page 562 2011 Microchip Technology Inc.
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02/18/11