MICROCHIP PIC18F442

PIC18FXX2
Data Sheet
High-Performance, Enhanced Flash
Microcontrollers with 10-Bit A/D
© 2006 Microchip Technology Inc.
DS39564C
Note the following details of the code protection feature on Microchip 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.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
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OTHERWISE, RELATED TO THE INFORMATION,
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Trademarks
The Microchip name and logo, the Microchip logo, Accuron,
dsPIC, KEELOQ, microID, MPLAB, PIC, PICmicro, PICSTART,
PRO MATE, PowerSmart, rfPIC and SmartShunt are
registered trademarks of Microchip Technology Incorporated
in the U.S.A. and other countries.
AmpLab, FilterLab, Migratable Memory, MXDEV, MXLAB,
SEEVAL, SmartSensor 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, ECAN,
ECONOMONITOR, FanSense, FlexROM, fuzzyLAB,
In-Circuit Serial Programming, ICSP, ICEPIC, Linear Active
Thermistor, Mindi, MiWi, MPASM, MPLIB, MPLINK, PICkit,
PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal,
PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB,
rfPICDEM, Select Mode, Smart Serial, SmartTel, Total
Endurance, UNI/O, WiperLock and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2006, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
Microchip received ISO/TS-16949:2002 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona, Gresham, Oregon and Mountain View, California. The
Company’s quality system processes and procedures are for its
PICmicro® 8-bit MCUs, KEELOQ® code hopping devices, Serial
EEPROMs, microperipherals, nonvolatile memory and analog
products. In addition, Microchip’s quality system for the design and
manufacture of development systems is ISO 9001:2000 certified.
DS39564C-page ii
© 2006 Microchip Technology Inc.
PIC18FXX2
28/40-pin High Performance, Enhanced FLASH
Microcontrollers with 10-Bit A/D
High Performance RISC CPU:
Peripheral Features (Continued):
• C compiler optimized architecture/instruction set
- Source code compatible with the PIC16 and
PIC17 instruction sets
• Linear program memory addressing to 32 Kbytes
• Linear data memory addressing to 1.5 Kbytes
• Addressable USART module:
- Supports RS-485 and RS-232
• Parallel Slave Port (PSP) module
On-Chip Program
Memory
Device
FLASH
(bytes)
On-Chip
Data
RAM EEPROM
# Single Word (bytes)
(bytes)
Instructions
PIC18F242
16K
8192
768
256
PIC18F252
32K
16384
1536
256
PIC18F442
16K
8192
768
256
PIC18F452
32K
16384
1536
256
• Up to 10 MIPs operation:
- DC - 40 MHz osc./clock input
- 4 MHz - 10 MHz osc./clock input with PLL active
• 16-bit wide instructions, 8-bit wide data path
• Priority levels for interrupts
• 8 x 8 Single Cycle Hardware Multiplier
Peripheral Features:
• High current sink/source 25 mA/25 mA
• Three external interrupt pins
• Timer0 module: 8-bit/16-bit timer/counter with
8-bit programmable prescaler
• Timer1 module: 16-bit timer/counter
• Timer2 module: 8-bit timer/counter with 8-bit
period register (time-base for PWM)
• Timer3 module: 16-bit timer/counter
• Secondary oscillator clock option - Timer1/Timer3
• Two Capture/Compare/PWM (CCP) modules.
CCP pins that can be configured as:
- Capture input: capture is 16-bit,
max. resolution 6.25 ns (TCY/16)
- Compare is 16-bit, max. resolution 100 ns (TCY)
- PWM output: PWM resolution is 1- to 10-bit,
max. PWM freq. @: 8-bit resolution = 156 kHz
10-bit resolution = 39 kHz
• Master Synchronous Serial Port (MSSP) module,
Two modes of operation:
- 3-wire SPI™ (supports all 4 SPI modes)
- I2C™ Master and Slave mode
© 2006 Microchip Technology Inc.
Analog Features:
• Compatible 10-bit Analog-to-Digital Converter
module (A/D) with:
- Fast sampling rate
- Conversion available during SLEEP
- Linearity ≤ 1 LSb
• Programmable Low Voltage Detection (PLVD)
- Supports interrupt on-Low Voltage Detection
• Programmable Brown-out Reset (BOR)
Special Microcontroller Features:
• 100,000 erase/write cycle Enhanced FLASH
program memory typical
• 1,000,000 erase/write cycle Data EEPROM
memory
• FLASH/Data EEPROM Retention: > 40 years
• Self-reprogrammable under software control
• Power-on Reset (POR), Power-up Timer (PWRT)
and Oscillator Start-up Timer (OST)
• Watchdog Timer (WDT) with its own On-Chip RC
Oscillator for reliable operation
• Programmable code protection
• Power saving SLEEP mode
• Selectable oscillator options including:
- 4X Phase Lock Loop (of primary oscillator)
- Secondary Oscillator (32 kHz) clock input
• Single supply 5V In-Circuit Serial Programming™
(ICSP™) via two pins
• In-Circuit Debug (ICD) via two pins
CMOS Technology:
• Low power, high speed FLASH/EEPROM
technology
• Fully static design
• Wide operating voltage range (2.0V to 5.5V)
• Industrial and Extended temperature ranges
• Low power consumption:
- < 1.6 mA typical @ 5V, 4 MHz
- 25 μA typical @ 3V, 32 kHz
- < 0.2 μA typical standby current
DS39564C-page 1
PIC18FXX2
RA3/AN3/VREF+
RA2/AN2/VREFRA1/AN1
RA0/AN0
MCLR/VPP
NC
RB7/PGD
RB6/PGC
RB5/PGM
RB4
NC
Pin Diagrams
6
5
4
3
2
1
44
43
42
41
40
PLCC
RA4/T0CKI
RA5/AN4/SS/LVDIN
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
VDD
VSS
OSC1/CLKI
OSC2/CLKO/RA6
RC0/T1OSO/T1CKI
NC
PIC18F442
PIC18F452
28
27
26
25
24
23
22
21
20
19
8
7
8
9
10
11
12
13
14
15
16
171
39
38
37
36
35
34
33
32
31
30
29
RB3/CCP2*
RB2/INT2
RB1/INT1
RB0/INT0
VDD
VSS
RD7/PSP7
RD6/PSP6
RD5/PSP5
RD4/PSP4
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
RD3/PSP3
RD2/PSP2
RD1/PSP1
RD0/PSP0
RC3/SCK/SCL
RC2/CCP1
RC1/T1OSI/CCP2*
NC
NC
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
RD3/PSP3
RD2/PSP2
RD1/PSP1
RD0/PSP0
RC3/SCK/SCL
RC2/CCP1
RC1/T1OSI/CCP2*
44
43
42
41
40
39
38
37
36
35
34
TQFP
1
2
3
4
5
6
7
8
9
10
11
PIC18F442
PIC18F452
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
RC7/RX/DT
RD4/PSP4
RD5/PSP5
RD6/PSP6
RD7/PSP7
VSS
VDD
RB0/INT0
RB1/INT1
RB2/INT2
RB3/CCP2*
NC
RC0/T1OSO/T1CKI
OSC2/CLKO/RA6
OSC1/CLKI
VSS
VDD
RE2/AN7/CS
RE1/AN6/WR
RE0/AN5/RD
RA5/AN4/SS/LVDIN
RA4/T0CKI
RA3/AN3/VREF+
RA2/AN2/VREFRA1/AN1
RA0/AN0
MCLR/VPP
RB7/PGD
RB6/PGC
RB5/PGM
RB4
NC
NC
* RB3 is the alternate pin for the CCP2 pin multiplexing.
DS39564C-page 2
© 2006 Microchip Technology Inc.
PIC18FXX2
Pin Diagrams (Cont.’d)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PIC18F452
MCLR/VPP
RA0/AN0
RA1/AN1
RA2/AN2/VREFRA3/AN3/VREF+
RA4/T0CKI
RA5/AN4/SS/LVDIN
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
VDD
VSS
OSC1/CLKI
OSC2/CLKO/RA6
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2*
RC2/CCP1
RC3/SCK/SCL
RD0/PSP0
RD1/PSP1
PIC18F442
DIP
RB7/PGD
RB6/PGC
RB5/PGM
RB4
RB3/CCP2*
RB2/INT2
RB1/INT1
RB0/INT0
VDD
VSS
RD7/PSP7
RD6/PSP6
RD5/PSP5
RD4/PSP4
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
RD3/PSP3
RD2/PSP2
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
Note: Pin compatible with 40-pin PIC16C7X devices.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
PIC18F252
MCLR/VPP
RA0/AN0
RA1/AN1
RA2/AN2/VREFRA3/AN3/VREF+
RA4/T0CKI
RA5/AN4/SS/LVDIN
VSS
OSC1/CLKI
OSC2/CLKO/RA6
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2*
RC2/CCP1
RC3/SCK/SCL
PIC18F242
DIP, SOIC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RB7/PGD
RB6/PGC
RB5/PGM
RB4
RB3/CCP2*
RB2/INT2
RB1/INT1
RB0/INT0
VDD
VSS
RC7/RX/DT
RC6/TX/CK
RC5/SDO
RC4/SDI/SDA
* RB3 is the alternate pin for the CCP2 pin multiplexing.
© 2006 Microchip Technology Inc.
DS39564C-page 3
PIC18FXX2
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7
2.0 Oscillator Configurations ............................................................................................................................................................ 17
3.0 Reset .......................................................................................................................................................................................... 25
4.0 Memory Organization ................................................................................................................................................................. 35
5.0 FLASH Program Memory ........................................................................................................................................................... 55
6.0 Data EEPROM Memory ............................................................................................................................................................. 65
7.0 8 X 8 Hardware Multiplier ........................................................................................................................................................... 71
8.0 Interrupts .................................................................................................................................................................................... 73
9.0 I/O Ports ..................................................................................................................................................................................... 87
10.0 Timer0 Module ......................................................................................................................................................................... 103
11.0 Timer1 Module ......................................................................................................................................................................... 107
12.0 Timer2 Module ......................................................................................................................................................................... 111
13.0 Timer3 Module ......................................................................................................................................................................... 113
14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 117
15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 125
16.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART).............................................................. 165
17.0 Compatible 10-bit Analog-to-Digital Converter (A/D) Module................................................................................................... 181
18.0 Low Voltage Detect .................................................................................................................................................................. 189
19.0 Special Features of the CPU .................................................................................................................................................... 195
20.0 Instruction Set Summary .......................................................................................................................................................... 211
21.0 Development Support............................................................................................................................................................... 253
22.0 Electrical Characteristics .......................................................................................................................................................... 259
23.0 DC and AC Characteristics Graphs and Tables ....................................................................................................................... 289
24.0 Packaging Information.............................................................................................................................................................. 305
Appendix A: Revision History ............................................................................................................................................................ 313
Appendix B: Device Differences........................................................................................................................................................ 313
Appendix C: Conversion Considerations........................................................................................................................................... 314
Appendix D: Migration from Baseline to Enhanced Devices ............................................................................................................. 314
Appendix E: Migration from Mid-range to Enhanced Devices........................................................................................................... 315
Appendix F: Migration from High-end to Enhanced Devices ............................................................................................................ 315
Index .................................................................................................................................................................................................. 317
On-Line Support................................................................................................................................................................................. 327
Reader Response .............................................................................................................................................................................. 328
PIC18FXX2 Product Identification System......................................................................................................................................... 329
DS39564C-page 4
© 2006 Microchip Technology Inc.
PIC18FXX2
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
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
E-mail at [email protected] or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We
welcome your feedback.
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To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
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
devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision
of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
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When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are
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© 2006 Microchip Technology Inc.
DS39564C-page 5
PIC18FXX2
NOTES:
DS39564C-page 6
© 2006 Microchip Technology Inc.
PIC18FXX2
1.0
DEVICE OVERVIEW
This document contains device specific information for
the following devices:
• PIC18F242
• PIC18F442
• PIC18F252
• PIC18F452
The following two figures are device block diagrams
sorted by pin count: 28-pin for Figure 1-1 and 40/44-pin
for Figure 1-2. The 28-pin and 40/44-pin pinouts are
listed in Table 1-2 and Table 1-3, respectively.
These devices come in 28-pin and 40/44-pin packages.
The 28-pin devices do not have a Parallel Slave Port
(PSP) implemented and the number of Analog-toDigital (A/D) converter input channels is reduced to 5.
An overview of features is shown in Table 1-1.
TABLE 1-1:
DEVICE FEATURES
Features
Operating Frequency
PIC18F242
PIC18F252
PIC18F442
PIC18F452
DC - 40 MHz
DC - 40 MHz
DC - 40 MHz
DC - 40 MHz
Program Memory (Bytes)
16K
32K
16K
32K
Program Memory (Instructions)
8192
16384
8192
16384
Data Memory (Bytes)
768
1536
768
1536
Data EEPROM Memory (Bytes)
256
256
256
256
18
18
Interrupt Sources
17
17
Ports A, B, C
Ports A, B, C
Timers
4
4
4
4
Capture/Compare/PWM Modules
2
2
2
2
MSSP,
Addressable
USART
MSSP,
Addressable
USART
MSSP,
Addressable
USART
MSSP,
Addressable
USART
I/O Ports
Serial Communications
Parallel Communications
10-bit Analog-to-Digital Module
RESETS (and Delays)
Programmable Low Voltage
Detect
Programmable Brown-out Reset
Instruction Set
Packages
© 2006 Microchip Technology Inc.
Ports A, B, C, D, E Ports A, B, C, D, E
—
—
PSP
PSP
5 input channels
5 input channels
8 input channels
8 input channels
POR, BOR,
RESET Instruction,
Stack Full,
Stack Underflow
(PWRT, OST)
POR, BOR,
RESET Instruction,
Stack Full,
Stack Underflow
(PWRT, OST)
Yes
Yes
POR, BOR,
POR, BOR,
RESET Instruction, RESET Instruction,
Stack Full,
Stack Full,
Stack Underflow
Stack Underflow
(PWRT, OST)
(PWRT, OST)
Yes
Yes
Yes
Yes
Yes
Yes
75 Instructions
75 Instructions
75 Instructions
75 Instructions
28-pin DIP
28-pin SOIC
28-pin DIP
28-pin SOIC
40-pin DIP
44-pin PLCC
44-pin TQFP
40-pin DIP
44-pin PLCC
44-pin TQFP
DS39564C-page 7
PIC18FXX2
FIGURE 1-1:
PIC18F2X2 BLOCK DIAGRAM
Data Bus<8>
21
Table Pointer
8
21
PORTA
Data Latch
8
8
RA0/AN0
RA1/AN1
RA2/AN2/VREFRA3/AN3/VREF+
RA4/T0CKI
RA5/AN4/SS/LVDIN
RA6
Data RAM
inc/dec logic
Address Latch
21
Address Latch
Program Memory
(up to 2 Mbytes)
PCLATU PCLATH
PCU PCH PCL
Program Counter
Data Latch
12
Address<12>
12
4
BSR
31 Level Stack
16
(2)
Decode
Table Latch
4
Bank0, F
FSR0
FSR1
FSR2
12
inc/dec
logic
PORTB
8
ROM Latch
RB0/INT0
RB1/INT1
RB2/INT2
RB3/CCP2(1)
RB4
RB5/PGM
RB6/PCG
RB7/PGD
Instruction
Register
8
Instruction
Decode &
Control
OSC2/CLKO
OSC1/CLKI
T1OSCI
T1OSCO
PRODH PRODL
3
Timing
Generation
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
4X PLL
Precision
Voltage
Reference
MCLR
8
BIT OP
WREG
8
8
8
8
Watchdog
Timer
ALU<8>
Brown-out
Reset
PORTC
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2(1)
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6/TX/CK
RC7/RX/DT
8
Low Voltage
Programming
In-Circuit
Debugger
VDD, VSS
Note
8 x 8 Multiply
Timer0
Timer1
CCP1
CCP2
Timer2
Master
Synchronous
Serial Port
A/D Converter
Timer3
Addressable
USART
Data EEPROM
1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit.
2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction).
3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations
are device dependent.
DS39564C-page 8
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 1-2:
PIC18F4X2 BLOCK DIAGRAM
Data Bus<8>
PORTA
21
8
21
RA0/AN0
RA1/AN1
RA2/AN2/VREFRA3/AN3/VREF+
RA4/T0CKI
RA5/AN4/SS/LVDIN
RA6
Data Latch
Table Pointer
8
Data RAM
(up to 4K
address reach)
8
inc/dec logic
Address Latch
Address Latch
21
Program Memory
(up to 2 Mbytes)
(2)
PCLATU PCLATH
PCU PCH PCL
Program Counter
Data Latch
12
Address<12>
PORTB
4
12
4
BSR
FSR0
FSR1
FSR2
Bank0, F
31 Level Stack
16
Decode
Table Latch
RB0/INT0
RB1/INT1
RB2/INT2
RB3/CCP2(1)
RB4
RB5/PGM
RB6/PCG
RB7/PGD
12
inc/dec
logic
8
PORTC
ROM Latch
RC0/T1OSO/T1CKI
RC1/T1OSI/CCP2(1)
RC2/CCP1
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO
RC6/TX/CK
RC7/RX/DT
Instruction
Register
8
Instruction
Decode &
Control
OSC2/CLKO
OSC1/CLKI
Timing
Generation
T1OSCI
T1OSCO
PRODH PRODL
3
Power-up
Timer
Oscillator
Start-up Timer
Power-on
Reset
4X PLL
Precision
Voltage
Reference
MCLR
Watchdog
Timer
8 x 8 Multiply
8
BIT OP
8
WREG
8
PORTD
RD0/PSP0
RD1/PSP1
RD2/PSP2
RD3/PSP3
RD4/PSP4
RD5/PSP5
RD6/PSP6
RD7/PSP7
8
8
ALU<8>
Brown-out
Reset
8
PORTE
Low Voltage
Programming
RE0/AN5/RD
In-Circuit
Debugger
VDD, VSS
RE1/AN6/WR
RE2/AN7/CS
Note
Timer0
Timer1
CCP1
CCP2
Timer2
Master
Synchronous
Serial Port
A/D Converter
Timer3
Addressable
USART
Parallel Slave Port
Data EEPROM
1: Optional multiplexing of CCP2 input/output with RB3 is enabled by selection of configuration bit.
2: The high order bits of the Direct Address for the RAM are from the BSR register (except for the MOVFF instruction).
3: Many of the general purpose I/O pins are multiplexed with one or more peripheral module functions. The multiplexing combinations
are device dependent.
© 2006 Microchip Technology Inc.
DS39564C-page 9
PIC18FXX2
TABLE 1-2:
PIC18F2X2 PINOUT I/O DESCRIPTIONS
Pin Number
Pin Name
DIP
MCLR/VPP
1
Pin
Type
SOIC
Buffer
Type
1
MCLR
I
ST
VPP
I
ST
—
—
NC
—
—
OSC1/CLKI
OSC1
9
9
I
ST
I
CMOS
O
—
CLKO
O
—
RA6
I/O
TTL
CLKI
OSC2/CLKO/RA6
OSC2
10
10
Description
Master Clear (input) or high voltage ICSP programming
enable pin.
Master Clear (Reset) input. This pin is an active low
RESET to the device.
High voltage ICSP programming enable pin.
These pins should be left unconnected.
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode, CMOS otherwise.
External clock source input. Always associated with
pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
Oscillator crystal or clock output.
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
In RC mode, OSC2 pin outputs CLKO which has 1/4
the frequency of OSC1, and denotes the instruction
cycle rate.
General Purpose I/O pin.
PORTA is a bi-directional I/O port.
RA0/AN0
RA0
AN0
2
RA1/AN1
RA1
AN1
3
RA2/AN2/VREFRA2
AN2
VREF-
4
RA3/AN3/VREF+
RA3
AN3
VREF+
5
RA4/T0CKI
RA4
T0CKI
6
RA5/AN4/SS/LVDIN
RA5
AN4
SS
LVDIN
7
2
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 2.
A/D Reference Voltage (Low) input.
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 3.
A/D Reference Voltage (High) input.
I/O
I
ST/OD
ST
Digital I/O. Open drain when configured as output.
Timer0 external clock input.
I/O
I
I
I
TTL
Analog
ST
Analog
Digital I/O.
Analog input 4.
SPI Slave Select input.
Low Voltage Detect Input.
3
4
5
6
7
RA6
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
DS39564C-page 10
See the OSC2/CLKO/RA6 pin.
CMOS = CMOS compatible input or output
I = Input
P = Power
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 1-2:
PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
Pin Name
DIP
Pin
Type
SOIC
Buffer
Type
Description
PORTB is a bi-directional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/INT0
RB0
INT0
21
21
RB1/INT1
RB1
INT1
22
RB2/INT2
RB2
INT2
23
RB3/CCP2
RB3
CCP2
24
RB4
25
25
RB5/PGM
RB5
PGM
26
26
RB6/PGC
RB6
PGC
27
RB7/PGD
RB7
PGD
28
I/O
I
TTL
ST
Digital I/O.
External Interrupt 0.
I/O
I
TTL
ST
External Interrupt 1.
I/O
I
TTL
ST
Digital I/O.
External Interrupt 2.
I/O
I/O
TTL
ST
Digital I/O.
Capture2 input, Compare2 output, PWM2 output.
I/O
TTL
Digital I/O.
Interrupt-on-change pin.
I/O
I/O
TTL
ST
Digital I/O. Interrupt-on-change pin.
Low Voltage ICSP programming enable pin.
I/O
I/O
TTL
ST
Digital I/O. Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming clock pin.
I/O
I/O
TTL
ST
Digital I/O. Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
22
23
24
27
28
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
© 2006 Microchip Technology Inc.
CMOS = CMOS compatible input or output
I = Input
P = Power
DS39564C-page 11
PIC18FXX2
TABLE 1-2:
PIC18F2X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
Pin Name
DIP
Pin
Type
SOIC
Buffer
Type
Description
PORTC is a bi-directional I/O port.
RC0/T1OSO/T1CKI
RC0
T1OSO
T1CKI
11
RC1/T1OSI/CCP2
RC1
T1OSI
CCP2
12
RC2/CCP1
RC2
CCP1
13
RC3/SCK/SCL
RC3
SCK
SCL
14
RC4/SDI/SDA
RC4
SDI
SDA
15
RC5/SDO
RC5
SDO
16
RC6/TX/CK
RC6
TX
CK
17
RC7/RX/DT
RC7
RX
DT
18
11
I/O
O
I
ST
—
ST
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
I/O
I
I/O
ST
CMOS
ST
Digital I/O.
Timer1 oscillator input.
Capture2 input, Compare2 output, PWM2 output.
I/O
I/O
ST
ST
Digital I/O.
Capture1 input/Compare1 output/PWM1 output.
I/O
I/O
I/O
ST
ST
ST
Digital I/O.
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C mode
I/O
I
I/O
ST
ST
ST
Digital I/O.
SPI Data In.
I2C Data I/O.
I/O
O
ST
—
Digital I/O.
SPI Data Out.
I/O
O
I/O
ST
—
ST
Digital I/O.
USART Asynchronous Transmit.
USART Synchronous Clock (see related RX/DT).
I/O
I
I/O
ST
ST
ST
Digital I/O.
USART Asynchronous Receive.
USART Synchronous Data (see related TX/CK).
12
13
14
15
16
17
18
VSS
8, 19
8, 19
P
—
Ground reference for logic and I/O pins.
VDD
20
20
P
—
Positive supply for logic and I/O pins.
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
DS39564C-page 12
CMOS = CMOS compatible input or output
I = Input
P = Power
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 1-3:
PIC18F4X2 PINOUT I/O DESCRIPTIONS
Pin Number
Pin Name
DIP
Pin
Type
PLCC TQFP
2
18
Description
I
ST
Master Clear (input) or high voltage ICSP
programming enable pin.
Master Clear (Reset) input. This pin is an active
low RESET to the device.
High voltage ICSP programming enable pin.
—
—
These pins should be left unconnected.
I
ST
I
CMOS
O
—
CLKO
O
—
RA6
I/O
TTL
MCLR/VPP
1
Buffer
Type
MCLR
VPP
NC
—
OSC1/CLKI
OSC1
13
14
14
15
ST
30
CLKI
OSC2/CLKO/RA6
OSC2
I
31
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source
input. ST buffer when configured in RC mode,
CMOS otherwise.
External clock source input. Always associated
with pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
Oscillator crystal or clock output.
Oscillator crystal output. Connects to crystal
or resonator in Crystal Oscillator mode.
In RC mode, OSC2 pin outputs CLKO,
which has 1/4 the frequency of OSC1 and
denotes the instruction cycle rate.
General Purpose I/O pin.
PORTA is a bi-directional I/O port.
RA0/AN0
RA0
AN0
2
RA1/AN1
RA1
AN1
3
RA2/AN2/VREFRA2
AN2
VREF-
4
RA3/AN3/VREF+
RA3
AN3
VREF+
5
RA4/T0CKI
RA4
T0CKI
6
RA5/AN4/SS/LVDIN
RA5
AN4
SS
LVDIN
7
3
4
5
6
7
8
19
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 2.
A/D Reference Voltage (Low) input.
I/O
I
I
TTL
Analog
Analog
Digital I/O.
Analog input 3.
A/D Reference Voltage (High) input.
I/O
I
ST/OD
ST
Digital I/O. Open drain when configured as output.
Timer0 external clock input.
I/O
I
I
I
TTL
Analog
ST
Analog
Digital I/O.
Analog input 4.
SPI Slave Select input.
Low Voltage Detect Input.
20
21
22
23
24
RA6
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
© 2006 Microchip Technology Inc.
(See the OSC2/CLKO/RA6 pin.)
CMOS = CMOS compatible input or output
I = Input
P = Power
DS39564C-page 13
PIC18FXX2
TABLE 1-3:
PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
Pin Name
DIP
Pin
Type
PLCC TQFP
Buffer
Type
Description
PORTB is a bi-directional I/O port. PORTB can be
software programmed for internal weak pull-ups on all
inputs.
RB0/INT0
RB0
INT0
33
36
RB1/INT1
RB1
INT1
34
RB2/INT2
RB2
INT2
35
RB3/CCP2
RB3
CCP2
36
RB4
37
41
14
RB5/PGM
RB5
PGM
38
42
15
RB6/PGC
RB6
PGC
39
RB7/PGD
RB7
PGD
40
37
38
39
43
44
8
I/O
I
TTL
ST
Digital I/O.
External Interrupt 0.
I/O
I
TTL
ST
External Interrupt 1.
I/O
I
TTL
ST
Digital I/O.
External Interrupt 2.
I/O
I/O
TTL
ST
Digital I/O.
Capture2 input, Compare2 output, PWM2 output.
I/O
TTL
Digital I/O. Interrupt-on-change pin.
I/O
I/O
TTL
ST
Digital I/O. Interrupt-on-change pin.
Low Voltage ICSP programming enable pin.
I/O
I/O
TTL
ST
Digital I/O. Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming clock
pin.
I/O
I/O
TTL
ST
Digital I/O. Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data
pin.
9
10
11
16
17
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
DS39564C-page 14
CMOS = CMOS compatible input or output
I = Input
P = Power
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 1-3:
PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
Pin Name
DIP
Pin
Type
PLCC TQFP
Buffer
Type
Description
PORTC is a bi-directional I/O port.
RC0/T1OSO/T1CKI
RC0
T1OSO
T1CKI
15
RC1/T1OSI/CCP2
RC1
T1OSI
CCP2
16
RC2/CCP1
RC2
CCP1
17
RC3/SCK/SCL
RC3
SCK
18
16
18
19
20
32
23
RC5/SDO
RC5
SDO
24
RC6/TX/CK
RC6
TX
CK
25
RC7/RX/DT
RC7
RX
DT
26
25
26
27
29
ST
—
ST
I/O
I
I/O
ST
CMOS
ST
Digital I/O.
Timer1 oscillator input.
Capture2 input, Compare2 output, PWM2 output.
I/O
I/O
ST
ST
Digital I/O.
Capture1 input/Compare1 output/PWM1 output.
I/O
I/O
ST
ST
I/O
ST
Digital I/O.
Synchronous serial clock input/output for
SPI mode.
Synchronous serial clock input/output for
I2C mode.
I/O
I
I/O
ST
ST
ST
Digital I/O.
SPI Data In.
I2C Data I/O.
I/O
O
ST
—
Digital I/O.
SPI Data Out.
I/O
O
I/O
ST
—
ST
Digital I/O.
USART Asynchronous Transmit.
USART Synchronous Clock (see related RX/DT).
I/O
I
I/O
ST
ST
ST
Digital I/O.
USART Asynchronous Receive.
USART Synchronous Data (see related TX/CK).
36
37
42
43
44
1
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
© 2006 Microchip Technology Inc.
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
35
SCL
RC4/SDI/SDA
RC4
SDI
SDA
I/O
O
I
CMOS = CMOS compatible input or output
I = Input
P = Power
DS39564C-page 15
PIC18FXX2
TABLE 1-3:
PIC18F4X2 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
Pin Name
DIP
Pin
Type
PLCC TQFP
Buffer
Type
Description
PORTD is a bi-directional I/O port, or a Parallel Slave
Port (PSP) for interfacing to a microprocessor port.
These pins have TTL input buffers when PSP module
is enabled.
RD0/PSP0
19
21
38
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD1/PSP1
20
22
39
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD2/PSP2
21
23
40
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD3/PSP3
22
24
41
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD4/PSP4
27
30
2
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD5/PSP5
28
31
3
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD6/PSP6
29
32
4
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RD7/PSP7
30
33
5
I/O
ST
TTL
Digital I/O.
Parallel Slave Port Data.
RE0/RD/AN5
RE0
RD
8
9
25
I/O
PORTE is a bi-directional I/O port.
ST
TTL
AN5
RE1/WR/AN6
RE1
WR
Analog
9
10
26
I/O
ST
TTL
AN6
RE2/CS/AN7
RE2
CS
Analog
10
11
27
Digital I/O.
Read control for parallel slave port
(see also WR and CS pins).
Analog input 5.
Digital I/O.
Write control for parallel slave port
(see CS and RD pins).
Analog input 6.
I/O
ST
TTL
AN7
Analog
Digital I/O.
Chip Select control for parallel slave port
(see related RD and WR).
Analog input 7.
VSS
12, 31 13, 34 6, 29
P
—
Ground reference for logic and I/O pins.
VDD
11, 32 12, 35 7, 28
P
—
Positive supply for logic and I/O pins.
Legend: TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
O = Output
OD = Open Drain (no P diode to VDD)
DS39564C-page 16
CMOS = CMOS compatible input or output
I = Input
P = Power
© 2006 Microchip Technology Inc.
PIC18FXX2
2.0
OSCILLATOR
CONFIGURATIONS
2.1
Oscillator Types
TABLE 2-1:
Ranges Tested:
The PIC18FXX2 can be operated in eight different
Oscillator modes. The user can program three configuration bits (FOSC2, FOSC1, and FOSC0) to select one
of these eight modes:
1.
2.
3.
4.
LP
XT
HS
HS + PLL
5.
6.
RC
RCIO
7.
8.
EC
ECIO
2.2
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
High Speed Crystal/Resonator
with PLL enabled
External Resistor/Capacitor
External Resistor/Capacitor with
I/O pin enabled
External Clock
External Clock with I/O pin
enabled
Crystal Oscillator/Ceramic
Resonators
In XT, LP, HS or HS+PLL Oscillator modes, a crystal or
ceramic resonator is connected to the OSC1 and
OSC2 pins to establish oscillation. Figure 2-1 shows
the pin connections.
The PIC18FXX2 oscillator design requires the use of a
parallel cut crystal.
Note:
Use of a series cut crystal may give a frequency out of the crystal manufacturers
specifications.
FIGURE 2-1:
C1(1)
CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS, XT OR LP
CONFIGURATION)
Mode
Freq
C1
C2
XT
455 kHz
68 - 100 pF 68 - 100 pF
2.0 MHz
15 - 68 pF
15 - 68 pF
4.0 MHz
15 - 68 pF
15 - 68 pF
HS
8.0 MHz
10 - 68 pF
10 - 68 pF
16.0 MHz
10 - 22 pF
10 - 22 pF
These values are for design guidance only.
See notes following this table.
Resonators Used:
455 kHz Panasonic EFO-A455K04B
± 0.3%
2.0 MHz Murata Erie CSA2.00MG
± 0.5%
4.0 MHz Murata Erie CSA4.00MG
± 0.5%
8.0 MHz Murata Erie CSA8.00MT
± 0.5%
16.0 MHz Murata Erie CSA16.00MX
± 0.5%
All resonators used did not have built-in capacitors.
Note 1: Higher capacitance increases the stability
of the oscillator, but also increases the
start-up time.
2: When operating below 3V VDD, or when
using certain ceramic resonators at any
voltage, it may be necessary to use
high-gain HS mode, try a lower frequency
resonator, or switch to a crystal oscillator.
3: Since each resonator/crystal has its own
characteristics, the user should consult the
resonator/crystal manufacturer for appropriate values of external components, or
verify oscillator performance.
OSC1
XTAL
RS(2)
C2(1)
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
OSC2
RF(3)
To
Internal
Logic
SLEEP
PIC18FXXX
Note 1: See Table 2-1 and Table 2-2
recommended values of C1 and C2.
for
2: A series resistor (RS) may be required for
AT strip cut crystals.
3: RF varies with the Oscillator mode chosen.
© 2006 Microchip Technology Inc.
DS39564C-page 17
PIC18FXX2
TABLE 2-2:
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Ranges Tested:
Mode
Freq
C1
C2
LP
32.0 kHz
33 pF
33 pF
XT
HS
200 kHz
15 pF
15 pF
200 kHz
22-68 pF
22-68 pF
1.0 MHz
15 pF
15 pF
4.0 MHz
15 pF
15 pF
4.0 MHz
15 pF
15 pF
8.0 MHz
15-33 pF
15-33 pF
20.0 MHz
15-33 pF
15-33 pF
25.0 MHz
15-33 pF
15-33 pF
These values are for design guidance only.
See notes following this table.
2.3
RC Oscillator
For timing-insensitive applications, the “RC” and
“RCIO” device options offer additional cost savings.
The RC oscillator frequency is a function of the supply
voltage, the resistor (REXT) and capacitor (CEXT) values and the operating temperature. In addition to this,
the oscillator frequency will vary from unit to unit due to
normal process parameter variation. Furthermore, the
difference in lead frame capacitance between package
types will also affect the oscillation frequency, especially for low CEXT values. The user also needs to take
into account variation due to tolerance of external R
and C components used. Figure 2-3 shows how the
R/C combination is connected.
In the RC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. This signal
may be used for test purposes or to synchronize other
logic.
Note:
Crystals Used
32.0 kHz
Epson C-001R32.768K-A
± 20 PPM
200 kHz
STD XTL 200.000KHz
± 20 PPM
1.0 MHz
ECS ECS-10-13-1
± 50 PPM
4.0 MHz
ECS ECS-40-20-1
± 50 PPM
8.0 MHz
Epson CA-301 8.000M-C
± 30 PPM
20.0 MHz
Epson CA-301 20.000M-C
± 30 PPM
If the oscillator frequency divided by 4 signal is not required in the application, it is
recommended to use RCIO mode to save
current.
FIGURE 2-3:
RC OSCILLATOR MODE
VDD
REXT
Note 1: Higher capacitance increases the stability
of the oscillator, but also increases the
start-up time.
2: Rs may be required in HS mode, as well
as XT mode, to avoid overdriving crystals
with low drive level specification.
3: Since each resonator/crystal has its own
characteristics, the user should consult the
resonator/crystal manufacturer for appropriate values of external components., or
verify oscillator performance.
An external clock source may also be connected to the
OSC1 pin in the HS, XT and LP modes, as shown in
Figure 2-2.
FIGURE 2-2:
Internal
Clock
OSC1
CEXT
PIC18FXXX
VSS
FOSC/4
OSC2/CLKO
Recommended values:3 kΩ ≤ REXT ≤ 100 kΩ
CEXT > 20pF
The RCIO Oscillator mode functions like the RC mode,
except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of
PORTA (RA6).
EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR LP
OSC CONFIGURATION)
OSC1
Clock from
Ext. System
PIC18FXXX
Open
DS39564C-page 18
OSC2
© 2006 Microchip Technology Inc.
PIC18FXX2
2.4
FIGURE 2-5:
External Clock Input
The EC and ECIO Oscillator modes require an external
clock source to be connected to the OSC1 pin. The
feedback device between OSC1 and OSC2 is turned
off in these modes to save current. There is no oscillator start-up time required after a Power-on Reset or
after a recovery from SLEEP mode.
2.5
EXTERNAL CLOCK INPUT
OPERATION
(EC CONFIGURATION)
HS/PLL
The PLL can only be enabled when the oscillator configuration bits are programmed for HS mode. If they are
programmed for any other mode, the PLL is not
enabled and the system clock will come directly from
OSC1.
OSC2
The ECIO Oscillator mode functions like the EC mode,
except that the OSC2 pin becomes an additional general purpose I/O pin. The I/O pin becomes bit 6 of
PORTA (RA6). Figure 2-5 shows the pin connections
for the ECIO Oscillator mode.
FIGURE 2-6:
I/O (OSC2)
A Phase Locked Loop circuit is provided as a programmable option for users that want to multiply the frequency of the incoming crystal oscillator signal by 4.
For an input clock frequency of 10 MHz, the internal
clock frequency will be multiplied to 40 MHz. This is
useful for customers who are concerned with EMI due
to high frequency crystals.
PIC18FXXX
FOSC/4
PIC18FXXX
RA6
OSC1
Clock from
Ext. System
OSC1
Clock from
Ext. System
In the EC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. This signal
may be used for test purposes or to synchronize other
logic. Figure 2-4 shows the pin connections for the EC
Oscillator mode.
FIGURE 2-4:
EXTERNAL CLOCK INPUT
OPERATION
(ECIO CONFIGURATION)
The PLL is one of the modes of the FOSC<2:0> configuration bits. The Oscillator mode is specified during
device programming.
A PLL lock timer is used to ensure that the PLL has
locked before device execution starts. The PLL lock
timer has a time-out that is called TPLL.
PLL BLOCK DIAGRAM
(from Configuration HS Osc
bit Register)
PLL Enable
Phase
Comparator
FIN
Loop
Filter
Crystal
Osc
VCO
FOUT
OSC1
© 2006 Microchip Technology Inc.
Divide by 4
MUX
OSC2
SYSCLK
DS39564C-page 19
PIC18FXX2
2.6
Oscillator Switching Feature
The PIC18FXX2 devices include a feature that allows
the system clock source to be switched from the main
oscillator to an alternate low frequency clock source.
For the PIC18FXX2 devices, this alternate clock source
is the Timer1 oscillator. If a low frequency crystal (32
kHz, for example) has been attached to the Timer1
oscillator pins and the Timer1 oscillator has been
enabled, the device can switch to a Low Power Execu-
FIGURE 2-7:
tion mode. Figure 2-7 shows a block diagram of the
system clock sources. The clock switching feature is
enabled by programming the Oscillator Switching
Enable (OSCSEN) bit in Configuration Register1H to a
’0’. Clock switching is disabled in an erased device.
See Section 11.0 for further details of the Timer1 oscillator. See Section 19.0 for Configuration Register
details.
DEVICE CLOCK SOURCES
PIC18FXXX
Main Oscillator
OSC2
SLEEP
TOSC/4
Timer1 Oscillator
T1OSO
MUX
TOSC
OSC1
T1OSI
4 x PLL
TSCLK
TT1P
T1OSCEN
Enable
Oscillator
Clock
Source
Clock Source option
for other modules
DS39564C-page 20
© 2006 Microchip Technology Inc.
PIC18FXX2
2.6.1
SYSTEM CLOCK SWITCH BIT
Note:
The system clock source switching is performed under
software control. The system clock switch bit, SCS
(OSCCON<0>) controls the clock switching. When the
SCS bit is ’0’, the system clock source comes from the
main oscillator that is selected by the FOSC configuration bits in Configuration Register1H. When the SCS bit
is set, the system clock source will come from the
Timer1 oscillator. The SCS bit is cleared on all forms of
RESET.
REGISTER 2-1:
The Timer1 oscillator must be enabled and
operating to switch the system clock
source. The Timer1 oscillator is enabled by
setting the T1OSCEN bit in the Timer1
control register (T1CON). If the Timer1
oscillator is not enabled, then any write to
the SCS bit will be ignored (SCS bit forced
cleared) and the main oscillator will
continue to be the system clock source.
OSCCON REGISTER
U-0
—
bit 7
U-0
—
U-0
—
bit 7-1
Unimplemented: Read as '0'
bit 0
SCS: System Clock Switch bit
U-0
—
U-0
—
U-0
—
U-0
—
R/W-1
SCS
bit 0
When OSCSEN configuration bit = ’0’ and T1OSCEN bit is set:
1 = Switch to Timer1 oscillator/clock pin
0 = Use primary oscillator/clock input pin
When OSCSEN and T1OSCEN are in other states:
bit is forced clear
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 21
PIC18FXX2
2.6.2
OSCILLATOR TRANSITIONS
A timing diagram indicating the transition from the main
oscillator to the Timer1 oscillator is shown in
Figure 2-8. The Timer1 oscillator is assumed to be running all the time. After the SCS bit is set, the processor
is frozen at the next occurring Q1 cycle. After eight synchronization cycles are counted from the Timer1 oscillator, operation resumes. No additional delays are
required after the synchronization cycles.
The PIC18FXX2 devices contain circuitry to prevent
“glitches” when switching between oscillator sources.
Essentially, the circuitry waits for eight rising edges of
the clock source that the processor is switching to. This
ensures that the new clock source is stable and that its
pulse width will not be less than the shortest pulse
width of the two clock sources.
FIGURE 2-8:
TIMING DIAGRAM FOR TRANSITION FROM OSC1 TO TIMER1 OSCILLATOR
Q1 Q2
Q3 Q4
Q1
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
TT1P
1
T1OSI
2
3
4
5
6
7
8
Tscs
OSC1
TOSC
Internal
System
Clock
SCS
(OSCCON<0>)
Program
Counter
TDLY
PC
PC + 4
PC + 2
Note 1: Delay on internal system clock is eight oscillator cycles for synchronization.
The sequence of events that takes place when switching from the Timer1 oscillator to the main oscillator will
depend on the mode of the main oscillator. In addition
to eight clock cycles of the main oscillator, additional
delays may take place.
FIGURE 2-9:
If the main oscillator is configured for an external crystal (HS, XT, LP), then the transition will take place after
an oscillator start-up time (TOST) has occurred. A timing
diagram, indicating the transition from the Timer1 oscillator to the main oscillator for HS, XT and LP modes, is
shown in Figure 2-9.
TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS, XT, LP)
Q3
Q4
Q1
Q1
TT1P
Q2 Q3
Q4
Q1
Q2
Q3
T1OSI
1
OSC1
TOST
2
3
4
5
6
7
8
TSCS
OSC2
TOSC
Internal System
Clock
SCS
(OSCCON<0>)
Program Counter
PC
PC + 2
PC + 6
Note 1: TOST = 1024 TOSC (drawing not to scale).
DS39564C-page 22
© 2006 Microchip Technology Inc.
PIC18FXX2
If the main oscillator is configured for HS-PLL mode, an
oscillator start-up time (TOST) plus an additional PLL
time-out (TPLL) will occur. The PLL time-out is typically
2 ms and allows the PLL to lock to the main oscillator
frequency. A timing diagram indicating the transition
from the Timer1 oscillator to the main oscillator for
HS-PLL mode is shown in Figure 2-10.
FIGURE 2-10:
TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (HS WITH PLL)
Q4
TT1P
Q1
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
T1OSI
OSC1
TOST
TPLL
OSC2
TSCS
TOSC
PLL Clock
Input
1
2
3
4
5
6
7
8
Internal System
Clock
SCS
(OSCCON<0>)
Program Counter
PC
PC + 2
PC + 4
Note 1: TOST = 1024 TOSC (drawing not to scale).
If the main oscillator is configured in the RC, RCIO, EC
or ECIO modes, there is no oscillator start-up time-out.
Operation will resume after eight cycles of the main
oscillator have been counted. A timing diagram, indicating the transition from the Timer1 oscillator to the
main oscillator for RC, RCIO, EC and ECIO modes, is
shown in Figure 2-11.
FIGURE 2-11:
TIMING FOR TRANSITION BETWEEN TIMER1 AND OSC1 (RC, EC)
Q3
Q4
T1OSI
Q1
Q1 Q2 Q3
TT1P
Q4 Q1 Q2
Q3 Q4
TOSC
OSC1
1
2
3
4
5
6
7
8
OSC2
Internal System
Clock
SCS
(OSCCON<0>)
TSCS
Program Counter
PC
PC + 2
PC + 4
Note 1: RC Oscillator mode assumed.
© 2006 Microchip Technology Inc.
DS39564C-page 23
PIC18FXX2
2.7
Effects of SLEEP Mode on the
On-Chip Oscillator
When the device executes a SLEEP instruction, the
on-chip clocks and oscillator are turned off and the
device is held at the beginning of an instruction cycle
(Q1 state). With the oscillator off, the OSC1 and OSC2
signals will stop oscillating. Since all the transistor
TABLE 2-3:
switching currents have been removed, SLEEP mode
achieves the lowest current consumption of the device
(only leakage currents). Enabling any on-chip feature
that will operate during SLEEP will increase the current
consumed during SLEEP. The user can wake from
SLEEP through external RESET, Watchdog Timer
Reset, or through an interrupt.
OSC1 AND OSC2 PIN STATES IN SLEEP MODE
OSC Mode
OSC1 Pin
OSC2 Pin
RC
Note:
2.8
Floating, external resistor
At logic low
should pull high
RCIO
Floating, external resistor
Configured as PORTA, bit 6
should pull high
ECIO
Floating
Configured as PORTA, bit 6
EC
Floating
At logic low
LP, XT, and HS
Feedback inverter disabled, at
Feedback inverter disabled, at
quiescent voltage level
quiescent voltage level
See Table 3-1, in the “Reset” section, for time-outs due to SLEEP and MCLR Reset.
Power-up Delays
Power up delays are controlled by two timers, so that
no external RESET circuitry is required for most applications. The delays ensure that the device is kept in
RESET, until the device power supply and clock are
stable. For additional information on RESET operation,
see Section 3.0.
The first timer is the Power-up Timer (PWRT), which
optionally provides a fixed delay of 72 ms (nominal) on
power-up only (POR and BOR). The second timer is
the Oscillator Start-up Timer (OST), intended to keep
the chip in RESET until the crystal oscillator is stable.
DS39564C-page 24
With the PLL enabled (HS/PLL Oscillator mode), the
time-out sequence following a Power-on Reset is different from other Oscillator modes. The time-out
sequence is as follows: First, the PWRT time-out is
invoked after a POR time delay has expired. Then, the
Oscillator Start-up Timer (OST) is invoked. However,
this is still not a sufficient amount of time to allow the
PLL to lock at high frequencies. The PWRT timer is
used to provide an additional fixed 2 ms (nominal)
time-out to allow the PLL ample time to lock to the
incoming clock frequency.
© 2006 Microchip Technology Inc.
PIC18FXX2
3.0
RESET
The PIC18FXXX differentiates between various kinds
of RESET:
a)
b)
c)
d)
e)
f)
g)
h)
Power-on Reset (POR)
MCLR Reset during normal operation
MCLR Reset during SLEEP
Watchdog Timer (WDT) Reset (during normal
operation)
Programmable Brown-out Reset (BOR)
RESET Instruction
Stack Full Reset
Stack Underflow Reset
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 3-1.
The Enhanced MCU devices have a MCLR noise filter
in the MCLR Reset path. The filter will detect and
ignore small pulses.
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” on Power-on Reset, MCLR, WDT Reset, Brownout Reset, MCLR Reset during SLEEP and by the
RESET instruction.
FIGURE 3-1:
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, RI, TO, PD,
POR and BOR, are set or cleared differently in different
RESET situations, as indicated in Table 3-2. These bits
are used in software to determine the nature of the
RESET. See Table 3-3 for a full description of the
RESET states of all registers.
The MCLR pin is not driven low by any internal
RESETS, including the WDT.
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
RESET
Instruction
Stack
Pointer
Stack Full/Underflow Reset
External Reset
MCLR
WDT
Module
SLEEP
WDT
Time-out
Reset
VDD Rise
Detect
Power-on Reset
VDD
Brown-out
Reset
S
BOREN
OST/PWRT
OST
Chip_Reset
10-bit Ripple Counter
R
Q
OSC1
PWRT
On-chip
RC OSC(1)
10-bit Ripple Counter
Enable PWRT
Enable OST(2)
Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin.
2: See Table 3-1 for time-out situations.
© 2006 Microchip Technology Inc.
DS39564C-page 25
PIC18FXX2
3.1
Power-On Reset (POR)
A Power-on Reset pulse is generated on-chip when
VDD rise is detected. To take advantage of the POR circuitry, just tie the MCLR pin directly (or through a resistor) to VDD. This will eliminate external RC components
usually needed to create a Power-on Reset delay. A
minimum rise rate for
VDD is specified
(parameter D004). For a slow rise time, see Figure 3-2.
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.
FIGURE 3-2:
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW VDD POWER-UP)
R
R1
MCLR
C
PIC18FXXX
Note 1: External Power-on Reset circuit is required
only if the VDD power-up slope is too slow.
The diode D helps discharge the capacitor
quickly when VDD powers down.
2: R < 40 kΩ is recommended to make sure that
the voltage drop across R does not violate
the device’s electrical specification.
3: R1 = 100Ω to 1 kΩ will limit any current flowing into MCLR from external capacitor C, in
the event of MCLR/VPP pin breakdown due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
3.2
Power-up Timer (PWRT)
The Power-up Timer provides a fixed nominal time-out
(parameter 33) only on power-up from the POR. The
Power-up Timer operates on an internal RC oscillator.
The chip is kept in RESET as long as the PWRT is
active. The PWRT’s time delay allows VDD to rise to an
acceptable level. A configuration bit is provided to
enable/disable the PWRT.
The power-up time delay will vary from chip-to-chip due
to VDD, temperature and process variation. See DC
parameter D033 for details.
DS39564C-page 26
Oscillator Start-up Timer (OST)
The Oscillator Start-up Timer (OST) provides a 1024
oscillator cycle (from OSC1 input) delay after the
PWRT delay is over (parameter 32). This ensures that
the crystal oscillator or resonator has started and
stabilized.
The OST time-out is invoked only for XT, LP and HS
modes and only on Power-on Reset or wake-up from
SLEEP.
3.4
PLL Lock Time-out
With the PLL enabled, the time-out sequence following
a Power-on Reset is different from other Oscillator
modes. A portion of the Power-up Timer is used to provide a fixed time-out that is sufficient for the PLL to lock
to the main oscillator frequency. This PLL lock time-out
(TPLL) is typically 2 ms and follows the oscillator
start-up time-out (OST).
3.5
VDD
D
3.3
Brown-out Reset (BOR)
A configuration bit, BOREN, can disable (if clear/
programmed), or enable (if set) the Brown-out Reset
circuitry. If VDD falls below parameter D005 for greater
than parameter 35, the brown-out situation will reset
the chip. A RESET may not occur if VDD falls below
parameter D005 for less than parameter 35. The chip
will remain in Brown-out Reset until VDD rises above
BVDD. If the Power-up Timer is enabled, it will be
invoked after VDD rises above BVDD; it then will keep
the chip in RESET for an additional time delay
(parameter 33). If VDD drops below BVDD while the
Power-up Timer is running, the chip will go back into a
Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises above BVDD, the Power-up Timer
will execute the additional time delay.
3.6
Time-out Sequence
On power-up, the time-out sequence is as follows:
First, PWRT time-out is invoked after the POR time
delay has expired. Then, OST is activated. The total
time-out will vary based on oscillator configuration and
the status of the PWRT. For example, in RC mode with
the PWRT disabled, there will be no time-out at all.
Figure 3-3, Figure 3-4, Figure 3-5, Figure 3-6 and
Figure 3-7 depict time-out sequences on power-up.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, the time-outs will expire.
Bringing MCLR high will begin execution immediately
(Figure 3-5). This is useful for testing purposes or to
synchronize more than one PIC18FXXX device operating in parallel.
Table 3-2 shows the RESET conditions for some
Special Function Registers, while Table 3-3 shows the
RESET conditions for all the registers.
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 3-1:
TIME-OUT IN VARIOUS SITUATIONS
Power-up(2)
Oscillator
Configuration
Brown-out
Wake-up from
SLEEP or
Oscillator Switch
PWRTE = 0
PWRTE = 1
HS with PLL enabled(1)
72 ms + 1024 TOSC
+ 2ms
1024 TOSC
+ 2 ms
72 ms(2) + 1024 TOSC
+ 2 ms
1024 TOSC + 2 ms
HS, XT, LP
72 ms + 1024 TOSC
1024 TOSC
72 ms(2) + 1024 TOSC
1024 TOSC
(2)
—
—
EC
72 ms
—
72 ms
External RC
72 ms
—
72 ms(2)
Note 1: 2 ms is the nominal time required for the 4x PLL to lock.
2: 72 ms is the nominal power-up timer delay, if implemented.
REGISTER 3-1:
RCON REGISTER BITS AND POSITIONS
R/W-0
U-0
U-0
R/W-1
R-1
R-1
R/W-0
R/W-0
IPEN
—
—
RI
TO
PD
POR
BOR
bit 7
bit 0
Note 1: Refer to Section 4.14 (page 53) for bit definitions.
TABLE 3-2:
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR
RCON REGISTER
Program
Counter
RCON
Register
RI
TO
PD
POR
BOR
STKFUL
STKUNF
Power-on Reset
0000h
0--1 1100
1
1
1
0
0
u
u
MCLR Reset during normal
operation
0000h
0--u uuuu
u
u
u
u
u
u
u
Software Reset during normal
operation
0000h
0--0 uuuu
0
u
u
u
u
u
u
Stack Full Reset during normal
operation
0000h
0--u uu11
u
u
u
u
u
u
1
Stack Underflow Reset during
normal operation
0000h
0--u uu11
u
u
u
u
u
1
u
MCLR Reset during SLEEP
0000h
0--u 10uu
u
1
0
u
u
u
u
WDT Reset
0000h
0--u 01uu
1
0
1
u
u
u
u
WDT Wake-up
PC + 2
u--u 00uu
u
0
0
u
u
u
u
0000h
0--1 11u0
1
1
1
1
0
u
u
PC + 2(1)
u--u 00uu
u
1
0
u
u
u
u
Condition
Brown-out Reset
Interrupt wake-up from SLEEP
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0'
Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the
interrupt vector (0x000008h or 0x000018h).
© 2006 Microchip Technology Inc.
DS39564C-page 27
PIC18FXX2
TABLE 3-3:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS
Applicable Devices
Power-on Reset,
Brown-out Reset
MCLR Resets
WDT Reset
RESET Instruction
Stack Resets
Wake-up via WDT
or Interrupt
TOSU
242
442
252
452
---0 0000
---0 0000
---0 uuuu(3)
TOSH
242
442
252
452
0000 0000
0000 0000
uuuu uuuu(3)
TOSL
242
442
252
452
0000 0000
0000 0000
uuuu uuuu(3)
STKPTR
242
442
252
452
00-0 0000
uu-0 0000
uu-u uuuu(3)
PCLATU
242
442
252
452
---0 0000
---0 0000
---u uuuu
PCLATH
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
PCL
242
442
252
452
0000 0000
0000 0000
PC + 2(2)
TBLPTRU
242
442
252
452
--00 0000
--00 0000
--uu uuuu
TBLPTRH
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
TBLPTRL
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
TABLAT
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
PRODH
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
PRODL
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
INTCON
242
442
252
452
0000 000x
0000 000u
uuuu uuuu(1)
INTCON2
242
442
252
452
1111 -1-1
1111 -1-1
uuuu -u-u(1)
INTCON3
242
442
252
452
11-0 0-00
11-0 0-00
uu-u u-uu(1)
INDF0
242
442
252
452
N/A
N/A
N/A
POSTINC0
242
442
252
452
N/A
N/A
N/A
POSTDEC0
242
442
252
452
N/A
N/A
N/A
PREINC0
242
442
252
452
N/A
N/A
N/A
PLUSW0
242
442
252
452
N/A
N/A
N/A
FSR0H
242
442
252
452
---- xxxx
---- uuuu
---- uuuu
FSR0L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
WREG
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
INDF1
242
442
252
452
N/A
N/A
N/A
POSTINC1
242
442
252
452
N/A
N/A
N/A
POSTDEC1
242
442
252
452
N/A
N/A
N/A
PREINC1
242
442
252
452
N/A
N/A
N/A
PLUSW1
242
442
252
452
N/A
N/A
N/A
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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: When the wake-up is due to an interrupt and the GIEL or GIEH bit is 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.
4: See Table 3-2 for RESET value for specific condition.
5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other
Oscillator modes, they are disabled and read ’0’.
6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.
DS39564C-page 28
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 3-3:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices
Power-on Reset,
Brown-out Reset
MCLR Resets
WDT Reset
RESET Instruction
Stack Resets
Wake-up via WDT
or Interrupt
FSR1H
242
442
252
452
---- xxxx
---- uuuu
---- uuuu
FSR1L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
BSR
242
442
252
452
---- 0000
---- 0000
---- uuuu
INDF2
242
442
252
452
N/A
N/A
N/A
POSTINC2
242
442
252
452
N/A
N/A
N/A
POSTDEC2
242
442
252
452
N/A
N/A
N/A
PREINC2
242
442
252
452
N/A
N/A
N/A
PLUSW2
242
442
252
452
N/A
N/A
N/A
FSR2H
242
442
252
452
---- xxxx
---- uuuu
---- uuuu
FSR2L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
STATUS
242
442
252
452
---x xxxx
---u uuuu
---u uuuu
TMR0H
242
442
252
452
0000 0000
uuuu uuuu
uuuu uuuu
TMR0L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
T0CON
242
442
252
452
1111 1111
1111 1111
uuuu uuuu
OSCCON
242
442
252
452
---- ---0
---- ---0
---- ---u
LVDCON
242
442
252
452
--00 0101
--00 0101
--uu uuuu
WDTCON
242
442
252
452
---- ---0
---- ---0
---- ---u
RCON
242
442
252
452
0--q 11qq
0--q qquu
u--u qquu
TMR1H
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR1L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
T1CON
242
442
252
452
0-00 0000
u-uu uuuu
u-uu uuuu
(4)
TMR2
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
PR2
242
442
252
452
1111 1111
1111 1111
1111 1111
T2CON
242
442
252
452
-000 0000
-000 0000
-uuu uuuu
SSPBUF
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
SSPADD
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
SSPSTAT
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
SSPCON1
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
SSPCON2
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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: When the wake-up is due to an interrupt and the GIEL or GIEH bit is 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.
4: See Table 3-2 for RESET value for specific condition.
5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other
Oscillator modes, they are disabled and read ’0’.
6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.
© 2006 Microchip Technology Inc.
DS39564C-page 29
PIC18FXX2
TABLE 3-3:
Register
ADRESH
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices
242
442
Power-on Reset,
Brown-out Reset
MCLR Resets
WDT Reset
RESET Instruction
Stack Resets
Wake-up via WDT
or Interrupt
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADRESL
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADCON0
242
442
252
452
0000 00-0
0000 00-0
uuuu uu-u
ADCON1
242
442
252
452
00-- 0000
00-- 0000
uu-- uuuu
CCPR1H
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCPR1L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCP1CON
242
442
252
452
--00 0000
--00 0000
--uu uuuu
CCPR2H
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCPR2L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCP2CON
242
442
252
452
--00 0000
--00 0000
--uu uuuu
TMR3H
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR3L
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
T3CON
242
442
252
452
0000 0000
uuuu uuuu
uuuu uuuu
SPBRG
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
RCREG
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
TXREG
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
TXSTA
242
442
252
452
0000 -010
0000 -010
uuuu -uuu
RCSTA
242
442
252
452
0000 000x
0000 000x
uuuu uuuu
EEADR
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
EEDATA
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
EECON1
242
442
252
452
xx-0 x000
uu-0 u000
uu-0 u000
EECON2
242
442
252
452
---- ----
---- ----
---- ----
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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: When the wake-up is due to an interrupt and the GIEL or GIEH bit is 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.
4: See Table 3-2 for RESET value for specific condition.
5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other
Oscillator modes, they are disabled and read ’0’.
6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.
DS39564C-page 30
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 3-3:
Register
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
Applicable Devices
Power-on Reset,
Brown-out Reset
MCLR Resets
WDT Reset
RESET Instruction
Stack Resets
Wake-up via WDT
or Interrupt
IPR2
242
442
252
452
---1 1111
---1 1111
---u uuuu
PIR2
242
442
252
452
---0 0000
---0 0000
---u uuuu(1)
PIE2
242
442
252
452
---0 0000
---0 0000
---u uuuu
IPR1
PIR1
PIE1
242
442
252
452
1111 1111
1111 1111
uuuu uuuu
242
442
252
452
-111 1111
-111 1111
-uuu uuuu
242
442
252
452
0000 0000
0000 0000
uuuu uuuu(1)
242
442
252
452
-000 0000
-000 0000
-uuu uuuu(1)
242
442
252
452
0000 0000
0000 0000
uuuu uuuu
242
442
252
452
-000 0000
-000 0000
-uuu uuuu
TRISE
242
442
252
452
0000 -111
0000 -111
uuuu -uuu
TRISD
242
442
252
452
1111 1111
1111 1111
uuuu uuuu
TRISC
242
442
252
452
1111 1111
1111 1111
uuuu uuuu
TRISB
242
442
252
452
1111 1111
1111 1111
uuuu uuuu
(5,6)
1111(5)
1111(5)
-uuu uuuu(5)
TRISA
242
442
252
452
-111
LATE
242
442
252
452
---- -xxx
---- -uuu
---- -uuu
LATD
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATC
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
-111
LATB
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATA(5,6)
242
442
252
452
-xxx xxxx(5)
-uuu uuuu(5)
-uuu uuuu(5)
PORTE
242
442
252
452
---- -000
---- -000
---- -uuu
PORTD
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTC
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTB
242
442
252
452
xxxx xxxx
uuuu uuuu
uuuu uuuu
(5,6)
PORTA
242
442
252
452
-x0x
0000(5)
-u0u
0000(5)
-uuu uuuu(5)
Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
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: When the wake-up is due to an interrupt and the GIEL or GIEH bit is 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.
4: See Table 3-2 for RESET value for specific condition.
5: Bit 6 of PORTA, LATA, and TRISA are enabled in ECIO and RCIO Oscillator modes only. In all other
Oscillator modes, they are disabled and read ’0’.
6: Bit 6 of PORTA, LATA and TRISA are not available on all devices. When unimplemented, they are read ’0’.
© 2006 Microchip Technology Inc.
DS39564C-page 31
PIC18FXX2
FIGURE 3-3:
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
FIGURE 3-4:
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
FIGURE 3-5:
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
DS39564C-page 32
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 3-6:
SLOW RISE TIME (MCLR TIED TO VDD)
5V
VDD
1V
0V
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 3-7:
TIME-OUT SEQUENCE ON POR W/ PLL ENABLED (MCLR TIED TO VDD)
VDD
MCLR
IINTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
TPLL
OST TIME-OUT
PLL TIME-OUT
INTERNAL RESET
Note:
TOST = 1024 clock cycles.
TPLL ≈ 2 ms max. First three stages of the PWRT timer.
© 2006 Microchip Technology Inc.
DS39564C-page 33
PIC18FXX2
NOTES:
DS39564C-page 34
© 2006 Microchip Technology Inc.
PIC18FXX2
4.0
MEMORY ORGANIZATION
There are three memory blocks in Enhanced MCU
devices. These memory blocks are:
• Program Memory
• Data RAM
• Data EEPROM
Data and program memory use separate busses,
which allows for concurrent access of these blocks.
Additional detailed information for FLASH program
memory and Data EEPROM is provided in Section 5.0
and Section 6.0, respectively.
4.1
Program Memory Organization
A 21-bit program counter is capable of addressing the
2-Mbyte program memory space. Accessing a location
between the physically implemented memory and the
2-Mbyte address will cause a read of all ’0’s (a NOP
instruction).
The PIC18F252 and PIC18F452 each have 32 Kbytes
of FLASH memory, while the PIC18F242 and
PIC18F442 have 16 Kbytes of FLASH. This means that
PIC18FX52 devices can store up to 16K of single word
instructions, and PIC18FX42 devices can store up to
8K of single word instructions.
The RESET vector address is at 0000h and the
interrupt vector addresses are at 0008h and 0018h.
Figure 4-1 shows the Program Memory Map for
PIC18F242/442 devices and Figure 4-2 shows the
Program Memory Map for PIC18F252/452 devices.
© 2006 Microchip Technology Inc.
DS39564C-page 35
PIC18FXX2
FIGURE 4-1:
PROGRAM MEMORY MAP
AND STACK FOR
PIC18F442/242
PC<20:0>
21
CALL,RCALL,RETURN
RETFIE,RETLW
Stack Level 1
FIGURE 4-2:
PROGRAM MEMORY MAP
AND STACK FOR
PIC18F452/252
PC<20:0>
21
CALL,RCALL,RETURN
RETFIE,RETLW
Stack Level 1
•
•
•
•
•
•
Stack Level 31
Stack Level 31
RESET Vector
0000h
RESET Vector
0000h
High Priority Interrupt Vector 0008h
High Priority Interrupt Vector 0008h
Low Priority Interrupt Vector 0018h
Low Priority Interrupt Vector 0018h
User Memory Space
3FFFh
4000h
Read '0'
On-Chip
Program Memory
7FFFh
8000h
User Memory Space
On-Chip
Program Memory
Read '0'
1FFFFFh
200000h
DS39564C-page 36
1FFFFFh
200000h
© 2006 Microchip Technology Inc.
PIC18FXX2
4.2
Return Address Stack
The return address stack allows any combination of up
to 31 program calls and interrupts to occur. The PC
(Program Counter) is pushed onto the stack when a
CALL or RCALL instruction is executed, or an interrupt
is acknowledged. The PC value is pulled off the stack
on a RETURN, RETLW or a RETFIE instruction.
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, with the stack pointer initialized to
00000b after all RESETS. There is no RAM associated
with stack pointer 00000b. This is only a RESET value.
During a CALL type instruction, causing a push onto the
stack, the stack pointer is first incremented and the
RAM location pointed to by the stack pointer is written
with the contents of the PC. During a RETURN type
instruction, causing a pop from the stack, the contents
of the RAM location pointed to by the STKPTR are
transferred to the PC and then the stack pointer is
decremented.
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 SFR registers. Data can also be pushed
to, or popped from, the stack using the top-of-stack
SFRs. Status bits indicate if the stack pointer is at, or
beyond the 31 levels provided.
4.2.1
TOP-OF-STACK ACCESS
The top of the stack is readable and writable. Three
register locations, TOSU, TOSH and TOSL hold the
contents of the stack location pointed to by the
STKPTR register. This allows users to implement a
software stack if necessary. After a CALL, RCALL or
interrupt, the software can read the pushed value by
reading the TOSU, TOSH and TOSL registers. These
values can be placed on a user defined software stack.
At return time, the software can replace the TOSU,
TOSH and TOSL and do a return.
4.2.2
RETURN STACK POINTER
(STKPTR)
The STKPTR register contains the stack pointer value,
the STKFUL (stack full) status bit, and the STKUNF
(stack underflow) status bits. Register 4-1 shows the
STKPTR register. The value of the stack pointer can be
0 through 31. The stack pointer increments when values are pushed onto the stack and decrements when
values are popped off the stack. At RESET, the stack
pointer value will be 0. The user may read and write the
stack pointer value. This feature can be used by a Real
Time Operating System 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 can only be cleared in software or
by a POR.
The action that takes place when the stack becomes
full depends on the state of the STVREN (Stack Overflow Reset Enable) configuration bit. Refer to
Section 20.0 for a description of the device configuration bits. 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 ‘0’.
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 STKPTR will remain at 31.
When the stack has been popped enough times to
unload the stack, the next pop will return a value of zero
to the PC and sets the STKUNF bit, while the stack
pointer remains at 0. The STKUNF bit will remain set
until cleared in software or a POR occurs.
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.
The user must disable the global interrupt enable bits
during this time to prevent inadvertent stack
operations.
© 2006 Microchip Technology Inc.
DS39564C-page 37
PIC18FXX2
REGISTER 4-1:
STKPTR REGISTER
R/C-0
STKOVF
R/C-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
STKUNF
—
SP4
SP3
SP2
SP1
SP0
bit 7
bit 0
bit 7(1)
STKOVF: Stack Full Flag bit
1 = Stack became full or overflowed
0 = Stack has not become full or overflowed
bit 6(1)
STKUNF: Stack Underflow Flag bit
1 = Stack underflow occurred
0 = Stack underflow did not occur
bit 5
Unimplemented: Read as '0'
bit 4-0
SP4:SP0: Stack Pointer Location bits
Note 1: Bit 7 and bit 6 can only be cleared in user software or by a POR.
Legend:
FIGURE 4-3:
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
RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
Return Address Stack
11111
11110
11101
TOSU
0x00
TOSH
0x1A
Top of Stack
4.2.3
STKPTR<4:0>
00010
TOSL
0x34
PUSH AND POP INSTRUCTIONS
Since the Top-of-Stack (TOS) is readable and writable,
the ability to push values onto the stack and pull values
off the stack without disturbing normal program execution is a desirable option. To push the current PC value
onto the stack, a PUSH instruction can be executed.
This will increment the stack pointer and load the current PC value onto the stack. TOSU, TOSH and TOSL
can then be modified to place a return address on the
stack.
00011
0x001A34 00010
0x000D58 00001
00000
4.2.4
STACK FULL/UNDERFLOW RESETS
These resets are enabled by programming the
STVREN configuration bit. When the STVREN bit is
disabled, a full or underflow condition will set the appropriate STKFUL or STKUNF bit, but not cause a device
RESET. When the STVREN bit is enabled, a full or
underflow will set the appropriate STKFUL or STKUNF
bit and then cause a device RESET. The STKFUL or
STKUNF bits are only cleared by the user software or
a POR Reset.
The ability to pull the TOS value off of the stack and
replace it with the value that was previously pushed
onto the stack, without disturbing normal execution, is
achieved by using the POP instruction. The POP instruction discards the current TOS by decrementing the
stack pointer. The previous value pushed onto the
stack then becomes the TOS value.
DS39564C-page 38
© 2006 Microchip Technology Inc.
PIC18FXX2
4.3
Fast Register Stack
4.4
A “fast interrupt return” option is available for interrupts.
A Fast Register Stack is provided for the STATUS,
WREG and BSR registers and are only one in depth.
The stack is not readable or writable and is loaded with
the current value of the corresponding register when
the processor vectors for an interrupt. The values in the
registers are then loaded back into the working registers, if the FAST RETURN instruction is used to return
from the interrupt.
PCL, PCLATH and PCLATU
The program counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 21-bits
wide. The low byte is called the PCL register. This register is readable and writable. The high byte is called
the PCH register. This register contains the PC<15:8>
bits and is not directly readable or writable. Updates to
the PCH register may be performed through the
PCLATH register. The upper byte is called PCU. This
register contains the PC<20:16> bits and is not directly
readable or writable. Updates to the PCU register may
be performed through the PCLATU register.
A low or high priority interrupt source will push values
into the stack registers. If both low and high priority
interrupts are enabled, the stack registers cannot be
used reliably for 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.
The PC addresses bytes in the program memory. To
prevent the PC from becoming misaligned with word
instructions, the LSB of PCL is fixed to a value of ’0’.
The PC increments by 2 to address sequential
instructions in the program memory.
If high priority interrupts are not disabled during low priority interrupts, users must save the key registers in
software during a low priority interrupt.
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.
If no interrupts are used, the fast register stack 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 FAST CALL instruction
must be executed.
Example 4-1 shows a source code example that uses
the fast register stack.
The contents of PCLATH and PCLATU will be transferred to the program counter by an operation that
writes PCL. Similarly, the upper two bytes of the program counter will be transferred to PCLATH and
PCLATU by an operation that reads PCL. This is useful
for computed offsets to the PC (see Section 4.8.1).
EXAMPLE 4-1:
4.5
CALL SUB1, FAST
FAST REGISTER STACK
CODE EXAMPLE
The clock input (from OSC1) is internally divided by
four to generate four non-overlapping quadrature
clocks, namely Q1, Q2, Q3 and Q4. Internally, the program counter (PC) is incremented every Q1, the
instruction is fetched from the program memory and
latched into the instruction register in Q4. The instruction is decoded and executed during the following Q1
through Q4. The clocks and instruction execution flow
are shown in Figure 4-4.
;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
•
•
•
•
•
RETURN FAST
SUB1
FIGURE 4-4:
Clocking Scheme/Instruction
Cycle
;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
CLOCK/INSTRUCTION CYCLE
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
OSC1
Q1
Q2
Internal
Phase
Clock
Q3
Q4
PC
OSC2/CLKO
(RC mode)
PC
Execute INST (PC-2)
Fetch INST (PC)
© 2006 Microchip Technology Inc.
PC+2
Execute INST (PC)
Fetch INST (PC+2)
PC+4
Execute INST (PC+2)
Fetch INST (PC+4)
DS39564C-page 39
PIC18FXX2
4.6
Instruction Flow/Pipelining
A fetch cycle begins with the program counter (PC)
incrementing in Q1.
An “Instruction Cycle” consists of four Q cycles (Q1,
Q2, Q3 and Q4). The instruction fetch and execute are
pipelined such that fetch takes one instruction cycle,
while decode and execute takes another instruction
cycle. However, due to the pipelining, each instruction
effectively executes in one cycle. If an instruction
causes the program counter to change (e.g., GOTO)
then two cycles are required to complete the instruction
(Example 4-2).
EXAMPLE 4-2:
INSTRUCTION PIPELINE FLOW
1. MOVLW 55h
TCY0
TCY1
Fetch 1
Execute 1
Fetch 2
2. MOVWF PORTB
3. BRA
4. BSF
In the execution cycle, the fetched instruction is latched
into the “Instruction Register” (IR) in cycle Q1. 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).
TCY2
TCY4
TCY5
Execute 2
Fetch 3
SUB_1
TCY3
Execute 3
Fetch 4
PORTA, BIT3 (Forced NOP)
Flush (NOP)
Fetch SUB_1 Execute SUB_1
5. Instruction @ address SUB_1
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 executed.
4.7
Instructions in Program Memory
The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program
memory. The Least Significant Byte of an instruction
word is always stored in a program memory location
with an even address (LSB =’0’). Figure 4-5 shows an
example of how instruction words are stored in the program memory. To maintain alignment with instruction
boundaries, the PC increments in steps of 2 and the
LSB will always read ’0’ (see Section 4.4).
FIGURE 4-5:
The CALL and GOTO instructions have an absolute program memory address embedded into the instruction.
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 4-5 shows how the
instruction “GOTO 000006h’ 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 20.0 provides further
details of the instruction set.
INSTRUCTIONS IN PROGRAM MEMORY
LSB = 1
LSB = 0
0Fh
EFh
F0h
C1h
F4h
55h
03h
00h
23h
56h
Program Memory
Byte Locations →
DS39564C-page 40
Instruction 1:
Instruction 2:
MOVLW
GOTO
055h
000006h
Instruction 3:
MOVFF
123h, 456h
Word Address
↓
000000h
000002h
000004h
000006h
000008h
00000Ah
00000Ch
00000Eh
000010h
000012h
000014h
© 2006 Microchip Technology Inc.
PIC18FXX2
4.7.1
TWO-WORD INSTRUCTIONS
The PIC18FXX2 devices have four two-word instructions: MOVFF, CALL, GOTO and LFSR. The second
word of these instructions has the 4 MSBs set to 1’s
and is a special kind of NOP instruction. The lower 12
bits of the second word contain data to be used by the
instruction. If the first word of the instruction is executed, the data in the second word is accessed. If the
EXAMPLE 4-3:
second word of the instruction is executed by itself (first
word was skipped), it will execute as a NOP. This action
is necessary when the two-word instruction is preceded
by a conditional instruction that changes the PC. A program example that demonstrates this concept is shown
in Example 4-3. Refer to Section 20.0 for further details
of the instruction set.
TWO-WORD INSTRUCTIONS
CASE 1:
Object Code
Source Code
0110 0110 0000 0000
TSTFSZ
REG1
1100 0001 0010 0011
MOVFF
REG1, REG2 ; No, execute 2-word instruction
1111 0100 0101 0110
0010 0100 0000 0000
; is RAM location 0?
; 2nd operand holds address of REG2
ADDWF
REG3
; continue code
CASE 2:
Object Code
Source Code
0110 0110 0000 0000
TSTFSZ
REG1
1100 0001 0010 0011
MOVFF
REG1, REG2 ; Yes
ADDWF
REG3
1111 0100 0101 0110
0010 0100 0000 0000
4.8
; 2nd operand becomes NOP
Lookup Tables
Lookup tables are implemented two ways. These are:
• Computed GOTO
• Table Reads
4.8.1
; is RAM location 0?
COMPUTED GOTO
A computed GOTO is accomplished by adding an offset
to the program counter (ADDWF PCL).
A lookup table can be formed with an ADDWF PCL
instruction and a group of RETLW 0xnn instructions.
WREG 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
instruction executed will be one of the RETLW 0xnn
instructions, that returns the value 0xnn to the calling
function.
; continue code
4.8.2
TABLE READS/TABLE WRITES
A better method of storing data in program memory
allows 2 bytes of data to be stored in each instruction
location.
Lookup table data may be stored 2 bytes per program
word by using table reads and writes. The table pointer
(TBLPTR) specifies the byte address and the table
latch (TABLAT) contains the data that is read from, or
written to program memory. Data is transferred to/from
program memory, one byte at a time.
A description of the Table Read/Table Write operation
is shown in Section 3.0.
The offset value (value in WREG) specifies the number
of bytes that the program counter should advance.
In this method, only one data byte may be stored in
each instruction location and room on the return
address stack is required.
Note:
The ADDWF PCL instruction does not
update PCLATH and PCLATU. A read
operation on PCL must be performed to
update PCLATH and PCLATU.
© 2006 Microchip Technology Inc.
DS39564C-page 41
PIC18FXX2
4.9
Data Memory Organization
The data memory is implemented as static RAM. Each
register in the data memory has a 12-bit address,
allowing up to 4096 bytes of data memory. Figure 4-6
and Figure 4-7 show the data memory organization for
the PIC18FXX2 devices.
The data memory map is divided into as many as 16
banks that contain 256 bytes each. The lower 4 bits of
the Bank Select Register (BSR<3:0>) select which
bank will be accessed. The upper 4 bits for the BSR are
not implemented.
The data memory contains Special Function Registers
(SFR) and General Purpose Registers (GPR). The
SFRs are used for control and status of the controller
and peripheral functions, while GPRs are used for data
storage and scratch pad operations in the user’s application. The SFRs start at the last location of Bank 15
(0xFFF) and extend downwards. Any remaining space
beyond the SFRs in the Bank may be implemented as
GPRs. GPRs start at the first location of Bank 0 and
grow upwards. Any read of an unimplemented location
will read as ’0’s.
The entire data memory may be accessed directly or
indirectly. Direct addressing may require the use of the
BSR register. Indirect addressing requires the use of a
File Select Register (FSRn) and a corresponding Indirect File Operand (INDFn). Each FSR holds a 12-bit
address value that can be used to access any location
in the Data Memory map without banking.
The instruction set and architecture allow operations
across all banks. This may be accomplished by indirect
addressing or by the use of the MOVFF instruction. The
MOVFF instruction is a two-word/two-cycle instruction
that moves a value from one register to another.
4.9.1
GENERAL PURPOSE REGISTER
FILE
The register file can be accessed either directly or indirectly. Indirect addressing operates using a File Select
Register and corresponding Indirect File Operand. The
operation of indirect addressing is shown in
Section 4.12.
Enhanced MCU devices may have banked memory in
the GPR area. GPRs are not initialized by a Power-on
Reset and are unchanged on all other RESETS.
Data RAM is available for use as GPR registers by all
instructions. The top half of Bank 15 (0xF80 to 0xFFF)
contains SFRs. All other banks of data memory contain
GPR registers, starting with Bank 0.
4.9.2
SPECIAL FUNCTION REGISTERS
The Special Function Registers (SFRs) are registers
used by the CPU and Peripheral Modules for controlling the desired operation of the device. These registers are implemented as static RAM. A list of these
registers is given in Table 4-1 and Table 4-2.
The SFRs can be classified into two sets; those associated with the “core” function and those related to the
peripheral functions. Those registers related to the
“core” are described in this section, while those related
to the operation of the peripheral features are
described in the section of that peripheral feature.
The SFRs are typically distributed among the
peripherals whose functions they control.
The unused SFR locations will be unimplemented and
read as '0's. See Table 4-1 for addresses for the SFRs.
To ensure that commonly used registers (SFRs and
select GPRs) can be accessed in a single cycle,
regardless of the current BSR values, an Access Bank
is implemented. A segment of Bank 0 and a segment of
Bank 15 comprise the Access RAM. Section 4.10
provides a detailed description of the Access RAM.
DS39564C-page 42
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 4-6:
DATA MEMORY MAP FOR PIC18F242/442
BSR<3:0>
= 0000
= 0001
= 0010
Data Memory Map
00h
Access RAM
FFh
00h
GPR
Bank 0
000h
07Fh
080h
0FFh
100h
GPR
Bank 1
1FFh
200h
FFh
00h
Bank 2
GPR
FFh
2FFh
300h
Access Bank
Access RAM low
= 0011
= 1110
= 1111
Bank 3
to
Bank 14
7Fh
Access RAM high 80h
(SFRs)
FFh
Unused
Read ’00h’
00h
Unused
FFh
SFR
Bank 15
00h
EFFh
F00h
F7Fh
F80h
FFFh
When a = 0,
the BSR is ignored and the
Access Bank is used.
The first 128 bytes are General
Purpose RAM (from Bank 0).
The second 128 bytes are
Special Function Registers
(from Bank 15).
When a = 1,
the BSR is used to specify the
RAM location that the
instruction uses.
© 2006 Microchip Technology Inc.
DS39564C-page 43
PIC18FXX2
FIGURE 4-7:
DATA MEMORY MAP FOR PIC18F252/452
BSR<3:0>
= 0000
= 0001
= 0010
= 0011
Data Memory Map
00h
Access RAM
FFh
00h
GPR
Bank 0
GPR
Bank 1
FFh
00h
Bank 2
1FFh
200h
GPR
2FFh
300h
FFh
00h
Bank 3
GPR
FFh
= 0100
= 0101
Bank 4
3FFh
400h
GPR
= 1110
= 1111
Access Bank
4FFh
500h
00h
GPR
Bank 5
FFh
= 0110
000h
07Fh
080h
0FFh
100h
Bank 6
to
Bank 14
5FFh
600h
Unused
Read ’00h’
00h
Unused
FFh
SFR
Bank 15
EFFh
F00h
F7Fh
F80h
FFFh
Access RAM low
00h
7Fh
Access RAM high 80h
(SFR’s)
FFh
When a = 0,
the BSR is ignored and the
Access Bank is used.
The first 128 bytes are General
Purpose RAM (from Bank 0).
The second 128 bytes are
Special Function Registers
(from Bank 15).
When a = 1,
the BSR is used to specify the
RAM location that the
instruction uses.
DS39564C-page 44
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 4-1:
Address
FFFh
FFEh
SPECIAL FUNCTION REGISTER MAP
Name
TOSU
TOSH
Address
Address
Name
FBFh
CCPR1H
F9Fh
IPR1
FDEh
POSTINC2(3)
FBEh
CCPR1L
F9Eh
PIR1
(3)
FBDh
CCP1CON
F9Dh
PIE1
FBCh
CCPR2H
F9Ch
—
FDFh
Name
INDF2
Address
(3)
FFDh
TOSL
FDDh
FFCh
STKPTR
FDCh
POSTDEC2
PREINC2(3)
Name
FFBh
PCLATU
FDBh
PLUSW2(3)
FBBh
CCPR2L
F9Bh
—
FFAh
PCLATH
FDAh
FSR2H
FBAh
CCP2CON
F9Ah
—
FF9h
PCL
FD9h
FSR2L
FB9h
—
F99h
—
FF8h
TBLPTRU
FD8h
STATUS
FB8h
—
F98h
—
FF7h
TBLPTRH
FD7h
TMR0H
FB7h
—
F97h
—
FF6h
TBLPTRL
FD6h
TMR0L
FB6h
—
F96h
TRISE(2)
FF5h
TABLAT
FD5h
T0CON
FB5h
—
F95h
TRISD(2)
FF4h
PRODH
FD4h
—
FB4h
—
F94h
TRISC
FF3h
PRODL
FD3h
OSCCON
FB3h
TMR3H
F93h
TRISB
FF2h
INTCON
FD2h
LVDCON
FB2h
TMR3L
F92h
TRISA
FF1h
INTCON2
FD1h
WDTCON
FB1h
T3CON
F91h
—
FF0h
INTCON3
FD0h
RCON
FB0h
—
F90h
—
(3)
FCFh
TMR1H
FAFh
SPBRG
F8Fh
—
FEEh
POSTINC0(3)
FCEh
TMR1L
FAEh
RCREG
F8Eh
—
FEDh
POSTDEC0(3)
FCDh
T1CON
FADh
TXREG
F8Dh
LATE(2)
FECh
PREINC0(3)
FCCh
TMR2
FACh
TXSTA
F8Ch
LATD(2)
FEBh
PLUSW0(3)
FCBh
PR2
FABh
RCSTA
F8Bh
LATC
FEAh
FSR0H
FCAh
T2CON
FAAh
—
F8Ah
LATB
FE9h
FSR0L
FC9h
SSPBUF
FA9h
EEADR
F89h
LATA
FE8h
WREG
FC8h
SSPADD
FA8h
EEDATA
F88h
—
FC7h
SSPSTAT
FA7h
EECON2
F87h
—
FE6h
POSTINC1(3)
FC6h
SSPCON1
FA6h
EECON1
F86h
—
FE5h
POSTDEC1(3)
FC5h
SSPCON2
FA5h
—
F85h
—
FE4h
PREINC1(3)
FC4h
ADRESH
FA4h
—
F84h
PORTE(2)
FE3h
PLUSW1(3)
FC3h
ADRESL
FA3h
—
F83h
PORTD(2)
FE2h
FSR1H
FC2h
ADCON0
FA2h
IPR2
F82h
PORTC
FE1h
FSR1L
FC1h
ADCON1
FA1h
PIR2
F81h
PORTB
FE0h
BSR
FC0h
—
FA0h
PIE2
F80h
PORTA
FEFh
FE7h
INDF0
(3)
INDF1
Note 1: Unimplemented registers are read as ’0’.
2: This register is not available on PIC18F2X2 devices.
3: This is not a physical register.
© 2006 Microchip Technology Inc.
DS39564C-page 45
PIC18FXX2
TABLE 4-2:
File Name
TOSU
REGISTER FILE SUMMARY
Bit 7
Bit 6
Bit 5
—
—
—
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Top-of-Stack upper Byte (TOS<20:16>)
Value on
Details
POR, BOR on page:
---0 0000
37
TOSH
Top-of-Stack High Byte (TOS<15:8>)
0000 0000
37
TOSL
Top-of-Stack Low Byte (TOS<7:0>)
0000 0000
37
38
STKPTR
STKFUL
STKUNF
—
Return Stack Pointer
00-0 0000
PCLATU
—
—
—
Holding Register for PC<20:16>
---0 0000
39
PCLATH
Holding Register for PC<15:8>
0000 0000
39
PCL
PC Low Byte (PC<7:0>)
0000 0000
39
--00 0000
58
TBLPTRU
—
bit21(2)
—
Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
TBLPTRH
Program Memory Table Pointer High Byte (TBLPTR<15:8>)
0000 0000
58
TBLPTRL
Program Memory Table Pointer Low Byte (TBLPTR<7:0>)
0000 0000
58
TABLAT
Program Memory Table Latch
0000 0000
58
PRODH
Product Register High Byte
xxxx xxxx
71
PRODL
Product Register Low Byte
xxxx xxxx
71
INTCON
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x
75
INTCON2
RBPU
INTEDG0
INTEDG1
INTEDG2
—
TMR0IP
—
RBIP
1111 -1-1
76
INT2IP
INT1IP
—
INT2IE
INT1IE
—
INT2IF
INT1IF
11-0 0-00
77
INTCON3
INDF0
n/a
50
POSTINC0 Uses contents of FSR0 to address data memory - value of FSR0 post-incremented (not a physical register)
n/a
50
POSTDEC0 Uses contents of FSR0 to address data memory - value of FSR0 post-decremented (not a physical register)
n/a
50
PREINC0
Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register)
n/a
50
PLUSW0
Uses contents of FSR0 to address data memory - value of FSR0 (not a physical register).
Offset by value in WREG.
n/a
50
FSR0H
Uses contents of FSR0 to address data memory - value of FSR0 not changed (not a physical register)
Indirect Data Memory Address Pointer 0 High Byte ---- 0000
50
FSR0L
Indirect Data Memory Address Pointer 0 Low Byte
xxxx xxxx
50
WREG
Working Register
xxxx xxxx
n/a
INDF1
Uses contents of FSR1 to address data memory - value of FSR1 not changed (not a physical register)
n/a
50
POSTINC1 Uses contents of FSR1 to address data memory - value of FSR1 post-incremented (not a physical register)
n/a
50
POSTDEC1 Uses contents of FSR1 to address data memory - value of FSR1 post-decremented (not a physical register)
n/a
50
PREINC1
Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register)
n/a
50
PLUSW1
Uses contents of FSR1 to address data memory - value of FSR1 (not a physical register).
Offset by value in WREG.
n/a
50
FSR1H
FSR1L
BSR
INDF2
—
—
—
—
—
—
—
—
Indirect Data Memory Address Pointer 1 High Byte ---- 0000
50
xxxx xxxx
50
---- 0000
49
n/a
50
Indirect Data Memory Address Pointer 1 Low Byte
—
—
—
—
Bank Select Register
Uses contents of FSR2 to address data memory - value of FSR2 not changed (not a physical register)
POSTINC2 Uses contents of FSR2 to address data memory - value of FSR2 post-incremented (not a physical register)
n/a
50
POSTDEC2 Uses contents of FSR2 to address data memory - value of FSR2 post-decremented (not a physical register)
n/a
50
PREINC2
Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register)
n/a
50
PLUSW2
Uses contents of FSR2 to address data memory - value of FSR2 (not a physical register).
Offset by value in WREG.
n/a
50
FSR2H
FSR2L
STATUS
—
—
—
—
Timer0 Register High Byte
TMR0L
Timer0 Register Low Byte
Legend:
Note 1:
2:
3:
—
Indirect Data Memory Address Pointer 2 High Byte ---- 0000
50
xxxx xxxx
50
Indirect Data Memory Address Pointer 2 Low Byte
TMR0H
T0CON
—
TMR0ON
T08BIT
—
T0CS
N
T0SE
OV
PSA
Z
T0PS2
DC
T0PS1
C
T0PS0
---x xxxx
52
0000 0000
105
xxxx xxxx
105
1111 1111
103
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes.
Bit 21 of the TBLPTRU allows access to the device configuration bits.
These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.
DS39564C-page 46
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 4-2:
REGISTER FILE SUMMARY (CONTINUED)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
Details
POR, BOR on page:
OSCCON
—
—
—
—
—
—
—
SCS
---- ---0
LVDCON
—
—
IRVST
LVDEN
LVDL3
LVDL2
LVDL1
LVDL0
--00 0101
191
WDTCON
—
—
—
—
—
—
—
SWDTE
---- ---0
203
IPEN
—
—
RI
TO
PD
POR
BOR
File Name
RCON
21
0--1 11qq 53, 28, 84
TMR1H
Timer1 Register High Byte
xxxx xxxx
107
TMR1L
Timer1 Register Low Byte
xxxx xxxx
107
TMR1ON 0-00 0000
107
T1CON
RD16
—
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR2
Timer2 Register
0000 0000
111
PR2
Timer2 Period Register
1111 1111
112
T2CON
T2CKPS0 -000 0000
111
SSPBUF
SSP Receive Buffer/Transmit Register
—
TOUTPS3
TOUTPS2
TOUTPS1
TOUTPS0
TMR2ON
T2CKPS1
xxxx xxxx
125
SSPADD
SSP Address Register in I2C Slave mode. SSP Baud Rate Reload Register in I2C Master mode.
0000 0000
134
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
0000 0000
126
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
0000 0000
127
SSPCON2
GCEN
ACKSTAT
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
0000 0000
137
ADRESH
A/D Result Register High Byte
xxxx xxxx 187,188
ADRESL
A/D Result Register Low Byte
xxxx xxxx 187,188
ADCON0
ADCS1
ADCS0
CHS2
CHS1
CHS0
GO/DONE
—
ADON
0000 00-0
181
ADCON1
ADFM
ADCS2
—
—
PCFG3
PCFG2
PCFG1
PCFG0
00-- 0000
182
CCPR1H
Capture/Compare/PWM Register1 High Byte
CCPR1L
Capture/Compare/PWM Register1 Low Byte
CCP1CON
—
—
DC1B1
DC1B0
xxxx xxxx 121, 123
xxxx xxxx 121, 123
CCP1M3
CCP1M2
CCP1M1
CCP1M0
--00 0000
117
CCPR2H
Capture/Compare/PWM Register2 High Byte
xxxx xxxx 121, 123
CCPR2L
Capture/Compare/PWM Register2 Low Byte
xxxx xxxx 121, 123
CCP2CON
--00 0000
117
TMR3H
Timer3 Register High Byte
xxxx xxxx
113
TMR3L
Timer3 Register Low Byte
xxxx xxxx
113
T3CON
—
RD16
—
T3CCP2
DC2B1
T3CKPS1
DC2B0
T3CKPS0
CCP2M3
T3CCP1
CCP2M2
T3SYNC
CCP2M1
TMR3CS
CCP2M0
TMR3ON 0000 0000
113
168
SPBRG
USART1 Baud Rate Generator
0000 0000
RCREG
USART1 Receive Register
0000 0000 175, 178,
180
TXREG
USART1 Transmit Register
0000 0000 173, 176,
179
TXSTA
RCSTA
EEADR
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
Data EEPROM Address Register
0000 -010
166
0000 000x
167
0000 0000
65, 69
EEDATA
Data EEPROM Data Register
0000 0000
69
EECON2
Data EEPROM Control Register 2 (not a physical register)
---- ----
65, 69
xx-0 x000
66
EECON1
Legend:
Note 1:
2:
3:
EEPGD
CFGS
—
FREE
WRERR
WREN
WR
RD
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes.
Bit 21 of the TBLPTRU allows access to the device configuration bits.
These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.
© 2006 Microchip Technology Inc.
DS39564C-page 47
PIC18FXX2
TABLE 4-2:
File Name
REGISTER FILE SUMMARY (CONTINUED)
Value on
Details
POR, BOR on page:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
IPR2
—
—
—
EEIP
BCLIP
LVDIP
TMR3IP
CCP2IP
---1 1111
83
PIR2
—
—
—
EEIF
BCLIF
LVDIF
TMR3IF
CCP2IF
---0 0000
79
PIE2
—
—
—
EEIE
BCLIE
LVDIE
TMR3IE
CCP2IE
---0 0000
81
IPR1
PSPIP(3)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
1111 1111
82
PIR1
PSPIF(3)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000
78
PIE1
PSPIE(3)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000
80
IBF
OBF
IBOV
PSPMODE
—
0000 -111
98
TRISE(3)
Data Direction bits for PORTE
TRISD(3)
Data Direction Control Register for PORTD
1111 1111
96
TRISC
Data Direction Control Register for PORTC
1111 1111
93
TRISB
Data Direction Control Register for PORTB
1111 1111
90
-111 1111
87
---- -xxx
99
TRISA
—
LATE(3)
—
TRISA6(1) Data Direction Control Register for PORTA
—
—
—
—
Read PORTE Data Latch,
Write PORTE Data Latch
LATD(3)
Read PORTD Data Latch, Write PORTD Data Latch
xxxx xxxx
95
LATC
Read PORTC Data Latch, Write PORTC Data Latch
xxxx xxxx
93
LATB
Read PORTB Data Latch, Write PORTB Data Latch
LATA
—
LATA6(1)
Read PORTA Data Latch, Write PORTA Data Latch(1)
xxxx xxxx
90
-xxx xxxx
87
---- -000
99
PORTE(3)
Read PORTE pins, Write PORTE Data Latch
(3)
PORTD
Read PORTD pins, Write PORTD Data Latch
xxxx xxxx
95
PORTC
Read PORTC pins, Write PORTC Data Latch
xxxx xxxx
93
PORTB
Read PORTB pins, Write PORTB Data Latch
PORTA
Legend:
Note 1:
2:
3:
—
RA6(1)
Read PORTA pins, Write PORTA Data Latch(1)
xxxx xxxx
90
-x0x 0000
87
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition
RA6 and associated bits are configured as port pins in RCIO and ECIO Oscillator mode only and read '0' in all other Oscillator modes.
Bit 21 of the TBLPTRU allows access to the device configuration bits.
These registers and bits are reserved on the PIC18F2X2 devices; always maintain these clear.
DS39564C-page 48
© 2006 Microchip Technology Inc.
PIC18FXX2
4.10
Access Bank
4.11
The Access Bank is an architectural enhancement
which is very useful for C compiler code optimization.
The techniques used by the C compiler may also be
useful for programs written in assembly.
The need for a large general purpose memory space
dictates a RAM banking scheme. The data memory is
partitioned into sixteen banks. When using direct
addressing, the BSR should be configured for the
desired bank.
This data memory region can be used for:
•
•
•
•
•
BSR<3:0> holds the upper 4 bits of the 12-bit RAM
address. The BSR<7:4> bits will always read ’0’s, and
writes will have no effect.
Intermediate computational values
Local variables of subroutines
Faster context saving/switching of variables
Common variables
Faster evaluation/control of SFRs (no banking)
A MOVLB instruction has been provided in the
instruction set to assist in selecting banks.
If the currently selected bank is not implemented, any
read will return all '0's and all writes are ignored. The
STATUS register bits will be set/cleared as appropriate
for the instruction performed.
The Access Bank is comprised of the upper 128 bytes
in Bank 15 (SFRs) and the lower 128 bytes in Bank 0.
These two sections will be referred to as Access RAM
High and Access RAM Low, respectively. Figure 4-6
and Figure 4-7 indicate the Access RAM areas.
Each Bank extends up to FFh (256 bytes). All data
memory is implemented as static RAM.
A bit in the instruction word specifies if the operation is
to occur in the bank specified by the BSR register or in
the Access Bank. This bit is denoted by the ’a’ bit (for
access bit).
A MOVFF instruction ignores the BSR, since the 12-bit
addresses are embedded into the instruction word.
Section 4.12 provides a description of indirect addressing, which allows linear addressing of the entire RAM
space.
When forced in the Access Bank (a = 0), the last
address in Access RAM Low is followed by the first
address in Access RAM High. Access RAM High maps
the Special Function registers, so that these registers
can be accessed without any software overhead. This is
useful for testing status flags and modifying control bits.
FIGURE 4-8:
Bank Select Register (BSR)
DIRECT ADDRESSING
Direct Addressing
BSR<3:0>
Bank Select(2)
7
From Opcode(3)
0
Location Select(3)
00h
01h
0Eh
0Fh
000h
100h
E00h
F00h
0FFh
1FFh
EFFh
FFFh
Bank 14
Bank 15
Data
Memory(1)
Bank 0
Bank 1
Note 1: For register file map detail, see Table 4-1.
2: The access 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.
3: The MOVFF instruction embeds the entire 12-bit address in the instruction.
© 2006 Microchip Technology Inc.
DS39564C-page 49
PIC18FXX2
4.12
Indirect Addressing, INDF and
FSR Registers
Indirect addressing is a mode of addressing data memory, where the data memory address in the instruction
is not fixed. An FSR register is used as a pointer to the
data memory location that is to be read or written. Since
this pointer is in RAM, the contents can be modified by
the program. This can be useful for data tables in the
data memory and for software stacks. Figure 4-9
shows the operation of indirect addressing. This shows
the moving of the value to the data memory address
specified by the value of the FSR register.
Indirect addressing is possible by using one of the
INDF registers. Any instruction using the INDF register
actually accesses the register pointed to by the File
Select Register, FSR. Reading the INDF register itself,
indirectly (FSR = 0), will read 00h. Writing to the INDF
register indirectly, results in a no operation. The FSR
register contains a 12-bit address, which is shown in
Figure 4-10.
The INDFn register is not a physical register. Addressing INDFn actually addresses the register whose
address is contained in the FSRn register (FSRn is a
pointer). This is indirect addressing.
Example 4-4 shows a simple use of indirect addressing
to clear the RAM in Bank1 (locations 100h-1FFh) in a
minimum number of instructions.
EXAMPLE 4-4:
HOW TO CLEAR RAM
(BANK1) USING INDIRECT
ADDRESSING
FSR0 ,0x100 ;
POSTINC0
; Clear INDF
; register and
; inc pointer
BTFSS FSR0H, 1
; All done with
; Bank1?
GOTO NEXT
; NO, clear next
CONTINUE
; YES, continue
NEXT
LFSR
CLRF
There are three indirect addressing registers. To
address the entire data memory space (4096 bytes),
these registers are 12-bit wide. To store the 12-bits of
addressing information, two 8-bit registers are
required. These indirect addressing registers are:
1.
2.
3.
FSR0: composed of FSR0H:FSR0L
FSR1: composed of FSR1H:FSR1L
FSR2: composed of FSR2H:FSR2L
In addition, there are registers INDF0, INDF1 and
INDF2, which are not physically implemented. Reading
or writing to these registers activates indirect addressing, with the value in the corresponding FSR register
being the address of the data. If an instruction writes a
value to INDF0, the value will be written to the address
pointed to by FSR0H:FSR0L. A read from INDF1 reads
DS39564C-page 50
the data from the address pointed to by
FSR1H:FSR1L. INDFn can be used in code anywhere
an operand can be used.
If INDF0, INDF1 or INDF2 are read indirectly via an
FSR, all '0's are read (zero bit is set). Similarly, if
INDF0, INDF1 or INDF2 are written to indirectly, the
operation will be equivalent to a NOP instruction and the
STATUS bits are not affected.
4.12.1
INDIRECT ADDRESSING
OPERATION
Each FSR register has an INDF register associated
with it, plus four additional register addresses. Performing an operation on one of these five registers determines how the FSR will be modified during indirect
addressing.
When data access is done to one of the five INDFn
locations, the address selected will configure the FSRn
register to:
• Do nothing to FSRn after an indirect access (no
change) - INDFn
• Auto-decrement FSRn after an indirect access
(post-decrement) - POSTDECn
• Auto-increment FSRn after an indirect access
(post-increment) - POSTINCn
• Auto-increment FSRn before an indirect access
(pre-increment) - PREINCn
• Use the value in the WREG register as an offset
to FSRn. Do not modify the value of the WREG or
the FSRn register after an indirect access (no
change) - PLUSWn
When using the auto-increment or auto-decrement features, the effect on the FSR is not reflected in the
STATUS register. For example, if the indirect address
causes the FSR to equal '0', the Z bit will not be set.
Incrementing or decrementing an FSR affects all 12
bits. That is, when FSRnL overflows from an increment,
FSRnH will be incremented automatically.
Adding these features allows the FSRn to be used as a
stack pointer, in addition to its uses for table operations
in data memory.
Each FSR has an address associated with it that performs an indexed indirect access. When a data access
to this INDFn location (PLUSWn) occurs, the FSRn is
configured to add the signed value in the WREG register and the value in FSR to form the address before an
indirect access. The FSR value is not changed.
If an FSR register contains a value that points to one of
the INDFn, an indirect read will read 00h (zero bit is
set), while an indirect write will be equivalent to a NOP
(STATUS bits are not affected).
If an indirect addressing operation is done where the
target address is an FSRnH or FSRnL register, the
write operation will dominate over the pre- or
post-increment/decrement functions.
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 4-9:
INDIRECT ADDRESSING OPERATION
RAM
0h
Instruction
Executed
Opcode
Address
FFFh
12
File Address = access of an indirect addressing register
BSR<3:0>
Instruction
Fetched
4
Opcode
FIGURE 4-10:
12
12
8
File
FSR
INDIRECT ADDRESSING
Indirect Addressing
11
FSR Register
0
Location Select
0000h
Data
Memory(1)
0FFFh
Note 1: For register file map detail, see Table 4-1.
© 2006 Microchip Technology Inc.
DS39564C-page 51
PIC18FXX2
4.13
STATUS Register
The STATUS register, shown in Register 4-2, contains
the arithmetic status of the ALU. The STATUS register
can be the destination 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.
REGISTER 4-2:
For example, CLRF STATUS will clear the upper three
bits and set the Z bit. This leaves the STATUS register
as 000u u1uu (where u = unchanged).
It is recommended, 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 from the
STATUS register. For other instructions not affecting
any status bits, see Table 20-2.
Note:
The C and DC bits operate as a borrow and
digit borrow bit respectively, in subtraction.
STATUS REGISTER
U-0
U-0
U-0
R/W-x
R/W-x
R/W-x
R/W-x
R/W-x
—
—
—
N
OV
Z
DC
C
bit 7
bit 0
bit 7-5
Unimplemented: Read as '0'
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 (bit7) 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
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
Note:
bit 0
For borrow, the polarity is reversed. A subtraction is executed by adding the two’s
complement of the second operand. For rotate (RRF, RLF) instructions, this bit is
loaded with either the bit 4 or bit 3 of the source register.
C: Carry/borrow bit
For ADDWF, ADDLW, SUBLW, and SUBWF instructions
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Note:
For borrow, the polarity is reversed. A subtraction is executed by adding the two’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.
Legend:
DS39564C-page 52
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
© 2006 Microchip Technology Inc.
PIC18FXX2
4.14
RCON Register
Note 1: If the BOREN configuration bit is set
(Brown-out Reset enabled), the BOR bit is
’1’ on a Power-on Reset. After a Brownout Reset has occurred, the BOR bit will
be cleared, and must be set by firmware to
indicate the occurrence of the next
Brown-out Reset.
The Reset Control (RCON) register contains flag bits
that allow differentiation between the sources of a
device RESET. These flags include the TO, PD, POR,
BOR and RI bits. This register is readable and writable.
2: 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.
REGISTER 4-3:
RCON REGISTER
R/W-0
U-0
U-0
R/W-1
R-1
R-1
R/W-0
R/W-0
IPEN
—
—
RI
TO
PD
POR
BOR
bit 7
bit 0
bit 7
IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (16CXXX Compatibility mode)
bit 6-5
Unimplemented: Read as '0'
bit 4
RI: RESET Instruction Flag bit
1 = The RESET instruction was not executed
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 = After power-up, CLRWDT instruction, or SLEEP instruction
0 = A WDT time-out occurred
bit 2
PD: Power-down Detection Flag bit
1 = After power-up or by the CLRWDT instruction
0 = By execution of the SLEEP instruction
bit 1
POR: Power-on Reset Status bit
1 = A Power-on Reset has not occurred
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
0 = A Brown-out Reset occurred
(must be set in software after a Brown-out Reset occurs)
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 53
PIC18FXX2
NOTES:
DS39564C-page 54
© 2006 Microchip Technology Inc.
PIC18FXX2
5.0
FLASH PROGRAM MEMORY
5.1
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:
The FLASH Program Memory is readable, writable,
and erasable during normal operation over the entire
VDD range.
A read from program memory is executed on one byte
at a time. A write to program memory is executed on
blocks of 8 bytes at a time. Program memory is erased
in blocks of 64 bytes at a time. A bulk erase operation
may not be issued from user code.
• 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).
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.
Table Read operations retrieve data from program
memory and places it into the data RAM space.
Figure 5-1 shows the operation of a Table Read with
program memory and data RAM.
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.
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 5.5,
'”Writing to FLASH Program Memory”. Figure 5-2
shows 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.
FIGURE 5-1:
TABLE READ OPERATION
Instruction: TBLRD*
Program Memory
Table Pointer(1)
TBLPTRU
TBLPTRH
Table Latch (8-bit)
TBLPTRL
TABLAT
Program Memory
(TBLPTR)
Note 1: Table Pointer points to a byte in program memory.
© 2006 Microchip Technology Inc.
DS39564C-page 55
PIC18FXX2
FIGURE 5-2:
TABLE WRITE OPERATION
Instruction: TBLWT*
Program Memory
Holding Registers
Table Pointer(1)
TBLPTRU
TBLPTRH
Table Latch (8-bit)
TBLPTRL
TABLAT
Program Memory
(TBLPTR)
Note 1: Table Pointer actually points to one of eight holding registers, the address of which is determined by
TBLPTRL<2:0>. The process for physically writing data to the Program Memory Array is discussed in
Section 5.5.
5.2
Control Registers
Several control registers are used in conjunction with
the TBLRD and TBLWT instructions. These include the:
•
•
•
•
EECON1 register
EECON2 register
TABLAT register
TBLPTR registers
5.2.1
EECON1 AND EECON2 REGISTERS
EECON1 is the control register for memory accesses.
EECON2 is not a physical register. Reading EECON2
will read all '0's. The EECON2 register is used
exclusively in the memory write and erase sequences.
Control bit EEPGD determines if the access will be a
program or data EEPROM memory access. When
clear, any subsequent operations will operate on the
data EEPROM memory. When set, any subsequent
operations will operate on the program memory.
Control bit CFGS determines if the access will be to the
configuration registers or to program memory/data
EEPROM memory. When set, subsequent operations
will operate on configuration registers, regardless of
EEPGD (see “Special Features of the CPU”,
Section 19.0). When clear, memory selection access is
determined by EEPGD.
DS39564C-page 56
The FREE bit, when set, will allow a program memory
erase operation. When the FREE bit 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 when a write operation is interrupted by a MCLR
Reset or a WDT Time-out Reset during normal operation. In these situations, the user can check the
WRERR bit and rewrite the location. It is necessary to
reload the data and address registers (EEDATA and
EEADR), due to RESET values of zero.
Control bit WR initiates write operations. This bit cannot
be cleared, only set, in software. It is cleared in hardware at the completion of the write operation. The
inability to clear the WR bit in software prevents the
accidental or premature termination of a write
operation.
Note:
Interrupt flag bit EEIF, in the PIR2 register,
is set when the write is complete. It must
be cleared in software.
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 5-1:
EECON1 REGISTER (ADDRESS FA6h)
R/W-x
R/W-x
U-0
R/W-0
R/W-x
R/W-0
R/S-0
R/S-0
EEPGD
CFGS
—
FREE
WRERR
WREN
WR
RD
bit 7
bit 0
bit 7
EEPGD: FLASH Program or Data EEPROM Memory Select bit
1 = Access FLASH Program memory
0 = Access Data EEPROM memory
bit 6
CFGS: FLASH Program/Data EE or Configuration Select bit
1 = Access Configuration registers
0 = Access FLASH Program or Data EEPROM memory
bit 5
Unimplemented: Read as '0'
bit 4
FREE: FLASH Row Erase Enable bit
1 = Erase the program memory row addressed by TBLPTR on the next WR command
(cleared by completion of erase operation)
0 = Perform write only
bit 3
WRERR: FLASH Program/Data EE Error Flag bit
1 = A write operation is prematurely terminated
(any RESET during self-timed programming in normal operation)
0 = The write operation completed
Note:
When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows
tracing of the error condition.
bit 2
WREN: FLASH Program/Data EE Write Enable bit
1 = Allows write cycles
0 = Inhibits write to the EEPROM
bit 1
WR: Write Control bit
1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.
(The operation is self timed and the bit is cleared by hardware once write is complete. The
WR bit can only be set (not cleared) in software.)
0 = Write cycle to the EEPROM is complete
bit 0
RD: Read Control bit
1 = Initiates an EEPROM read
(Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared)
in software. RD bit cannot be set when EEPGD = 1.)
0 = Does not initiate an EEPROM read
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 57
PIC18FXX2
5.2.2
TABLAT - TABLE LATCH REGISTER
5.2.4
The Table Latch (TABLAT) is an 8-bit register mapped
into the SFR space. The Table Latch is used to hold
8-bit data during data transfers between program
memory and data RAM.
5.2.3
TBLPTR is used in reads, writes, and erases of the
FLASH program memory.
When a TBLRD is executed, all 22 bits of the Table
Pointer determine which byte is read from program
memory into TABLAT.
TBLPTR - TABLE POINTER
REGISTER
When a TBLWT is executed, the three LSbs of the Table
Pointer (TBLPTR<2:0>) determine which of the eight
program memory holding registers is written to. When
the timed write to program memory (long write) begins,
the 19 MSbs of the Table Pointer, TBLPTR
(TBLPTR<21:3>), will determine which program memory block of 8 bytes is written to. For more detail, see
Section 5.5 (“Writing to FLASH Program Memory”).
The Table Pointer (TBLPTR) addresses a byte within
the program memory. The TBLPTR is comprised of
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.
When an erase of program memory is executed, the 16
MSbs of the Table Pointer (TBLPTR<21:6>) point to the
64-byte block that will be erased. The Least Significant
bits (TBLPTR<5:0>) are ignored.
The table pointer, 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. These operations are shown in Table 5-1. These
operations on the TBLPTR only affect the low order
21 bits.
TABLE 5-1:
Operation on Table Pointer
TBLRD*
TBLWT*
TBLRD*+
TBLWT*+
TBLRD*TBLWT*TBLRD+*
TBLWT+*
21
Figure 5-3 describes the relevant boundaries of
TBLPTR based on FLASH program memory
operations.
TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
Example
FIGURE 5-3:
TABLE POINTER BOUNDARIES
TBLPTR is not modified
TBLPTR is incremented after the read/write
TBLPTR is decremented after the read/write
TBLPTR is incremented before the read/write
TABLE POINTER BOUNDARIES BASED ON OPERATION
TBLPTRU
16
15
TBLPTRH
8
7
TBLPTRL
0
ERASE - TBLPTR<21:6>
WRITE - TBLPTR<21:3>
READ - TBLPTR<21:0>
DS39564C-page 58
© 2006 Microchip Technology Inc.
PIC18FXX2
5.3
Reading the FLASH Program
Memory
The TBLRD instruction is used to retrieve data from program memory and place into data RAM. Table Reads
from program memory are performed one byte at a
time.
FIGURE 5-4:
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 Least Significant bit of the address selects
between the high and low bytes of the word. Figure 5-4
shows the interface between the internal program
memory and the TABLAT.
READS FROM FLASH PROGRAM MEMORY
Program Memory
(Even Byte Address)
(Odd Byte Address)
TBLPTR = xxxxx1
Instruction Register
(IR)
EXAMPLE 5-1:
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
FETCH
TBLRD
TBLPTR = xxxxx0
TABLAT
Read Register
READING A FLASH PROGRAM MEMORY WORD
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; Load TBLPTR with the base
; address of the word
READ_WORD
TBLRD*+
MOVF TABLAT, W
MOVWF WORD_EVEN
TBLRD*+
MOVF TABLAT, W
MOVWF WORD_ODD
© 2006 Microchip Technology Inc.
; read into TABLAT and increment
; get data
; read into TABLAT and increment
; get data
DS39564C-page 59
PIC18FXX2
5.4
5.4.1
Erasing FLASH Program memory
The minimum erase block is 32 words or 64 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.
FLASH PROGRAM MEMORY
ERASE SEQUENCE
The sequence of events for erasing a block of internal
program memory location is:
1.
When initiating an erase sequence from the microcontroller itself, a block of 64 bytes of program memory
is erased. The Most Significant 16 bits of the
TBLPTR<21:6> point to the block being erased.
TBLPTR<5:0> are ignored.
2.
3.
4.
5.
6.
The EECON1 register commands the erase operation.
The EEPGD bit must be set to point to the FLASH program memory. The WREN bit must be set to enable
write operations. The FREE bit is set to select an erase
operation.
7.
For protection, the write initiate sequence for EECON2
must be used.
8.
Load table pointer with address of row being
erased.
Set EEPGD bit to point to program memory,
clear CFGS bit to access program memory, set
WREN bit to enable writes, and set FREE bit to
enable the erase.
Disable interrupts.
Write 55h to EECON2.
Write AAh to EECON2.
Set the WR bit. This will begin the row erase
cycle.
The CPU will stall for duration of the erase
(about 2 ms using internal timer).
Re-enable interrupts.
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.
EXAMPLE 5-2:
ERASING A FLASH PROGRAM MEMORY ROW
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; load TBLPTR with the base
; address of the memory block
BSF
BCF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
EECON1,EEPGD
EECON1,CFGS
EECON1,WREN
EECON1,FREE
INTCON,GIE
55h
EECON2
AAh
EECON2
EECON1,WR
INTCON,GIE
;
;
;
;
;
ERASE_ROW
Required
Sequence
DS39564C-page 60
point to FLASH program memory
access FLASH program memory
enable write to memory
enable Row Erase operation
disable interrupts
; write 55h
; write AAh
; start erase (CPU stall)
; re-enable interrupts
© 2006 Microchip Technology Inc.
PIC18FXX2
5.5
Writing to FLASH Program
Memory
The minimum programming block is 4 words or 8 bytes.
Word or byte programming is not supported.
Table Writes are used internally to load the holding registers needed to program the FLASH memory. There
are 8 holding registers used by the Table Writes for
programming.
Since the Table Latch (TABLAT) is only a single byte,
the TBLWT instruction has to be executed 8 times for
each programming operation. All of the Table Write
FIGURE 5-5:
operations will essentially be short writes, because only
the holding registers are written. At the end of updating
8 registers, the EECON1 register must be written to, 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 EEPROM 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 for byte or word operations.
TABLE WRITES TO FLASH PROGRAM MEMORY
TABLAT
Write Register
8
8
TBLPTR = xxxxx0
8
TBLPTR = xxxxx2
TBLPTR = xxxxx1
Holding Register
Holding Register
8
TBLPTR = xxxxx7
Holding Register
Holding Register
Program Memory
5.5.1
FLASH PROGRAM MEMORY WRITE
SEQUENCE
The sequence of events for programming an internal
program memory location should be:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Read 64 bytes into RAM.
Update data values in RAM as necessary.
Load Table Pointer with address being erased.
Do the row erase procedure.
Load Table Pointer with address of first byte
being written.
Write the first 8 bytes into the holding registers
with auto-increment (TBLWT*+ or TBLWT+*).
Set EEPGD bit to point to program memory,
clear the CFGS bit to access program memory,
and set WREN to enable byte writes.
Disable interrupts.
Write 55h to EECON2.
© 2006 Microchip Technology Inc.
10. Write AAh to EECON2.
11. Set the WR bit. This will begin the write cycle.
12. The CPU will stall for duration of the write (about
2 ms using internal timer).
13. Re-enable interrupts.
14. Repeat steps 6-14 seven times, to write
64 bytes.
15. Verify the memory (Table Read).
This procedure will require about 18 ms to update one
row of 64 bytes of memory. An example of the required
code is given in Example 5-3.
Note:
Before setting the WR bit, the table pointer
address needs to be within the intended
address range of the 8 bytes in the holding
registers.
DS39564C-page 61
PIC18FXX2
EXAMPLE 5-3:
WRITING TO FLASH PROGRAM MEMORY
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
D'64
COUNTER
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
TBLRD*+
MOVF
MOVWF
DECFSZ
BRA
TABLAT, W
POSTINC0
COUNTER
READ_BLOCK
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
DATA_ADDR_HIGH
FSR0H
DATA_ADDR_LOW
FSR0L
NEW_DATA_LOW
POSTINC0
NEW_DATA_HIGH
INDF0
; number of bytes in erase block
; point to buffer
; Load TBLPTR with the base
; address of the memory block
READ_BLOCK
;
;
;
;
;
read into TABLAT, and inc
get data
store data
done?
repeat
MODIFY_WORD
; point to buffer
; update buffer word
ERASE_BLOCK
MOVLW
CODE_ADDR_UPPER
MOVWF
TBLPTRU
MOVLW
CODE_ADDR_HIGH
MOVWF
TBLPTRH
MOVLW
CODE_ADDR_LOW
MOVWF
TBLPTRL
BSF
EECON1,EEPGD
BCF
EECON1,CFGS
BSF
EECON1,WREN
BSF
EECON1,FREE
BCF
INTCON,GIE
MOVLW
55h
MOVWF
EECON2
MOVLW
AAh
MOVWF
EECON2
BSF
EECON1,WR
BSF
INTCON,GIE
TBLRD*WRITE_BUFFER_BACK
MOVLW
8
MOVWF
COUNTER_HI
MOVLW
BUFFER_ADDR_HIGH
MOVWF
FSR0H
MOVLW
BUFFER_ADDR_LOW
MOVWF
FSR0L
PROGRAM_LOOP
MOVLW
8
MOVWF
COUNTER
WRITE_WORD_TO_HREGS
MOVF
POSTINC0, W
MOVWF
TABLAT
TBLWT+*
DECFSZ COUNTER
BRA
WRITE_WORD_TO_HREGS
DS39564C-page 62
; load TBLPTR with the base
; address of the memory block
;
;
;
;
;
point to FLASH program memory
access FLASH program memory
enable write to memory
enable Row Erase operation
disable interrupts
; write 55h
;
;
;
;
write AAh
start erase (CPU stall)
re-enable interrupts
dummy read decrement
; number of write buffer groups of 8 bytes
; point to buffer
; number of bytes in holding register
;
;
;
;
;
get low byte of buffer data
present data to table latch
write data, perform a short write
to internal TBLWT holding register.
loop until buffers are full
© 2006 Microchip Technology Inc.
PIC18FXX2
EXAMPLE 5-3:
WRITING TO FLASH PROGRAM MEMORY (CONTINUED)
PROGRAM_MEMORY
BSF
BCF
BSF
BCF
MOVLW
Required
MOVWF
Sequence
MOVLW
MOVWF
BSF
BSF
DECFSZ
BRA
BCF
5.5.2
EECON1,EEPGD
EECON1,CFGS
EECON1,WREN
INTCON,GIE
55h
EECON2
AAh
EECON2
EECON1,WR
INTCON,GIE
COUNTER_HI
PROGRAM_LOOP
EECON1,WREN
;
;
;
;
point to FLASH program memory
access FLASH program memory
enable write to memory
disable interrupts
; write 55h
;
;
;
;
write AAh
start program (CPU stall)
re-enable interrupts
loop until done
; disable write to memory
5.5.4
WRITE VERIFY
PROTECTION AGAINST SPURIOUS
WRITES
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.
To protect against spurious writes to FLASH program
memory, the write initiate sequence must also be followed. See “Special Features of the CPU”
(Section 19.0) for more detail.
5.5.3
5.6
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 reprogrammed if needed.The WRERR bit is set when a write
operation is interrupted by a MCLR Reset, or a WDT
Time-out Reset during normal operation. In these situations, users can check the WRERR bit and rewrite the
location.
TABLE 5-2:
Address
FLASH Program Operation During
Code Protection
See “Special Features of the CPU” (Section 19.0) for
details on code protection of FLASH program memory.
REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY
Bit 6
Bit 5
FF8h
TBLPTRU
—
—
bit21
FF7h
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>)
0000 0000 0000 0000
FF6h
TBLPTRL Program Memory Table Pointer High Byte (TBLPTR<7:0>)
0000 0000 0000 0000
FF5h
TABLAT
FF2h
INTCON
EECON2
FA6h
EECON1
FA2h
Bit 3
Bit 2
Bit 1
Bit 0
Value on
All Other
RESETS
Bit 7
FA7h
Bit 4
Value on:
POR, BOR
Name
Program Memory Table Pointer Upper Byte
(TBLPTR<20:16>)
--00 0000 --00 0000
Program Memory Table Latch
GIE/
GIEH
PEIE/
GIEL
TMR0IE
0000 0000 0000 0000
INTE
RBIE
TMR0IF
INTF
RBIF
0000 000x 0000 000u
EEPROM Control Register2 (not a physical register)
—
—
EEPGD
CFGS
—
FREE
WRERR
WREN
WR
RD
xx-0 x000 uu-0 u000
IPR2
—
—
—
EEIP
BCLIP
LVDIP
TMR3IP
CCP2IP
---1 1111 ---1 1111
FA1h
PIR2
—
—
—
EEIF
BCLIF
LVDIF
TMR3IF
CCP2IF
---0 0000 ---0 0000
FA0h
PIE2
—
—
—
EEIE
BCLIE
LVDIE
TMR3IE
CCP2IE
---0 0000 ---0 0000
Legend:
x = unknown, u = unchanged, r = reserved, - = unimplemented read as '0'.
Shaded cells are not used during FLASH/EEPROM access.
© 2006 Microchip Technology Inc.
DS39564C-page 63
PIC18FXX2
NOTES:
DS39564C-page 64
© 2006 Microchip Technology Inc.
PIC18FXX2
6.0
DATA EEPROM MEMORY
The Data EEPROM is readable and writable during
normal operation over the entire VDD range. The data
memory is not directly mapped in the register file
space. Instead, it is indirectly addressed through the
Special Function Registers (SFR).
There are four SFRs used to read and write the
program and data EEPROM memory. These registers
are:
•
•
•
•
EECON1
EECON2
EEDATA
EEADR
The EEPROM data memory allows byte read and write.
When interfacing to the data memory block, EEDATA
holds the 8-bit data for read/write and EEADR holds the
address of the EEPROM location being accessed.
These devices have 256 bytes of data EEPROM with
an address range from 0h to FFh.
The EEPROM data memory is rated for high erase/
write cycles. A byte write automatically erases the location and writes the new data (erase-before-write). The
write time is controlled by an on-chip timer. The write
time will vary with voltage and temperature, as well as
from chip to chip. Please refer to parameter D122
(Electrical Characteristics, Section 22.0) for exact
limits.
© 2006 Microchip Technology Inc.
6.1
EEADR
The address register can address up to a maximum of
256 bytes of data EEPROM.
6.2
EECON1 and EECON2 Registers
EECON1 is the control register for EEPROM memory
accesses.
EECON2 is not a physical register. Reading EECON2
will read all '0's. The EECON2 register is used
exclusively in the EEPROM write sequence.
Control bits RD and WR initiate read and write operations, respectively. These bits cannot be cleared, only
set, in software. They are cleared in hardware at the
completion of the read or write operation. The inability
to clear the WR bit in software prevents the accidental
or premature termination of a write operation.
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear. The WRERR bit is
set when a write operation is interrupted by a MCLR
Reset, or a WDT Time-out Reset during normal operation. In these situations, the user can check the
WRERR bit and rewrite the location. It is necessary to
reload the data and address registers (EEDATA and
EEADR), due to the RESET condition forcing the
contents of the registers to zero.
Note:
Interrupt flag bit, EEIF in the PIR2 register,
is set when write is complete. It must be
cleared in software.
DS39564C-page 65
PIC18FXX2
REGISTER 6-1:
EECON1 REGISTER (ADDRESS FA6h)
R/W-x
R/W-x
U-0
R/W-0
R/W-x
R/W-0
R/S-0
R/S-0
EEPGD
CFGS
—
FREE
WRERR
WREN
WR
RD
bit 7
bit 0
bit 7
EEPGD: FLASH Program or Data EEPROM Memory Select bit
1 = Access FLASH Program memory
0 = Access Data EEPROM memory
bit 6
CFGS: FLASH Program/Data EE or Configuration Select bit
1 = Access Configuration or Calibration registers
0 = Access FLASH Program or Data EEPROM memory
bit 5
Unimplemented: Read as '0'
bit 4
FREE: FLASH Row Erase Enable bit
1 = Erase the program memory row addressed by TBLPTR on the next WR command
(cleared by completion of erase operation)
0 = Perform write only
bit 3
WRERR: FLASH Program/Data EE Error Flag bit
1 = A write operation is prematurely terminated
(any MCLR or any WDT Reset during self-timed programming in normal operation)
0 = The write operation completed
Note:
When a WRERR occurs, the EEPGD or FREE bits are not cleared. This allows tracing
of the error condition.
bit 2
WREN: FLASH Program/Data EE Write Enable bit
1 = Allows write cycles
0 = Inhibits write to the EEPROM
bit 1
WR: Write Control bit
1 = Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.
(The operation is self-timed and the bit is cleared by hardware once write is complete. The
WR bit can only be set (not cleared) in software.)
0 = Write cycle to the EEPROM is complete
bit 0
RD: Read Control bit
1 = Initiates an EEPROM read
(Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared)
in software. RD bit cannot be set when EEPGD = 1.)
0 = Does not initiate an EEPROM read
Legend:
DS39564C-page 66
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
© 2006 Microchip Technology Inc.
PIC18FXX2
6.3
Reading the Data EEPROM
Memory
To read a data memory location, the user must write the
address to the EEADR register, clear the EEPGD control bit (EECON1<7>), clear the CFGS control bit
EXAMPLE 6-1:
MOVLW
MOVWF
BCF
BCF
BSF
MOVF
6.4
DATA EEPROM READ
DATA_EE_ADDR
EEADR
EECON1, EEPGD
EECON1, CFGS
EECON1, RD
EEDATA, W
;
;
;
;
;
;
Data Memory Address to read
Point to DATA memory
Access program FLASH or Data EEPROM memory
EEPROM Read
W = EEDATA
Writing to the Data EEPROM
Memory
cution (i.e., runaway programs). The WREN bit should
be kept clear at all times, except when updating the
EEPROM. The WREN bit is not cleared by hardware.
To write an EEPROM data location, the address must
first be written to the EEADR register and the data written to the EEDATA register. Then the sequence in
Example 6-2 must be followed to initiate the write cycle.
The write will not initiate if the above sequence is not
exactly followed (write 55h to EECON2, write AAh to
EECON2, then set WR bit) for each byte. It is strongly
recommended that interrupts be disabled during this
code segment.
Additionally, the WREN bit in EECON1 must be set to
enable writes. This mechanism prevents accidental
writes to data EEPROM due to unexpected code exe-
EXAMPLE 6-2:
Required
Sequence
(EECON1<6>), and then set control bit RD
(EECON1<0>). The data is available for the very next
instruction cycle; therefore, the EEDATA register can
be read by the next instruction. EEDATA will hold this
value until another read operation, or until it is written to
by the user (during a write operation).
After a write sequence has been initiated, EECON1,
EEADR and EDATA cannot be modified. The WR bit
will be inhibited from being set unless the WREN bit is
set. The WREN bit must be set on a previous instruction. Both WR and WREN cannot be set with the same
instruction.
At the completion of the write cycle, the WR bit is
cleared in hardware and the EEPROM Write Complete
Interrupt Flag bit (EEIF) is set. The user may either
enable this interrupt, or poll this bit. EEIF must be
cleared by software.
DATA EEPROM WRITE
MOVLW
MOVWF
MOVLW
MOVWF
BCF
BCF
BSF
DATA_EE_ADDR
EEADR
DATA_EE_DATA
EEDATA
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
;
;
;
;
;
;
;
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BSF
INTCON, GIE
55h
EECON2
AAh
EECON2
EECON1, WR
INTCON, GIE
;
;
;
;
;
;
;
.
.
.
BCF
Data Memory Address to read
Data Memory Value to write
Point to DATA memory
Access program FLASH or Data EEPROM memory
Enable writes
Disable interrupts
Write 55h
Write AAh
Set WR bit to begin write
Enable interrupts
; user code execution
EECON1, WREN
© 2006 Microchip Technology Inc.
; Disable writes on write complete (EEIF set)
DS39564C-page 67
PIC18FXX2
6.5
Write Verify
6.7
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.
6.6
Protection Against Spurious Write
There are conditions when the device may not want to
write to the data EEPROM memory. To protect against
spurious EEPROM writes, various mechanisms have
been built-in. On power-up, the WREN bit is cleared.
Also, the Power-up Timer (72 ms duration) prevents
EEPROM write.
The write initiate sequence and the WREN bit together
help prevent an accidental write during brown-out,
power glitch, or software malfunction.
Operation During Code Protect
Data EEPROM memory has its own code protect
mechanism. External Read and Write operations are
disabled if either of these mechanisms are enabled.
The microcontroller itself can both read and write to the
internal Data EEPROM, regardless of the state of the
code protect configuration bit. Refer to “Special Features
of the CPU” (Section 19.0) for additional information.
6.8
Using the Data EEPROM
The data EEPROM is a high endurance, byte addressable array that has been optimized for the storage of
frequently changing information (e.g., program variables or other data that are updated often). Frequently
changing values will typically be updated more often
than specification D124. If this is not the case, an array
refresh must be performed. For this reason, variables
that change infrequently (such as constants, IDs, calibration, etc.) should be stored in FLASH program
memory.
A simple data EEPROM refresh routine is shown in
Example 6-3.
Note:
EXAMPLE 6-3:
DATA EEPROM REFRESH ROUTINE
clrf
bcf
bcf
bcf
bsf
EEADR
EECON1,CFGS
EECON1,EEPGD
INTCON,GIE
EECON1,WREN
bsf
movlw
movwf
movlw
movwf
bsf
btfsc
bra
incfsz
bra
EECON1,RD
55h
EECON2
AAh
EECON2
EECON1,WR
EECON1,WR
$-2
EEADR,F
Loop
bcf
bsf
EECON1,WREN
INTCON,GIE
Loop
DS39564C-page 68
If data EEPROM is only used to store constants and/or data that changes rarely, an
array refresh is likely not required. See
specification D124.
;
;
;
;
;
;
;
;
;
;
;
;
;
Start at address 0
Set for memory
Set for Data EEPROM
Disable interrupts
Enable writes
Loop to refresh array
Read current address
Write 55h
Write AAh
Set WR bit to begin write
Wait for write to complete
; Increment address
; Not zero, do it again
; Disable writes
; Enable interrupts
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 6-1:
Address
FF2h
REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on:
POR, BOR
Value on
All Other
RESETS
INTCON
GIE/
GIEH
PEIE/
GIEL
T0IE
INTE
RBIE
T0IF
INTF
RBIF
0000 000x
0000 000u
FA9h
EEADR
EEPROM Address Register
0000 0000
0000 0000
FA8h
EEDATA
EEPROM Data Register
0000 0000
0000 0000
FA7h
EECON2 EEPROM Control Register2 (not a physical register)
FA6h
EECON1
FA2h
FA1h
FA0h
Legend:
—
—
xx-0 x000
uu-0 u000
LVDIP
TMR3IP CCP2IP ---1 1111
---1 1111
LVDIF
TMR3IF CCP2IF ---0 0000
---0 0000
LVDIE
TMR3IE CCP2IE ---0 0000
---0 0000
EEPGD
CFGS
—
FREE
WRERR
WREN
IPR2
—
—
—
EEIP
BCLIP
PIR2
—
—
—
EEIF
BCLIF
PIE2
—
—
—
EEIE
BCLIE
WR
RD
x = unknown, u = unchanged, r = reserved, - = unimplemented, read as '0'.
Shaded cells are not used during FLASH/EEPROM access.
© 2006 Microchip Technology Inc.
DS39564C-page 69
PIC18FXX2
NOTES:
DS39564C-page 70
© 2006 Microchip Technology Inc.
PIC18FXX2
7.0
8 X 8 HARDWARE MULTIPLIER
Making the 8 x 8 multiplier execute in a single cycle
gives the following advantages:
7.1
Introduction
• Higher computational throughput
• Reduces code size requirements for multiply
algorithms
An 8 x 8 hardware multiplier is included in the ALU of
the PIC18FXX2 devices. By making the multiply a
hardware operation, it completes in a single instruction
cycle. This is an unsigned multiply that gives a 16-bit
result. The result is stored into the 16-bit product register pair (PRODH:PRODL). The multiplier does not
affect any flags in the ALUSTA register.
TABLE 7-1:
8 x 8 unsigned
8 x 8 signed
16 x 16 unsigned
16 x 16 signed
Program
Memory
(Words)
Cycles
(Max)
Without hardware multiply
13
Hardware multiply
1
Without hardware multiply
33
Hardware multiply
6
Without hardware multiply
Hardware multiply
Multiply Method
@ 10 MHz
@ 4 MHz
69
6.9 μs
27.6 μs
69 μs
1
100 ns
400 ns
1 μs
91
9.1 μs
36.4 μs
91 μs
6
600 ns
2.4 μs
6 μs
21
242
24.2 μs
96.8 μs
242 μs
24
24
2.4 μs
9.6 μs
24 μs
Without hardware multiply
52
254
25.4 μs
102.6 μs
254 μs
Hardware multiply
36
36
3.6 μs
14.4 μs
36 μs
Operation
EXAMPLE 7-2:
Example 7-2 shows the sequence to do an 8 x 8 signed
multiply. 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 7-1:
ARG1, W
ARG2
Time
@ 40 MHz
Example 7-1 shows the sequence to do an 8 x 8
unsigned multiply. Only one instruction is required
when one argument of the multiply is already loaded in
the WREG register.
MOVF
MULWF
Table 7-1 shows a performance comparison between
enhanced devices using the single cycle hardware multiply, and performing the same function without the
hardware multiply.
PERFORMANCE COMPARISON
Routine
7.2
The performance increase allows the device to be used
in applications previously reserved for Digital Signal
Processors.
8 x 8 UNSIGNED
MULTIPLY ROUTINE
;
; ARG1 * ARG2 ->
;
PRODH:PRODL
MOVF
MULWF
ARG1,
ARG2
BTFSC
SUBWF
ARG2, SB
PRODH, F
MOVF
BTFSC
SUBWF
ARG2, W
ARG1, SB
PRODH, F
W
;
;
;
;
;
ARG1 * ARG2 ->
PRODH:PRODL
Test Sign Bit
PRODH = PRODH
- ARG1
; Test Sign Bit
; PRODH = PRODH
;
- ARG2
Example 7-3 shows the sequence to do a 16 x 16
unsigned multiply. Equation 7-1 shows the algorithm
that is used. The 32-bit result is stored in four registers,
RES3:RES0.
EQUATION 7-1:
RES3:RES0
© 2006 Microchip Technology Inc.
8 x 8 SIGNED MULTIPLY
ROUTINE
=
=
16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
ARG1H:ARG1L • ARG2H:ARG2L
(ARG1H • ARG2H • 216) +
(ARG1H • ARG2L • 28) +
(ARG1L • ARG2H • 28) +
(ARG1L • ARG2L)
DS39564C-page 71
PIC18FXX2
EXAMPLE 7-3:
MOVF
MULWF
16 x 16 UNSIGNED
MULTIPLY ROUTINE
EXAMPLE 7-4:
ARG1L, W
ARG2L
MOVFF
MOVFF
; ARG1L * ARG2L ->
; PRODH:PRODL
PRODH, RES1 ;
PRODL, RES0 ;
MOVF
MULWF
ARG1H, W
ARG2H
;
16 x 16 SIGNED
MULTIPLY ROUTINE
MOVF
MULWF
ARG1L, W
ARG2L
MOVFF
MOVFF
PRODH, RES1
PRODL, RES0
MOVF
MULWF
ARG1H, W
ARG2H
MOVFF
MOVFF
PRODH, RES3
PRODL, RES2
MOVF
MULWF
ARG1L, W
ARG2H
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL,
RES1,
PRODH,
RES2,
WREG
RES3,
MOVF
MULWF
ARG1H, W
ARG2L
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL,
RES1,
PRODH,
RES2,
WREG
RES3,
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB
ARG2H, 7
SIGN_ARG1
ARG1L, W
RES2
ARG1H, W
RES3
; ARG2H:ARG2L neg?
; no, check ARG1
;
;
;
ARG1H, 7
CONT_CODE
ARG2L, W
RES2
ARG2H, W
RES3
; ARG1H:ARG1L neg?
; no, done
;
;
;
; ARG1L * ARG2L ->
; PRODH:PRODL
;
;
;
MOVFF
MOVFF
; ARG1H * ARG2H ->
; PRODH:PRODL
PRODH, RES3 ;
PRODL, RES2 ;
MOVF
MULWF
ARG1L, W
ARG2H
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL,
RES1,
PRODH,
RES2,
WREG
RES3,
;
; ARG1H * ARG2H ->
; PRODH:PRODL
;
;
;
W
F
W
F
F
;
;
;
;
;
;
;
;
ARG1L * ARG2H ->
PRODH:PRODL
Add cross
products
;
W
F
W
F
F
;
;
;
;
;
;
;
;
ARG1L * ARG2H ->
PRODH:PRODL
Add cross
products
;
MOVF
MULWF
ARG1H, W
ARG2L
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL,
RES1,
PRODH,
RES2,
WREG
RES3,
W
F
W
F
F
;
;
;
;
;
;
;
;
;
ARG1H * ARG2L ->
PRODH:PRODL
Add cross
products
W
F
W
F
F
;
;
;
;
;
;
;
;
;
ARG1H * ARG2L ->
PRODH:PRODL
Add cross
products
;
Example 7-4 shows the sequence to do a 16 x 16
signed multiply. Equation 7-2 shows the algorithm
used. The 32-bit result is stored in four registers,
RES3:RES0. To account for the sign bits of the arguments, each argument pairs Most Significant bit (MSb)
is tested and the appropriate subtractions are done.
EQUATION 7-2:
16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
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)
DS39564C-page 72
;
SIGN_ARG1
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB
;
CONT_CODE
:
© 2006 Microchip Technology Inc.
PIC18FXX2
8.0
INTERRUPTS
The PIC18FXX2 devices have multiple interrupt
sources and an interrupt priority feature that allows
each interrupt source to be assigned a high priority
level or a low priority level. The high priority interrupt
vector is at 000008h and the low priority interrupt vector
is at 000018h. High priority interrupt events will override any low priority interrupts that may be in progress.
There are ten registers which are used to control
interrupt operation. These registers are:
•
•
•
•
•
•
•
RCON
INTCON
INTCON2
INTCON3
PIR1, PIR2
PIE1, PIE2
IPR1, IPR2
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.
Each interrupt source, except INT0, has three bits to
control its operation. The functions of these bits 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. Setting the GIEL
bit (INTCON<6>) enables all interrupts that have the
priority bit cleared. When the interrupt flag, enable bit
and appropriate global interrupt enable bit are set, the
interrupt will vector immediately to address 000008h or
000018h, depending on the priority level. Individual
interrupts can be disabled through their corresponding
enable bits.
© 2006 Microchip Technology Inc.
When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PICmicro® 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
000008h in Compatibility mode.
When an interrupt is responded to, the Global Interrupt
Enable bit is cleared to disable 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 or GIEL bit.
High priority interrupt sources can interrupt a low
priority interrupt.
The return address is pushed onto the stack and the
PC is loaded with the interrupt vector address
(000008h or 000018h). Once in the Interrupt Service
Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt
flag bits must be cleared in software before re-enabling
interrupts 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 INT 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.
DS39564C-page 73
PIC18FXX2
FIGURE 8-1:
INTERRUPT LOGIC
TMR0IF
TMR0IE
TMR0IP
RBIF
RBIE
RBIP
INT0IF
INT0IE
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
Peripheral Interrupt Flag bit
Peripheral Interrupt Enable bit
Peripheral Interrupt Priority bit
Wake-up if in SLEEP mode
Interrupt to CPU
Vector to location
0008h
GIEH/GIE
TMR1IF
TMR1IE
TMR1IP
IPE
IPEN
XXXXIF
XXXXIE
XXXXIP
GIEL/PEIE
IPEN
Additional Peripheral Interrupts
High Priority Interrupt Generation
Low Priority Interrupt Generation
Peripheral Interrupt Flag bit
Peripheral Interrupt Enable bit
Peripheral Interrupt Priority bit
TMR0IF
TMR0IE
TMR0IP
TMR1IF
TMR1IE
TMR1IP
RBIF
RBIE
RBIP
XXXXIF
XXXXIE
XXXXIP
INT1IF
INT1IE
INT1IP
Additional Peripheral Interrupts
DS39564C-page 74
Interrupt to CPU
Vector to Location
0018h
GIEL/PEIE
GIE/GIEH
INT2IF
INT2IE
INT2IP
© 2006 Microchip Technology Inc.
PIC18FXX2
8.1
INTCON Registers
Note:
The INTCON Registers are readable and writable registers, which contain various enable, priority and flag
bits.
REGISTER 8-1:
Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the global
enable bit. User software should ensure
the appropriate interrupt flag bits are clear
prior to enabling an interrupt. This feature
allows for software polling.
INTCON REGISTER
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
bit 7
bit 0
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
0 = Disables all interrupts
bit 6
PEIE/GIEL: Peripheral Interrupt Enable bit
When IPEN = 0:
1 = Enables all unmasked peripheral interrupts
0 = Disables all peripheral interrupts
When IPEN = 1:
1 = Enables all low priority peripheral interrupts
0 = Disables all low priority peripheral interrupts
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 = At least one of the RB7:RB4 pins changed state (must be cleared in software)
0 = None of the RB7:RB4 pins have changed state
Note:
A mismatch condition will continue to set this bit. Reading PORTB will end the
mismatch condition and allow the bit to be cleared.
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 75
PIC18FXX2
REGISTER 8-2:
INTCON2 REGISTER
R/W-1
R/W-1
R/W-1
R/W-1
U-0
R/W-1
U-0
R/W-1
RBPU
INTEDG0
INTEDG1
INTEDG2
—
TMR0IP
—
RBIP
bit 7
bit 0
bit 7
RBPU: PORTB Pull-up Enable bit
1 = All PORTB pull-ups are disabled
0 = PORTB pull-ups are enabled by individual port latch values
bit 6
INTEDG0:External Interrupt0 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 5
INTEDG1: External Interrupt1 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 4
INTEDG2: External Interrupt2 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 3
Unimplemented: Read as '0'
bit 2
TMR0IP: TMR0 Overflow Interrupt Priority bit
1 = High priority
0 = Low priority
bit 1
Unimplemented: Read as '0'
bit 0
RBIP: RB Port Change Interrupt Priority bit
1 = High priority
0 = Low priority
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
Note:
DS39564C-page 76
x = Bit is unknown
Interrupt flag bits are set when an interrupt condition occurs, regardless of the state
of its corresponding enable bit or the global enable bit. User software should ensure
the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature
allows for software polling.
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 8-3:
INTCON3 REGISTER
R/W-1
R/W-1
U-0
R/W-0
R/W-0
U-0
R/W-0
R/W-0
INT2IP
INT1IP
—
INT2IE
INT1IE
—
INT2IF
INT1IF
bit 7
bit 0
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
Unimplemented: Read as '0'
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
Unimplemented: Read as '0'
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
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
Note:
© 2006 Microchip Technology Inc.
x = Bit is unknown
Interrupt flag bits are set when an interrupt condition occurs, regardless of the state
of its corresponding enable bit or the global enable bit. User software should ensure
the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature
allows for software polling.
DS39564C-page 77
PIC18FXX2
8.2
PIR Registers
Note 1: Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the global
enable bit, GIE (INTCON<7>).
The PIR registers contain the individual flag bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are two Peripheral Interrupt
Flag Registers (PIR1, PIR2).
REGISTER 8-4:
2: User software should ensure the appropriate
interrupt flag bits are cleared prior to enabling
an interrupt, and after servicing that interrupt.
PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
R/W-0
(1)
PSPIF
R/W-0
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
bit 7
bit 0
bit 7
PSPIF(1): Parallel Slave Port Read/Write Interrupt Flag bit
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
RCIF: USART Receive Interrupt Flag bit
1 = The USART receive buffer, RCREG, is full (cleared when RCREG is read)
0 = The USART receive buffer is empty
bit 4
TXIF: USART Transmit Interrupt Flag bit (see Section 16.0 for details on TXIF functionality)
1 = The USART transmit buffer, TXREG, is empty (cleared when TXREG is written)
0 = The USART transmit buffer is full
bit 3
SSPIF: Master Synchronous Serial Port Interrupt Flag bit
1 = The transmission/reception is complete (must be cleared in software)
0 = Waiting to transmit/receive
bit 2
CCP1IF: CCP1 Interrupt Flag bit
Capture mode:
1 = A TMR1 register capture occurred (must be cleared in software)
0 = No TMR1 register capture occurred
Compare mode:
1 = A TMR1 register compare match occurred (must be cleared in software)
0 = No TMR1 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 = MR1 register did not overflow
Note 1: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear.
Legend:
DS39564C-page 78
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
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 8-5:
PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
—
EEIF
BCLIF
LVDIF
TMR3IF
CCP2IF
bit 7
bit 0
bit 7-5
Unimplemented: Read as '0'
bit 4
EEIF: Data EEPROM/FLASH Write Operation Interrupt Flag bit
1 = The Write operation is complete (must be cleared in software)
0 = The Write operation is not complete, or has not been started
bit 3
BCLIF: Bus Collision Interrupt Flag bit
1 = A bus collision occurred (must be cleared in software)
0 = No bus collision occurred
bit 2
LVDIF: Low Voltage Detect Interrupt Flag bit
1 = A low voltage condition occurred (must be cleared in software)
0 = The device voltage is above the Low Voltage Detect trip point
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: CCPx Interrupt Flag bit
Capture mode:
1 = A TMR1 register capture occurred (must be cleared in software)
0 = No TMR1 register capture occurred
Compare mode:
1 = A TMR1 register compare match occurred (must be cleared in software)
0 = No TMR1 register compare match occurred
PWM mode:
Unused in this mode
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 79
PIC18FXX2
8.3
PIE Registers
The PIE registers contain the individual enable bits for
the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Enable Registers (PIE1, PIE2). When IPEN = 0,
the PEIE bit must be set to enable any of these
peripheral interrupts.
REGISTER 8-6:
PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
R/W-0
(1)
PSPIE
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
bit 7
bit 0
bit 7
PSPIE(1): Parallel Slave Port Read/Write Interrupt Enable bit
1 = Enables the PSP read/write interrupt
0 = Disables the PSP 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
RCIE: USART Receive Interrupt Enable bit
1 = Enables the USART receive interrupt
0 = Disables the USART receive interrupt
bit 4
TXIE: USART Transmit Interrupt Enable bit
1 = Enables the USART transmit interrupt
0 = Disables the USART transmit interrupt
bit 3
SSPIE: Master Synchronous Serial Port Interrupt Enable bit
1 = Enables the MSSP interrupt
0 = Disables the MSSP interrupt
bit 2
CCP1IE: CCP1 Interrupt Enable bit
1 = Enables the CCP1 interrupt
0 = Disables the CCP1 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: This bit is reserved on PIC18F2X2 devices; always maintain this bit clear.
Legend:
DS39564C-page 80
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
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 8-7:
PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
—
EEIE
BCLIE
LVDIE
TMR3IE
CCP2IE
bit 7
bit 0
bit 7-5
Unimplemented: Read as '0'
bit 4
EEIE: Data EEPROM/FLASH Write Operation Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 3
BCLIE: Bus Collision Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 2
LVDIE: Low Voltage Detect Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 1
TMR3IE: TMR3 Overflow Interrupt Enable bit
1 = Enables the TMR3 overflow interrupt
0 = Disables the TMR3 overflow interrupt
bit 0
CCP2IE: CCP2 Interrupt Enable bit
1 = Enables the CCP2 interrupt
0 = Disables the CCP2 interrupt
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 81
PIC18FXX2
8.4
IPR Registers
The IPR registers contain the individual priority bits for
the peripheral interrupts. Due to the number of peripheral interrupt sources, there are two Peripheral Interrupt Priority Registers (IPR1, IPR2). The operation of
the priority bits requires that the Interrupt Priority
Enable (IPEN) bit be set.
REGISTER 8-8:
IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
bit 7
bit 0
bit 7
PSPIP(1): Parallel Slave Port Read/Write Interrupt Priority bit
1 = High priority
0 = Low priority
bit 6
ADIP: A/D Converter Interrupt Priority bit
1 = High priority
0 = Low priority
bit 5
RCIP: USART Receive Interrupt Priority bit
1 = High priority
0 = Low priority
bit 4
TXIP: USART Transmit Interrupt Priority bit
1 = High priority
0 = Low priority
bit 3
SSPIP: Master Synchronous Serial Port Interrupt Priority bit
1 = High priority
0 = Low priority
bit 2
CCP1IP: CCP1 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: This bit is reserved on PIC18F2X2 devices; always maintain this bit set.
Legend:
DS39564C-page 82
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
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 8-9:
IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
U-0
U-0
U-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
—
—
—
EEIP
BCLIP
LVDIP
TMR3IP
CCP2IP
bit 7
bit 0
bit 7-5
Unimplemented: Read as '0'
bit 4
EEIP: Data EEPROM/FLASH Write Operation Interrupt Priority bit
1 = High priority
0 = Low priority
bit 3
BCLIP: Bus Collision Interrupt Priority bit
1 = High priority
0 = Low priority
bit 2
LVDIP: 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: CCP2 Interrupt Priority bit
1 = High priority
0 = Low priority
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 83
PIC18FXX2
8.5
RCON Register
The RCON register contains the bit which is used to
enable prioritized interrupts (IPEN).
REGISTER 8-10:
RCON REGISTER
R/W-0
U-0
U-0
R/W-1
R-1
R-1
R/W-0
R/W-0
IPEN
—
—
RI
TO
PD
POR
BOR
bit 7
bit 0
bit 7
IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (16CXXX Compatibility mode)
bit 6-5
Unimplemented: Read as '0'
bit 4
RI: RESET Instruction Flag bit
For details of bit operation, see Register 4-3
bit 3
TO: Watchdog Time-out Flag bit
For details of bit operation, see Register 4-3
bit 2
PD: Power-down Detection Flag bit
For details of bit operation, see Register 4-3
bit 1
POR: Power-on Reset Status bit
For details of bit operation, see Register 4-3
bit 0
BOR: Brown-out Reset Status bit
For details of bit operation, see Register 4-3
Legend:
DS39564C-page 84
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
© 2006 Microchip Technology Inc.
PIC18FXX2
8.6
INT0 Interrupt
8.7
External interrupts on the RB0/INT0, RB1/INT1 and
RB2/INT2 pins are edge triggered: either rising, if the
corresponding INTEDGx bit is set in the INTCON2 register, or falling, if the INTEDGx bit is clear. When a valid
edge appears on the RBx/INTx pin, the corresponding
flag bit INTxF is set. This interrupt can be disabled by
clearing the corresponding enable bit INTxE. Flag bit
INTxF must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1 and INT2) can wake-up the
processor from SLEEP, if bit INTxE was set prior to
going into SLEEP. If the global interrupt enable bit GIE
is set, the processor will branch to the interrupt vector
following wake-up.
Interrupt priority for INT1 and INT2 is determined by the
value contained in the interrupt priority bits, INT1IP
(INTCON3<6>) and INT2IP (INTCON3<7>). There is
no priority bit associated with INT0. It is always a high
priority interrupt source.
TMR0 Interrupt
In 8-bit mode (which is the default), an overflow
(FFh → 00h) in the TMR0 register will set flag bit
TMR0IF. In 16-bit mode, an overflow (FFFFh → 0000h)
in the TMR0H:TMR0L registers will set flag bit TMR0IF.
The interrupt can be enabled/disabled by setting/
clearing enable bit T0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in
the interrupt priority bit TMR0IP (INTCON2<2>). See
Section 10.0 for further details on the Timer0 module.
8.8
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>).
8.9
Context Saving During Interrupts
During an interrupt, the return PC value 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 4.3), the user
may need to save the WREG, STATUS and BSR registers in software. Depending on the user’s application,
other registers may also need to be saved. Equation 8-1
saves and restores the WREG, STATUS and BSR
registers during an Interrupt Service Routine.
EXAMPLE 8-1:
MOVWF
MOVFF
MOVFF
;
; USER
;
MOVFF
MOVF
MOVFF
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
W_TEMP
STATUS, STATUS_TEMP
BSR,
BSR_TEMP
; W_TEMP is in virtual bank
; STATUS_TEMP located anywhere
; BSR located anywhere
ISR CODE
BSR_TEMP, BSR
W_TEMP,
W
STATUS_TEMP,STATUS
© 2006 Microchip Technology Inc.
; Restore BSR
; Restore WREG
; Restore STATUS
DS39564C-page 85
PIC18FXX2
NOTES:
DS39564C-page 86
© 2006 Microchip Technology Inc.
PIC18FXX2
9.0
I/O PORTS
Depending on the device selected, there are either five
ports or three 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 (output latch)
The data latch (LAT register) is useful for read-modifywrite operations on the value that the I/O pins are
driving.
9.1
EXAMPLE 9-1:
INITIALIZING PORTA
CLRF PORTA
;
;
;
;
;
;
;
;
;
;
;
;
;
CLRF LATA
MOVLW 0x07
MOVWF ADCON1
MOVLW 0xCF
MOVWF TRISA
Initialize PORTA by
clearing output
data latches
Alternate method
to clear output
data latches
Configure A/D
for digital inputs
Value used to
initialize data
direction
Set RA<3:0> as inputs
RA<5:4> as outputs
FIGURE 9-1:
BLOCK DIAGRAM OF
RA3:RA0 AND RA5 PINS
PORTA, TRISA and LATA
Registers
PORTA is a 7-bit wide, bi-directional port. The corresponding Data Direction register is TRISA. Setting a
TRISA bit (= 1) will make the corresponding PORTA pin
an input (i.e., put the corresponding output driver in a
Hi-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.
RD LATA
Data
Bus
D
Q
VDD
WR LATA
or
PORTA
CK
Q
D
CK
On a Power-on Reset, RA5 and RA3:RA0
are configured as analog inputs and read
as ‘0’. RA6 and RA4 are configured as
digital inputs.
I/O pin(1)
VSS
Analog
Input
Mode
Q
TRIS Latch
TTL
Input
Buffer
RD TRISA
The RA4 pin is multiplexed with the Timer0 module
clock input to become the RA4/T0CKI pin. The RA4/
T0CKI pin is a Schmitt Trigger input and an open drain
output. All other RA port pins have TTL input levels and
full CMOS output drivers.
Note:
N
Q
WR TRISA
The Data Latch register (LATA) is also memory
mapped. Read-modify-write operations on the LATA
register reads and writes the latched output value for
PORTA.
The other PORTA pins are multiplexed with analog
inputs and the analog VREF+ and VREF- inputs. The
operation of each pin is selected by clearing/setting the
control bits in the ADCON1 register (A/D Control
Register1).
P
Data Latch
Q
D
EN
RD PORTA
SS Input (RA5 only)
To A/D Converter and LVD Modules
Note 1:
I/O pins have protection diodes to VDD and VSS.
The TRISA register controls the direction of the RA
pins, even when they are being used as analog inputs.
The user must ensure the bits in the TRISA register are
maintained set when using them as analog inputs.
© 2006 Microchip Technology Inc.
DS39564C-page 87
PIC18FXX2
FIGURE 9-2:
BLOCK DIAGRAM OF
RA4/T0CKI PIN
FIGURE 9-3:
BLOCK DIAGRAM OF
RA6 PIN
ECRA6 or
RCRA6 Enable
Data
Bus
RD LATA
Data
Bus
RD LATA
WR LATA
or
PORTA
D
Q
CK
Q
N
Data Latch
WR TRISA
D
Q
CK
Q
VSS
I/O pin(1)
WR LATA
or
PORTA
Q
CK
Q
VDD
P
Data Latch
Schmitt
Trigger
Input
Buffer
TRIS Latch
D
WR
TRISA
D
Q
CK
Q
N
I/O pin(1)
VSS
TRIS Latch
RD TRISA
Q
TTL
Input
Buffer
D
RD TRISA
ENEN
RD PORTA
ECRA6 or
RCRA6
Enable
Q
D
EN
TMR0 Clock Input
RD PORTA
Note 1:
I/O pin has protection diode to VSS only.
DS39564C-page 88
Note 1:
I/O pins have protection diodes to VDD and VSS.
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 9-1:
PORTA FUNCTIONS
Name
Bit#
Buffer
Function
RA0/AN0
bit0
TTL
Input/output or analog input.
RA1/AN1
bit1
TTL
Input/output or analog input.
RA2/AN2/VREF-
bit2
TTL
Input/output or analog input or VREF-.
RA3/AN3/VREF+
bit3
TTL
Input/output or analog input or VREF+.
RA4/T0CKI
bit4
ST
Input/output or external clock input for Timer0.
Output is open drain type.
RA5/SS/AN4/LVDIN
bit5
TTL
Input/output or slave select input for synchronous serial port or analog
input, or low voltage detect input.
OSC2/CLKO/RA6
bit6
TTL
OSC2 or clock output or I/O pin.
Legend: TTL = TTL input, ST = Schmitt Trigger input
TABLE 9-2:
Name
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR,
BOR
Value on
All Other
RESETS
RA6
RA5
RA4
RA3
RA2
RA1
RA0
PORTA
—
-x0x 0000
-u0u 0000
LATA
—
LATA Data Output Register
-xxx xxxx
-uuu uuuu
TRISA
—
PORTA Data Direction Register
-111 1111
-111 1111
00-- 0000
00-- 0000
ADCON1
ADFM
ADCS2
—
—
PCFG3
PCFG2
PCFG1
PCFG0
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA.
© 2006 Microchip Technology Inc.
DS39564C-page 89
PIC18FXX2
9.2
PORTB, TRISB and LATB
Registers
PORTB is an 8-bit wide, bi-directional port. The corresponding 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
Hi-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 reads and writes the latched output value for
PORTB.
EXAMPLE 9-2:
CLRF
PORTB
CLRF
LATB
MOVLW 0xCF
MOVWF TRISB
INITIALIZING PORTB
;
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTB by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RB<3:0> as inputs
RB<5:4> as outputs
RB<7:6> as inputs
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 Power-on Reset.
Note:
On a Power-on Reset, these pins are
configured as digital inputs.
Four of the PORTB pins, RB7:RB4, have an interrupton-change feature. Only pins configured as inputs can
cause this interrupt to occur (i.e., any RB7:RB4 pin
configured as an output is excluded from the interrupton-change comparison). The input pins (of RB7:RB4)
are compared with the old value latched on the last
read of PORTB. The “mismatch” outputs of RB7:RB4
are OR’ed together to generate the RB Port Change
Interrupt with flag bit, RBIF (INTCON<0>).
This interrupt can wake the device from SLEEP. The
user, in the Interrupt Service Routine, can clear the
interrupt in the following manner:
a)
b)
Any read or write of PORTB (except with the
MOVFF instruction). This will end the mismatch
condition.
Clear flag bit RBIF.
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.
RB3 can be configured by the configuration bit
CCP2MX as the alternate peripheral pin for the CCP2
module (CCP2MX=’0’).
FIGURE 9-4:
BLOCK DIAGRAM OF
RB7:RB4 PINS
VDD
RBPU(2)
Weak
P Pull-up
Data Latch
Data Bus
D
Q
I/O pin(1)
WR LATB
or
PORTB
CK
TRIS Latch
D
Q
WR TRISB
TTL
Input
Buffer
CK
ST
Buffer
RD TRISB
RD LATB
Q
Latch
D
EN
RD PORTB
Q1
Set RBIF
Q
D
RD PORTB
From other
RB7:RB4 pins
EN
Q3
RB7:RB5 in Serial Programming mode
Note 1:
2:
I/O pins have diode protection to VDD and VSS.
To enable weak pull-ups, set the appropriate TRIS bit(s)
and clear the RBPU bit (INTCON2<7>).
Note 1: While in Low Voltage ICSP mode, the
RB5 pin can no longer be used as a general purpose I/O pin, and should be held
low during normal operation to protect
against inadvertent ICSP mode entry.
2: When using Low Voltage ICSP programming (LVP), the pull-up on RB5 becomes
disabled. If TRISB bit 5 is cleared,
thereby setting RB5 as an output, LATB
bit 5 must also be cleared for proper
operation.
A mismatch condition will continue to set flag bit RBIF.
Reading PORTB will end the mismatch condition and
allow flag bit RBIF to be cleared.
DS39564C-page 90
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 9-5:
BLOCK DIAGRAM OF RB2:RB0 PINS
VDD
RBPU(2)
Weak
P Pull-up
Data Latch
D
Q
Data Bus
I/O pin(1)
WR Port
CK
TRIS Latch
D
Q
WR TRIS
TTL
Input
Buffer
CK
RD TRIS
Q
D
EN
RD Port
RB0/INT
Schmitt Trigger
Buffer
Note 1:
2:
RD Port
I/O pins have diode protection to VDD and VSS.
To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>).
FIGURE 9-6:
BLOCK DIAGRAM OF RB3 PIN
VDD
RBPU
Weak
P Pull-up
(2)
CCP2MX
CCP Output(3)
1
VDD
P
Enable(3)
CCP Output
Data Bus
WR LATB or
WR PORTB
0
Data Latch
D
I/O pin(1)
Q
N
CK
VSS
TRIS Latch
D
WR TRISB
CK
TTL
Input
Buffer
Q
RD TRISB
RD LATB
Q
RD PORTB
D
EN
RD PORTB
CCP2 Input(3)
Schmitt Trigger
Buffer
Note 1:
2:
3:
CCP2MX = 0
I/O pin has diode protection to VDD and VSS.
To enable weak pull-ups, set the appropriate DDR bit(s) and clear the RBPU bit (INTCON2<7>).
The CCP2 input/output is multiplexed with RB3 if the CCP2MX bit is enabled (=’0’) in the configuration register.
© 2006 Microchip Technology Inc.
DS39564C-page 91
PIC18FXX2
TABLE 9-3:
PORTB FUNCTIONS
Name
Bit#
Buffer
Function
RB0/INT0
bit0
TTL/ST(1)
Input/output pin or external interrupt input0.
Internal software programmable weak pull-up.
RB1/INT1
bit1
TTL/ST(1)
Input/output pin or external interrupt input1.
Internal software programmable weak pull-up.
RB2/INT2
bit2
TTL/ST(1)
Input/output pin or external interrupt input2.
Internal software programmable weak pull-up.
RB3/CCP2(3)
bit3
TTL/ST(4)
Input/output pin or Capture2 input/Compare2 output/PWM output when
CCP2MX configuration bit is enabled.
Internal software programmable weak pull-up.
RB4
bit4
TTL
Input/output pin (with interrupt-on-change).
Internal software programmable weak pull-up.
RB5/PGM(5)
bit5
TTL/ST(2)
Input/output pin (with interrupt-on-change).
Internal software programmable weak pull-up.
Low voltage ICSP enable pin.
RB6/PGC
bit6
TTL/ST(2)
Input/output pin (with interrupt-on-change).
Internal software programmable weak pull-up.
Serial programming clock.
RB7/PGD
bit7
TTL/ST(2)
Input/output pin (with interrupt-on-change).
Internal software programmable weak pull-up.
Serial programming data.
Legend: TTL = TTL input, ST = Schmitt Trigger input
Note 1:
2:
3:
4:
5:
This buffer is a Schmitt Trigger input when configured as the external interrupt.
This buffer is a Schmitt Trigger input when used in Serial Programming mode.
A device configuration bit selects which I/O pin the CCP2 pin is multiplexed on.
This buffer is a Schmitt Trigger input when configured as the CCP2 input.
Low Voltage ICSP Programming (LVP) is enabled by default, which disables the RB5 I/O function. LVP
must be disabled to enable RB5 as an I/O pin and allow maximum compatibility to the other 28-pin and
40-pin mid-range devices.
TABLE 9-4:
Name
PORTB
SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATB
LATB Data Output Register
xxxx xxxx
TRISB
PORTB Data Direction Register
1111 1111
1111 1111
0000 000x
0000 000u
GIE/
GIEH
PEIE/
GIEL
TMR0IE
INT0IE
INTCON2
RBPU
INTEDG0
INTEDG1
INTCON3
INT2IP
INT1IP
—
INTCON
RBIE
TMR0IF
INT0IF
RBIF
INTEDG2
—
TMR0IP
—
RBIP
1111 -1-1
1111 -1-1
INT2IE
INT1IE
—
INT2IF
INT1IF
11-0 0-00
11-0 0-00
Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB.
DS39564C-page 92
© 2006 Microchip Technology Inc.
PIC18FXX2
9.3
PORTC, TRISC and LATC
Registers
The pin override value is not loaded into the TRIS register. This allows read-modify-write of the TRIS register,
without concern due to peripheral overrides.
PORTC is an 8-bit wide, bi-directional port. The corresponding 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 Hi-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 reads and writes the latched output value for
PORTC.
PORTC is multiplexed with several peripheral functions
(Table 9-5). PORTC pins have Schmitt Trigger input
buffers.
RC1 is normally configured by configuration bit,
CCP2MX, as the default peripheral pin of the CCP2
module (default/erased state, CCP2MX = ’1’).
EXAMPLE 9-3:
CLRF
PORTC
CLRF
LATC
INITIALIZING PORTC
;
;
;
;
;
;
;
;
;
;
;
;
MOVLW 0xCF
MOVWF TRISC
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 the correct TRIS bit
settings.
Note:
Initialize PORTC by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RC<3:0> as inputs
RC<5:4> as outputs
RC<7:6> as inputs
On a Power-on Reset, these pins are
configured as digital inputs.
FIGURE 9-7:
PORTC BLOCK DIAGRAM (PERIPHERAL OUTPUT OVERRIDE)
Port/Peripheral Select(2)
VDD
Peripheral Data Out
RD LATC
Data Bus
WR LATC or
WR PORTC
Data Latch
D
Q
CK
Q
0
P
1
I/O pin(1)
TRIS Latch
D
Q
WR TRISC
CK
Q
N
RD TRISC
VSS
Schmitt
Trigger
Peripheral Output
Enable(3)
Q
D
EN
RD PORTC
Peripheral Data In
Note 1:
I/O pins have diode protection to VDD and VSS.
2:
Port/Peripheral Select signal selects between port data (input) and peripheral output.
3:
Peripheral Output Enable is only active if peripheral select is active.
© 2006 Microchip Technology Inc.
DS39564C-page 93
PIC18FXX2
TABLE 9-5:
PORTC FUNCTIONS
Name
Bit#
Buffer Type
Function
RC0/T1OSO/T1CKI
bit0
ST
Input/output port pin or Timer1 oscillator output/Timer1 clock input.
RC1/T1OSI/CCP2
bit1
ST
Input/output port pin, Timer1 oscillator input, or Capture2 input/
Compare2 output/PWM output when CCP2MX configuration bit is
set.
RC2/CCP1
bit2
ST
Input/output port pin or Capture1 input/Compare1 output/PWM1
output.
RC3/SCK/SCL
bit3
ST
RC3 can also be the synchronous serial clock for both SPI and I2C
modes.
RC4/SDI/SDA
bit4
ST
RC4 can also be the SPI Data In (SPI mode) or Data I/O (I2C mode).
RC5/SDO
bit5
ST
Input/output port pin or Synchronous Serial Port data output.
RC6/TX/CK
bit6
ST
Input/output port pin, Addressable USART Asynchronous Transmit, or
Addressable USART Synchronous Clock.
RC7/RX/DT
bit7
ST
Input/output port pin, Addressable USART Asynchronous Receive, or
Addressable USART Synchronous Data.
Legend: ST = Schmitt Trigger input
TABLE 9-6:
Name
PORTC
SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
RC7
RC6
RC5
RC4
RC3
RC2
RC1
RC0
xxxx xxxx
uuuu uuuu
LATC
LATC Data Output Register
xxxx xxxx
uuuu uuuu
TRISC
PORTC Data Direction Register
1111 1111
1111 1111
Legend: x = unknown, u = unchanged
DS39564C-page 94
© 2006 Microchip Technology Inc.
PIC18FXX2
9.4
PORTD, TRISD and LATD
Registers
FIGURE 9-8:
PORTD BLOCK DIAGRAM
IN I/O PORT MODE
This section is applicable only to the PIC18F4X2
devices.
PORTD is an 8-bit wide, bi-directional port. The corresponding 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 Hi-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 reads and writes the latched output value for
PORTD.
RD LATD
Data
Bus
D
I/O pin(1)
WR LATD
or
PORTD
CK
Data Latch
D
WR TRISD
EXAMPLE 9-4:
CLRF
PORTD
CLRF
LATD
MOVLW 0xCF
MOVWF TRISD
Schmitt
Trigger
Input
Buffer
CK
RD TRISD
Q
On a Power-on Reset, these pins are
configured as digital inputs.
PORTD can be configured as an 8-bit wide microprocessor port (parallel slave port) by setting control bit
PSPMODE (TRISE<4>). In this mode, the input buffers
are TTL. See Section 9.6 for additional information on
the Parallel Slave Port (PSP).
Q
TRIS Latch
PORTD is an 8-bit port with Schmitt Trigger input buffers. Each pin is individually configurable as an input or
output.
Note:
Q
D
ENEN
RD PORTD
Note 1:
I/O pins have diode protection to VDD and VSS.
INITIALIZING PORTD
;
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTD by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RD<3:0> as inputs
RD<5:4> as outputs
RD<7:6> as inputs
© 2006 Microchip Technology Inc.
DS39564C-page 95
PIC18FXX2
TABLE 9-7:
PORTD FUNCTIONS
Name
Bit#
Buffer Type
RD0/PSP0
bit0
ST/TTL(1)
Input/output port pin or parallel slave port bit0.
RD1/PSP1
bit1
ST/TTL(1)
Input/output port pin or parallel slave port bit1.
bit2
ST/TTL
(1)
Input/output port pin or parallel slave port bit2.
bit3
ST/TTL(1)
Input/output port pin or parallel slave port bit3.
RD4/PSP4
bit4
ST/TTL
(1)
Input/output port pin or parallel slave port bit4.
RD5/PSP5
bit5
ST/TTL(1)
Input/output port pin or parallel slave port bit5.
RD6/PSP6
bit6
ST/TTL(1)
Input/output port pin or parallel slave port bit6.
RD7/PSP7
bit7
ST/TTL(1)
Input/output port pin or parallel slave port bit7.
RD2/PSP2
RD3/PSP3
Function
Legend: ST = Schmitt Trigger input, TTL = TTL input
Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffer when in Parallel Slave Port mode.
TABLE 9-8:
SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
PORTD
RD7
RD6
RD5
RD4
RD3
RD2
RD1
RD0
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATD
LATD Data Output Register
xxxx xxxx
TRISD
PORTD Data Direction Register
1111 1111
1111 1111
0000 -111
0000 -111
TRISE
IBF
OBF
IBOV
PSPMODE
—
PORTE Data Direction bits
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTD.
DS39564C-page 96
© 2006 Microchip Technology Inc.
PIC18FXX2
9.5
PORTE, TRISE and LATE
Registers
FIGURE 9-9:
PORTE BLOCK DIAGRAM
IN I/O PORT MODE
This section is only applicable to the PIC18F4X2
devices.
PORTE is a 3-bit wide, bi-directional port. 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
Hi-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).
The Data Latch register (LATE) is also memory
mapped. Read-modify-write operations on the LATE
register reads and writes the latched output value for
PORTE.
RD LATE
Data
Bus
D
Q
I/O pin(1)
WR LATE
or
PORTE
CK
Data Latch
D
WR TRISE
Q
TRIS Latch
PORTE has three pins (RE0/RD/AN5, RE1/WR/AN6
and RE2/CS/AN7) which are individually configurable
as inputs or outputs. These pins have Schmitt Trigger
input buffers.
RD TRISE
Q
Register 9-1 shows the TRISE register, which also
controls the parallel slave port operation.
PORTE pins are multiplexed with analog inputs. When
selected as an analog input, these pins will read as '0's.
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.
Note:
Schmitt
Trigger
Input
Buffer
CK
D
ENEN
RD PORTE
To Analog Converter
Note 1:
I/O pins have diode protection to VDD and VSS.
On a Power-on Reset, these pins are
configured as analog inputs.
EXAMPLE 9-5:
CLRF
PORTE
CLRF
LATE
MOVLW
MOVWF
MOVLW
0x07
ADCON1
0x05
MOVWF
TRISE
INITIALIZING PORTE
;
;
;
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTE by
clearing output
data latches
Alternate method
to clear output
data latches
Configure A/D
for digital inputs
Value used to
initialize data
direction
Set RE<0> as inputs
RE<1> as outputs
RE<2> as inputs
© 2006 Microchip Technology Inc.
DS39564C-page 97
PIC18FXX2
REGISTER 9-1:
TRISE REGISTER
R-0
R-0
R/W-0
R/W-0
U-0
R/W-1
R/W-1
R/W-1
IBF
OBF
IBOV
PSPMODE
—
TRISE2
TRISE1
TRISE0
bit 7
bit 0
bit 7
IBF: Input Buffer Full Status bit
1 = A word has been received and waiting to be read by the CPU
0 = No word has been received
bit 6
OBF: Output Buffer Full Status bit
1 = The output buffer still holds a previously written word
0 = The output buffer has been read
bit 5
IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode)
1 = A write occurred when a previously input word has not been read
(must be cleared in software)
0 = No overflow occurred
bit 4
PSPMODE: Parallel Slave Port Mode Select bit
1 = Parallel Slave Port mode
0 = General purpose I/O mode
bit 3
Unimplemented: Read as '0'
bit 2
TRISE2: RE2 Direction Control bit
1 = Input
0 = Output
bit 1
TRISE1: RE1 Direction Control bit
1 = Input
0 = Output
bit 0
TRISE0: RE0 Direction Control bit
1 = Input
0 = Output
Legend:
DS39564C-page 98
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
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 9-9:
PORTE FUNCTIONS
Name
Bit#
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
bit0
bit1
bit2
Buffer Type
Function
ST/TTL(1)
Input/output port pin or read control input in Parallel Slave Port mode
or analog input:
RD
1 = Not a read operation
0 = Read operation. Reads PORTD register (if chip selected).
ST/TTL(1)
Input/output port pin or write control input in Parallel Slave Port mode
or analog input:
WR
1 = Not a write operation
0 = Write operation. Writes PORTD register (if chip selected).
ST/TTL(1)
Input/output port pin or chip select control input in Parallel Slave Port
mode or analog input:
CS
1 = Device is not selected
0 = Device is selected
Legend: ST = Schmitt Trigger input, TTL = TTL input
Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.
TABLE 9-10:
Name
SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
RE2
RE1
RE0
---- -000
---- -000
---- -xxx
---- -uuu
0000 -111
0000 -111
00-- 0000
00-- 0000
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
PORTE
—
—
—
—
—
LATE
—
—
—
—
—
LATE Data Output Register
IBF
OBF
IBOV
PSPMODE
—
PORTE Data Direction bits
ADFM
ADCS2
—
—
PCFG3
TRISE
ADCON1
PCFG2
PCFG1
PCFG0
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTE.
© 2006 Microchip Technology Inc.
DS39564C-page 99
PIC18FXX2
9.6
FIGURE 9-10:
Parallel Slave Port
PORTD AND PORTE
BLOCK DIAGRAM
(PARALLEL SLAVE
PORT)
The Parallel Slave Port is implemented on the 40-pin
devices only (PIC18F4X2).
PORTD operates as an 8-bit wide Parallel Slave Port,
or microprocessor port when control bit, PSPMODE
(TRISE<4>) is set. It is asynchronously readable and
writable by the external world through RD control input
pin, RE0/RD and WR control input pin, RE1/WR.
Data Bus
D
WR LATD
or
PORTD
It can directly interface to an 8-bit microprocessor data
bus. The external microprocessor can read or write the
PORTD latch as an 8-bit latch. Setting bit PSPMODE
enables port pin RE0/RD to be the RD input, RE1/WR
to be the WR input and RE2/CS to be the CS (chip
select) input. For this functionality, the corresponding
data direction bits of the TRISE register (TRISE<2:0>)
must be configured as inputs (set). The A/D port configuration bits PCFG2:PCFG0 (ADCON1<2:0>) must be
set, which will configure pins RE2:RE0 as digital I/O.
Q
RDx
Pin
CK
TTL
Data Latch
Q
RD PORTD
D
ENEN
TRIS Latch
RD LATD
A write to the PSP occurs when both the CS and WR
lines are first detected low. A read from the PSP occurs
when both the CS and RD lines are first detected low.
One bit of PORTD
Set Interrupt Flag
The PORTE I/O pins become control inputs for the
microprocessor port when bit PSPMODE (TRISE<4>)
is set. In this mode, the user must make sure that the
TRISE<2:0> bits are set (pins are configured as digital
inputs), and the ADCON1 is configured for digital I/O.
In this mode, the input buffers are TTL.
PSPIF (PIR1<7>)
Read
TTL
RD
Chip Select
TTL
CS
Write
WR
TTL
Note: I/O pin has protection diodes to VDD and VSS.
FIGURE 9-11:
PARALLEL SLAVE PORT WRITE WAVEFORMS
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
CS
WR
RD
PORTD<7:0>
IBF
OBF
PSPIF
DS39564C-page 100
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 9-12:
PARALLEL SLAVE PORT READ WAVEFORMS
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
CS
WR
RD
PORTD<7:0>
IBF
OBF
PSPIF
TABLE 9-11:
REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT
Value on
POR, BOR
Value on
All Other
RESETS
Port Data Latch when written; Port pins when read
xxxx xxxx
uuuu uuuu
LATD
LATD Data Output bits
xxxx xxxx
uuuu uuuu
TRISD
PORTD Data Direction bits
1111 1111
1111 1111
---- -000
---- -000
---- -xxx
---- -uuu
Name
PORTD
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
—
—
—
—
—
LATE
—
—
—
—
—
LATE Data Output bits
PORTE Data Direction bits
INTCON
IBF
OBF
IBOV
PSPMODE
—
GIE/
GIEH
PEIE/
GIEL
TMR0IF
INT0IE
RBIE
TMR0IF
RE1
Bit 0
PORTE
TRISE
RE2
Bit 1
INT0IF
RE0
RBIF
0000 -111
0000 -111
0000 000x
0000 000u
PIR1
PSPIF
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000
0000 0000
PIE1
PSPIE
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000
0000 0000
IPR1
PSPIP
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000
0000 0000
ADCON1
ADFM
ADCS2
—
—
PCFG3
PCFG2
PCFG1
PCFG0
00-- 0000
00-- 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Parallel Slave Port.
© 2006 Microchip Technology Inc.
DS39564C-page 101
PIC18FXX2
NOTES:
DS39564C-page 102
© 2006 Microchip Technology Inc.
PIC18FXX2
10.0
TIMER0 MODULE
The Timer0 module has the following features:
• Software selectable as an 8-bit or 16-bit timer/
counter
• Readable and writable
• Dedicated 8-bit software programmable prescaler
• Clock source selectable to be external or internal
• Interrupt-on-overflow from FFh to 00h in 8-bit
mode and FFFFh to 0000h in 16-bit mode
• Edge select for external clock
REGISTER 10-1:
Figure 10-1 shows a simplified block diagram of the
Timer0 module in 8-bit mode and Figure 10-2 shows a
simplified block diagram of the Timer0 module in 16-bit
mode.
The T0CON register (Register 10-1) is a readable and
writable register that controls all the aspects of Timer0,
including the prescale selection.
T0CON: TIMER0 CONTROL REGISTER
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
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
0 = Internal instruction cycle clock (CLKO)
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
T0PS2:T0PS0: 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
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 103
PIC18FXX2
FIGURE 10-1:
TIMER0 BLOCK DIAGRAM IN 8-BIT MODE
Data Bus
FOSC/4
0
8
1
1
RA4/T0CKI pin
Programmable
Prescaler
0
Sync with
Internal
Clocks
TMR0L
(2 TCY delay)
T0SE
3
PSA
Set Interrupt
Flag bit TMR0IF
on Overflow
T0PS2, T0PS1, T0PS0
T0CS
Note:
Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
FIGURE 10-2:
FOSC/4
TIMER0 BLOCK DIAGRAM IN 16-BIT MODE
0
1
1
Programmable
Prescaler
T0CKI pin
0
T0SE
Sync with
Internal
Clocks
TMR0L
TMR0
High Byte
8
(2 TCY delay)
3
Set Interrupt
Flag bit TMR0IF
on Overflow
Read TMR0L
T0PS2, T0PS1, T0PS0
T0CS
PSA
Write TMR0L
8
8
TMR0H
8
Data Bus<7:0>
Note:
Upon RESET, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
DS39564C-page 104
© 2006 Microchip Technology Inc.
PIC18FXX2
10.1
Timer0 Operation
10.2.1
Timer0 can operate as a timer or as a counter.
The prescaler assignment is fully under software control, (i.e., it can be changed “on-the-fly” during program
execution).
Timer mode is selected by clearing the T0CS bit. In
Timer mode, the Timer0 module will increment every
instruction cycle (without prescaler). If the TMR0L register is written, the increment is inhibited for the following two instruction cycles. The user can work around
this by writing an adjusted value to the TMR0L register.
10.3
When an external clock input is used for Timer0, it must
meet certain requirements. The requirements ensure
the external clock can be synchronized with the internal
phase clock (TOSC). Also, there is a delay in the actual
incrementing of Timer0 after synchronization.
10.4
Prescaler
The PSA and T0PS2:T0PS0 bits determine the
prescaler assignment and prescale ratio.
Clearing bit PSA will assign the prescaler to the Timer0
module. When the prescaler is assigned to the Timer0
module, prescale values of 1:2, 1:4,..., 1:256 are
selectable.
A write to the high byte of Timer0 must also take place
through the TMR0H buffer register. Timer0 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.
When assigned to the Timer0 module, all instructions
writing to the TMR0L register (e.g., CLRF TMR0,
MOVWF TMR0, BSF TMR0, x....etc.) will clear the
prescaler count.
Writing to TMR0L when the prescaler is
assigned to Timer0 will clear the prescaler
count, but will not change the prescaler
assignment.
TABLE 10-1:
Name
16-Bit Mode Timer Reads and
Writes
TMR0H is not the high byte of the timer/counter in
16-bit mode, but is actually a buffered version of the
high byte of Timer0 (refer to Figure 10-2). The high byte
of the Timer0 counter/timer is not directly readable nor
writable. 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.
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not readable or writable.
Note:
Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or FFFFh
to 0000h in 16-bit mode. This overflow sets the TMR0IF
bit. The interrupt can be masked by clearing the
TMR0IE bit. The TMR0IE bit must be cleared in software by the Timer0 module Interrupt Service Routine
before re-enabling this interrupt. The TMR0 interrupt
cannot awaken the processor from SLEEP, since the
timer is shut-off during SLEEP.
Counter mode is selected by setting the T0CS bit. In
Counter mode, Timer0 will increment, either on every
rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge
Select bit (T0SE). Clearing the T0SE bit selects the rising edge. Restrictions on the external clock input are
discussed below.
10.2
SWITCHING PRESCALER ASSIGNMENT
REGISTERS ASSOCIATED WITH TIMER0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
TMR0L
Timer0 Module Low Byte Register
xxxx xxxx
uuuu uuuu
TMR0H
Timer0 Module High Byte Register
0000 0000
0000 0000
INTCON
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x
0000 000u
T0CON
TMR0ON
T08BIT
T0CS
T0SE
PSA
T0PS2
T0PS1
T0PS0
1111 1111
1111 1111
TRISA
—
-111 1111
-111 1111
PORTA Data Direction Register
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0.
© 2006 Microchip Technology Inc.
DS39564C-page 105
PIC18FXX2
NOTES:
DS39564C-page 106
© 2006 Microchip Technology Inc.
PIC18FXX2
11.0
TIMER1 MODULE
Figure 11-1 is a simplified block diagram of the Timer1
module.
The Timer1 module timer/counter has the following
features:
• 16-bit timer/counter
(two 8-bit registers; TMR1H and TMR1L)
• Readable and writable (both registers)
• Internal or external clock select
• Interrupt-on-overflow from FFFFh to 0000h
• RESET from CCP module special event trigger
REGISTER 11-1:
Register 11-1 details the Timer1 control register. This
register controls the Operating mode of the Timer1
module, and contains the Timer1 oscillator enable bit
(T1OSCEN). Timer1 can be enabled or disabled by
setting or clearing control bit TMR1ON (T1CON<0>).
T1CON: TIMER1 CONTROL REGISTER
R/W-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
RD16
—
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
bit 7
bit 0
bit 7
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 6
Unimplemented: Read as '0'
bit 5-4
T1CKPS1:T1CKPS0: 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 Enable bit
1 = Timer1 Oscillator is enabled
0 = Timer1 Oscillator is shut-off
The oscillator inverter and feedback resistor are turned off to eliminate power drain.
bit 2
T1SYNC: Timer1 External Clock Input Synchronization Select bit
When TMR1CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
bit 1
TMR1CS: Timer1 Clock Source Select bit
1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge)
0 = Internal clock (FOSC/4)
bit 0
TMR1ON: Timer1 On bit
1 = Enables Timer1
0 = Stops Timer1
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 107
PIC18FXX2
11.1
Timer1 Operation
When TMR1CS = 0, Timer1 increments every instruction cycle. When TMR1CS = 1, Timer1 increments on
every rising edge of the external clock input or the
Timer1 oscillator, if enabled.
Timer1 can operate in one of these modes:
• As a timer
• As a synchronous counter
• As an asynchronous counter
When the Timer1 oscillator is enabled (T1OSCEN is
set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins
become inputs. That is, the TRISC<1:0> value is
ignored, and the pins are read as ‘0’.
The Operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>).
Timer1 also has an internal “RESET input”. This
RESET can be generated by the CCP module
(Section 14.0).
FIGURE 11-1:
TIMER1 BLOCK DIAGRAM
CCP Special Event Trigger
TMR1IF
Overflow
Interrupt
Flag Bit
TMR1
CLR
TMR1L
TMR1H
1
TMR1ON
On/Off
T1OSC
T1CKI/T1OSO
T1OSCEN
Enable
Oscillator(1)
T1OSI
Synchronized
Clock Input
0
T1SYNC
1
Synchronize
Prescaler
1, 2, 4, 8
FOSC/4
Internal
Clock
det
0
2
T1CKPS1:T1CKPS0
SLEEP Input
TMR1CS
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
FIGURE 11-2:
TIMER1 BLOCK DIAGRAM: 16-BIT READ/WRITE MODE
Data Bus<7:0>
8
TMR1H
8
8
Write TMR1L
CCP Special Event Trigger
Read TMR1L
TMR1IF
Overflow
Interrupt
Flag bit
TMR1
8
Timer 1
High Byte
TMR1L
1
TMR1ON
on/off
T1OSC
T13CKI/T1OSO
T1OSI
Synchronized
Clock Input
0
CLR
T1SYNC
1
T1OSCEN
Enable
Oscillator(1)
FOSC/4
Internal
Clock
Synchronize
Prescaler
1, 2, 4, 8
det
0
2
SLEEP Input
TMR1CS
T1CKPS1:T1CKPS0
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
DS39564C-page 108
© 2006 Microchip Technology Inc.
PIC18FXX2
11.2
Timer1 Oscillator
11.4
A crystal oscillator circuit is built-in between pins T1OSI
(input) and T1OSO (amplifier output). It is enabled by
setting control bit T1OSCEN (T1CON<3>). The oscillator is a low power oscillator rated up to 200 kHz. It will
continue to run during SLEEP. It is primarily intended
for a 32 kHz crystal. Table 11-1 shows the capacitor
selection for the Timer1 oscillator.
If the CCP module is configured in Compare mode to
generate a “special event trigger” (CCP1M3:CCP1M0
= 1011), this signal will reset Timer1 and start an A/D
conversion (if the A/D module is enabled).
Note:
The user must provide a software time delay to ensure
proper start-up of the Timer1 oscillator.
TABLE 11-1:
CAPACITOR SELECTION FOR
THE ALTERNATE
OSCILLATOR
Osc Type
Freq
C1
C2
LP
32 kHz
TBD(1)
TBD(1)
Crystal to be Tested:
32.768 kHz Epson C-001R32.768K-A
± 20 PPM
Note 1: Microchip suggests 33 pF as a starting
point in validating the oscillator circuit.
2: Higher capacitance increases the stability
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.
11.3
Timer1 Interrupt
The TMR1 Register pair (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
TMR1 Interrupt, if enabled, is generated on overflow,
which is latched in interrupt flag bit TMR1IF (PIR1<0>).
This interrupt can be enabled/disabled by setting/
clearing TMR1 interrupt enable bit, TMR1IE (PIE1<0>).
© 2006 Microchip Technology Inc.
Resetting Timer1 using a CCP
Trigger Output
The special event triggers from the CCP1
module will not set interrupt flag bit
TMR1IF (PIR1<0>).
Timer1 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature.
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 from CCP1, the write will take
precedence.
In this mode of operation, the CCPR1H:CCPR1L registers pair effectively becomes the period register for
Timer1.
11.5
Timer1 16-Bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes
(see Figure 11-2). When the RD16 control bit
(T1CON<7>) is set, the address for TMR1H is mapped
to a buffer register for the high byte of Timer1. A read
from TMR1L will load the contents of the high byte of
Timer1 into the Timer1 high byte buffer. 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 is valid,
due to a rollover between reads.
A write to the high byte of Timer1 must also take place
through the TMR1H buffer register. 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.
DS39564C-page 109
PIC18FXX2
TABLE 11-2:
Name
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Bit 7
Bit 6
Value on
All Other
RESETS
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
INTCON
GIE/GIEH PEIE/GIEL
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000 0000 0000
TMR1L
Holding Register for the Least Significant Byte of the 16-bit TMR1 Register
xxxx xxxx uuuu uuuu
TMR1H
Holding Register for the Most Significant Byte of the 16-bit TMR1 Register
xxxx xxxx uuuu uuuu
T1CON
Legend:
RD16
—
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
DS39564C-page 110
© 2006 Microchip Technology Inc.
PIC18FXX2
12.0
TIMER2 MODULE
12.1
The Timer2 module timer has the following features:
•
•
•
•
•
•
•
8-bit timer (TMR2 register)
8-bit period register (PR2)
Readable and writable (both registers)
Software programmable prescaler (1:1, 1:4, 1:16)
Software programmable postscaler (1:1 to 1:16)
Interrupt on TMR2 match of PR2
SSP module optional use of TMR2 output to
generate clock shift
Timer2 has a control register shown in Register 12-1.
Timer2 can be shut-off by clearing control bit TMR2ON
(T2CON<2>) to minimize power consumption.
Figure 12-1 is a simplified block diagram of the Timer2
module. Register 12-1 shows the Timer2 control register. The prescaler and postscaler selection of Timer2
are controlled by this register.
REGISTER 12-1:
Timer2 Operation
Timer2 can be used as the PWM time-base for the
PWM mode of the CCP module. The TMR2 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
T2CKPS1:T2CKPS0 (T2CON<1:0>). The match output of TMR2 goes through a 4-bit postscaler (which
gives a 1:1 to 1:16 scaling inclusive) to generate a
TMR2 interrupt (latched in flag bit TMR2IF, (PIR1<1>)).
The prescaler and postscaler counters are cleared
when any of the following occurs:
• a write to the TMR2 register
• a write to the T2CON register
• any device RESET (Power-on Reset, MCLR
Reset, Watchdog Timer Reset, or Brown-out
Reset)
TMR2 is not cleared when T2CON is written.
T2CON: TIMER2 CONTROL REGISTER
U-0
R/W-0
R/W-0
R/W-0
R/W-0
—
TOUTPS3
TOUTPS2
TOUTPS1
TOUTPS0
R/W-0
R/W-0
TMR2ON T2CKPS1
R/W-0
T2CKPS0
bit 7
bit 0
bit 7
Unimplemented: Read as '0'
bit 6-3
TOUTPS3:TOUTPS0: 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
T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits
00 = Prescaler is 1
01 = Prescaler is 4
1x = Prescaler is 16
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 111
PIC18FXX2
12.2
Timer2 Interrupt
12.3
The Timer2 module has an 8-bit period register, PR2.
Timer2 increments from 00h until it matches PR2 and
then resets to 00h on the next increment cycle. PR2 is
a readable and writable register. The PR2 register is
initialized to FFh upon RESET.
FIGURE 12-1:
Output of TMR2
The output of TMR2 (before the postscaler) is fed to the
Synchronous Serial Port module, which optionally uses
it to generate the shift clock.
TIMER2 BLOCK DIAGRAM
Sets Flag
bit TMR2IF
TMR2
Output(1)
Prescaler
1:1, 1:4, 1:16
FOSC/4
2
TMR2
RESET
Comparator
EQ
Postscaler
1:1 to 1:16
T2CKPS1:T2CKPS0
4
PR2
TOUTPS3:TOUTPS0
Note 1: TMR2 register output can be software selected by the SSP Module as a baud clock.
TABLE 12-1:
Name
REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000 0000 0000
INTCON GIE/GIEH PEIE/GIEL
TMR2
T2CON
PR2
Timer2 Module Register
—
0000 0000 0000 0000
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
Timer2 Period Register
1111 1111 1111 1111
Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the Timer2 module.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
DS39564C-page 112
© 2006 Microchip Technology Inc.
PIC18FXX2
13.0
TIMER3 MODULE
Figure 13-1 is a simplified block diagram of the Timer3
module.
The Timer3 module timer/counter has the following
features:
• 16-bit timer/counter
(two 8-bit registers; TMR3H and TMR3L)
• Readable and writable (both registers)
• Internal or external clock select
• Interrupt-on-overflow from FFFFh to 0000h
• RESET from CCP module trigger
REGISTER 13-1:
Register 13-1 shows the Timer3 control register. This
register controls the Operating mode of the Timer3
module and sets the CCP clock source.
Register 11-1 shows the Timer1 control register. This
register controls the Operating mode of the Timer1
module, as well as contains the Timer1 oscillator
enable bit (T1OSCEN), which can be a clock source for
Timer3.
T3CON: TIMER3 CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
RD16
T3CCP2
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON
bit 7
bit 0
bit 7
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 6-3
T3CCP2:T3CCP1: Timer3 and Timer1 to CCPx Enable bits
1x = Timer3 is the clock source for compare/capture CCP modules
01 = Timer3 is the clock source for compare/capture of CCP2,
Timer1 is the clock source for compare/capture of CCP1
00 = Timer1 is the clock source for compare/capture CCP modules
bit 5-4
T3CKPS1:T3CKPS0: 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 2
T3SYNC: Timer3 External Clock Input Synchronization Control bit
(Not usable if the system clock comes from Timer1/Timer3)
When TMR3CS = 1:
1 = Do not synchronize external clock input
0 = Synchronize external clock input
When TMR3CS = 0:
This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0.
bit 1
TMR3CS: Timer3 Clock Source Select bit
1 = External clock input from Timer1 oscillator or T1CKI
(on the rising edge after the first falling edge)
0 = Internal clock (FOSC/4)
bit 0
TMR3ON: Timer3 On bit
1 = Enables Timer3
0 = Stops Timer3
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 113
PIC18FXX2
13.1
Timer3 Operation
When TMR3CS = 0, Timer3 increments every instruction cycle. When TMR3CS = 1, Timer3 increments on
every rising edge of the Timer1 external clock input or
the Timer1 oscillator, if enabled.
Timer3 can operate in one of these modes:
• As a timer
• As a synchronous counter
• As an asynchronous counter
When the Timer1 oscillator is enabled (T1OSCEN is
set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins
become inputs. That is, the TRISC<1:0> value is
ignored, and the pins are read as ‘0’.
The Operating mode is determined by the clock select
bit, TMR3CS (T3CON<1>).
Timer3 also has an internal “RESET input”. This RESET
can be generated by the CCP module (Section 14.0).
FIGURE 13-1:
TIMER3 BLOCK DIAGRAM
CCP Special Trigger
T3CCPx
TMR3IF
Overflow
Interrupt
Flag bit
TMR3H
Synchronized
Clock Input
0
CLR
TMR3L
1
TMR3ON
On/Off
T1OSC
T1OSO/
T13CKI
T3SYNC
(3)
1
T1OSI
Synchronize
Prescaler
1, 2, 4, 8
T1OSCEN FOSC/4
Enable
Internal
Oscillator(1) Clock
det
0
2
SLEEP Input
TMR3CS
T3CKPS1:T3CKPS0
Note 1: When enable bit T1OSCEN is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
FIGURE 13-2:
TIMER3 BLOCK DIAGRAM CONFIGURED IN 16-BIT READ/WRITE MODE
Data Bus<7:0>
8
TMR3H
8
8
Write TMR3L
Read TMR3L
Set TMR3IF Flag bit
on Overflow
8
CCP Special Trigger
T3CCPx
0
TMR3
Timer3
High Byte
TMR3L
CLR
Synchronized
Clock Input
1
To Timer1 Clock Input
T1OSO/
T13CKI
T1OSI
TMR3ON
On/Off
T1OSC
T3SYNC
1
T1OSCEN
Enable
Oscillator(1)
FOSC/4
Internal
Clock
Synchronize
Prescaler
1, 2, 4, 8
det
0
2
T3CKPS1:T3CKPS0
TMR3CS
SLEEP Input
Note 1: When the T1OSCEN bit is cleared, the inverter and feedback resistor are turned off. This eliminates power drain.
DS39564C-page 114
© 2006 Microchip Technology Inc.
PIC18FXX2
13.2
Timer1 Oscillator
13.4
The Timer1 oscillator may be used as the clock source
for Timer3. The Timer1 oscillator is enabled by setting
the T1OSCEN (T1CON<3>) bit. The oscillator is a low
power oscillator rated up to 200 KHz. See Section 11.0
for further details.
13.3
If the CCP module is configured in Compare mode to
generate a “special event trigger” (CCP1M3:CCP1M0
= 1011), this signal will reset Timer3.
Note:
Timer3 Interrupt
The TMR3 Register pair (TMR3H:TMR3L) increments
from 0000h to FFFFh and rolls over to 0000h. The
TMR3 Interrupt, if enabled, is generated on overflow,
which is latched in interrupt flag bit, TMR3IF
(PIR2<1>). This interrupt can be enabled/disabled by
setting/clearing TMR3 interrupt enable bit, TMR3IE
(PIE2<1>).
TABLE 13-1:
Resetting Timer3 Using a CCP
Trigger Output
The special event triggers from the CCP
module will not set interrupt flag bit,
TMR3IF (PIR1<0>).
Timer3 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature.
If Timer3 is running in Asynchronous Counter mode,
this RESET operation may not work. In the event that a
write to Timer3 coincides with a special event trigger
from CCP1, the write will take precedence. In this mode
of operation, the CCPR1H:CCPR1L registers pair
effectively becomes the period register for Timer3.
REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Value on
All Other
RESETS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
INTCON
GIE/
GIEH
PEIE/
GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
PIR2
—
—
—
EEIF
BCLIF
LVDIF
TMR3IF
CCP2IF
---0 0000 ---0 0000
PIE2
—
—
—
EEIE
BCLIE
LVDIE
TMR3IE
CCP2IE
---0 0000 ---0 0000
IPR2
—
—
—
EEIP
BCLIP
LVDIP
TMR3IP
CCP2IP
---1 1111 ---1 1111
TMR3L
Holding Register for the Least Significant Byte of the 16-bit TMR3 Register
xxxx xxxx uuuu uuuu
TMR3H
Holding Register for the Most Significant Byte of the 16-bit TMR3 Register
xxxx xxxx uuuu uuuu
T1CON
RD16
—
T3CON
RD16
T3CCP2
Legend:
T1CKPS1 T1CKPS0 T1OSCEN
T1SYNC
TMR1CS TMR1ON 0-00 0000 u-uu uuuu
T3CKPS1 T3CKPS0
T3SYNC
TMR3CS TMR3ON 0000 0000 uuuu uuuu
T3CCP1
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module.
© 2006 Microchip Technology Inc.
DS39564C-page 115
PIC18FXX2
NOTES:
DS39564C-page 116
© 2006 Microchip Technology Inc.
PIC18FXX2
14.0
CAPTURE/COMPARE/PWM
(CCP) MODULES
Each CCP (Capture/Compare/PWM) module contains
a 16-bit register which can operate as a 16-bit Capture
register, as a 16-bit Compare register or as a PWM
Master/Slave Duty Cycle register. Table 14-1 shows
the timer resources of the CCP Module modes.
REGISTER 14-1:
The operation of CCP1 is identical to that of CCP2, with
the exception of the special event trigger. Therefore,
operation of a CCP module in the following sections is
described with respect to CCP1.
Table 14-2 shows the interaction of the CCP modules.
CCP1CON REGISTER/CCP2CON REGISTER
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
DCxB1
DCxB0
CCPxM3
CCPxM2
R/W-0
R/W-0
CCPxM1 CCPxM0
bit 7
bit 0
bit 7-6
Unimplemented: Read as '0'
bit 5-4
DCxB1:DCxB0: PWM Duty Cycle bit1 and bit0
Capture mode:
Unused
Compare mode:
Unused
PWM mode:
These bits are the two LSbs (bit1 and bit0) of the 10-bit PWM duty cycle. The upper eight bits
(DCx9:DCx2) of the duty cycle are found in CCPRxL.
bit 3-0
CCPxM3:CCPxM0: CCPx Mode Select bits
0000 = Capture/Compare/PWM disabled (resets CCPx module)
0001 = Reserved
0010 = Compare mode, toggle output on match (CCPxIF bit is set)
0011 = Reserved
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 CCP pin Low, on compare match force CCP pin High (CCPIF bit is set)
1001 = Compare mode,
Initialize CCP pin High, on compare match force CCP pin Low (CCPIF bit is set)
1010 = Compare mode,
Generate software interrupt on compare match (CCPIF bit is set, CCP pin is unaffected)
1011 = Compare mode,
Trigger special event (CCPIF bit is set)
11xx = PWM mode
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 117
PIC18FXX2
14.1
CCP1 Module
14.2
Capture/Compare/PWM Register 1 (CCPR1) is comprised of two 8-bit registers: CCPR1L (low byte) and
CCPR1H (high byte). The CCP1CON register controls
the operation of CCP1. All are readable and writable.
TABLE 14-1:
Capture/Compare/PWM Register2 (CCPR2) is comprised of two 8-bit registers: CCPR2L (low byte) and
CCPR2H (high byte). The CCP2CON register controls
the operation of CCP2. All are readable and writable.
CCP MODE - TIMER
RESOURCE
CCP Mode
Timer Resource
Capture
Compare
PWM
Timer1 or Timer3
Timer1 or Timer3
Timer2
TABLE 14-2:
CCP2 Module
INTERACTION OF TWO CCP MODULES
CCPx Mode CCPy Mode
Interaction
Capture
Capture
TMR1 or TMR3 time-base. Time-base can be different for each CCP.
Capture
Compare
The compare could be configured for the special event trigger,
which clears either TMR1 or TMR3 depending upon which time-base is used.
Compare
Compare
The compare(s) could be configured for the special event trigger,
which clears TMR1 or TMR3 depending upon which time-base is used.
PWM
PWM
PWM
Capture
None
PWM
Compare
None
DS39564C-page 118
The PWMs will have the same frequency and update rate
(TMR2 interrupt).
© 2006 Microchip Technology Inc.
PIC18FXX2
14.3
14.3.3
Capture Mode
In Capture mode, CCPR1H:CCPR1L captures the
16-bit value of the TMR1 or TMR3 registers when an
event occurs on pin RC2/CCP1. An event is defined as
one of the following:
•
•
•
•
every falling edge
every rising edge
every 4th rising edge
every 16th rising edge
14.3.1
CCP PIN CONFIGURATION
In Capture mode, the RC2/CCP1 pin should be
configured as an input by setting the TRISC<2> bit.
Note:
14.3.2
If the RC2/CCP1 is configured as an output, a write to the port can cause a capture
condition.
TIMER1/TIMER3 MODE SELECTION
The timers that are to be used with the capture feature
(either 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 CCP module is
selected in the T3CON register.
FIGURE 14-1:
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep bit
CCP1IE (PIE1<2>) clear to avoid false interrupts and
should clear the flag bit, CCP1IF, following any such
change in Operating mode.
14.3.4
The event is selected by control bits CCP1M3:CCP1M0
(CCP1CON<3:0>). When a capture is made, the interrupt request flag bit CCP1IF (PIR1<2>) is set; it must be
cleared in software. If another capture occurs before the
value in register CCPR1 is read, the old captured value
is overwritten by the new captured value.
SOFTWARE INTERRUPT
CCP PRESCALER
There are four prescaler settings, specified by bits
CCP1M3:CCP1M0. Whenever the CCP module is
turned off or the CCP module is not in Capture mode,
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 14-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter
and will not generate the “false” interrupt.
EXAMPLE 14-1:
CLRF
MOVLW
MOVWF
CHANGING BETWEEN
CAPTURE PRESCALERS
CCP1CON, F ; Turn CCP module off
NEW_CAPT_PS ; Load WREG with the
; new prescaler mode
; value and CCP ON
CCP1CON
; Load CCP1CON with
; this value
CAPTURE MODE OPERATION BLOCK DIAGRAM
TMR3H
TMR3L
Set Flag bit CCP1IF
T3CCP2
Prescaler
÷ 1, 4, 16
CCP1 pin
TMR3
Enable
CCPR1H
and
Edge Detect
T3CCP2
CCPR1L
TMR1
Enable
TMR1H
TMR1L
TMR3H
TMR3L
CCP1CON<3:0>
Q’s
Set Flag bit CCP2IF
T3CCP1
T3CCP2
TMR3
Enable
Prescaler
÷ 1, 4, 16
CCP2 pin
CCPR2H
and
Edge Detect
CCPR2L
TMR1
Enable
T3CCP2
T3CCP1
TMR1H
TMR1L
CCP2CON<3:0>
Q’s
© 2006 Microchip Technology Inc.
DS39564C-page 119
PIC18FXX2
14.4
14.4.2
Compare Mode
Timer1 and/or Timer3 must be running in Timer mode
or Synchronized Counter mode if the CCP module is
using the compare feature. In Asynchronous Counter
mode, the compare operation may not work.
In Compare mode, the 16-bit CCPR1 (CCPR2) register
value is constantly compared against either the TMR1
register pair value, or the TMR3 register pair value.
When a match occurs, the RC2/CCP1 (RC1/CCP2) pin
is:
•
•
•
•
TIMER1/TIMER3 MODE SELECTION
14.4.3
driven High
driven Low
toggle output (High to Low or Low to High)
remains unchanged
SOFTWARE INTERRUPT MODE
When generate software interrupt is chosen, the CCP1
pin is not affected. Only a CCP interrupt is generated (if
enabled).
The action on the pin is based on the value of control
bits CCP1M3:CCP1M0 (CCP2M3:CCP2M0). At the
same time, interrupt flag bit CCP1IF (CCP2IF) is set.
14.4.4
14.4.1
The special event trigger output of CCP1 resets the
TMR1 register pair. This allows the CCPR1 register to
effectively be a 16-bit programmable period register for
Timer1.
In this mode, an internal hardware trigger is generated,
which may be used to initiate an action.
CCP PIN CONFIGURATION
The user must configure the CCPx pin as an output by
clearing the appropriate TRISC bit.
Note:
SPECIAL EVENT TRIGGER
Clearing the CCP1CON register will force
the RC2/CCP1 compare output latch to the
default low level. This is not the PORTC
I/O data latch.
The special trigger output of CCPx resets either the
TMR1 or TMR3 register pair. Additionally, the CCP2
Special Event Trigger will start an A/D conversion if the
A/D module is enabled.
Note:
FIGURE 14-2:
The special event trigger from the CCP2
module will not set the Timer1 or Timer3
interrupt flag bits.
COMPARE MODE OPERATION BLOCK DIAGRAM
Special Event Trigger will:
Reset Timer1 or Timer3, but not set Timer1 or Timer3 interrupt flag bit,
and set bit GO/DONE (ADCON0<2>)
which starts an A/D conversion (CCP2 only)
Special Event Trigger
Set Flag bit CCP1IF
CCPR1H CCPR1L
Q
RC2/CCP1 pin
S
R
TRISC<2>
Output Enable
Output
Logic
Comparator
Match
CCP1CON<3:0>
Mode Select
0
T3CCP2
TMR1H
1
TMR1L
TMR3H
TMR3L
Special Event Trigger
Set Flag bit CCP2IF
Q
RC1/CCP2 pin
TRISC<1>
Output Enable
DS39564C-page 120
S
R
Output
Logic
T3CCP1
T3CCP2
0
1
Comparator
Match
CCPR2H CCPR2L
CCP2CON<3:0>
Mode Select
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 14-3:
Name
REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3
Bit 7
Bit 6
Value on
All Other
RESETS
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
INTCON
GIE/GIEH PEIE/GIEL
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000 0000 0000
TRISC
PORTC Data Direction Register
1111 1111 1111 1111
TMR1L
Holding Register for the Least Significant Byte of the 16-bit TMR1 Register
xxxx xxxx uuuu uuuu
TMR1H
Holding Register for the Most Significant Byte of the 16-bit TMR1 Register
xxxx xxxx uuuu uuuu
T1CON
RD16
—
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 0-00 0000 u-uu uuuu
CCPR1L
Capture/Compare/PWM Register1 (LSB)
CCPR1H
Capture/Compare/PWM Register1 (MSB)
CCP1CON
—
—
DC1B1
DC1B0
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
CCP1M3
CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000
CCPR2L
Capture/Compare/PWM Register2 (LSB)
xxxx xxxx uuuu uuuu
CCPR2H
Capture/Compare/PWM Register2 (MSB)
xxxx xxxx uuuu uuuu
CCP2CON
—
—
DC2B1
DC2B0
CCP2M3
PIR2
—
—
—
EEIE
BCLIF
CCP2M2 CCP2M1 CCP2M0 --00 0000 --00 0000
LVDIF
TMR3IF
CCP2IF
---0 0000 ---0 0000
PIE2
—
—
—
EEIF
BCLIE
LVDIE
TMR3IE
CCP2IE
---0 0000 ---0 0000
IPR2
—
—
—
EEIP
BCLIP
LVDIP
TMR3IP
CCP2IP
---1 1111 ---1 1111
TMR3L
Holding Register for the Least Significant Byte of the 16-bit TMR3 Register
xxxx xxxx uuuu uuuu
TMR3H
Holding Register for the Most Significant Byte of the 16-bit TMR3 Register
xxxx xxxx uuuu uuuu
T3CON
Legend:
RD16
T3CCP2
T3CKPS1 T3CKPS0
T3CCP1
T3SYNC TMR3CS TMR3ON 0000 0000 uuuu uuuu
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Capture and Timer1.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2x2 devices; always maintain these bits clear.
© 2006 Microchip Technology Inc.
DS39564C-page 121
PIC18FXX2
14.5
14.5.1
PWM Mode
In Pulse Width Modulation (PWM) mode, the CCP1 pin
produces up to a 10-bit resolution PWM output. Since
the CCP1 pin is multiplexed with the PORTC data latch,
the TRISC<2> bit must be cleared to make the CCP1
pin an output.
Note:
Clearing the CCP1CON register will force
the CCP1 PWM output latch to the default
low level. This is not the PORTC I/O data
latch.
Figure 14-3 shows a simplified block diagram of the
CCP module in PWM mode.
For a step-by-step procedure on how to set up the CCP
module for PWM operation, see Section 14.5.3.
FIGURE 14-3:
SIMPLIFIED PWM BLOCK
DIAGRAM
The PWM period is specified by writing to the PR2
register. The PWM period can be calculated using the
following formula:
PWM period = (PR2) + 1] • 4 • TOSC •
(TMR2 prescale value)
PWM frequency is defined as 1 / [PWM period].
When TMR2 is equal to PR2, the following three events
occur on the next increment cycle:
• TMR2 is cleared
• The CCP1 pin is set (exception: if PWM duty
cycle = 0%, the CCP1 pin will not be set)
• The PWM duty cycle is latched from CCPR1L into
CCPR1H
Note:
CCP1CON<5:4>
Duty Cycle Registers
PWM PERIOD
The Timer2 postscaler (see Section 12.0)
is 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.
CCPR1L
14.5.2
CCPR1H (Slave)
R
Comparator
Q
RC2/CCP1
TMR2
(Note 1)
S
The PWM duty cycle is specified by writing to the
CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available. The CCPR1L contains
the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPR1L:CCP1CON<5:4>. The following equation is
used to calculate the PWM duty cycle in time:
PWM duty cycle
TRISC<2>
Comparator
Clear Timer,
CCP1 pin and
latch D.C.
PR2
Note: 8-bit timer is concatenated with 2-bit internal Q clock or 2
bits of the prescaler to create 10-bit time-base.
A PWM output (Figure 14-4) 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 14-4:
PWM OUTPUT
Period
PWM DUTY CYCLE
= (CCPR1L:CCP1CON<5:4>) •
TOSC • (TMR2 prescale value)
CCPR1L and CCP1CON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPR1H until after a match between PR2 and TMR2
occurs (i.e., the period is complete). In PWM mode,
CCPR1H is a read only register.
The CCPR1H 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 CCPR1H and 2-bit latch match TMR2 concatenated with an internal 2-bit Q clock or 2 bits of the
TMR2 prescaler, the CCP1 pin is cleared.
The maximum PWM resolution (bits) for a given PWM
frequency is given by the equation:
F OSC
log ⎛ ---------------⎞
⎝ F PWM⎠
PWM Resolution (max) = -----------------------------bits
log ( 2 )
Duty Cycle
TMR2 = PR2
TMR2 = Duty Cycle
TMR2 = PR2
DS39564C-page 122
Note:
If the PWM duty cycle value is longer than
the PWM period, the CCP1 pin will not be
cleared.
© 2006 Microchip Technology Inc.
PIC18FXX2
14.5.3
SETUP FOR PWM OPERATION
3.
The following steps should be taken when configuring
the CCP module for PWM operation:
4.
1.
2.
5.
Set the PWM period by writing to the PR2 register.
Set the PWM duty cycle by writing to the
CCPR1L register and CCP1CON<5:4> bits.
TABLE 14-4:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
PWM Frequency
2.44 kHz
Timer Prescaler (1, 4, 16)
PR2 Value
Maximum Resolution (bits)
TABLE 14-5:
Name
Make the CCP1 pin an output by clearing the
TRISC<2> bit.
Set the TMR2 prescale value and enable Timer2
by writing to T2CON.
Configure the CCP1 module for PWM operation.
9.77 kHz
39.06 kHz
156.25 kHz
312.50 kHz
416.67 kHz
16
4
1
1
1
1
0xFF
0xFF
0xFF
0x3F
0x1F
0x17
14
12
10
8
7
6.58
Value on
All Other
RESETS
REGISTERS ASSOCIATED WITH PWM AND TIMER2
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
INTCON
GIE/GIEH PEIE/GIEL
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000 0000 0000
TRISC
PORTC Data Direction Register
1111 1111 1111 1111
TMR2
Timer2 Module Register
0000 0000 0000 0000
PR2
Timer2 Module Period Register
1111 1111 1111 1111
T2CON
—
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
CCPR1L
Capture/Compare/PWM Register1 (LSB)
CCPR1H
Capture/Compare/PWM Register1 (MSB)
CCP1CON
—
—
DC1B1
DC1B0
CCPR2L
Capture/Compare/PWM Register2 (LSB)
CCPR2H
Capture/Compare/PWM Register2 (MSB)
CCP2CON
—
—
DC2B1
DC2B0
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
CCP1M3
CCP1M2
CCP1M1
CCP1M0 --00 0000 --00 0000
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
CCP2M3
CCP2M2
CCP2M1
CCP2M0 --00 0000 --00 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PWM and Timer2.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
© 2006 Microchip Technology Inc.
DS39564C-page 123
PIC18FXX2
NOTES:
DS39564C-page 124
© 2006 Microchip Technology Inc.
PIC18FXX2
15.0
15.1
MASTER SYNCHRONOUS
SERIAL PORT (MSSP)
MODULE
Master SSP (MSSP) Module
Overview
The Master Synchronous Serial Port (MSSP) module is
a serial interface useful for communicating with other
peripheral or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers, display drivers, A/D converters, etc. 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)
15.3
SPI Mode
The SPI mode allows 8-bits of data to be synchronously
transmitted and received, simultaneously. All four modes
of SPI are supported. To accomplish communication,
typically three pins are used:
• Serial Data Out (SDO) - RC5/SDO
• Serial Data In (SDI) - RC4/SDI/SDA
• Serial Clock (SCK) - RC3/SCK/SCL/LVDIN
Additionally, a fourth pin may be used when in a Slave
mode of operation:
• Slave Select (SS) - RA5/SS/AN4
Figure 15-1 shows the block diagram of the MSSP
module when operating in SPI mode.
FIGURE 15-1:
MSSP BLOCK DIAGRAM
(SPI MODE)
The I2C interface supports the following modes in
hardware:
Internal
Data Bus
• Master mode
• Multi-Master mode
• Slave mode
15.2
Read
Write
SSPBUF reg
Control Registers
RC4/SDI/SDA
The MSSP module has three associated registers.
These include a status register (SSPSTAT) and two
control registers (SSPCON1 and SSPCON2). The use
of these registers and their individual configuration bits
differ significantly, depending on whether the MSSP
module is operated in SPI or I2C mode.
Additional details are provided under the individual
sections.
SSPSR reg
shift
clock
RC5/SDO
bit0
RA5/SS/AN4
SS Control
Enable
Edge
Select
2
Clock Select
RC3/SCK/
SCL/LVDIN
SSPM3:SSPM0
SMP:CKE 4
TMR2 output
2
2
(
Edge
Select
)
Prescaler TOSC
4, 16, 64
Data to TX/RX in SSPSR
TRIS bit
© 2006 Microchip Technology Inc.
DS39564C-page 125
PIC18FXX2
15.3.1
REGISTERS
The MSSP module has four registers for SPI mode
operation. These are:
•
•
•
•
MSSP Control Register1 (SSPCON1)
MSSP Status Register (SSPSTAT)
Serial Receive/Transmit Buffer (SSPBUF)
MSSP Shift Register (SSPSR) - Not directly
accessible
SSPCON1 and SSPSTAT are the control and status
registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the
SSPSTAT are read only. The upper two bits of the
SSPSTAT are read/write.
REGISTER 15-1:
SSPSR is the shift register used for shifting data in or
out. SSPBUF is the buffer register to which data bytes
are written to or read from.
In receive operations, SSPSR and SSPBUF together
create a double buffered receiver. When SSPSR
receives a complete byte, it is transferred to SSPBUF
and the SSPIF interrupt is set.
During transmission, the SSPBUF is not double buffered. A write to SSPBUF will write to both SSPBUF and
SSPSR.
SSPSTAT: MSSP STATUS REGISTER (SPI MODE)
R/W-0
SMP
R/W-0
CKE
R-0
R-0
R-0
R-0
R-0
R-0
D/A
P
S
R/W
UA
BF
bit 7
bit 0
bit 7
SMP: Sample bit
SPI Master mode:
1 = Input data sampled at end of data output time
0 = Input data sampled at middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode
bit 6
CKE: SPI Clock Edge Select
When CKP = 0:
1 = Data transmitted on rising edge of SCK
0 = Data transmitted on falling edge of SCK
When CKP = 1:
1 = Data transmitted on falling edge of SCK
0 = Data transmitted on rising edge of SCK
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 bit information
Used in I2C mode only
bit 1
UA: Update Address
Used in I2C mode only
bit 0
BF: Buffer Full Status bit (Receive mode only)
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty
Legend:
DS39564C-page 126
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
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 15-2:
SSPCON1: MSSP CONTROL REGISTER1 (SPI MODE)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
bit 7
bit 0
bit 7
WCOL: Write Collision Detect bit (Transmit mode only)
1 = The SSPBUF 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
SPI Slave mode:
1 = A new byte is received while the SSPBUF register is still holding the previous data. In case
of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode.The user
must read the SSPBUF, even if only transmitting data, to avoid setting overflow
(must be cleared in software).
0 = No overflow
Note:
bit 5
In Master mode, the overflow bit is not set since each new reception (and
transmission) is initiated by writing to the SSPBUF register.
SSPEN: Synchronous Serial Port Enable bit
1 = Enables serial port and configures SCK, SDO, SDI, and SS as serial port pins
0 = Disables serial port and configures these pins as I/O port pins
Note:
When enabled, these pins must be properly configured as input or output.
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
SSPM3:SSPM0: Synchronous Serial Port Mode Select bits
0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin
0100 = SPI Slave mode, clock = SCK pin, SS pin control 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:
Bit combinations not specifically listed here are either reserved, or implemented in
I2C mode only.
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 127
PIC18FXX2
15.3.2
OPERATION
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits (SSPCON1<5:0>) and SSPSTAT<7:6>.
These control bits allow the following to be specified:
•
•
•
•
Master mode (SCK is the clock output)
Slave mode (SCK is the clock input)
Clock Polarity (IDLE state of SCK)
Data input sample phase (middle or end of data
output time)
• Clock edge (output data on rising/falling edge of
SCK)
• Clock Rate (Master mode only)
• Slave Select mode (Slave mode only)
The MSSP consists of a transmit/receive Shift Register
(SSPSR) and a buffer register (SSPBUF). The SSPSR
shifts the data in and out of the device, MSb first. The
SSPBUF holds the data that was written to the SSPSR,
until the received data is ready. Once the 8 bits of data
have been received, that byte is moved to the SSPBUF
register. Then the buffer full detect bit, BF
(SSPSTAT<0>), and the interrupt flag bit, SSPIF, are
set. This double buffering of the received data
(SSPBUF) allows the next byte to start reception before
reading the data that was just received. Any write to the
EXAMPLE 15-1:
SSPBUF register during transmission/reception of data
will be ignored, and the write collision detect bit, WCOL
(SSPCON1<7>), will be set. User software must clear
the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed
successfully.
When the application software is expecting to receive
valid data, the SSPBUF should be read before the next
byte of data to transfer is written to the SSPBUF. Buffer
full bit, BF (SSPSTAT<0>), indicates when SSPBUF
has been loaded with the received data (transmission
is complete). When the SSPBUF 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. The SSPBUF must be read and/or written. 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 15-1 shows the loading of the
SSPBUF (SSPSR) for data transmission.
The SSPSR is not directly readable or writable, and
can only be accessed by addressing the SSPBUF register. Additionally, the MSSP status register (SSPSTAT)
indicates the various status conditions.
LOADING THE SSPBUF (SSPSR) REGISTER
LOOP BTFSS SSPSTAT, BF
BRA
LOOP
MOVF SSPBUF, W
;Has data been received(transmit complete)?
;No
;WREG reg = contents of SSPBUF
MOVWF RXDATA
;Save in user RAM, if data is meaningful
MOVF TXDATA, W
MOVWF SSPBUF
;W reg = contents of TXDATA
;New data to xmit
DS39564C-page 128
© 2006 Microchip Technology Inc.
PIC18FXX2
15.3.3
ENABLING SPI I/O
15.3.4
To enable the serial port, SSP Enable bit, SSPEN
(SSPCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, re-initialize the
SSPCON registers, and then set the SSPEN bit. This
configures the SDI, SDO, SCK, and SS pins as serial
port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the
TRIS register) appropriately programmed. That is:
• SDI is automatically controlled by the SPI module
• SDO must have TRISC<5> bit cleared
• SCK (Master mode) must have TRISC<3> bit
cleared
• SCK (Slave mode) must have TRISC<3> bit set
• SS must have TRISC<4> bit set
TYPICAL CONNECTION
Figure 15-2 shows a typical connection between two
microcontrollers. The master controller (Processor 1)
initiates the data transfer by sending the SCK signal.
Data is shifted out of both shift registers on their programmed 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 data — Slave sends dummy data
• Master sends data — Slave sends data
• Master sends dummy data — Slave sends data
Any serial port function that is not desired may be
overridden by programming the corresponding data
direction (TRIS) register to the opposite value.
FIGURE 15-2:
SPI MASTER/SLAVE CONNECTION
SPI Master SSPM3:SSPM0 = 00xxb
SPI Slave SSPM3:SSPM0 = 010xb
SDO
SDI
Serial Input Buffer
(SSPBUF)
SDI
Shift Register
(SSPSR)
MSb
Serial Input Buffer
(SSPBUF)
LSb
© 2006 Microchip Technology Inc.
Shift Register
(SSPSR)
MSb
SCK
PROCESSOR 1
SDO
Serial Clock
LSb
SCK
PROCESSOR 2
DS39564C-page 129
PIC18FXX2
15.3.5
MASTER MODE
Figure 15-3, Figure 15-5, and Figure 15-6, where the
MSB is transmitted first. In Master mode, the SPI clock
rate (bit rate) is user programmable to be one of the
following:
The master can initiate the data transfer at any time
because it controls the SCK. The master determines
when the slave (Processor 2, Figure 15-2) is to
broadcast data by the software protocol.
•
•
•
•
In Master mode, the data is transmitted/received as
soon as the SSPBUF register is written to. If the SPI is
only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register
will continue to shift in the signal present on the SDI pin
at the programmed clock rate. As each byte is
received, it will be loaded into the SSPBUF 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.
This allows a maximum data rate (at 40 MHz) of
10.00 Mbps.
Figure 15-3 shows the waveforms for Master mode.
When the CKE bit is set, the SDO data is valid before
there is a clock edge on SCK. The change of the input
sample is shown based on the state of the SMP bit. The
time when the SSPBUF is loaded with the received
data is shown.
The clock polarity is selected by appropriately programming the CKP bit (SSPCON1<4>). This then, would
give waveforms for SPI communication as shown in
FIGURE 15-3:
FOSC/4 (or TCY)
FOSC/16 (or 4 • TCY)
FOSC/64 (or 16 • TCY)
Timer2 output/2
SPI MODE WAVEFORM (MASTER MODE)
Write to
SSPBUF
SCK
(CKP = 0
CKE = 0)
SCK
(CKP = 1
CKE = 0)
4 Clock
Modes
SCK
(CKP = 0
CKE = 1)
SCK
(CKP = 1
CKE = 1)
SDO
(CKE = 0)
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
SDO
(CKE = 1)
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
SDI
(SMP = 0)
bit0
bit7
Input
Sample
(SMP = 0)
SDI
(SMP = 1)
bit7
bit0
Input
Sample
(SMP = 1)
SSPIF
SSPSR to
SSPBUF
DS39564C-page 130
Next Q4 cycle
after Q2↓
© 2006 Microchip Technology Inc.
PIC18FXX2
15.3.6
SLAVE MODE
In Slave mode, the data is transmitted and received as
the external clock pulses appear on SCK. When the
last bit is latched, the SSPIF interrupt flag bit is set.
While in Slave mode, the external clock is supplied by
the external clock source on the SCK pin. This external
clock must meet the minimum high and low times as
specified in the electrical specifications.
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.
Note 1: When the SPI is in Slave mode with SS
pin control enabled (SSPCON<3:0> =
0100), the SPI module will reset if the SS
pin is set to VDD.
2: If the SPI is used in Slave mode with CKE
set, then the SS pin control must be
enabled.
While in SLEEP mode, the slave can transmit/receive
data. When a byte is received, the device will wake-up
from sleep.
15.3.7
When the SPI module resets, the bit counter is forced
to 0. This can be done by either forcing the SS pin to a
high level or clearing the SSPEN bit.
SLAVE SELECT
SYNCHRONIZATION
The SS pin allows a Synchronous Slave mode. The
SPI must be in Slave mode with SS pin control enabled
(SSPCON1<3:0> = 04h). The pin must not be driven
low for the SS pin to function as an input. The Data
Latch must be high. When the SS pin is low, transmission and reception are enabled and the SDO pin is
driven. When the SS pin goes high, the SDO pin is no
FIGURE 15-4:
To emulate two-wire communication, the SDO pin can
be connected to the SDI pin. When the SPI needs to
operate as a receiver the SDO pin can be configured as
an input. This disables transmissions from the SDO.
The SDI can always be left as an input (SDI function),
since it cannot create a bus conflict.
SLAVE SYNCHRONIZATION WAVEFORM
SS
SCK
(CKP = 0
CKE = 0)
SCK
(CKP = 1
CKE = 0)
Write to
SSPBUF
SDO
SDI
(SMP = 0)
bit7
bit6
bit7
bit0
bit0
bit7
bit7
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
© 2006 Microchip Technology Inc.
Next Q4 cycle
after Q2↓
DS39564C-page 131
PIC18FXX2
FIGURE 15-5:
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
SS
Optional
SCK
(CKP = 0
CKE = 0)
SCK
(CKP = 1
CKE = 0)
Write to
SSPBUF
SDO
SDI
(SMP = 0)
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
bit0
bit7
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
Next Q4 cycle
after Q2↓
SSPSR to
SSPBUF
FIGURE 15-6:
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
SS
Not Optional
SCK
(CKP = 0
CKE = 1)
SCK
(CKP = 1
CKE = 1)
Write to
SSPBUF
SDO
SDI
(SMP = 0)
bit7
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
bit0
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
DS39564C-page 132
Next Q4 cycle
after Q2↓
© 2006 Microchip Technology Inc.
PIC18FXX2
15.3.8
SLEEP OPERATION
15.3.10
In Master mode, all module clocks are halted and the
transmission/reception will remain in that state until the
device wakes from SLEEP. After the device returns to
Normal mode, the module will continue to transmit/
receive data.
Table 15-1 shows the compatibility between the
standard SPI modes and the states the CKP and CKE
control bits.
TABLE 15-1:
In Slave mode, the SPI transmit/receive shift register
operates asynchronously to the device. This allows the
device to be placed in SLEEP 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
from SLEEP.
15.3.9
SPI BUS MODES
Control Bits State
Standard SPI Mode
Terminology
0,
0,
1,
1,
EFFECTS OF A RESET
0
1
0
1
CKP
CKE
0
0
1
1
1
0
1
0
There is also a SMP bit which controls when the data is
sampled.
A RESET disables the MSSP module and terminates
the current transfer.
TABLE 15-2:
BUS MODE COMPATIBILITY
REGISTERS ASSOCIATED WITH SPI OPERATION
Value on
All Other
RESETS
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
INTCON
GIE/GIEH
PEIE/
GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000 0000 0000
Name
TRISC
PORTC Data Direction Register
1111 1111 1111 1111
SSPBUF
Synchronous Serial Port Receive Buffer/Transmit Register
xxxx xxxx uuuu uuuu
SSPCON
TRISA
SSPSTAT
WCOL
—
SMP
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
PORTA Data Direction Register
CKE
D/A
P
0000 0000 0000 0000
-111 1111 -111 1111
S
R/W
UA
BF
0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the MSSP in SPI mode.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18C2X2 devices; always maintain these bits clear.
© 2006 Microchip Technology Inc.
DS39564C-page 133
PIC18FXX2
15.4
I2C Mode
15.4.1
The MSSP module in I 2C 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, as well as 7-bit and 10-bit
addressing.
Two pins are used for data transfer:
• Serial clock (SCL) - RC3/SCK/SCL
• Serial data (SDA) - RC4/SDI/SDA
The user must configure these pins as inputs or outputs
through the TRISC<4:3> bits.
FIGURE 15-7:
MSSP BLOCK DIAGRAM
(I2C MODE)
Internal
Data Bus
Read
Write
Shift
Clock
LSb
MSb
Match Detect
MSSP Control Register1 (SSPCON1)
MSSP Control Register2 (SSPCON2)
MSSP Status Register (SSPSTAT)
Serial Receive/Transmit Buffer (SSPBUF)
MSSP Shift Register (SSPSR) - Not directly
accessible
• MSSP Address Register (SSPADD)
SSPCON, SSPCON2 and SSPSTAT are the control
and status registers in I2C mode operation. The
SSPCON and SSPCON2 registers are readable and
writable. The lower 6 bits of the SSPSTAT are read
only. The upper two bits of the SSPSTAT are read/
write.
SSPSR is the shift register used for shifting data in or
out. SSPBUF is the buffer register to which data bytes
are written to or read from.
Addr Match
During transmission, the SSPBUF is not double buffered. A write to SSPBUF will write to both SSPBUF and
SSPSR.
SSPADD reg
START and
STOP bit Detect
DS39564C-page 134
•
•
•
•
•
In receive operations, SSPSR and SSPBUF together,
create a double buffered receiver. When SSPSR
receives a complete byte, it is transferred to SSPBUF
and the SSPIF interrupt is set.
SSPSR reg
RC4/
SDI/
SDA
The MSSP module has six registers for I2C operation.
These are:
SSPADD register holds the slave device address
when the SSP is configured in I2C Slave mode. When
the SSP is configured in Master mode, the lower
seven bits of SSPADD act as the baud rate generator
reload value.
SSPBUF reg
RC3/SCK/SCL
REGISTERS
Set, Reset
S, P bits
(SSPSTAT reg)
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 15-3:
SSPSTAT: MSSP STATUS REGISTER (I2C MODE)
R/W-0
R/W-0
R-0
R-0
R-0
R-0
R-0
R-0
SMP
CKE
D/A
P
S
R/W
UA
BF
bit 7
bit 0
bit 7
SMP: Slew Rate Control bit
In Master or Slave mode:
1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz)
0 = Slew rate control 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 = Indicates that a STOP bit has been detected last
0 = STOP bit was not detected last
Note:
This bit is cleared on RESET and when SSPEN is cleared.
bit 3
S: START bit
1 = Indicates that a start bit has been detected last
0 = START bit was not detected last
Note:
This bit is cleared on RESET and when SSPEN is cleared.
bit 2
R/W: Read/Write bit Information (I2C mode only)
In Slave mode:
1 = Read
0 = Write
Note:
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.
In Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
Note:
ORing this bit with SEN, RSEN, PEN, RCEN, or ACKEN will indicate if the MSSP is
in IDLE mode.
bit 1
UA: Update Address (10-bit Slave mode only)
1 = Indicates that the user needs to update the address in the SSPADD register
0 = Address does not need to be updated
bit 0
BF: Buffer Full Status bit
In Transmit mode:
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty
In Receive mode:
1 = Data transmit in progress (does not include the ACK and STOP bits), SSPBUF is full
0 = Data transmit complete (does not include the ACK and STOP bits), SSPBUF is empty
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 135
PIC18FXX2
REGISTER 15-4:
SSPCON1: MSSP CONTROL REGISTER1 (I2C MODE)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
bit 7
bit 0
bit 7
WCOL: Write Collision Detect bit
In Master Transmit mode:
1 = A write to the SSPBUF 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 SSPBUF 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 SSPBUF 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: Synchronous Serial Port Enable bit
1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins
0 = Disables serial port and configures these pins as I/O port pins
Note:
When enabled, the SDA and SCL pins must be properly configured as input or output.
bit 4
CKP: SCK Release Control bit
In Slave mode:
1 = Release clock
0 = Holds clock low (clock stretch), used to ensure data setup time
In Master mode:
Unused in this mode
bit 3-0
SSPM3:SSPM0: Synchronous Serial Port Mode Select bits
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)
1000 = I2C Master mode, clock = FOSC / (4 * (SSPADD+1))
0111 = I2C Slave mode, 10-bit address
0110 = I2C Slave mode, 7-bit address
Note:
Bit combinations not specifically listed here are either reserved, or implemented in
SPI mode only.
Legend:
DS39564C-page 136
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
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 15-5:
SSPCON2: MSSP CONTROL REGISTER 2 (I2C MODE)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
GCEN
ACKSTAT
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
bit 7
bit 0
bit 7
GCEN: General Call Enable bit (Slave mode only)
1 = Enable interrupt when a general call address (0000h) is received in the SSPSR
0 = General call address 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 = Not Acknowledge
0 = Acknowledge
Note:
Value that will be transmitted when the user initiates an Acknowledge sequence at
the end of a receive.
bit 4
ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)
1 = Initiate Acknowledge sequence on SDA and SCL pins, and transmit ACKDT data bit.
Automatically cleared by hardware.
0 = Acknowledge sequence IDLE
bit 3
RCEN: Receive Enable bit (Master mode only)
1 = Enables Receive mode for I2C
0 = Receive IDLE
bit 2
PEN: STOP Condition Enable bit (Master mode only)
1 = Initiate STOP condition on SDA and SCL pins. Automatically cleared by hardware.
0 = STOP condition IDLE
bit 1
RSEN: Repeated START Condition Enabled bit (Master mode only)
1 = Initiate Repeated START condition on SDA and SCL pins.
Automatically cleared by hardware.
0 = Repeated START condition IDLE
bit 0
SEN: START Condition Enabled/Stretch Enabled bit
In Master mode:
1 = Initiate START condition on SDA and SCL pins. Automatically cleared by hardware.
0 = START condition IDLE
In Slave mode:
1 = Clock stretching is enabled for both Slave Transmit and Slave Receive (stretch enabled)
0 = Clock stretching is enabled for slave transmit only (Legacy mode)
Note:
For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C module is not in the IDLE
mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or
writes to the SSPBUF are disabled).
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 137
PIC18FXX2
15.4.2
OPERATION
The MSSP module functions are enabled by setting
MSSP Enable bit, SSPEN (SSPCON<5>).
The SSPCON1 register allows control of the I 2C operation. Four mode selection bits (SSPCON<3:0>) allow
one of the following I 2C modes to be selected:
I2C Master mode, clock = OSC/4 (SSPADD +1)
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 operation, slave
is IDLE
•
•
•
•
Selection of any I 2C mode, with the SSPEN bit set,
forces the SCL and SDA pins to be open drain, provided these pins are programmed to inputs by setting
the appropriate TRISC bits. To guarantee proper operation of the module, pull-up resistors must be provided
externally to the SCL and SDA pins.
15.4.3
SLAVE MODE
In Slave mode, the SCL and SDA pins must be configured as inputs (TRISC<4:3> set). The MSSP module
will override the input state with the output data when
required (slave-transmitter).
15.4.3.1
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 SSPSR register. All
incoming bits are sampled with the rising edge of the
clock (SCL) line. The value of register SSPSR<7:1> is
compared to the value of the SSPADD register. The
address is compared on the falling edge of the eighth
clock (SCL) pulse. If the addresses match, and the BF
and SSPOV bits are clear, the following events occur:
1.
2.
3.
4.
When an address is matched or the data transfer after
an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse and
load the SSPBUF register with the received value
currently in the SSPSR register.
1.
2.
3.
4.
5.
Any combination of the following conditions will cause
the MSSP module not to give this ACK pulse:
• The buffer full bit BF (SSPSTAT<0>) was set
before the transfer was received.
• The overflow bit SSPOV (SSPCON<6>) was set
before the transfer was received.
In this case, the SSPSR register value is not loaded
into the SSPBUF, but bit SSPIF (PIR1<3>) is set. The
BF bit is cleared by reading the SSPBUF register, while
bit SSPOV is cleared through software.
The SSPSR register value is loaded into the
SSPBUF register.
The buffer full bit BF is set.
An ACK pulse is generated.
MSSP interrupt flag bit, SSPIF (PIR1<3>) is set
(interrupt is generated if enabled) on the falling
edge of the ninth SCL pulse.
In 10-bit Address 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 (SSPSTAT<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
address is as follows, with steps 7 through 9 for the
slave-transmitter:
2C
Slave mode hardware will always generate an
The I
interrupt on an address match. Through the mode
select bits, the user can also choose to interrupt on
START and STOP bits
Addressing
6.
7.
8.
9.
Receive first (high) byte of Address (bits SSPIF,
BF and bit UA (SSPSTAT<1>) are set).
Update the SSPADD register with second (low)
byte of Address (clears bit UA and releases the
SCL line).
Read the SSPBUF register (clears bit BF) and
clear flag bit SSPIF.
Receive second (low) byte of Address (bits
SSPIF, BF, and UA are set).
Update the SSPADD register with the first (high)
byte of Address. If match releases SCL line, this
will clear bit UA.
Read the SSPBUF register (clears bit BF) and
clear flag bit SSPIF.
Receive Repeated START condition.
Receive first (high) byte of Address (bits SSPIF
and BF are set).
Read the SSPBUF register (clears bit BF) and
clear flag bit SSPIF.
The SCL 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.
DS39564C-page 138
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.3.2
Reception
When the R/W bit of the address byte is clear and an
address match occurs, the R/W bit of the SSPSTAT
register is cleared. The received address is loaded into
the SSPBUF register and the SDA 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 (SSPSTAT<0>) is
set, or bit SSPOV (SSPCON1<6>) is set.
An MSSP interrupt is generated for each data transfer
byte. Flag bit SSPIF (PIR1<3>) must be cleared in software. The SSPSTAT register is used to determine the
status of the byte.
The ACK pulse from the master-receiver is latched on
the rising edge of the ninth SCL input pulse. If the SDA
line is high (not ACK), then the data transfer is complete. In this case, when the ACK is latched by the
slave, the slave logic is reset (resets SSPSTAT register) and the slave monitors for another occurrence of
the START bit. If the SDA line was low (ACK), the next
transmit data must be loaded into the SSPBUF register.
Again, pin RC3/SCK/SCL must be enabled by setting
bit CKP.
An MSSP interrupt is generated for each data transfer
byte. The SSPIF bit must be cleared in software and
the SSPSTAT register is used to determine the status
of the byte. The SSPIF bit is set on the falling edge of
the ninth clock pulse.
If SEN is enabled (SSPCON1<0>=1), RC3/SCK/SCL
will be held low (clock stretch) following each data transfer. The clock must be released by setting bit CKP
(SSPCON<4>). See Section 15.4.4 (“Clock Stretching”),
for more detail.
15.4.3.3
Transmission
When the R/W bit of the incoming address byte is set
and an address match occurs, the R/W bit of the
SSPSTAT register is set. The received address is
loaded into the SSPBUF register. The ACK pulse will
be sent on the ninth bit and pin RC3/SCK/SCL is held
low, regardless of SEN (see “Clock Stretching”,
Section 15.4.4, for more detail). 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 SSPBUF register,
which also loads the SSPSR register. Then pin RC3/
SCK/SCL should be enabled by setting bit CKP
(SSPCON1<4>). The eight data bits are shifted out on
the falling edge of the SCL input. This ensures that the
SDA signal is valid during the SCL high time
(Figure 15-9).
© 2006 Microchip Technology Inc.
DS39564C-page 139
DS39564C-page 140
CKP
2
A6
3
4
A4
5
A3
Receiving Address
A5
6
A2
(CKP does not reset to ‘0’ when SEN = 0)
SSPOV (SSPCON<6>)
BF (SSPSTAT<0>)
(PIR1<3>)
SSPIF
1
SCL
S
A7
7
A1
8
9
ACK
R/W = 0
1
D7
3
4
D4
5
D3
Receiving Data
D5
Cleared in software
SSPBUF is read
2
D6
6
D2
7
D1
8
D0
9
ACK
1
D7
2
D6
3
4
D4
5
D3
Receiving Data
D5
6
D2
7
D1
8
D0
Bus Master
terminates
transfer
P
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
9
ACK
FIGURE 15-8:
SDA
PIC18FXX2
I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
© 2006 Microchip Technology Inc.
© 2006 Microchip Technology Inc.
1
CKP
2
A6
Data in
sampled
BF (SSPSTAT<0>)
SSPIF (PIR1<3>)
S
A7
3
A5
4
A4
5
A3
6
A2
Receiving Address
7
A1
8
R/W = 1
9
ACK
SCL held low
while CPU
responds to SSPIF
1
D7
3
D5
4
D4
5
D3
6
D2
CKP is set in software
SSPBUF is written in software
Cleared in software
2
D6
Transmitting Data
7
8
D0
9
ACK
From SSPIF ISR
D1
1
D7
4
D4
5
D3
6
D2
CKP is set in software
7
8
D0
9
ACK
From SSPIF ISR
D1
Transmitting Data
Cleared in software
3
D5
SSPBUF is written in software
2
D6
P
FIGURE 15-9:
SCL
SDA
PIC18FXX2
I2C SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
DS39564C-page 141
DS39564C-page 142
2
1
4
1
5
0
7
UA is set indicating that
the SSPADD needs to be
updated
SSPBUF is written with
contents of SSPSR
6
A9 A8
8
9
(CKP does not reset to ‘0’ when SEN = 0)
UA (SSPSTAT<1>)
SSPOV (SSPCON<6>)
CKP
3
1
Cleared in software
BF (SSPSTAT<0>)
(PIR1<3>)
SSPIF
1
SCL
S
1
ACK
R/W = 0
A7
2
4
A4
5
A3
6
8
9
A0 ACK
UA is set indicating that
SSPADD needs to be
updated
Cleared by hardware
when SSPADD is updated
with low byte of address
7
A2 A1
Cleared in software
3
A5
Dummy read of SSPBUF
to clear BF flag
1
A6
Receive Second Byte of Address
1
D7
4
5
6
Cleared in software
3
7
8
9
1
2
4
5
6
Cleared in software
3
D3 D2
Receive Data Byte
D1 D0 ACK D7 D6 D5 D4
Cleared by hardware when
SSPADD is updated with high
byte of address
2
D3 D2
Receive Data Byte
D6 D5 D4
Clock is held low until
update of SSPADD has
taken place
7
8
D1 D0
9
P
Bus Master
terminates
transfer
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
ACK
FIGURE 15-10:
SDA
Receive First Byte of Address
Clock is held low until
update of SSPADD has
taken place
PIC18FXX2
I2C SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
© 2006 Microchip Technology Inc.
© 2006 Microchip Technology Inc.
2
CKP (SSPCON<4>)
UA (SSPSTAT<1>)
BF (SSPSTAT<0>)
(PIR1<3>)
SSPIF
1
S
SCL
1
4
1
5
0
6
7
A9 A8
UA is set indicating that
the SSPADD needs to be
updated
SSPBUF is written with
contents of SSPSR
3
1
Receive First Byte of Address
1
8
9
ACK
1
3
4
5
Cleared in software
2
7
UA is set indicating that
SSPADD needs to be
updated
Cleared by hardware when
SSPADD is updated with low
byte of address
6
A6 A5 A4 A3 A2 A1
8
A0
Receive Second Byte of Address
Dummy read of SSPBUF
to clear BF flag
A7
9
ACK
2
3
1
4
1
Cleared in software
1
1
5
0
6
8
9
ACK
R/W=1
1
2
4
5
6
CKP is set in software
9
P
Completion of
data transmission
clears BF flag
8
ACK
Bus Master
terminates
transfer
CKP is automatically cleared in hardware holding SCL low
7
D4 D3 D2 D1 D0
Cleared in software
3
D7 D6 D5
Transmitting Data Byte
Clock is held low until
CKP is set to ‘1’
Write of SSPBUF
BF flag is clear
initiates transmit
at the end of the
third address sequence
7
A9 A8
Cleared by hardware when
SSPADD is updated with high
byte of address.
Dummy read of SSPBUF
to clear BF flag
Sr
1
Receive First Byte of Address
Clock is held low until
update of SSPADD has
taken place
FIGURE 15-11:
SDA
R/W = 0
Clock is held low until
update of SSPADD has
taken place
PIC18FXX2
I2C SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
DS39564C-page 143
PIC18FXX2
15.4.4
CLOCK STRETCHING
Both 7- and 10-bit Slave modes implement automatic
clock stretching during a transmit sequence.
The SEN bit (SSPCON2<0>) allows clock stretching to
be enabled during receives. Setting SEN will cause
the SCL pin to be held low at the end of each data
receive sequence.
15.4.4.1
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 SSPCON1 register is automatically cleared, forcing the SCL output to be held
low. The CKP being cleared to ‘0’ will assert the SCL
line low. The CKP bit must be set in the user’s ISR
before reception is allowed to continue. By holding the
SCL line low, the user has time to service the ISR and
read the contents of the SSPBUF before the master
device can initiate another receive sequence. This will
prevent buffer overruns from occurring (see
Figure 15-13).
Note 1: If the user reads the contents of the
SSPBUF 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.
15.4.4.2
15.4.4.3
Clock Stretching for 7-bit Slave
Transmit Mode
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 ISR must set the CKP bit before transmission is allowed to continue. By holding the SCL line
low, the user has time to service the ISR and load the
contents of the SSPBUF before the master device can
initiate another transmit sequence (see Figure 15-9).
Note 1: If the user loads the contents of SSPBUF,
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.
15.4.4.4
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 to ‘1’. 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 15-11).
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
SSPADD. Clock stretching will occur on each data
receive sequence as described in 7-bit mode.
Note:
If the user polls the UA bit and clears it by
updating the SSPADD register before the
falling edge of the ninth clock occurs, and if
the user hasn’t cleared the BF bit by reading the SSPBUF 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.
DS39564C-page 144
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.4.5
Clock Synchronization and
the CKP bit
If a user clears the CKP bit, the SCL output is forced to
‘0’. Setting the CKP bit will not assert the SCL output
low until the SCL output is already sampled low. If the
user attempts to drive SCL low, the CKP bit will not
assert the SCL line until an external I2C master device
has already asserted the SCL line. The SCL output will
remain low until the CKP bit is set, and all other
devices on the I2C bus have de-asserted SCL. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCL (see
Figure 15-12).
FIGURE 15-12:
CLOCK SYNCHRONIZATION TIMING
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
SDA
DX
DX-1
SCL
CKP
Master device
asserts clock
Master device
de-asserts clock
WR
SSPCON
© 2006 Microchip Technology Inc.
DS39564C-page 145
DS39564C-page 146
CKP
SSPOV (SSPCON<6>)
BF (SSPSTAT<0>)
(PIR1<3>)
SSPIF
1
SCL
S
A7
2
A6
3
4
A4
5
A3
Receiving Address
A5
6
A2
7
A1
8
9
ACK
R/W = 0
3
4
D4
5
D3
Receiving Data
D5
Cleared in software
2
D6
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
SSPBUF is read
1
D7
6
D2
7
D1
9
ACK
1
D7
BF is set after falling
edge of the 9th clock,
CKP is reset to ‘0’ and
clock stretching occurs
8
D0
CKP
written
to ‘1’ in
software
2
D6
Clock is held low until
CKP is set to ‘1’
3
4
D4
5
D3
Receiving Data
D5
6
D2
7
D1
8
D0
Bus Master
terminates
transfer
P
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
9
ACK
Clock is not held low
because ACK = 1
FIGURE 15-13:
SDA
Clock is not held low
because buffer full bit is
clear prior to falling edge
of 9th clock
PIC18FXX2
I2C SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
© 2006 Microchip Technology Inc.
© 2006 Microchip Technology Inc.
2
1
UA (SSPSTAT<1>)
SSPOV (SSPCON<6>)
CKP
3
1
4
1
5
0
6
7
A9 A8
8
UA is set indicating that
the SSPADD needs to be
updated
SSPBUF is written with
contents of SSPSR
Cleared in software
BF (SSPSTAT<0>)
(PIR1<3>)
SSPIF
1
SCL
S
1
9
ACK
R/W = 0
A7
2
4
A4
5
A3
6
8
A0
Note:
An update of the SSPADD
register before the falling
edge of the ninth clock will
have no effect on UA, and
UA will remain set.
UA is set indicating that
SSPADD needs to be
updated
Cleared by hardware when
SSPADD is updated with low
byte of address after falling edge
of ninth clock.
7
A2 A1
Cleared in software
3
A5
Dummy read of SSPBUF
to clear BF flag
1
A6
Receive Second Byte of Address
9
ACK
2
4
5
6
Cleared in software
3
D3 D2
7
Note:
An update of the SSPADD
register before the falling
edge of the ninth clock will
have no effect on UA, and
UA will remain set.
8
9
ACK
1
4
5
6
D2
Cleared in software
3
CKP written to ‘1’
in software
2
D3
Receive Data Byte
D7 D6 D5 D4
Clock is held low until
CKP is set to ‘1’
D1 D0
Cleared by hardware when
SSPADD is updated with high
byte of address after falling edge
of ninth clock.
Dummy read of SSPBUF
to clear BF flag
1
D7 D6 D5 D4
Receive Data Byte
Clock is held low until
update of SSPADD has
taken place
7
8
9
Bus Master
terminates
transfer
P
SSPOV is set
because SSPBUF is
still full. ACK is not sent.
D1 D0
ACK
Clock is not held low
because ACK = 1
FIGURE 15-14:
SDA
Receive First Byte of Address
Clock is held low until
update of SSPADD has
taken place
PIC18FXX2
I2C SLAVE MODE TIMING SEN = 1 (RECEPTION, 10-BIT ADDRESS)
DS39564C-page 147
PIC18FXX2
15.4.5
GENERAL CALL ADDRESS
SUPPORT
If the general call address matches, the SSPSR is
transferred to the SSPBUF, the BF flag bit is set (eighth
bit), and on the falling edge of the ninth bit (ACK bit),
the SSPIF interrupt flag bit is set.
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.
When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the
SSPBUF. The value can be used to determine if the
address was device specific or a general call address.
In 10-bit mode, the SSPADD is required to be updated
for the second half of the address to match, and the UA
bit is set (SSPSTAT<1>). If the general call address is
sampled when the GCEN bit is set, while the slave is
configured in 10-bit Address 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 15-15).
The general call address is one of eight addresses
reserved for specific purposes by the I2C protocol. It
consists of all 0’s with R/W = 0.
The general call address is recognized when the General Call Enable bit (GCEN) is enabled (SSPCON2<7>
set). Following a START bit detect, 8-bits are shifted
into the SSPSR and the address is compared against
the SSPADD. It is also compared to the general call
address and fixed in hardware.
FIGURE 15-15:
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE
(7 OR 10-BIT ADDRESS MODE)
Address is compared to General Call Address
after ACK, set interrupt
R/W = 0
ACK D7
General Call Address
SDA
Receiving data
ACK
D6
D5
D4
D3
D2
D1
D0
2
3
4
5
6
7
8
SCL
S
1
2
3
4
5
6
7
8
9
1
9
SSPIF
BF (SSPSTAT<0>)
Cleared in software
SSPBUF is read
SSPOV (SSPCON1<6>)
'0'
GCEN (SSPCON2<7>)
'1'
DS39564C-page 148
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.6
MASTER MODE
Note:
Master mode is enabled by setting and clearing the
appropriate SSPM bits in SSPCON1 and by setting the
SSPEN bit. In Master mode, the SCL and SDA lines
are manipulated by the MSSP hardware.
Master mode of operation is supported by interrupt
generation on the detection of the START and STOP
conditions. The STOP (P) and START (S) bits are
cleared from a RESET or when the MSSP module is
disabled. Control of the I 2C bus may be taken when the
P bit is set or the bus is IDLE, with both the S and P bits
clear.
The following events will cause SSP interrupt flag bit,
SSPIF, to be set (SSP interrupt if enabled):
In Firmware Controlled Master mode, user code conducts all I 2C bus operations based on START and
STOP bit conditions.
•
•
•
•
•
Once Master mode is enabled, the user has six
options.
3.
4.
5.
6.
START condition
STOP condition
Data transfer byte transmitted/received
Acknowledge Transmit
Repeated START
Assert a START condition on SDA and SCL.
Assert a Repeated START condition on SDA
and SCL.
Write to the SSPBUF register initiating
transmission of data/address.
Configure the I2C port to receive data.
Generate an Acknowledge condition at the end
of a received byte of data.
Generate a STOP condition on SDA and SCL.
FIGURE 15-16:
MSSP BLOCK DIAGRAM (I2C MASTER MODE)
SSPM3:SSPM0
SSPADD<6:0>
Internal
Data Bus
Read
Write
SSPBUF
Baud
Rate
Generator
Shift
Clock
SDA
SDA in
SCL in
Bus Collision
© 2006 Microchip Technology Inc.
LSb
START bit, STOP bit,
Acknowledge
Generate
START bit Detect
STOP bit Detect
Write Collision Detect
Clock Arbitration
State Counter for
end of XMIT/RCV
Clock Cntl
SCL
Receive Enable
SSPSR
MSb
Clock Arbitrate/WCOL Detect
(hold off clock source)
1.
2.
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 SSPBUF register to
initiate transmission before the START
condition is complete. In this case, the
SSPBUF will not be written to and the
WCOL bit will be set, indicating that a write
to the SSPBUF did not occur.
Set/Reset, S, P, WCOL (SSPSTAT)
Set SSPIF, BCLIF
Reset ACKSTAT, PEN (SSPCON2)
DS39564C-page 149
PIC18FXX2
15.4.6.1
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 SDA, while SCL 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 transmitted, an Acknowledge bit is received. START and STOP
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 receive bit. Serial
data is received via SDA, while SCL outputs the serial
clock. Serial data is received 8 bits at a time. After each
byte is received, an Acknowledge bit is transmitted.
START and STOP conditions indicate the beginning
and end of transmission.
The baud rate generator used for the SPI mode operation is used to set the SCL clock frequency for either
100 kHz, 400 kHz or 1 MHz I2C operation. See
Section 15.4.7 (“Baud Rate Generator”), for more
detail.
DS39564C-page 150
A typical transmit sequence would go as follows:
1.
The user generates a START condition by setting
the
START
enable
bit,
SEN
(SSPCON2<0>).
2. SSPIF is set. The MSSP module will wait the
required start time before any other operation
takes place.
3. The user loads the SSPBUF with the slave
address to transmit.
4. Address is shifted out the SDA 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
SSPCON2 register (SSPCON2<6>).
6. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the SSPIF
bit.
7. The user loads the SSPBUF with eight bits of
data.
8. Data is shifted out the SDA 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
SSPCON2 register (SSPCON2<6>).
10. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the SSPIF
bit.
11. The user generates a STOP condition by setting
the STOP enable bit PEN (SSPCON2<2>).
12. Interrupt is generated once the STOP condition
is complete.
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.7
BAUD RATE GENERATOR
In I2C Master mode, the baud rate generator (BRG)
reload value is placed in the lower 7 bits of the
SSPADD register (Figure 15-17). When a write occurs
to SSPBUF, 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
decremented twice per instruction cycle (TCY) on the
Q2 and Q4 clocks. In I2C Master mode, the BRG is
reloaded automatically.
FIGURE 15-17:
Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal
clock will automatically stop counting and the SCL pin
will remain in its last state.
Table 15-3 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPADD.
BAUD RATE GENERATOR BLOCK DIAGRAM
SSPM3:SSPM0
SSPM3:SSPM0
Reload
SCL
Control
CLKO
TABLE 15-3:
SSPADD<6:0>
Reload
BRG Down Counter
Fosc/4
I2C CLOCK RATE W/BRG
FCY
FCY*2
BRG Value
FSCL(2)
(2 Rollovers of BRG)
10 MHz
20 MHz
19h
400 kHz(1)
10 MHz
20 MHz
20h
312.5 kHz
10 MHz
20 MHz
3Fh
100 kHz
4 MHz
8 MHz
0Ah
400 kHz(1)
4 MHz
8 MHz
0Dh
308 kHz
4 MHz
8 MHz
28h
100 kHz
1 MHz
2 MHz
03h
333 kHz(1)
1 MHz
2 MHz
0Ah
100kHz
1 MHz
2 MHz
00h
1 MHz(1)
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.
2: Actual frequency will depend on bus conditions. Theoretically, bus conditions will add rise time and extend
low time of clock period, producing the effective frequency.
© 2006 Microchip Technology Inc.
DS39564C-page 151
PIC18FXX2
15.4.7.1
Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated START/STOP condition,
de-asserts the SCL pin (SCL allowed to float high).
When the SCL pin is allowed to float high, the baud rate
generator (BRG) is suspended from counting until the
SCL pin is actually sampled high. When the SCL pin is
FIGURE 15-18:
sampled high, the baud rate generator is reloaded with
the contents of SSPADD<6:0> and begins counting.
This ensures that the SCL 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 15-18).
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
SDA
DX
DX-1
SCL de-asserted but slave holds
SCL low (clock arbitration)
SCL allowed to transition high
SCL
BRG decrements on
Q2 and Q4 cycles
BRG
Value
03h
02h
01h
00h (hold off)
03h
02h
SCL is sampled high, reload takes
place and BRG starts its count.
BRG
Reload
DS39564C-page 152
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.8
I2C MASTER MODE START
CONDITION TIMING
15.4.8.1
If the user writes the SSPBUF when a START
sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn’t
occur).
To initiate a START condition, the user sets the START
condition enable bit, SEN (SSPCON2<0>). If the SDA
and SCL pins are sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and
starts its count. If SCL and SDA are both sampled high
when the baud rate generator times out (TBRG), the
SDA pin is driven low. The action of the SDA being
driven low, while SCL is high, is the START condition
and causes the S bit (SSPSTAT<3>) to be set. Following this, the baud rate generator is reloaded with the
contents of SSPADD<6:0> and resumes its count.
When the baud rate generator times out (TBRG), the
SEN bit (SSPCON2<0>) will be automatically cleared
by hardware, the baud rate generator is suspended,
leaving the SDA line held low and the START condition
is complete.
Note:
WCOL Status Flag
Note:
Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPCON2 is disabled until the START
condition is complete.
If at the beginning of the START condition,
the SDA and SCL pins are already sampled low, or if during the START condition
the SCL line is sampled low before the
SDA line is driven low, a bus collision
occurs, the Bus Collision Interrupt Flag,
BCLIF is set, the START condition is
aborted, and the I2C module is reset into its
IDLE state.
FIGURE 15-19:
FIRST START BIT TIMING
Set S bit (SSPSTAT<3>)
Write to SEN bit occurs here
SDA = 1,
SCL = 1
TBRG
At completion of START bit,
Hardware clears SEN bit
and sets SSPIF bit
TBRG
Write to SSPBUF occurs here
1st bit
SDA
2nd bit
TBRG
SCL
TBRG
S
© 2006 Microchip Technology Inc.
DS39564C-page 153
PIC18FXX2
15.4.9
I2C MASTER MODE REPEATED
START CONDITION TIMING
Immediately following the SSPIF bit getting set, the
user may write the SSPBUF 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 eight
bits of address (10-bit mode) or eight bits of data (7-bit
mode).
A Repeated START condition occurs when the RSEN
bit (SSPCON2<1>) is programmed high and the I2C
logic module is in the IDLE state. When the RSEN bit is
set, the SCL pin is asserted low. When the SCL pin is
sampled low, the baud rate generator is loaded with the
contents of SSPADD<5:0> and begins counting. The
SDA pin is released (brought high) for one baud rate
generator count (TBRG). When the baud rate generator
times out, if SDA is sampled high, the SCL pin will be
de-asserted (brought high). When SCL is sampled
high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and
SCL must be sampled high for one TBRG. This action is
then followed by assertion of the SDA pin (SDA = 0) for
one TBRG, while SCL is high. Following this, the RSEN
bit (SSPCON2<1>) will be automatically cleared and
the baud rate generator will not be reloaded, leaving
the SDA pin held low. As soon as a START condition is
detected on the SDA and SCL pins, the S bit
(SSPSTAT<3>) will be set. The SSPIF bit will not be set
until the baud rate generator has timed out.
15.4.9.1
WCOL Status Flag
If the user writes the SSPBUF when a Repeated
START sequence is in progress, the WCOL is set and
the contents of the buffer are unchanged (the write
doesn’t occur).
Note:
Because queueing of events is not
allowed, writing of the lower 5 bits of
SSPCON2 is disabled until the Repeated
START condition is complete.
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:
• SDA is sampled low when SCL goes
from low to high.
• SCL goes low before SDA is
asserted low. This may indicate that
another master is attempting to
transmit a data "1".
FIGURE 15-20:
REPEAT START CONDITION WAVEFORM
Set S (SSPSTAT<3>)
Write to SSPCON2
occurs here.
SDA = 1,
SCL (no change)
SDA = 1,
SCL = 1
TBRG
TBRG
At completion of START bit,
hardware clear RSEN bit
and set SSPIF
TBRG
1st bit
SDA
Falling edge of ninth clock
End of Xmit
SCL
Write to SSPBUF occurs here
TBRG
TBRG
Sr = Repeated START
DS39564C-page 154
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.10
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 SSPBUF register. This action will
set the buffer full flag bit, BF, and allow the baud rate
generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto
the SDA pin after the falling edge of SCL is asserted
(see data hold time specification parameter 106). SCL
is held low for one baud rate generator rollover count
(TBRG). Data should be valid before SCL is released
high (see data setup time specification parameter 107).
When the SCL pin is released high, it is held that way
for TBRG. The data on the SDA pin must remain stable
for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the
falling edge of the eighth clock), the BF flag is cleared
and the master releases SDA. 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
Acknowledge status bit, ACKSTAT, is cleared. If not,
the bit is set. After the ninth clock, the SSPIF bit is set
and the master clock (baud rate generator) is suspended until the next data byte is loaded into the
SSPBUF, leaving SCL low and SDA unchanged
(Figure 15-21).
After the write to the SSPBUF, each bit of address will
be shifted out on the falling edge of SCL until all seven
address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will de-assert
the SDA pin, allowing the slave to respond with an
Acknowledge. On the falling edge of the ninth clock, the
master will sample the SDA pin to see if the address
was recognized by a slave. The status of the ACK bit is
loaded into the ACKSTAT status bit (SSPCON2<6>).
Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is
cleared and the baud rate generator is turned off until
another write to the SSPBUF takes place, holding SCL
low and allowing SDA to float.
15.4.10.1
BF Status Flag
15.4.10.3
ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is
cleared when the slave has sent an Acknowledge (ACK
= 0), and is set when the slave does not Acknowledge
(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.
15.4.11
I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the
receive enable bit, RCEN (SSPCON2<3>).
Note:
In the MSSP module, the RCEN bit must
be set after the ACK sequence or the
RCEN bit will be disregarded.
The baud rate generator begins counting, and on each
rollover, the state of the SCL pin changes (high to low/
low to high) and data is shifted into the SSPSR. After
the falling edge of the eighth clock, the receive enable
flag is automatically cleared, the contents of the
SSPSR are loaded into the SSPBUF, the BF flag bit is
set, the SSPIF flag bit is set and the baud rate generator is suspended from counting, holding SCL 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
(SSPCON2<4>).
15.4.11.1
BF Status Flag
In receive operation, the BF bit is set when an address
or data byte is loaded into SSPBUF from SSPSR. It is
cleared when the SSPBUF register is read.
15.4.11.2
SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits
are received into the SSPSR and the BF flag bit is
already set from a previous reception.
15.4.11.3
WCOL Status Flag
If the user writes the SSPBUF when a receive is
already in progress (i.e., SSPSR is still shifting in a data
byte), the WCOL bit is set and the contents of the buffer
are unchanged (the write doesn’t occur).
In Transmit mode, the BF bit (SSPSTAT<0>) is set
when the CPU writes to SSPBUF and is cleared when
all 8 bits are shifted out.
15.4.10.2
WCOL Status Flag
If the user writes the SSPBUF when a transmit is
already in progress (i.e., SSPSR is still shifting out a
data byte), the WCOL is set and the contents of the
buffer are unchanged (the write doesn’t occur).
WCOL must be cleared in software.
© 2006 Microchip Technology Inc.
DS39564C-page 155
DS39564C-page 156
S
R/W
PEN
SEN
BF (SSPSTAT<0>)
SSPIF
SCL
SDA
A6
A5
A4
A3
A2
A1
3
4
5
Cleared in software
2
6
7
8
9
D7
1
SCL held low
while CPU
responds to SSPIF
After START condition, SEN cleared by hardware
SSPBUF written
1
ACK = 0
R/W = 0
SSPBUF written with 7-bit address and R/W
start transmit
A7
Transmit Address to Slave
3
D5
4
D4
5
D3
6
D2
7
D1
8
D0
SSPBUF is written in software
Cleared in software service routine
From SSP interrupt
2
D6
Transmitting Data or Second Half
of 10-bit Address
From slave clear ACKSTAT bit SSPCON2<6>
P
Cleared in software
9
ACK
ACKSTAT in
SSPCON2 = 1
FIGURE 15-21:
SEN = 0
Write SSPCON2<0> SEN = 1
START condition begins
PIC18FXX2
I 2C MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
© 2006 Microchip Technology Inc.
© 2006 Microchip Technology Inc.
S
ACKEN
SSPOV
BF
(SSPSTAT<0>)
SDA = 0, SCL = 1
while CPU
responds to SSPIF
SSPIF
SCL
SDA
1
A7
2
4
5
Cleared in software
3
6
A6 A5 A4 A3 A2
Transmit Address to Slave
7
A1
8
9
R/W = 1
ACK
ACK from Slave
2
3
5
6
7
8
D0
9
ACK
2
3
4
5
6
7
Cleared in software
Set SSPIF interrupt
at end of Acknowledge
sequence
Data shifted in on falling edge of CLK
1
D7 D6 D5 D4 D3 D2 D1
Cleared in
software
Set SSPIF at end
of receive
9
ACK is not sent
ACK
P
Set SSPIF interrupt
at end of Acknowledge sequence
Bus Master
terminates
transfer
Set P bit
(SSPSTAT<4>)
and SSPIF
PEN bit = 1
written here
SSPOV is set because
SSPBUF is still full
8
D0
RCEN cleared
automatically
Set ACKEN, start Acknowledge sequence
SDA = ACKDT = 1
Receiving Data from Slave
RCEN = 1 start
next receive
ACK from Master
SDA = ACKDT = 0
Last bit is shifted into SSPSR and
contents are unloaded into SSPBUF
Cleared in software
Set SSPIF interrupt
at end of receive
4
Cleared in software
1
D7 D6 D5 D4 D3 D2 D1
Receiving Data from Slave
RCEN cleared
automatically
Master configured as a receiver
by programming SSPCON2<3>, (RCEN = 1)
FIGURE 15-22:
SEN = 0
Write to SSPBUF occurs here
Start XMIT
Write to SSPCON2<0> (SEN = 1)
Begin START Condition
Write to SSPCON2<4>
to start Acknowledge sequence
SDA = ACKDT (SSPCON2<5>) = 0
PIC18FXX2
I 2C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
DS39564C-page 157
PIC18FXX2
15.4.12
ACKNOWLEDGE SEQUENCE
TIMING
15.4.13
A STOP bit is asserted on the SDA pin at the end of a
receive/transmit by setting the STOP sequence enable
bit, PEN (SSPCON2<2>). At the end of a receive/transmit the SCL line is held low after the falling edge of the
ninth clock. When the PEN bit is set, the master will
assert the SDA line low. When the SDA line is sampled
low, the baud rate generator is reloaded and counts
down to 0. When the baud rate generator times out, the
SCL pin will be brought high, and one TBRG (baud rate
generator rollover count) later, the SDA pin will be
de-asserted. When the SDA pin is sampled high while
SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG
later, the PEN bit is cleared and the SSPIF bit is set
(Figure 15-24).
An Acknowledge sequence is enabled by setting the
Acknowledge
sequence
enable
bit,
ACKEN
(SSPCON2<4>). When this bit is set, the SCL pin is
pulled low and the contents of the Acknowledge data bit
are presented on the SDA 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 baud rate generator then counts for one rollover period (TBRG) and the
SCL pin is de-asserted (pulled high). When the SCL pin
is sampled high (clock arbitration), the baud rate generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the
baud rate generator is turned off and the MSSP module
then goes into IDLE mode (Figure 15-23).
15.4.12.1
15.4.13.1
WCOL Status Flag
If the user writes the SSPBUF when a STOP sequence
is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn’t
occur).
WCOL Status Flag
If the user writes the SSPBUF when an Acknowledge
sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur).
FIGURE 15-23:
STOP CONDITION TIMING
ACKNOWLEDGE SEQUENCE WAVEFORM
Acknowledge sequence starts here,
Write to SSPCON2
ACKEN = 1, ACKDT = 0
ACKEN automatically cleared
TBRG
TBRG
SDA
D0
SCL
ACK
8
9
SSPIF
Cleared in
software
Set SSPIF at the end
of receive
Cleared in
software
Set SSPIF at the end
of Acknowledge sequence
Note: TBRG = one baud rate generator period.
FIGURE 15-24:
STOP CONDITION RECEIVE OR TRANSMIT MODE
SCL = 1 for TBRG, followed by SDA = 1 for TBRG
after SDA sampled high. P bit (SSPSTAT<4>) is set.
Write to SSPCON2
Set PEN
PEN bit (SSPCON2<2>) is cleared by
hardware and the SSPIF bit is set
Falling edge of
9th clock
TBRG
SCL
SDA
ACK
P
TBRG
TBRG
TBRG
SCL brought high after TBRG
SDA asserted low before rising edge of clock
to setup STOP condition.
Note: TBRG = one baud rate generator period.
DS39564C-page 158
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.14
SLEEP OPERATION
15.4.17
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).
15.4.15
EFFECT OF A RESET
A RESET disables the MSSP module and terminates
the current transfer.
15.4.16
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 STOP (P)
and START (S) 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 (SSPSTAT<4>) is set, or
the bus is idle with both the S and P bits clear. When the
bus is busy, enabling the SSP interrupt will generate the
interrupt when the STOP condition occurs.
In multi-master operation, the SDA 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 BCLIF bit.
The states where arbitration can be lost are:
•
•
•
•
•
Address Transfer
Data Transfer
A START Condition
A Repeated START Condition
An Acknowledge Condition
MULTI -MASTER COMMUNICATION,
BUS COLLISION, AND BUS
ARBITRATION
Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto
the SDA pin, arbitration takes place when the master
outputs a '1' on SDA, by letting SDA float high and
another master asserts a '0'. When the SCL pin floats
high, data should be stable. If the expected data on
SDA is a '1' and the data sampled on the SDA pin = '0',
then a bus collision has taken place. The master will set
the Bus Collision Interrupt Flag BCLIF and reset the I2C
port to its IDLE state (Figure 15-25).
If a transmit was in progress when the bus collision
occurred, the transmission is halted, the BF flag is
cleared, the SDA and SCL lines are de-asserted, and
the SSPBUF 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 condition is aborted, the SDA and SCL
lines are de-asserted, and the respective control bits in
the SSPCON2 register are cleared. 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.
The master will continue to monitor the SDA and SCL
pins. If a STOP condition occurs, the SSPIF bit will be set.
A write to the SSPBUF 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
determination of when the bus is free. Control of the I2C
bus can be taken when the P bit is set in the SSPSTAT
register, or the bus is IDLE and the S and P bits are
cleared.
FIGURE 15-25:
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
Data changes
while SCL = 0
SDA line pulled low
by another source
SDA released
by master
Sample SDA. While SCL is high,
data doesn’t match what is driven
by the master.
Bus collision has occurred.
SDA
SCL
Set bus collision
interrupt (BCLIF)
BCLIF
© 2006 Microchip Technology Inc.
DS39564C-page 159
PIC18FXX2
15.4.17.1
Bus Collision During a START
Condition
During a START condition, a bus collision occurs if:
a)
SDA or SCL are sampled low at the beginning of
the START condition (Figure 15-26).
SCL is sampled low before SDA is asserted low
(Figure 15-27).
b)
During a START condition, both the SDA and the SCL
pins are monitored.
If the SDA pin is sampled low during this count, the
BRG is reset and the SDA line is asserted early
(Figure 15-28). If, however, a '1' is sampled on the SDA
pin, the SDA pin is asserted low at the end of the BRG
count. The baud rate generator is then reloaded and
counts down to 0, and during this time, if the SCL pins
are sampled as '0', a bus collision does not occur. At
the end of the BRG count, the SCL pin is asserted low.
Note:
If the SDA pin is already low, or the SCL pin is already
low, then all of the following occur:
• the START condition is aborted,
• the BCLIF flag is set, and
• the MSSP module is reset to its IDLE state
(Figure 15-26).
The START condition begins with the SDA and SCL
pins de-asserted. When the SDA pin is sampled high,
the baud rate generator is loaded from SSPADD<6:0>
and counts down to 0. If the SCL pin is sampled low
while SDA is high, a bus collision occurs, because it is
assumed that another master is attempting to drive a
data '1' during the START condition.
FIGURE 15-26:
The reason that bus collision is not a factor
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 SDA 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.
BUS COLLISION DURING START CONDITION (SDA ONLY)
SDA goes low before the SEN bit is set.
Set BCLIF,
S bit and SSPIF set because
SDA = 0, SCL = 1.
SDA
SCL
Set SEN, enable START
condition if SDA = 1, SCL=1
SEN cleared automatically because of bus collision.
SSP module reset into IDLE state.
SEN
BCLIF
SDA sampled low before
START condition. Set BCLIF.
S bit and SSPIF set because
SDA = 0, SCL = 1.
SSPIF and BCLIF are
cleared in software.
S
SSPIF
SSPIF and BCLIF are
cleared in software.
DS39564C-page 160
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 15-27:
BUS COLLISION DURING START CONDITION (SCL = 0)
SDA = 0, SCL = 1
TBRG
TBRG
SDA
Set SEN, enable START
sequence if SDA = 1, SCL = 1
SCL
SCL = 0 before SDA = 0,
bus collision occurs. set BCLIF
SEN
SCL = 0 before BRG time-out,
bus collision occurs. Set BCLIF.
BCLIF
Interrupt cleared
in software
S
'0'
'0'
SSPIF
'0'
'0'
FIGURE 15-28:
BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION
SDA = 0, SCL = 1
Set S
Less than TBRG
SDA
Set SSPIF
TBRG
SDA pulled low by other master.
Reset BRG and assert SDA.
SCL
S
SCL pulled low after BRG
Time-out
SEN
BCLIF
Set SEN, enable START
sequence if SDA = 1, SCL = 1
'0'
S
SSPIF
SDA = 0, SCL = 1
Set SSPIF
© 2006 Microchip Technology Inc.
Interrupts cleared
in software
DS39564C-page 161
PIC18FXX2
15.4.17.2
Bus Collision During a Repeated
START Condition
reloaded and begins counting. If SDA goes from high to
low before the BRG times out, no bus collision occurs
because no two masters can assert SDA at exactly the
same time.
During a Repeated START condition, a bus collision
occurs if:
a)
b)
If SCL goes from high to low before the BRG times out
and SDA 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, Figure 15-30.
A low level is sampled on SDA when SCL goes
from low level to high level.
SCL goes low before SDA is asserted low, indicating that another master is attempting to
transmit a data ’1’.
If, at the end of the BRG time-out both SCL and SDA
are still high, the SDA pin is driven low and the BRG is
reloaded and begins counting. At the end of the count,
regardless of the status of the SCL pin, the SCL pin is
driven low and the Repeated START condition is
complete.
When the user de-asserts SDA and the pin is allowed
to float high, the BRG is loaded with SSPADD<6:0>
and counts down to 0. The SCL pin is then de-asserted,
and when sampled high, the SDA pin is sampled.
If SDA is low, a bus collision has occurred (i.e., another
master is attempting to transmit a data ’0’,
Figure 15-29). If SDA is sampled high, the BRG is
FIGURE 15-29:
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SDA
SCL
Sample SDA when SCL goes high.
If SDA = 0, set BCLIF and release SDA and SCL.
RSEN
BCLIF
Cleared in software
'0'
S
'0'
SSPIF
FIGURE 15-30:
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
TBRG
TBRG
SDA
SCL
BCLIF
SCL goes low before SDA,
Set BCLIF. Release SDA and SCL.
Interrupt cleared
in software
RSEN
S
'0'
SSPIF
DS39564C-page 162
© 2006 Microchip Technology Inc.
PIC18FXX2
15.4.17.3
Bus Collision During a STOP
Condition
The STOP condition begins with SDA asserted low.
When SDA is sampled low, the SCL pin is allowed to
float. When the pin is sampled high (clock arbitration),
the baud rate generator is loaded with SSPADD<6:0>
and counts down to 0. After the BRG times out, SDA is
sampled. If SDA is sampled low, a bus collision has
occurred. This is due to another master attempting to
drive a data '0' (Figure 15-31). If the SCL pin is sampled
low before SDA is allowed to float high, a bus collision
occurs. This is another case of another master
attempting to drive a data '0' (Figure 15-32).
Bus collision occurs during a STOP condition if:
a)
b)
After the SDA pin has been de-asserted and
allowed to float high, SDA is sampled low after
the BRG has timed out.
After the SCL pin is de-asserted, SCL is
sampled low before SDA goes high.
FIGURE 15-31:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
TBRG
TBRG
SDA sampled
low after TBRG,
Set BCLIF
TBRG
SDA
SDA asserted low
SCL
PEN
BCLIF
P
'0'
SSPIF
'0'
FIGURE 15-32:
BUS COLLISION DURING A STOP CONDITION (CASE 2)
TBRG
TBRG
TBRG
SDA
Assert SDA
SCL
SCL goes low before SDA goes high
Set BCLIF
PEN
BCLIF
P
'0'
SSPIF
'0'
© 2006 Microchip Technology Inc.
DS39564C-page 163
PIC18FXX2
NOTES:
DS39564C-page 164
© 2006 Microchip Technology Inc.
PIC18FXX2
16.0
ADDRESSABLE UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (USART)
The Universal Synchronous Asynchronous Receiver
Transmitter (USART) module is one of the two serial
I/O modules. (USART is also known as a Serial Communications Interface or SCI.) The USART can be configured as a full duplex asynchronous system that can
communicate with peripheral devices, such as CRT terminals and personal computers, or it can 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, etc.
The USART can be configured in the following modes:
• Asynchronous (full-duplex)
• Synchronous - Master (half-duplex)
• Synchronous - Slave (half-duplex)
In order to configure pins RC6/TX/CK and RC7/RX/DT
as the Universal Synchronous Asynchronous Receiver
Transmitter:
• bit SPEN (RCSTA<7>) must be set (= 1),
• bit TRISC<6> must be cleared (= 0), and
• bit TRISC<7> must be set (=1).
Register 16-1 shows the Transmit Status and Control
Register (TXSTA) and Register 16-2 shows the
Receive Status and Control Register (RCSTA).
© 2006 Microchip Technology Inc.
DS39564C-page 165
PIC18FXX2
REGISTER 16-1:
TXSTA: TRANSMIT STATUS AND CONTROL REGISTER
R/W-0
CSRC
bit 7
R/W-0
TX9
R/W-0
TXEN
R/W-0
SYNC
U-0
—
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 = Transmit enabled
0 = Transmit disabled
Note:
bit 4
R/W-0
BRGH
R-1
TRMT
R/W-0
TX9D
bit 0
SREN/CREN overrides TXEN in SYNC mode.
SYNC: USART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3
Unimplemented: Read as '0'
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 empty
0 = TSR full
bit 0
TX9D: 9th bit of Transmit Data
Can be Address/Data bit or a parity bit.
Legend:
DS39564C-page 166
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
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 16-2:
RCSTA: RECEIVE STATUS AND CONTROL REGISTER
R/W-0
SPEN
bit 7
R/W-0
RX9
R/W-0
SREN
R/W-0
CREN
R/W-0
ADDEN
R-0
FERR
R-0
OERR
R-x
RX9D
bit 0
bit 7
SPEN: Serial Port Enable bit
1 = Serial port enabled (configures RX/DT and TX/CK pins as serial port pins)
0 = Serial port disabled
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, enable interrupt and load of 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
bit 2
FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREG register and receive 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.
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 167
PIC18FXX2
16.1
USART Baud Rate Generator
(BRG)
Example 16-1 shows the calculation of the baud rate
error for the following conditions:
The BRG supports both the Asynchronous and Synchronous modes of the USART. It is a dedicated 8-bit
baud rate generator. The SPBRG register controls the
period of a free running 8-bit timer. In Asynchronous
mode, bit BRGH (TXSTA<2>) also controls the baud
rate. In Synchronous mode, bit BRGH is ignored.
Table 16-1 shows the formula for computation of the
baud rate for different USART modes, which only apply
in Master mode (internal clock).
Given the desired baud rate and Fosc, the nearest integer value for the SPBRG register can be calculated
using the formula in Table 16-1. From this, the error in
baud rate can be determined.
•
•
•
•
FOSC = 16 MHz
Desired Baud Rate = 9600
BRGH = 0
SYNC = 0
It may be advantageous to use the high baud rate
(BRGH = 1) even for slower baud clocks. This is
because the FOSC/(16(X + 1)) equation can reduce the
baud rate error in some cases.
Writing a new value to the SPBRG register 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.
16.1.1
SAMPLING
The data on the RC7/RX/DT pin is sampled three times
by a majority detect circuit to determine if a high or a
low level is present at the RX pin.
EXAMPLE 16-1:
Desired Baud Rate
CALCULATING BAUD RATE ERROR
= FOSC / (64 (X + 1))
Solving for X:
= ( (FOSC / Desired Baud Rate) / 64 ) – 1
= ((16000000 / 9600) / 64) – 1
= [25.042] = 25
X
X
X
Calculated Baud Rate
=
=
16000000 / (64 (25 + 1))
9615
Error
=
(Calculated Baud Rate – Desired Baud Rate)
Desired Baud Rate
(9615 – 9600) / 9600
0.16%
=
=
TABLE 16-1:
BAUD RATE FORMULA
SYNC
BRGH = 0 (Low Speed)
BRGH = 1 (High Speed)
0
(Asynchronous) Baud Rate = FOSC/(64(X+1))
(Synchronous) Baud Rate = FOSC/(4(X+1))
1
Legend: X = value in SPBRG (0 to 255)
TABLE 16-2:
Name
TXSTA
RCSTA
SPBRG
Baud Rate = FOSC/(16(X+1))
N/A
REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
0000 -010
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
Baud Rate Generator Register
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used by the BRG.
DS39564C-page 168
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 16-3:
BAUD
RATE
(Kbps)
BAUD RATES FOR SYNCHRONOUS MODE
FOSC = 40 MHz
SPBRG
value
(decimal)
33 MHz
SPBRG
value
(decimal)
25 MHz
SPBRG
value
(decimal)
20 MHz
SPBRG
value
(decimal)
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
0.3
NA
-
-
NA
-
-
NA
-
-
NA
-
-
1.2
NA
-
-
NA
-
-
NA
-
-
NA
-
-
2.4
NA
-
-
NA
-
-
NA
-
-
NA
-
-
9.6
NA
-
-
NA
-
-
NA
-
-
NA
-
-
19.2
NA
-
-
NA
-
-
NA
-
-
NA
-
-
76.8
76.92
+0.16
129
77.10
+0.39
106
77.16
+0.47
80
76.92
+0.16
64
96
96.15
+0.16
103
95.93
-0.07
85
96.15
+0.16
64
96.15
+0.16
51
300
303.03
+1.01
32
294.64
-1.79
27
297.62
-0.79
20
294.12
-1.96
16
500
500
0
19
485.30
-2.94
16
480.77
-3.85
12
500
0
9
HIGH
10000
-
0
8250
-
0
6250
-
0
5000
-
0
LOW
39.06
-
255
32.23
-
255
24.41
-
255
19.53
-
255
FOSC = 16 MHz
SPBRG
value
(decimal)
10 MHz
SPBRG
value
(decimal)
7.15909 MHz
SPBRG
value
(decimal)
5.0688 MHz
SPBRG
value
(decimal)
BAUD
RATE
(Kbps)
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
0.3
NA
-
-
NA
-
-
NA
-
-
NA
-
-
1.2
NA
-
-
NA
-
-
NA
-
-
NA
-
-
2.4
NA
-
-
NA
-
-
NA
-
-
NA
-
-
9.6
NA
-
-
NA
-
-
9.62
+0.23
185
9.60
0
131
19.2
19.23
+0.16
207
19.23
+0.16
129
19.24
+0.23
92
19.20
0
65
76.8
76.92
+0.16
51
75.76
-1.36
32
77.82
+1.32
22
74.54
-2.94
16
96
95.24
-0.79
41
96.15
+0.16
25
94.20
-1.88
18
97.48
+1.54
12
300
307.70
+2.56
12
312.50
+4.17
7
298.35
-0.57
5
316.80
+5.60
3
500
500
0
7
500
0
4
447.44
-10.51
3
422.40
-15.52
2
HIGH
4000
-
0
2500
-
0
1789.80
-
0
1267.20
-
0
LOW
15.63
-
255
9.77
-
255
6.99
-
255
4.95
-
255
FOSC = 4 MHz
BAUD
RATE
(Kbps)
KBAUD
%
ERROR
0.3
NA
-
1.2
NA
-
2.4
NA
SPBRG
value
(decimal)
3.579545 MHz
SPBRG
value
(decimal)
1 MHz
KBAUD
%
ERROR
-
NA
-
-
NA
-
-
NA
-
-
1.20
+0.16
-
-
NA
-
-
2.40
+0.16
KBAUD
%
ERROR
SPBRG
value
(decimal)
32.768 kHz
SPBRG
value
(decimal)
KBAUD
%
ERROR
-
0.30
+1.14
207
1.17
-2.48
6
103
2.73
+13.78
2
0
26
9.6
9.62
+0.16
103
9.62
+0.23
92
9.62
+0.16
25
8.20
-14.67
19.2
19.23
+0.16
51
19.04
-0.83
46
19.23
+0.16
12
NA
-
-
76.8
76.92
+0.16
12
74.57
-2.90
11
83.33
+8.51
2
NA
-
-
96
1000
+4.17
9
99.43
+3.57
8
83.33
-13.19
2
NA
-
300
333.33
+11.11
2
298.30
-0.57
2
250
-16.67
0
NA
-
-
500
500
0
1
447.44
-10.51
1
NA
-
-
NA
-
-
HIGH
1000
-
0
894.89
-
0
250
-
0
8.20
-
0
LOW
3.91
-
255
3.50
-
255
0.98
-
255
0.03
-
255
© 2006 Microchip Technology Inc.
DS39564C-page 169
PIC18FXX2
TABLE 16-4:
BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0)
FOSC = 40 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
NA
-
-
1.2
NA
-
2.4
NA
-
BAUD
RATE
(Kbps)
0.3
33 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
NA
-
-
-
NA
-
-
2.40
-0.07
25 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
NA
-
-
-
NA
-
-
214
2.40
-0.15
162
20 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
NA
-
-
NA
-
-
2.40
+0.16
129
9.6
9.62
+0.16
64
9.55
-0.54
53
9.53
-0.76
40
9.47
-1.36
32
19.2
18.94
-1.36
32
19.10
-0.54
26
19.53
+1.73
19
19.53
+1.73
15
76.8
78.13
+1.73
7
73.66
-4.09
6
78.13
+1.73
4
78.13
+1.73
3
96
89.29
-6.99
6
103.13
+7.42
4
97.66
+1.73
3
104.17
+8.51
2
300
312.50
+4.17
1
257.81
-14.06
1
NA
-
-
312.50
+4.17
0
500
625
+25.00
0
NA
-
-
NA
-
-
NA
-
-
HIGH
625
-
0
515.63
-
0
390.63
-
0
312.50
-
0
LOW
2.44
-
255
2.01
-
255
1.53
-
255
1.22
-
255
BAUD
RATE
(Kbps)
FOSC = 16 MHz
SPBRG
value
(decimal)
10 MHz
SPBRG
value
(decimal)
7.15909 MHz
SPBRG
value
(decimal)
5.0688 MHz
KBAUD
KBAUD
%
ERROR
KBAUD
%
ERROR
0.3
NA
-
-
NA
-
-
NA
-
-
NA
-
-
1.2
1.20
+0.16
207
1.20
+0.16
129
1.20
+0.23
92
1.20
0
65
KBAUD
%
ERROR
SPBRG
value
(decimal)
%
ERROR
2.4
2.40
+0.16
103
2.40
+0.16
64
2.38
-0.83
46
2.40
0
32
9.6
9.62
+0.16
25
9.77
+1.73
15
9.32
-2.90
11
9.90
+3.13
7
19.2
19.23
+0.16
12
19.53
+1.73
7
18.64
-2.90
5
19.80
+3.13
3
76.8
83.33
+8.51
2
78.13
+1.73
1
111.86
+45.65
0
79.20
+3.13
0
96
83.33
-13.19
2
78.13
-18.62
1
NA
-
-
NA
-
-
300
250
-16.67
0
156.25
-47.92
0
NA
-
-
NA
-
-
500
NA
-
-
NA
-
-
NA
-
-
NA
-
-
HIGH
250
-
0
156.25
-
0
111.86
-
0
79.20
-
0
LOW
0.98
-
255
0.61
-
255
0.44
-
255
0.31
-
255
FOSC = 4 MHz
SPBRG
value
(decimal)
3.579545 MHz
SPBRG
value
(decimal)
1 MHz
SPBRG
value
(decimal)
32.768 kHz
SPBRG
value
(decimal)
BAUD
RATE
(Kbps)
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
0.3
0.30
-0.16
207
0.30
+0.23
185
0.30
+0.16
51
0.26
-14.67
1.2
1.20
+1.67
51
1.19
-0.83
46
1.20
+0.16
12
NA
-
-
2.4
2.40
+1.67
25
2.43
+1.32
22
2.23
-6.99
6
NA
-
-
1
9.6
8.93
-6.99
6
9.32
-2.90
5
7.81
-18.62
1
NA
-
-
19.2
20.83
+8.51
2
18.64
-2.90
2
15.63
-18.62
0
NA
-
-
76.8
62.50
-18.62
0
55.93
-27.17
0
NA
-
-
NA
-
-
96
NA
-
-
NA
-
-
NA
-
-
NA
-
-
300
NA
-
-
NA
-
-
NA
-
-
NA
-
-
500
NA
-
-
NA
-
-
NA
-
-
NA
-
-
HIGH
62.50
-
0
55.93
-
0
15.63
-
0
0.51
-
0
LOW
0.24
-
255
0.22
-
255
0.06
-
255
0.002
-
255
DS39564C-page 170
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 16-5:
BAUD
RATE
(Kbps)
BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1)
FOSC = 40 MHz
SPBRG
value
(decimal)
33 MHz
SPBRG
value
(decimal)
25 MHz
SPBRG
value
(decimal)
20 MHz
SPBRG
value
(decimal)
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
0.3
NA
-
-
NA
-
-
NA
-
-
NA
-
-
1.2
NA
-
-
NA
-
-
NA
-
-
NA
-
-
2.4
NA
-
-
NA
-
-
NA
-
-
NA
-
-
9.6
NA
-
-
9.60
-0.07
214
9.59
-0.15
162
9.62
+0.16
129
19.2
19.23
+0.16
129
19.28
+0.39
106
19.30
+0.47
80
19.23
+0.16
64
76.8
75.76
-1.36
32
76.39
-0.54
26
78.13
+1.73
19
78.13
+1.73
15
96
96.15
+0.16
25
98.21
+2.31
20
97.66
+1.73
15
96.15
+0.16
12
300
312.50
+4.17
7
294.64
-1.79
6
312.50
+4.17
4
312.50
+4.17
3
500
500
0
4
515.63
+3.13
3
520.83
+4.17
2
416.67
-16.67
2
HIGH
2500
-
0
2062.50
-
0
1562.50
-
0
1250
-
0
LOW
9.77
-
255
8,06
-
255
6.10
-
255
4.88
-
255
FOSC = 16 MHz
SPBRG
value
(decimal)
10 MHz
SPBRG
value
(decimal)
7.15909 MHz
SPBRG
value
(decimal)
BAUD
RATE
(Kbps)
KBAUD
%
ERROR
KBAUD
%
ERROR
KBAUD
%
ERROR
0.3
NA
-
-
NA
-
-
NA
-
-
1.2
NA
-
-
NA
-
-
NA
-
-
2.4
NA
-
-
NA
-
-
2.41
+0.23
185
5.0688 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
NA
-
-
NA
-
-
2.40
0
131
9.6
9.62
+0.16
103
9.62
+0.16
64
9.52
-0.83
46
9.60
0
32
19.2
19.23
+0.16
51
18.94
-1.36
32
19.45
+1.32
22
18.64
-2.94
16
76.8
76.92
+0.16
12
78.13
+1.73
7
74.57
-2.90
5
79.20
+3.13
3
96
100
+4.17
9
89.29
-6.99
6
89.49
-6.78
4
105.60
+10.00
2
300
333.33
+11.11
2
312.50
+4.17
1
447.44
+49.15
0
316.80
+5.60
0
500
500
0
1
625
+25.00
0
447.44
-10.51
0
NA
-
-
HIGH
1000
-
0
625
-
0
447.44
-
0
316.80
-
0
LOW
3.91
-
255
2.44
-
255
1.75
-
255
1.24
-
255
BAUD
RATE
(Kbps)
FOSC = 4 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
3.579545 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
1 MHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
32.768 kHz
KBAUD
%
ERROR
SPBRG
value
(decimal)
0.3
NA
-
-
NA
-
-
0.30
+0.16
207
0.29
-2.48
6
1.2
1.20
+0.16
207
1.20
+0.23
185
1.20
+0.16
51
1.02
-14.67
1
2.4
2.40
+0.16
103
2.41
+0.23
92
2.40
+0.16
25
2.05
-14.67
0
9.6
9.62
+0.16
25
9.73
+1.32
22
8.93
-6.99
6
NA
-
-
19.2
19.23
+0.16
12
18.64
-2.90
11
20.83
+8.51
2
NA
-
-
76.8
NA
-
-
74.57
-2.90
2
62.50
-18.62
0
NA
-
-
96
NA
-
-
111.86
+16.52
1
NA
-
-
NA
-
-
300
NA
-
-
223.72
-25.43
0
NA
-
-
NA
-
-
500
NA
-
-
NA
-
-
NA
-
-
NA
-
-
HIGH
250
-
0
55.93
-
0
62.50
-
0
2.05
-
0
LOW
0.98
-
255
0.22
-
255
0.24
-
255
0.008
-
255
© 2006 Microchip Technology Inc.
DS39564C-page 171
PIC18FXX2
16.2
USART Asynchronous Mode
flag bit TXIF (PIR1<4>) is set. This interrupt can be
enabled/disabled by setting/clearing enable bit TXIE
( PIE1<4>). Flag bit TXIF will be set, regardless of the
state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the
TXREG register. While flag bit TXIF indicated the status of the TXREG register, another bit, TRMT
(TXSTA<1>), shows the status of the TSR register. Status bit TRMT is a read-only bit, which is set when the
TSR register is empty. No interrupt logic is tied to this
bit, so the user has to poll this bit in order to determine
if the TSR register is empty.
In this mode, the USART uses standard non-return-tozero (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 baud rate generator can be used to derive standard baud rate frequencies from the oscillator. The USART transmits and
receives the LSb first. The USART’s transmitter and
receiver are functionally independent, but use the
same data format and baud rate. The baud rate generator produces a clock, either x16 or x64 of the bit shift
rate, depending on bit BRGH (TXSTA<2>). Parity is not
supported by the hardware, but can be implemented in
software (and stored as the ninth data bit).
Asynchronous mode is stopped during SLEEP.
Note 1: The TSR register is not mapped in data
memory, so it is not available to the user.
2: Flag bit TXIF is set when enable bit TXEN
is set.
Asynchronous mode is selected by clearing bit SYNC
(TXSTA<4>).
To set up an asynchronous transmission:
The USART Asynchronous module consists of the
following important elements:
•
•
•
•
1.
Baud Rate Generator
Sampling Circuit
Asynchronous Transmitter
Asynchronous Receiver
16.2.1
2.
3.
4.
USART ASYNCHRONOUS
TRANSMITTER
5.
The USART transmitter block diagram is shown in
Figure 16-1. The heart of the transmitter is the Transmit
(serial) Shift Register (TSR). The shift register obtains
its data from the read/write transmit buffer, TXREG. The
TXREG 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 TXREG register (if available). Once the
TXREG register transfers the data to the TSR register
(occurs in one TCY), the TXREG register is empty and
FIGURE 16-1:
Initialize the SPBRG register for the appropriate
baud rate. If a high speed baud rate is desired,
set bit BRGH (Section 16.1).
Enable the asynchronous serial port by clearing
bit SYNC and setting bit SPEN.
If interrupts are desired, set enable bit TXIE.
If 9-bit transmission is desired, set transmit bit
TX9. Can be used as address/data bit.
Enable the transmission by setting bit TXEN,
which will also set bit TXIF.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
Load data to the TXREG register (starts
transmission).
6.
7.
Note:
TXIF is not cleared immediately upon loading data into the transmit buffer TXREG.
The flag bit becomes valid in the second
instruction cycle following the load
instruction.
USART TRANSMIT BLOCK DIAGRAM
Data Bus
TXIF
TXREG Register
TXIE
8
MSb
LSb
• • •
(8)
Pin Buffer
and Control
0
TSR Register
RC6/TX/CK pin
Interrupt
TXEN
Baud Rate CLK
TRMT
SPEN
SPBRG
Baud Rate Generator
TX9
TX9D
DS39564C-page 172
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 16-2:
ASYNCHRONOUS TRANSMISSION
Write to TXREG
BRG Output
(Shift Clock)
Word 1
RC6/TX/CK (pin)
START bit
bit 0
bit 1
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
FIGURE 16-3:
bit 7/8
STOP bit
Word 1
Word 1
Transmit Shift Reg
ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
Write to TXREG
RC6/TX/CK (pin)
TXIF bit
(Interrupt Reg. Flag)
START bit
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Note:
bit 0
bit 1
Word 1
bit 7/8
STOP bit
START bit
bit 0
Word 2
Word 1
Transmit Shift Reg.
Word 2
Transmit Shift Reg.
This timing diagram shows two consecutive transmissions.
TABLE 16-6:
Name
Word 2
Word 1
BRG Output
(Shift Clock)
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 7
Bit 6
Bit 5
Bit 4
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE
Bit 3
RBIE
Bit 2
Bit 1
TMR0IF INT0IF
Value on
All Other
RESETS
Bit 0
Value on
POR, BOR
RBIF
0000 000x 0000 000u
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000
SPEN
RX9
SREN
RCSTA
TXREG
TXSTA
CREN ADDEN
FERR
OERR
RX9D
0000 -00x 0000 -00x
SYNC
BRGH
TRMT
TX9D
0000 -010 0000 -010
USART Transmit Register
CSRC
TX9
TXEN
SPBRG Baud Rate Generator Register
0000 0000 0000 0000
—
0000 0000 0000 0000
Legend: x = unknown, - = unimplemented locations read as '0'.
Shaded cells are not used for Asynchronous Transmission.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
© 2006 Microchip Technology Inc.
DS39564C-page 173
PIC18FXX2
16.2.2
USART ASYNCHRONOUS
RECEIVER
16.2.3
The receiver block diagram is shown in Figure 16-4.
The data is received on the RC7/RX/DT 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.
To set up an Asynchronous Reception:
1.
Initialize the SPBRG register for the appropriate
baud rate. If a high speed baud rate is desired,
set bit BRGH (Section 16.1).
2. Enable the asynchronous serial port by clearing
bit SYNC and setting bit SPEN.
3. If interrupts are desired, set enable bit RCIE.
4. If 9-bit reception is desired, set bit RX9.
5. Enable the reception by setting bit CREN.
6. Flag bit RCIF will be set when reception is complete and an interrupt will be generated if enable
bit RCIE was set.
7. Read the RCSTA 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
RCREG 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.
FIGURE 16-4:
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 SPBRG register for the appropriate
baud rate. If a high speed baud rate is required,
set the BRGH bit.
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 RCIP 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 RCIF bit will be set when reception is complete. The interrupt will be acknowledged if the
RCIE and GIE bits are set.
8. Read the RCSTA register to determine if any
error occurred during reception, as well as read
bit 9 of data (if applicable).
9. Read RCREG 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.
USART RECEIVE BLOCK DIAGRAM
CREN
FERR
OERR
x64 Baud Rate CLK
SPBRG
÷ 64
or
÷ 16
RSR Register
MSb
STOP (8)
7
• • •
1
LSb
0 START
Baud Rate Generator
RX9
RC7/RX/DT
Pin Buffer
and Control
Data
Recovery
RX9D
RCREG Register
FIFO
SPEN
8
Interrupt
RCIF
Data Bus
RCIE
DS39564C-page 174
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 16-5:
ASYNCHRONOUS RECEPTION
START
bit
bit0
RX (pin)
bit1
bit7/8 STOP
bit
Rcv Shift
Reg
Rcv Buffer Reg
START
bit
bit0
START
bit
bit7/8
STOP
bit
Word 2
RCREG
Word 1
RCREG
Read Rcv
Buffer Reg
RCREG
bit7/8 STOP
bit
RCIF
(Interrupt Flag)
OERR bit
CREN
Note:
This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing
the OERR (overrun) bit to be set.
TABLE 16-7:
Name
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
RBIF
0000 000x
0000 000u
TXIF
SSPIF CCP1IF TMR2IF TMR1IF 0000 0000
0000 0000
RCIE
TXIE
SSPIE CCP1IE TMR2IE TMR1IE 0000 0000
0000 0000
RCIP
TXIP
SSPIP CCP1IP TMR2IP TMR1IP 0000 0000
0000 0000
Bit 7
Bit 6
INTCON
GIE/GIEH
PEIE/
GIEL
PIR1
PSPIF(1)
ADIF
RCIF
PIE1
PSPIE(1)
ADIE
IPR1
PSPIP(1)
ADIP
SPEN
RX9
SREN
RCSTA
RCREG
TXSTA
SPBRG
Bit 5
Bit 4
TMR0IE INT0IE
Bit 3
RBIE
Bit 2
Bit 1
TMR0IF INT0IF
CREN ADDEN FERR
OERR
RX9D
USART Receive Register
CSRC
TX9
TXEN
Baud Rate Generator Register
SYNC
—
BRGH
TRMT
TX9D
0000 -00x
0000 -00x
0000 0000
0000 0000
0000 -010
0000 -010
0000 0000
0000 0000
Legend: x = unknown, - = unimplemented locations read as '0'.
Shaded cells are not used for Asynchronous Reception.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits
clear.
© 2006 Microchip Technology Inc.
DS39564C-page 175
PIC18FXX2
16.3
USART Synchronous Master
Mode
In Synchronous Master 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 (TXSTA<4>). In
addition, enable bit SPEN (RCSTA<7>) is set in order
to configure the RC6/TX/CK and RC7/RX/DT I/O pins
to CK (clock) and DT (data) lines, respectively. The
Master mode indicates that the processor transmits the
master clock on the CK line. The Master mode is
entered by setting bit CSRC (TXSTA<7>).
16.3.1
USART SYNCHRONOUS MASTER
TRANSMISSION
The USART transmitter block diagram is shown in
Figure 16-1. 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
TXREG. The TXREG 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 TXREG (if available). Once the
TXREG register transfers the data to the TSR register
(occurs in one TCYCLE), the TXREG is empty and interrupt bit TXIF (PIR1<4>) is set. The interrupt can be
enabled/disabled by setting/clearing enable bit TXIE
TABLE 16-8:
Bit 7
Bit 6
INTCON
GIE/
GIEH
PEIE/
GIEL
PIR1
PSPIF(1)
ADIF
RCIF
PIE1
(1)
PSPIE
ADIE
RCIE
IPR1
PSPIP(1)
ADIP
RCIP
SPEN
RX9
SREN
TXREG
TXSTA
SPBRG
To set up a Synchronous Master Transmission:
1.
Initialize the SPBRG register for the appropriate
baud rate (Section 16.1).
Enable the synchronous master serial port by
setting bits SYNC, SPEN, and CSRC.
If interrupts are desired, set enable bit TXIE.
If 9-bit transmission is desired, set bit TX9.
Enable the transmission by setting bit TXEN.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
Start transmission by loading data to the TXREG
register.
2.
3.
4.
5.
6.
7.
Note:
TXIF is not cleared immediately upon loading data into the transmit buffer TXREG.
The flag bit becomes valid in the second
instruction cycle following the load
instruction.
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Name
RCSTA
(PIE1<4>). Flag bit TXIF will be set, regardless of the
state of enable bit TXIE, and cannot be cleared in software. It will reset only when new data is loaded into the
TXREG register. While flag bit TXIF indicates the status
of the TXREG register, another bit TRMT (TXSTA<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 has to 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.
Bit 5
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
All Other
RESETS
RBIE
TMR0IF
INT0IF
RBIF
0000 000x
0000 000u
TXIF
SSPIF
CCP1IF TMR2IF
TMR1IF
0000 0000
0000 0000
TXIE
SSPIE
CCP1IE TMR2IE TMR1IE
0000 0000
0000 0000
TXIP
SSPIP
CCP1IP TMR2IP TMR1IP
0000 0000
0000 0000
0000 -00x
0000 -00x
0000 0000
0000 0000
0000 -010
0000 -010
0000 0000
0000 0000
Bit 4
TMR0IE INT0IE
CREN ADDEN
FERR
OERR
RX9D
BRGH
TRMT
TX9D
USART Transmit Register
CSRC
TX9
TXEN
SYNC
Baud Rate Generator Register
—
Legend: x = unknown, - = unimplemented, read as '0'.
Shaded cells are not used for Synchronous Master Transmission.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits
clear.
DS39564C-page 176
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 16-6:
SYNCHRONOUS TRANSMISSION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX/DT
pin
bit 0
bit 1
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
bit 2
bit 7
Word 1
bit 0
bit 1
Word 2
bit 7
RC6/TX/CK
pin
Write to
TXREG Reg
Write Word1
Write Word2
TXIF bit
(Interrupt Flag)
TRMT bit TRMT
TXEN bit
Note:
'1'
'1'
Sync Master mode; SPBRG = '0'. Continuous transmission of two 8-bit words.
FIGURE 16-7:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RC7/RX/DT pin
bit0
bit1
bit2
bit6
bit7
RC6/TX/CK pin
Write to
TXREG reg
TXIF bit
TRMT bit
TXEN bit
© 2006 Microchip Technology Inc.
DS39564C-page 177
PIC18FXX2
16.3.2
USART SYNCHRONOUS MASTER
RECEPTION
Once Synchronous mode is selected, reception is
enabled by setting either enable bit SREN
(RCSTA<5>), or enable bit CREN (RCSTA<4>). Data is
sampled on the RC7/RX/DT 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.
2.
3.
Initialize the SPBRG register for the appropriate
baud rate (Section 16.1).
Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC.
Ensure bits CREN and SREN are clear.
TABLE 16-9:
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
TXIF
SSPIF
CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
TXIE
SSPIE
CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
TXIP
SSPIP
CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000
CREN
ADDEN
FERR
OERR
RX9D
—
BRGH
TRMT
TX9D
Bit 6
INTCON
GIE/
GIEH
PEIE/
GIEL
PIR1
PSPIF(1)
ADIF
RCIF
PIE1
PSPIE(1)
ADIE
RCIE
IPR1
PSPIP(1)
ADIP
RCIP
SPEN
RX9
SREN
Bit 5
Bit 4
SYNC
TMR0IE INT0IE
0000 -00x 0000 -00x
USART Receive Register
TXSTA
CSRC
SPBRG
TX9
TXEN
Value on
All Other
RESETS
Bit 3
Bit 7
RCREG
If interrupts are desired, set enable bit RCIE.
If 9-bit reception is desired, set bit RX9.
If a single reception is required, set bit SREN.
For continuous reception, set bit CREN.
7. Interrupt flag bit RCIF will be set when reception
is complete and an interrupt will be generated if
the enable bit RCIE was set.
8. Read the RCSTA 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
RCREG 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.
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Name
RCSTA
4.
5.
6.
0000 0000 0000 0000
0000 -010 0000 -010
Baud Rate Generator Register
0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for Synchronous Master Reception.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
FIGURE 16-8:
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
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 Q1 Q2 Q3 Q4
RC7/RX/DT pin
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
RC6/TX/CK pin
Write to
bit SREN
SREN bit
CREN bit
'0'
'0'
RCIF bit
(Interrupt)
Read
RXREG
Note:
Timing diagram demonstrates Sync Master mode with bit SREN = '1' and bit BRGH = '0'.
DS39564C-page 178
© 2006 Microchip Technology Inc.
PIC18FXX2
16.4
USART Synchronous Slave Mode
Synchronous Slave mode differs from the Master mode
in the fact that the shift clock is supplied externally at
the RC6/TX/CK pin (instead of being supplied internally
in Master mode). This allows the device to transfer or
receive data while in SLEEP mode. Slave mode is
entered by clearing bit CSRC (TXSTA<7>).
16.4.1
USART SYNCHRONOUS SLAVE
TRANSMIT
If two words are written to the TXREG and then the
SLEEP instruction is executed, the following will occur:
b)
c)
d)
e)
1.
2.
3.
4.
5.
6.
The operation of the Synchronous Master and Slave
modes are identical, except in the case of the SLEEP
mode.
a)
To set up a Synchronous Slave Transmission:
7.
8.
The first word will immediately transfer to the
TSR register and transmit.
The second word will remain in TXREG register.
Flag bit TXIF will not be set.
When the first word has been shifted out of TSR,
the TXREG register will transfer the second
word to the TSR and flag bit TXIF will now be
set.
If enable bit TXIE is set, the interrupt will wake
the chip from SLEEP. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
Enable the synchronous slave serial port by setting bits SYNC and SPEN and clearing bit
CSRC.
Clear bits CREN and SREN.
If interrupts are desired, set enable bit TXIE.
If 9-bit transmission is desired, set bit TX9.
Enable the transmission by setting enable bit
TXEN.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
Start transmission by loading data to the TXREG
register.
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Name
Bit 7
Bit 6
INTCON
GIE/
GIEH
PEIE/
GIEL
Bit 5
Bit 4
TMR0IE INT0IE
Value on
All Other
RESETS
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000
SPEN
RX9
SREN
RCSTA
TXREG
TXSTA
SPBRG
CREN ADDEN
FERR
OERR
RX9D
USART Transmit Register
CSRC
TX9
TXEN
0000 -00x 0000 -00x
0000 0000 0000 0000
SYNC
Baud Rate Generator Register
—
BRGH
TRMT
TX9D
0000 -010 0000 -010
0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as '0'.
Shaded cells are not used for Synchronous Slave Transmission.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits
clear.
© 2006 Microchip Technology Inc.
DS39564C-page 179
PIC18FXX2
16.4.2
USART SYNCHRONOUS SLAVE
RECEPTION
To set up a Synchronous Slave Reception:
1.
The operation of the Synchronous Master and Slave
modes is identical, except in the case of the SLEEP
mode and bit SREN, which is a “don't care” in Slave
mode.
2.
3.
4.
5.
If receive is enabled by setting bit CREN prior to the
SLEEP instruction, then a word may be received during
SLEEP. On completely receiving the word, the RSR
register will transfer the data to the RCREG register,
and if enable bit RCIE bit is set, the interrupt generated
will wake the chip from SLEEP. If the global interrupt is
enabled, the program will branch to the interrupt vector.
6.
7.
8.
9.
Enable the synchronous master serial port by
setting bits SYNC and SPEN and clearing bit
CSRC.
If interrupts are desired, set enable bit RCIE.
If 9-bit reception is desired, set bit RX9.
To enable reception, set enable bit CREN.
Flag bit RCIF will be set when reception is complete. An interrupt will be generated if enable bit
RCIE was set.
Read the RCSTA register to get the ninth bit (if
enabled) and determine if any error occurred
during reception.
Read the 8-bit received data by reading the
RCREG register.
If any error occurred, clear the error by clearing
bit CREN.
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 16-11: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name
Bit 7
Bit 6
INTCON
GIE/
GIEH
PEIE/
GIEL
Bit 5
Bit 4
TMR0IE INT0IE
Bit 3
RBIE
Bit 2
Bit 1
TMR0IF INT0IF
Value on
All Other
RESETS
Bit 0
Value on
POR, BOR
RBIF
0000 000x 0000 000u
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000
SPEN
RX9
SREN
CREN
ADDEN
RCSTA
RCREG
TXSTA
SPBRG
FERR
OERR
RX9D
USART Receive Register
CSRC
TX9
TXEN
Baud Rate Generator Register
0000 -00x 0000 -00x
0000 0000 0000 0000
SYNC
—
BRGH
TRMT
TX9D
0000 -010 0000 -010
0000 0000 0000 0000
Legend: x = unknown, - = unimplemented, read as '0'.
Shaded cells are not used for Synchronous Slave Reception.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits
clear.
DS39564C-page 180
© 2006 Microchip Technology Inc.
PIC18FXX2
17.0
COMPATIBLE 10-BIT
ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The A/D module has four registers. These registers
are:
•
•
•
•
The Analog-to-Digital (A/D) converter module has five
inputs for the PIC18F2X2 devices and eight for the
PIC18F4X2 devices. This module has the ADCON0
and ADCON1 register definitions that are compatible
with the mid-range A/D module.
The ADCON0 register, shown in Register 17-1, controls the operation of the A/D module. The ADCON1
register, shown in Register 17-2, configures the
functions of the port pins.
The A/D allows conversion of an analog input signal to
a corresponding 10-bit digital number.
REGISTER 17-1:
A/D Result High Register (ADRESH)
A/D Result Low Register (ADRESL)
A/D Control Register 0 (ADCON0)
A/D Control Register 1 (ADCON1)
ADCON0 REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
U-0
R/W-0
ADCS1
ADCS0
CHS2
CHS1
CHS0
GO/DONE
—
ADON
bit 7
bit 7-6
bit 5-3
bit 0
ADCS1:ADCS0: A/D Conversion Clock Select bits (ADCON0 bits in bold)
ADCON1
<ADCS2>
ADCON0
<ADCS1:ADCS0>
0
0
0
0
1
1
1
1
00
01
10
11
00
01
10
11
Clock Conversion
FOSC/2
FOSC/8
FOSC/32
FRC (clock derived from the internal A/D RC oscillator)
FOSC/4
FOSC/16
FOSC/64
FRC (clock derived from the internal A/D RC oscillator)
CHS2:CHS0: Analog Channel Select bits
000 = channel 0, (AN0)
001 = channel 1, (AN1)
010 = channel 2, (AN2)
011 = channel 3, (AN3)
100 = channel 4, (AN4)
101 = channel 5, (AN5)
110 = channel 6, (AN6)
111 = channel 7, (AN7)
Note: The PIC18F2X2 devices do not implement the full 8 A/D channels; the unimplemented
selections are reserved. Do not select any unimplemented channel.
bit 2
GO/DONE: A/D Conversion Status bit
When ADON = 1:
1 = A/D conversion in progress (setting this bit starts the A/D conversion which is automatically
cleared by hardware when the A/D conversion is complete)
0 = A/D conversion not in progress
bit 1
Unimplemented: Read as '0'
bit 0
ADON: A/D On bit
1 = A/D converter module is powered up
0 = A/D converter module is shut-off and consumes no operating current
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 181
PIC18FXX2
REGISTER 17-2:
ADCON1 REGISTER
R/W-0
R/W-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
ADFM
ADCS2
—
—
PCFG3
PCFG2
PCFG1
PCFG0
bit 7
bit 0
bit 7
ADFM: A/D Result Format Select bit
1 = Right justified. Six (6) Most Significant bits of ADRESH are read as ’0’.
0 = Left justified. Six (6) Least Significant bits of ADRESL are read as ’0’.
bit 6
ADCS2: A/D Conversion Clock Select bit (ADCON1 bits in bold)
ADCON1
ADCON0
<ADCS2> <ADCS1:ADCS0>
FOSC/2
FOSC/8
FOSC/32
FRC (clock derived from the internal A/D RC oscillator)
FOSC/4
FOSC/16
FOSC/64
FRC (clock derived from the internal A/D RC oscillator)
00
01
10
11
00
01
10
11
0
0
0
0
1
1
1
1
Clock Conversion
bit 5-4
Unimplemented: Read as '0'
bit 3-0
PCFG3:PCFG0: A/D Port Configuration Control bits
PCFG
<3:0>
AN7
AN6
AN5
AN4
0000
A
A
A
A
A
A
A
A
0001
A
A
A
A
VREF+
A
A
A
0010
D
D
D
A
A
A
A
A
0011
D
D
D
A
VREF+
A
A
0100
D
D
D
D
A
D
A
0101
D
D
D
D
VREF+
D
011x
D
D
D
D
D
AN3
AN2
AN1
AN0
VREF+
VREF-
C/R
VDD
VSS
8/0
AN3
VSS
7/1
VDD
VSS
5/0
A
AN3
VSS
4/1
A
VDD
VSS
3/0
A
A
AN3
VSS
2/1
D
D
D
—
—
0/0
1000
A
A
A
A
VREF+
VREF-
A
A
AN3
AN2
6/2
1001
D
D
A
A
A
A
A
A
VDD
VSS
6/0
1010
D
D
A
A
VREF+
A
A
A
AN3
VSS
5/1
1011
D
D
A
A
VREF+
VREF-
A
A
AN3
AN2
4/2
1100
D
D
D
A
VREF+
VREF-
A
A
AN3
AN2
3/2
1101
D
D
D
D
VREF+
VREF-
A
A
AN3
AN2
2/2
1110
D
D
D
D
D
D
D
A
VDD
VSS
1/0
1111
D
D
D
D
VREF+
VREF-
D
A
AN3
AN2
1/2
A = Analog input D = Digital I/O
C/R = # of analog input channels / # of A/D voltage references
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
Note:
DS39564C-page 182
x = Bit is unknown
On any device RESET, the port pins that are multiplexed with analog functions (ANx) are
forced to be an analog input.
© 2006 Microchip Technology Inc.
PIC18FXX2
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(VDD and VSS), or the voltage level on the RA3/AN3/
VREF+ pin and RA2/AN2/VREF- pin.
Each port pin associated with the A/D converter can be
configured as an analog input (RA3 can also be a
voltage reference) 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
complete, the result is loaded into the ADRESH/
ADRESL registers, the GO/DONE bit (ADCON0<2>) is
cleared, and A/D interrupt flag bit, ADIF is set. The block
diagram of the A/D module is shown in Figure 17-1.
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.
A device RESET forces all registers to their RESET
state. This forces the A/D module to be turned off and
any conversion is aborted.
FIGURE 17-1:
A/D BLOCK DIAGRAM
CHS<2:0>
111
110
101
100
VAIN
011
(Input Voltage)
010
10-bit
Converter
A/D
001
PCFG<3:0>
000
VDD
AN7*
AN6*
AN5*
AN4
AN3
AN2
AN1
AN0
VREF+
Reference
Voltage
VREFVSS
* These channels are implemented only on the PIC18F4X2 devices.
© 2006 Microchip Technology Inc.
DS39564C-page 183
PIC18FXX2
The value that is in the ADRESH/ADRESL registers is
not modified for a Power-on Reset. The ADRESH/
ADRESL registers will contain unknown data after a
Power-on Reset.
5.
OR
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 17.1.
After this acquisition time has elapsed, the A/D conversion can be started. The following steps should be
followed for doing an A/D conversion:
1.
2.
3.
4.
Wait for A/D conversion to complete, by either:
• Polling for the GO/DONE bit to be cleared
(interrupts disabled)
• Waiting for the A/D interrupt
Read A/D Result registers (ADRESH/ADRESL);
clear bit ADIF if required.
For next conversion, go to step 1 or step 2 as
required. The A/D conversion time per bit is
defined as TAD. A minimum wait of 2 TAD is
required before the next acquisition starts.
6.
7.
Configure the A/D module:
• Configure analog pins, voltage reference and
digital I/O (ADCON1)
• Select A/D input channel (ADCON0)
• Select A/D conversion clock (ADCON0)
• Turn on A/D module (ADCON0)
Configure A/D interrupt (if desired):
• Clear ADIF bit
• Set ADIE bit
• Set GIE bit
• Set PEIE bit
Wait the required acquisition time.
Start conversion:
• Set GO/DONE bit (ADCON0)
17.1
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 shown in Figure 17-2. 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 kΩ. After the analog input channel is
selected (changed), this acquisition must be done
before the conversion can be started.
Note:
FIGURE 17-2:
A/D Acquisition Requirements
When the conversion is started, the holding capacitor is disconnected from the
input pin.
ANALOG INPUT MODEL
VDD
Sampling
Switch
VT = 0.6V
Rs
RIC ≤ 1k
ANx
CPIN
VAIN
5 pF
VT = 0.6V
SS
RSS
I LEAKAGE
± 500 nA
CHOLD = 120 pF
VSS
Legend: CPIN
= input capacitance
VT
= threshold voltage
I LEAKAGE = leakage current at the pin due to
various junctions
RIC
SS
CHOLD
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
VDD
6V
5V
4V
3V
2V
5 6 7 8 9 10 11
Sampling Switch (kΩ)
DS39564C-page 184
© 2006 Microchip Technology Inc.
PIC18FXX2
To calculate the minimum acquisition time,
Equation 17-1 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 17-1:
TACQ
ACQUISITION TIME
=
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
=
TAMP + TC + TCOFF
EQUATION 17-2:
VHOLD =
or
=
TC
A/D MINIMUM CHARGING TIME
(VREF – (VREF/2048)) • (1 – e(-Tc/CHOLD(RIC + RSS + RS)))
-(120 pF)(1 kΩ + RSS + RS) ln(1/2048)
Example 17-1 shows the calculation of the minimum
required acquisition time, TACQ. This calculation is
based on the following application system assumptions:
•
•
•
•
•
•
CHOLD
Rs
Conversion Error
VDD
Temperature
VHOLD
EXAMPLE 17-1:
TACQ =
=
=
≤
=
=
=
120 pF
2.5 kΩ
1/2 LSb
5V → Rss = 7 kΩ
50°C (system max.)
0V @ time = 0
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
TAMP + TC + TCOFF
Temperature coefficient is only required for temperatures > 25°C.
TACQ =
TC
=
TACQ =
2 μs + TC + [(Temp – 25°C)(0.05 μs/°C)]
-CHOLD (RIC + RSS + RS) ln(1/2048)
-120 pF (1 kΩ + 7 kΩ + 2.5 kΩ) ln(0.0004883)
-120 pF (10.5 kΩ) ln(0.0004883)
-1.26 μs (-7.6246)
9.61 μs
2 μs + 9.61 μs + [(50°C – 25°C)(0.05 μs/°C)]
11.61 μs + 1.25 μs
12.86 μs
© 2006 Microchip Technology Inc.
DS39564C-page 185
PIC18FXX2
17.2
Selecting the A/D Conversion Clock
The A/D conversion time per bit is defined as TAD. The
A/D conversion requires 12 TAD per 10-bit conversion.
The source of the A/D conversion clock is software
selectable. The seven possible options for TAD are:
•
•
•
•
•
•
•
2 TOSC
4 TOSC
8 TOSC
16 TOSC
32 TOSC
64 TOSC
Internal A/D module RC oscillator (2-6 μs)
For correct A/D conversions, the A/D conversion clock
(TAD) must be selected to ensure a minimum TAD time
of 1.6 μs.
17.3
Configuring Analog Port Pins
The ADCON1, TRISA and TRISE registers control the
operation of the A/D port pins. The port pins that are
desired 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
CHS2:CHS0 bits and the TRIS bits.
Note 1: When reading the port register, all pins configured as analog input channels will read
as cleared (a low level). Pins configured as
digital inputs will convert an analog input.
Analog levels on a digitally configured input
will not affect the conversion accuracy.
2: Analog levels on any pin that is defined as
a digital input (including the AN4:AN0
pins) may cause the input buffer to consume current that is out of the device’s
specification.
Table 17-1 shows the resultant TAD times derived from
the device operating frequencies and the A/D clock
source selected.
TABLE 17-1:
TAD vs. DEVICE OPERATING FREQUENCIES
AD Clock Source (TAD)
Maximum Device Frequency
Operation
ADCS2:ADCS0
PIC18FXX2
PIC18LFXX2
2 TOSC
000
1.25 MHz
666 kHz
4 TOSC
100
2.50 MHz
1.33 MHz
8 TOSC
001
5.00 MHz
2.67 MHz
16 TOSC
101
10.00 MHz
5.33 MHz
32 TOSC
010
20.00 MHz
10.67 MHz
64 TOSC
110
40.00 MHz
21.33 MHz
RC
011
—
—
DS39564C-page 186
© 2006 Microchip Technology Inc.
PIC18FXX2
17.4
A/D Conversions
(or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is aborted, a 2 TAD wait
is required before the next acquisition is started. After
this 2 TAD wait, acquisition on the selected channel is
automatically started. The GO/DONE bit can then be
set to start the conversion.
Figure 17-3 shows the operation of the A/D converter
after the GO bit has been set. 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.
That is, the ADRESH:ADRESL registers will continue
to contain the value of the last completed conversion
FIGURE 17-3:
Note:
The GO/DONE bit should NOT be set in
the same instruction that turns on the A/D.
A/D CONVERSION TAD CYCLES
TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11
b8
b9
b7
b6
b5
b4
b3
b2
b1
b0
b0
Conversion Starts
Holding capacitor is disconnected from analog input (typically 100 ns)
Set GO bit
Next Q4: ADRESH/ADRESL is loaded, GO bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
17.4.1
A/D RESULT REGISTERS
The ADRESH:ADRESL register pair is the location
where the 10-bit A/D result is loaded at the completion
of the A/D conversion. This register pair is 16-bits wide.
The A/D module gives the flexibility to left or right justify
the 10-bit result in the 16-bit result register. The A/D
FIGURE 17-4:
Format Select bit (ADFM) controls this justification.
Figure 17-4 shows the operation of the A/D result justification. The extra bits are loaded with ’0’s. When an
A/D result will not overwrite these locations (A/D
disable), these registers may be used as two general
purpose 8-bit registers.
A/D RESULT JUSTIFICATION
10-bit Result
ADFM = 0
ADFM = 1
7
0
2107
7
0765
0000 00
0000 00
ADRESH
ADRESL
10-bit Result
Right Justified
© 2006 Microchip Technology Inc.
0
ADRESH
ADRESL
10-bit Result
Left Justified
DS39564C-page 187
PIC18FXX2
17.5
Use of the CCP2 Trigger
(moving ADRESH/ADRESL to the desired location).
The appropriate analog input channel must be selected
and the minimum acquisition done before the “special
event trigger” sets the GO/DONE bit (starts a
conversion).
An A/D conversion can be started by the “special event
trigger” of the CCP2 module. This requires that the
CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be programmed as 1011 and 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 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
TABLE 17-2:
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.
SUMMARY OF A/D REGISTERS
Value on
All Other
RESETS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
INTCON
GIE/
GIEH
PEIE/
GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
0000 000x 0000 000u
PIR1
PSPIF(1)
ADIF
RCIF
TXIF
SSPIF
CCP1IF
TMR2IF
TMR1IF
0000 0000 0000 0000
PIE1
PSPIE(1)
ADIE
RCIE
TXIE
SSPIE
CCP1IE
TMR2IE
TMR1IE
0000 0000 0000 0000
IPR1
PSPIP(1)
ADIP
RCIP
TXIP
SSPIP
CCP1IP
TMR2IP
TMR1IP
0000 0000 0000 0000
PIR2
—
—
—
EEIF
BCLIF
LVDIF
TMR3IF
CCP2IF
---0 0000 ---0 0000
PIE2
—
—
—
EEIE
BCLIE
LVDIE
TMR3IE
CCP2IE
---0 0000 ---0 0000
—
—
—
EEIP
BCLIP
LVDIP
TMR3IP
CCP2IP
---1 1111 ---1 0000
IPR2
ADRESH
A/D Result Register
xxxx xxxx uuuu uuuu
ADRESL
A/D Result Register
xxxx xxxx uuuu uuuu
ADCON0
ADCS1
ADCS0
CHS2
CHS1
CHS0
GO/DONE
—
ADON
0000 00-0 0000 00-0
ADCON1
ADFM
ADCS2
—
—
PCFG3
PCFG2
PCFG1
PCFG0
---- -000 ---- -000
RA6
RA5
RA4
RA3
RA2
RA1
RA0
--0x 0000 --0u 0000
PORTA
—
TRISA
—
PORTE
—
—
—
—
—
RE2
RE1
RE0
---- -000 ---- -000
LATE
—
—
—
—
—
LATE2
LATE1
LATE0
---- -xxx ---- -uuu
TRISE
IBF
OBF
IBOV
PSPMODE
—
PORTA Data Direction Register
--11 1111 --11 1111
PORTE Data Direction bits
0000 -111 0000 -111
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for A/D conversion.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X2 devices; always maintain these bits clear.
DS39564C-page 188
© 2006 Microchip Technology Inc.
PIC18FXX2
18.0
LOW VOLTAGE DETECT
In many applications, the ability to determine if the
device voltage (VDD) is below a specified voltage level
is a desirable feature. A window of operation for the
application can be created, where the application software can do “housekeeping tasks” before the device
voltage exits the valid operating range. This can be
done using the Low Voltage Detect module.
This module is a software programmable circuitry,
where a device voltage trip point can be specified.
When the voltage of the device becomes lower then the
specified point, an interrupt flag is set. If the interrupt is
enabled, the program execution will branch to the interrupt vector address and the software can then respond
to that interrupt source.
Figure 18-1 shows a possible application voltage curve
(typically for batteries). Over time, the device voltage
decreases. When the device voltage equals voltage VA,
the LVD logic generates an interrupt. This occurs at
time TA. The application software then has the time,
until the device voltage is no longer in valid operating
range, to shutdown the system. Voltage point VB is the
minimum valid operating voltage specification. This
occurs at time TB. The difference TB - TA is the total
time for shutdown.
TYPICAL LOW VOLTAGE DETECT APPLICATION
Voltage
FIGURE 18-1:
The Low Voltage Detect circuitry is completely under
software control. This allows the circuitry to be “turned
off” by the software, which minimizes the current
consumption for the device.
VA
VB
Legend:
VA = LVD trip point
VB = Minimum valid device
operating voltage
Time
TA
TB
The block diagram for the LVD module is shown in
Figure 18-2. A comparator uses an internally generated reference voltage as the set point. When the
selected tap output of the device voltage crosses the
set point (is lower than), the LVDIF bit is set.
Each node in the resistor divider represents a “trip
point” voltage. The “trip point” voltage is the minimum
supply voltage level at which the device can operate
before the LVD module asserts an interrupt. When the
© 2006 Microchip Technology Inc.
supply voltage is equal to the trip point, the voltage
tapped off of the resistor array is equal to the 1.2V
internal reference voltage generated by the voltage
reference module. The comparator then generates an
interrupt signal setting the LVDIF bit. This voltage is
software programmable to any one of 16 values (see
Figure 18-2). The trip point is selected by
programming the LVDL3:LVDL0 bits (LVDCON<3:0>).
DS39564C-page 189
PIC18FXX2
FIGURE 18-2:
LOW VOLTAGE DETECT (LVD) BLOCK DIAGRAM
LVDIN
LVD Control
Register
16 to 1 MUX
VDD
LVDIF
+
Internally Generated
Reference Voltage
1.2V Typical
LVDEN
The LVD module has an additional feature that allows
the user to supply the trip voltage to the module from
an external source. This mode is enabled when bits
LVDL3:LVDL0 are set to 1111. In this state, the comparator input is multiplexed from the external input pin,
FIGURE 18-3:
–
LVDIN (Figure 18-3). This gives users flexibility,
because it allows them to configure the Low Voltage
Detect interrupt to occur at any voltage in the valid
operating range.
LOW VOLTAGE DETECT (LVD) WITH EXTERNAL INPUT BLOCK DIAGRAM
VDD
VDD
16 to 1 MUX
LVD Control
Register
LVDIN
Externally Generated
Trip Point
LVDEN
–
+
LVD
VxEN
BODEN
EN
BGAP
DS39564C-page 190
© 2006 Microchip Technology Inc.
PIC18FXX2
18.1
Control Register
The Low Voltage Detect Control register controls the
operation of the Low Voltage Detect circuitry.
REGISTER 18-1:
LVDCON REGISTER
U-0
U-0
R-0
R/W-0
R/W-0
R/W-1
R/W-0
R/W-1
—
—
IRVST
LVDEN
LVDL3
LVDL2
LVDL1
LVDL0
bit 7
bit 0
bit 7-6
Unimplemented: Read as '0'
bit 5
IRVST: Internal Reference Voltage Stable Flag bit
1 = Indicates that the Low Voltage Detect logic will generate the interrupt flag at the
specified voltage range
0 = Indicates that the Low Voltage Detect logic will not generate the interrupt flag at the
specified voltage range and the LVD interrupt should not be enabled
bit 4
LVDEN: Low Voltage Detect Power Enable bit
1 = Enables LVD, powers up LVD circuit
0 = Disables LVD, powers down LVD circuit
bit 3-0
LVDL3:LVDL0: Low Voltage Detection Limit bits
1111 = External analog input is used (input comes from the LVDIN pin)
1110 = 4.5V - 4.77V
1101 = 4.2V - 4.45V
1100 = 4.0V - 4.24V
1011 = 3.8V - 4.03V
1010 = 3.6V - 3.82V
1001 = 3.5V - 3.71V
1000 = 3.3V - 3.50V
0111 = 3.0V - 3.18V
0110 = 2.8V - 2.97V
0101 = 2.7V - 2.86V
0100 = 2.5V - 2.65V
0011 = 2.4V - 2.54V
0010 = 2.2V - 2.33V
0001 = 2.0V - 2.12V
0000 = Reserved
Note:
LVDL3:LVDL0 modes which result in a trip point below the valid operating voltage
of the device are not tested.
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
© 2006 Microchip Technology Inc.
x = Bit is unknown
DS39564C-page 191
PIC18FXX2
18.2
Operation
Depending on the power source for the device voltage,
the voltage normally decreases relatively slowly. This
means that the LVD module does not need to be constantly operating. To decrease the current requirements, the LVD circuitry only needs to be enabled for
short periods, where the voltage is checked. After
doing the check, the LVD module may be disabled.
Each time that the LVD module is enabled, the circuitry
requires some time to stabilize. After the circuitry has
stabilized, all status flags may be cleared. The module
will then indicate the proper state of the system.
The following steps are needed to set up the LVD
module:
1.
2.
3.
4.
5.
6.
Write the value to the LVDL3:LVDL0 bits
(LVDCON register), which selects the desired
LVD Trip Point.
Ensure that LVD interrupts are disabled (the
LVDIE bit is cleared or the GIE bit is cleared).
Enable the LVD module (set the LVDEN bit in
the LVDCON register).
Wait for the LVD module to stabilize (the IRVST
bit to become set).
Clear the LVD interrupt flag, which may have
falsely become set until the LVD module has
stabilized (clear the LVDIF bit).
Enable the LVD interrupt (set the LVDIE and the
GIE bits).
Figure 18-4 shows typical waveforms that the LVD
module may be used to detect.
FIGURE 18-4:
LOW VOLTAGE DETECT WAVEFORMS
CASE 1:
LVDIF may not be set
VDD
VLVD
LVDIF
Enable LVD
Internally Generated
Reference Stable
TIVRST
LVDIF cleared in software
CASE 2:
VDD
VLVD
LVDIF
Enable LVD
Internally Generated
Reference Stable
TIVRST
LVDIF cleared in software
LVDIF cleared in software,
LVDIF remains set since LVD condition still exists
DS39564C-page 192
© 2006 Microchip Technology Inc.
PIC18FXX2
18.2.1
REFERENCE VOLTAGE SET POINT
The Internal Reference Voltage of the LVD module may
be used by other internal circuitry (the Programmable
Brown-out Reset). If these circuits are disabled (lower
current consumption), the reference voltage circuit
requires a time to become stable before a low voltage
condition can be reliably detected. This time is invariant
of system clock speed. This start-up time is specified in
electrical specification parameter 36. The low voltage
interrupt flag will not be enabled until a stable reference
voltage is reached. Refer to the waveform in Figure 18-4.
18.2.2
18.3
Operation During SLEEP
When enabled, the LVD circuitry continues to operate
during SLEEP. If the device voltage crosses the trip
point, the LVDIF bit will be set and the device will wakeup from SLEEP. Device execution will continue from
the interrupt vector address if interrupts have been
globally enabled.
18.4
Effects of a RESET
A device RESET forces all registers to their RESET
state. This forces the LVD module to be turned off.
CURRENT CONSUMPTION
When the module is enabled, the LVD comparator and
voltage divider are enabled and will consume static current. The voltage divider can be tapped from multiple
places in the resistor array. Total current consumption,
when enabled, is specified in electrical specification
parameter #D022B.
© 2006 Microchip Technology Inc.
DS39564C-page 193
PIC18FXX2
NOTES:
DS39564C-page 194
© 2006 Microchip Technology Inc.
PIC18FXX2
19.0
SPECIAL FEATURES OF THE
CPU
There are several features intended to maximize system reliability, minimize cost through elimination of
external components, provide power saving Operating
modes and offer code protection. These are:
• OSC Selection
• RESET
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
• Interrupts
• Watchdog Timer (WDT)
• SLEEP
• Code Protection
• ID Locations
• In-Circuit Serial Programming
All PIC18FXX2 devices have a Watchdog Timer, which
is permanently enabled via the configuration bits or
software controlled. It runs off its own RC oscillator for
added reliability. There are two timers that offer necessary delays on power-up. One is the Oscillator Start-up
Timer (OST), intended to keep the chip in RESET until
the crystal oscillator is stable. The other is the Powerup Timer (PWRT), which provides a fixed delay on
power-up only, designed to keep the part in RESET
while the power supply stabilizes. With these two timers on-chip, most applications need no external
RESET circuitry.
19.1
Configuration Bits
The configuration bits can be programmed (read as '0'),
or left unprogrammed (read as '1'), to select various
device configurations. These bits are mapped starting
at program memory location 300000h.
The user will note that address 300000h is beyond the
user program memory space. In fact, it belongs to the
configuration memory space (300000h - 3FFFFFh),
which can only be accessed using Table Reads and
Table Writes.
Programming the configuration registers is done in a
manner similar to programming the FLASH memory
(see Section 5.5.1). The only difference is the configuration registers are written a byte at a time. The
sequence of events for programming configuration
registers is:
1.
Load table pointer with address of configuration
register being written.
2. Write a single byte using the TBLWT instruction.
3. Set EEPGD to point to program memory, set the
CFGS bit to access configuration registers, and
set WREN to enable byte writes.
4. Disable interrupts.
5. Write 55h to EECON2.
6. Write AAh to EECON2.
7. Set the WR bit. This will begin the write cycle.
8. CPU will stall for duration of write (approximately
2 ms using internal timer).
9. Execute a NOP.
10. Re-enable interrupts.
SLEEP mode is designed to offer a very low current
Power-down mode. The user can wake-up from
SLEEP through external RESET, Watchdog Timer
Wake-up or through an interrupt. Several oscillator
options are also made available to allow the part to fit
the application. The RC oscillator option saves system
cost, while the LP crystal option saves power. A set of
configuration bits are used to select various options.
© 2006 Microchip Technology Inc.
DS39564C-page 195
PIC18FXX2
TABLE 19-1:
CONFIGURATION BITS AND DEVICE IDS
File Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Default/
Unprogrammed
Value
—
FOSC2
FOSC1
FOSC0
--1- -111
300001h
CONFIG1H
—
—
OSCSEN
—
300002h
CONFIG2L
—
—
—
—
BORV1
BORV0
BOREN
PWRTEN
---- 1111
300003h
CONFIG2H
—
—
—
—
WDTPS2
WDTPS1
WDTPS0
WDTEN
---- 1111
300005h
CONFIG3H
—
—
—
—
—
—
—
CCP2MX
---- ---1
300006h
CONFIG4L
DEBUG
—
—
—
—
LVP
—
STVREN
1--- -1-1
300008h
CONFIG5L
—
—
—
—
CP3
CP2
CP1
CP0
---- 1111
300009h
CONFIG5H
CPD
CPB
—
—
—
—
—
—
11-- ----
30000Ah
CONFIG6L
—
—
—
—
WRT3
WRT2
WRT1
WRT0
---- 1111
30000Bh
CONFIG6H
WRTD
WRTB
WRTC
—
—
—
—
—
111- ----
30000Ch
CONFIG7L
—
—
—
—
EBTR3
EBTR2
EBTR1
EBTR0
---- 1111
30000Dh
CONFIG7H
—
EBTRB
—
—
—
—
—
—
-1-- ----
3FFFFEh
DEVID1
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
(1)
3FFFFFh
DEVID2
DEV10
DEV9
DEV8
DEV7
DEV6
DEV5
DEV4
DEV3
0000 0100
Legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition.
Shaded cells are unimplemented, read as ‘0’.
Note 1: See Register 19-12 for DEVID1 values.
REGISTER 19-1:
CONFIGURATION REGISTER 1 HIGH (CONFIG1H: BYTE ADDRESS 300001h)
U-0
U-0
R/P-1
U-0
U-0
R/P-1
R/P-1
R/P-1
—
—
OSCSEN
—
—
FOSC2
FOSC1
FOSC0
bit 7
bit 0
bit 7-6
Unimplemented: Read as ‘0’
bit 5
OSCSEN: Oscillator System Clock Switch Enable bit
1 = Oscillator system clock switch option is disabled (main oscillator is source)
0 = Oscillator system clock switch option is enabled (oscillator switching is enabled)
bit 4-3
Unimplemented: Read as ‘0’
bit 2-0
FOSC2:FOSC0: Oscillator Selection bits
111 = RC oscillator w/ OSC2 configured as RA6
110 = HS oscillator with PLL enabled/Clock frequency = (4 x FOSC)
101 = EC oscillator w/ OSC2 configured as RA6
100 = EC oscillator w/ OSC2 configured as divide-by-4 clock output
011 = RC oscillator
010 = HS oscillator
001 = XT oscillator
000 = LP oscillator
Legend:
R = Readable bit
P = Programmable bit
- n = Value when device is unprogrammed
DS39564C-page 196
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 19-2:
CONFIGURATION REGISTER 2 LOW (CONFIG2L: BYTE ADDRESS 300002h)
U-0
U-0
U-0
U-0
R/P-1
R/P-1
R/P-1
R/P-1
—
—
—
—
BORV1
BORV0
BOREN
PWRTEN
bit 7
bit 0
bit 7-4
Unimplemented: Read as ‘0’
bit 3-2
BORV1:BORV0: Brown-out Reset Voltage bits
11 = VBOR set to 2.5V
10 = VBOR set to 2.7V
01 = VBOR set to 4.2V
00 = VBOR set to 4.5V
bit 1
BOREN: Brown-out Reset Enable bit
1 = Brown-out Reset enabled
0 = Brown-out Reset disabled
bit 0
PWRTEN: Power-up Timer Enable bit
1 = PWRT disabled
0 = PWRT enabled
Legend:
R = Readable bit
P = Programmable bit
- n = Value when device is unprogrammed
REGISTER 19-3:
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
CONFIGURATION REGISTER 2 HIGH (CONFIG2H: BYTE ADDRESS 300003h)
U-0
U-0
U-0
U-0
R/P-1
R/P-1
R/P-1
R/P-1
—
—
—
—
WDTPS2
WDTPS1
WDTPS0
WDTEN
bit 7
bit 0
bit 7-4
Unimplemented: Read as ‘0’
bit 3-1
WDTPS2:WDTPS0: Watchdog Timer Postscale Select bits
111 = 1:128
110 = 1:64
101 = 1:32
100 = 1:16
011 = 1:8
010 = 1:4
001 = 1:2
000 = 1:1
bit 0
WDTEN: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled (control is placed on the SWDTEN bit)
Legend:
R = Readable bit
P = Programmable bit
- n = Value when device is unprogrammed
© 2006 Microchip Technology Inc.
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
DS39564C-page 197
PIC18FXX2
REGISTER 19-4:
CONFIGURATION REGISTER 3 HIGH (CONFIG3H: BYTE ADDRESS 300005h)
U-0
U-0
U-0
U-0
U-0
U-0
U-0
R/P-1
—
—
—
—
—
—
—
CCP2MX
bit 7
bit 0
bit 7-1
Unimplemented: Read as ‘0’
bit 0
CCP2MX: CCP2 Mux bit
1 = CCP2 input/output is multiplexed with RC1
0 = CCP2 input/output is multiplexed with RB3
Legend:
R = Readable bit
P = Programmable bit
- n = Value when device is unprogrammed
REGISTER 19-5:
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
CONFIGURATION REGISTER 4 LOW (CONFIG4L: BYTE ADDRESS 300006h)
R/P-1
U-0
U-0
U-0
U-0
R/P-1
U-0
R/P-1
BKBUG
—
—
—
—
LVP
—
STVREN
bit 7
bit 0
bit 7
DEBUG: Background Debugger Enable bit
1 = Background Debugger disabled. RB6 and RB7 configured as general purpose I/O pins.
0 = Background Debugger enabled. RB6 and RB7 are dedicated to In-Circuit Debug.
bit 6-3
Unimplemented: Read as ‘0’
bit 2
LVP: Low Voltage ICSP Enable bit
1 = Low Voltage ICSP enabled
0 = Low Voltage ICSP disabled
bit 1
Unimplemented: Read as ‘0’
bit 0
STVREN: Stack Full/Underflow Reset Enable bit
1 = Stack Full/Underflow will cause RESET
0 = Stack Full/Underflow will not cause RESET
Legend:
R = Readable bit
C = Clearable bit
- n = Value when device is unprogrammed
DS39564C-page 198
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 19-6:
CONFIGURATION REGISTER 5 LOW (CONFIG5L: BYTE ADDRESS 300008h)
U-0
—
U-0
—
U-0
—
U-0
—
R/C-1
R/C-1
(1)
(1)
CP3
CP2
R/C-1
R/C-1
CP1
CP0
bit 7
bit 0
bit 7-4
Unimplemented: Read as ‘0’
bit 3
CP3: Code Protection bit(1)
1 = Block 3 (006000-007FFFh) not code protected
0 = Block 3 (006000-007FFFh) code protected
bit 2
CP2: Code Protection bit(1)
1 = Block 2 (004000-005FFFh) not code protected
0 = Block 2 (004000-005FFFh) code protected
bit 1
CP1: Code Protection bit
1 = Block 1 (002000-003FFFh) not code protected
0 = Block 1 (002000-003FFFh) code protected
bit 0
CP0: Code Protection bit
1 = Block 0 (000200-001FFFh) not code protected
0 = Block 0 (000200-001FFFh) code protected
Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set.
Legend:
R = Readable bit
C = Clearable bit
- n = Value when device is unprogrammed
REGISTER 19-7:
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
CONFIGURATION REGISTER 5 HIGH (CONFIG5H: BYTE ADDRESS 300009h)
R/C-1
R/C-1
U-0
U-0
U-0
U-0
U-0
U-0
CPD
CPB
—
—
—
—
—
—
bit 7
bit 0
bit 7
CPD: Data EEPROM Code Protection bit
1 = Data EEPROM not code protected
0 = Data EEPROM code protected
bit 6
CPB: Boot Block Code Protection bit
1 = Boot Block (000000-0001FFh) not code protected
0 = Boot Block (000000-0001FFh) code protected
bit 5-0
Unimplemented: Read as ‘0’
Legend:
R = Readable bit
C = Clearable bit
- n = Value when device is unprogrammed
© 2006 Microchip Technology Inc.
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
DS39564C-page 199
PIC18FXX2
REGISTER 19-8:
CONFIGURATION REGISTER 6 LOW (CONFIG6L: BYTE ADDRESS 30000Ah)
U-0
—
U-0
—
U-0
—
U-0
—
R/C-1
WRT3
(1)
R/C-1
WRT2
(1)
R/C-1
R/C-1
WRT1
WRT0
bit 7
bit 0
bit 7-4
Unimplemented: Read as ‘0’
bit 3
WRT3: Write Protection bit(1)
1 = Block 3 (006000-007FFFh) not write protected
0 = Block 3 (006000-007FFFh) write protected
bit 2
WRT2: Write Protection bit(1)
1 = Block 2 (004000-005FFFh) not write protected
0 = Block 2 (004000-005FFFh) write protected
bit 1
WRT1: Write Protection bit
1 = Block 1 (002000-003FFFh) not write protected
0 = Block 1 (002000-003FFFh) write protected
bit 0
WRT0: Write Protection bit
1 = Block 0 (000200h-001FFFh) not write protected
0 = Block 0 (000200h-001FFFh) write protected
Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set.
Legend:
R = Readable bit
C = Clearable bit
- n = Value when device is unprogrammed
REGISTER 19-9:
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
CONFIGURATION REGISTER 6 HIGH (CONFIG6H: BYTE ADDRESS 30000Bh)
R/C-1
R/C-1
C-1
U-0
U-0
U-0
U-0
U-0
WRTD
WRTB
WRTC
—
—
—
—
—
bit 7
bit 0
bit 7
WRTD: Data EEPROM Write Protection bit
1 = Data EEPROM not write protected
0 = Data EEPROM write protected
bit 6
WRTB: Boot Block Write Protection bit
1 = Boot Block (000000-0001FFh) not write protected
0 = Boot Block (000000-0001FFh) write protected
bit 5
WRTC: Configuration Register Write Protection bit
1 = Configuration registers (300000-3000FFh) not write protected
0 = Configuration registers (300000-3000FFh) write protected
bit 4-0
Unimplemented: Read as ‘0’
Note:
This bit is read only, and cannot be changed in User mode.
Legend:
R = Readable bit
C =Clearable bit
- n = Value when device is unprogrammed
DS39564C-page 200
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
© 2006 Microchip Technology Inc.
PIC18FXX2
REGISTER 19-10: CONFIGURATION REGISTER 7 LOW (CONFIG7L: BYTE ADDRESS 30000Ch)
U-0
—
U-0
—
U-0
—
U-0
—
R/C-1
EBTR3
(1)
R/C-1
EBTR2
(1)
R/C-1
R/C-1
EBTR1
EBTR0
bit 7
bit 0
bit 7-4
Unimplemented: Read as ‘0’
bit 3
EBTR3: Table Read Protection bit(1)
1 = Block 3 (006000-007FFFh) not protected from Table Reads executed in other blocks
0 = Block 3 (006000-007FFFh) protected from Table Reads executed in other blocks
bit 2
EBTR2: Table Read Protection bit(1)
1 = Block 2 (004000-005FFFh) not protected from Table Reads executed in other blocks
0 = Block 2 (004000-005FFFh) protected from Table Reads executed in other blocks
bit 1
EBTR1: Table Read Protection bit
1 = Block 1 (002000-003FFFh) not protected from Table Reads executed in other blocks
0 = Block 1 (002000-003FFFh) protected from Table Reads executed in other blocks
bit 0
EBTR0: Table Read Protection bit
1 = Block 0 (000200h-001FFFh) not protected from Table Reads executed in other blocks
0 = Block 0 (000200h-001FFFh) protected from Table Reads executed in other blocks
Note 1: Unimplemented in PIC18FX42 devices; maintain this bit set.
Legend:
R = Readable bit
C = Clearable bit
- n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
REGISTER 19-11: CONFIGURATION REGISTER 7 HIGH (CONFIG7H: BYTE ADDRESS 30000Dh)
U-0
R/C-1
U-0
U-0
U-0
U-0
U-0
U-0
—
EBTRB
—
—
—
—
—
—
bit 7
bit 0
bit 7
Unimplemented: Read as ‘0’
bit 6
EBTRB: Boot Block Table Read Protection bit
1 = Boot Block (000000-0001FFh) not protected from Table Reads executed in other blocks
0 = Boot Block (000000-0001FFh) protected from Table Reads executed in other blocks
bit 5-0
Unimplemented: Read as ‘0’
Legend:
R = Readable bit
C =Clearable bit
- n = Value when device is unprogrammed
© 2006 Microchip Technology Inc.
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
DS39564C-page 201
PIC18FXX2
REGISTER 19-12: DEVICE ID REGISTER 1 FOR PIC18FXX2 (DEVID1: BYTE ADDRESS 3FFFFEh)
R
R
R
R
R
R
R
R
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
bit 7
bit 0
bit 7-5
DEV2:DEV0: Device ID bits
000 = PIC18F252
001 = PIC18F452
100 = PIC18F242
101 = PIC18F442
bit 4-0
REV4:REV0: Revision ID bits
These bits are used to indicate the device revision.
Legend:
R = Readable bit
P =Programmable bit
- n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
REGISTER 19-13: DEVICE ID REGISTER 2 FOR PIC18FXX2 (DEVID2: BYTE ADDRESS 3FFFFFh)
R
R
R
R
R
R
R
R
DEV10
DEV9
DEV8
DEV7
DEV6
DEV5
DEV4
DEV3
bit 7
bit 7-0
bit 0
DEV10:DEV3: Device ID bits
These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the
part number.
Legend:
R = Readable bit
P =Programmable bit
- n = Value when device is unprogrammed
DS39564C-page 202
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
© 2006 Microchip Technology Inc.
PIC18FXX2
19.2
Watchdog Timer (WDT)
The Watchdog Timer is a free running on-chip RC oscillator, which does not require any external components.
This RC oscillator is separate from the RC oscillator of
the OSC1/CLKI pin. That means that the WDT will run,
even if the clock on the OSC1/CLKI and OSC2/CLKO/
RA6 pins of the device has been stopped, for example,
by execution of a SLEEP instruction.
During normal operation, a WDT time-out generates a
device RESET (Watchdog Timer Reset). If the device is
in SLEEP mode, a WDT time-out causes the device to
wake-up and continue with normal operation (Watchdog Timer Wake-up). The TO bit in the RCON register
will be cleared upon a WDT time-out.
The Watchdog Timer is enabled/disabled by a device
configuration bit. If the WDT is enabled, software execution may not disable this function. When the WDTEN
configuration bit is cleared, the SWDTEN bit enables/
disables the operation of the WDT.
The WDT time-out period values may be found in the
Electrical Specifications (Section 22.0) under parameter D031. Values for the WDT postscaler may be
assigned using the configuration bits.
Note:
The CLRWDT and SLEEP instructions clear
the WDT and the postscaler, if assigned to
the WDT and prevent it from timing out and
generating a device RESET condition.
Note:
When a CLRWDT instruction is executed
and the postscaler is assigned to the WDT,
the postscaler count will be cleared, but the
postscaler assignment is not changed.
19.2.1
CONTROL REGISTER
Register 19-14 shows the WDTCON register. This is a
readable and writable register, which contains a control
bit that allows software to override the WDT enable
configuration bit, only when the configuration bit has
disabled the WDT.
REGISTER 19-14: WDTCON REGISTER
U-0
U-0
U-0
U-0
U-0
U-0
U-0
R/W-0
—
—
—
—
—
—
—
SWDTEN
bit 7
bit 0
bit 7-1
Unimplemented: Read as ’0’
bit 0
SWDTEN: Software Controlled Watchdog Timer Enable bit
1 = Watchdog Timer is on
0 = Watchdog Timer is turned off if the WDTEN configuration bit in the configuration
register = ‘0’
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
- n = Value at POR
© 2006 Microchip Technology Inc.
DS39564C-page 203
PIC18FXX2
19.2.2
WDT POSTSCALER
The WDT has a postscaler that can extend the WDT
Reset period. The postscaler is selected at the time of
the device programming, by the value written to the
CONFIG2H configuration register.
FIGURE 19-1:
WATCHDOG TIMER BLOCK DIAGRAM
WDT Timer
Postscaler
8
8 - to - 1 MUX
WDTEN
Configuration bit
WDTPS2:WDTPS0
SWDTEN bit
WDT
Time-out
Note:
TABLE 19-2:
WDPS2:WDPS0 are bits in register CONFIG2H.
SUMMARY OF WATCHDOG TIMER REGISTERS
Name
CONFIG2H
RCON
WDTCON
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
—
—
—
—
WDTPS2
WDTPS2
WDTPS0
WDTEN
IPEN
—
—
RI
TO
PD
POR
BOR
—
—
—
—
—
—
—
SWDTEN
Legend: Shaded cells are not used by the Watchdog Timer.
DS39564C-page 204
© 2006 Microchip Technology Inc.
PIC18FXX2
19.3
Power-down Mode (SLEEP)
Power-down mode is entered by executing a SLEEP
instruction.
If enabled, the Watchdog Timer will be cleared, but
keeps running, the PD bit (RCON<3>) is cleared, the
TO (RCON<4>) bit is set, and the oscillator driver is
turned off. The I/O ports maintain the status they had
before the SLEEP instruction was executed (driving
high, low or hi-impedance).
For lowest current consumption in this mode, place all
I/O pins at either VDD or VSS, ensure no external circuitry is drawing current from the I/O pin, power-down
the A/D and disable external clocks. Pull all I/O pins
that are hi-impedance inputs, high or low externally, to
avoid switching currents caused by floating inputs. The
T0CKI input should also be at VDD or VSS for lowest
current consumption. The contribution from on-chip
pull-ups on PORTB should be considered.
The MCLR pin must be at a logic high level (VIHMC).
19.3.1
WAKE-UP FROM SLEEP
The device can wake-up from SLEEP through one of
the following events:
1.
2.
3.
External RESET input on MCLR pin.
Watchdog Timer Wake-up (if WDT was
enabled).
Interrupt from INT pin, RB port change or a
Peripheral Interrupt.
The following peripheral interrupts can wake the device
from SLEEP:
1.
2.
PSP read or write.
TMR1 interrupt. Timer1 must be operating as
an asynchronous counter.
3. TMR3 interrupt. Timer3 must be operating as
an asynchronous counter.
4. CCP Capture mode interrupt.
5. Special event trigger (Timer1 in Asynchronous
mode using an external clock).
6. MSSP (START/STOP) bit detect interrupt.
7. MSSP transmit or receive in Slave mode
(SPI/I2C).
8. USART RX or TX (Synchronous Slave mode).
9. A/D conversion (when A/D clock source is RC).
10. EEPROM write operation complete.
11. LVD interrupt.
External MCLR Reset will cause a device RESET. All
other events are considered a continuation of program
execution and will cause a “wake-up”. The TO and PD
bits in the RCON register can be used to determine the
cause of the device RESET. The PD bit, which is set on
power-up, is cleared when SLEEP is invoked. The TO
bit is cleared, if a WDT time-out occurred (and caused
wake-up).
When the SLEEP instruction is being executed, the next
instruction (PC + 2) is pre-fetched. For the device to
wake-up through an interrupt event, the corresponding
interrupt enable bit must be set (enabled). Wake-up is
regardless of the state of the GIE bit. If the GIE bit is
clear (disabled), the device continues execution at the
instruction after the SLEEP instruction. If the GIE bit is
set (enabled), the device executes the instruction after
the SLEEP instruction and then branches to the interrupt address. In cases where the execution of the
instruction following SLEEP is not desirable, the user
should have a NOP after the SLEEP instruction.
19.3.2
WAKE-UP USING INTERRUPTS
When global interrupts are disabled (GIE cleared) and
any interrupt source has both its interrupt enable bit
and interrupt flag bit set, one of the following will occur:
• If an interrupt condition (interrupt flag bit and interrupt enable bits are set) occurs before the execution of a SLEEP instruction, the SLEEP instruction
will complete as a NOP. Therefore, the WDT and
WDT postscaler will not be cleared, the TO bit will
not be set and PD bits will not be cleared.
• If the interrupt condition occurs during or after
the execution of a SLEEP instruction, the device
will immediately wake-up from SLEEP. The
SLEEP instruction will be completely executed
before the wake-up. Therefore, the WDT and
WDT postscaler will be cleared, the TO bit will be
set and the PD bit will be cleared.
Even if the flag bits were checked before executing a
SLEEP instruction, it may be possible for flag bits to
become set before the SLEEP instruction completes. To
determine whether a SLEEP instruction executed, test
the PD bit. If the PD bit is set, the SLEEP instruction
was executed as a NOP.
To ensure that the WDT is cleared, a CLRWDT instruction
should be executed before a SLEEP instruction.
Other peripherals cannot generate interrupts, since
during SLEEP, no on-chip clocks are present.
© 2006 Microchip Technology Inc.
DS39564C-page 205
PIC18FXX2
WAKE-UP FROM SLEEP THROUGH INTERRUPT(1,2)
FIGURE 19-2:
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
TOST(2)
CLKO(4)
INT pin
INTF flag
(INTCON<1>)
Interrupt Latency(3)
GIEH bit
(INTCON<7>)
Processor in
SLEEP
INSTRUCTION FLOW
PC
Instruction
Fetched
Instruction
Executed
Note
1:
2:
3:
4:
PC
PC+2
PC+4
PC+4
Inst(PC) = SLEEP
Inst(PC + 2)
Inst(PC + 4)
Inst(PC - 1)
SLEEP
Inst(PC + 2)
PC + 4
Dummy Cycle
0008h
000Ah
Inst(0008h)
Inst(000Ah)
Dummy Cycle
Inst(0008h)
XT, HS or LP Oscillator mode assumed.
GIE = '1' assumed. In this case, after wake-up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line.
TOST = 1024 TOSC (drawing not to scale). This delay will not occur for RC and EC Osc modes.
CLKO is not available in these Osc modes, but shown here for timing reference.
DS39564C-page 206
© 2006 Microchip Technology Inc.
PIC18FXX2
19.4
Program Verification and
Code Protection
Each of the five blocks has three code protection bits
associated with them. They are:
The overall structure of the code protection on the
PIC18 FLASH devices differs significantly from other
PICmicro devices.
• Code Protect bit (CPn)
• Write Protect bit (WRTn)
• External Block Table Read bit (EBTRn)
The user program memory is divided into five blocks.
One of these is a boot block of 512 bytes. The remainder of the memory is divided into four blocks on binary
boundaries.
Figure 19-3 shows the program memory organization
for 16- and 32-Kbyte devices, and the specific code
protection bit associated with each block. The actual
locations of the bits are summarized in Table 19-3.
FIGURE 19-3:
CODE PROTECTED PROGRAM MEMORY FOR PIC18F2XX/4XX
MEMORY SIZE/DEVICE
16 Kbytes
(PIC18FX42)
32 Kbytes
(PIC18FX52)
Address
Range
Boot Block
Boot Block
000000h
0001FFh
Block 0
Block 0
Block Code Protection
Controlled By:
CPB, WRTB, EBTRB
000200h
CP0, WRT0, EBTR0
001FFFh
002000h
Block 1
Block 1
CP1, WRT1, EBTR1
003FFFh
004000h
Unimplemented
Read 0’s
Block 2
Unimplemented
Read 0’s
Block 3
CP2, WRT2, EBTR2
005FFFh
006000h
CP3, WRT3, EBTR3
007FFFh
008000h
Unimplemented
Read 0’s
Unimplemented
Read 0’s
(Unimplemented Memory Space)
1FFFFFh
TABLE 19-3:
SUMMARY OF CODE PROTECTION REGISTERS
File Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
300008h
CONFIG5L
—
—
—
—
CP3
CP2
CP1
CP0
300009h
CONFIG5H
CPD
CPB
—
—
—
—
—
—
30000Ah
CONFIG6L
—
—
—
—
WRT3
WRT2
WRT1
WRT0
30000Bh
CONFIG6H
WRTD
WRTB
WRTC
—
—
—
—
—
30000Ch
CONFIG7L
—
—
—
—
EBTR3
EBTR2
EBTR1
EBTR0
30000Dh
CONFIG7H
—
EBTRB
—
—
—
—
—
—
Legend: Shaded cells are unimplemented.
© 2006 Microchip Technology Inc.
DS39564C-page 207
PIC18FXX2
19.4.1
PROGRAM MEMORY
CODE PROTECTION
The user memory may be read to or written from any
location using the Table Read and Table Write instructions. The device ID may be read with Table Reads.
The configuration registers may be read and written
with the Table Read and Table Write instructions.
outside of that block is not allowed to read, and will
result in reading ‘0’s. Figures 19-4 through 19-6
illustrate Table Write and Table Read protection.
Note:
In User mode, the CPn bits have no direct effect. CPn
bits inhibit external reads and writes. A block of user
memory may be protected from Table Writes if the
WRTn configuration bit is ‘0’. The EBTRn bits control
Table Reads. For a block of user memory with the
EBTRn bit set to ‘0’, a Table Read instruction that
executes from within that block is allowed to read. A
Table Read instruction that executes from a location
FIGURE 19-4:
Code protection bits may only be written to
a ‘0’ from a ‘1’ state. It is not possible to
write a ‘1’ to a bit in the ‘0’ state. Code protection bits are only set to ‘1’ by a full chip
erase or block erase function. The full chip
erase and block erase functions can only
be initiated via ICSP or an external
programmer.
TABLE WRITE (WRTn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
0001FFh
000200h
WRTB,EBTRB = 11
TBLPTR = 000FFF
WRT0,EBTR0 = 01
PC = 001FFE
TBLWT *
001FFFh
002000h
WRT1,EBTR1 = 11
003FFFh
004000h
PC = 004FFE
WRT2,EBTR2 = 11
TBLWT *
005FFFh
006000h
WRT3,EBTR3 = 11
007FFFh
Results: All Table Writes disabled to Blockn whenever WRTn = ‘0’.
DS39564C-page 208
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 19-5:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
WRTB,EBTRB = 11
0001FFh
000200h
TBLPTR = 000FFF
WRT0,EBTR0 = 10
001FFFh
002000h
PC = 002FFE
TBLRD *
WRT1,EBTR1 = 11
003FFFh
004000h
WRT2,EBTR2 = 11
005FFFh
006000h
WRT3,EBTR3 = 11
007FFFh
Results: All Table Reads from external blocks to Blockn are disabled whenever EBTRn = ‘0’.
TABLAT register returns a value of “0”.
FIGURE 19-6:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
WRTB,EBTRB = 11
0001FFh
000200h
TBLPTR = 000FFF
PC = 001FFE
WRT0,EBTR0 = 10
TBLRD *
001FFFh
002000h
WRT1,EBTR1 = 11
003FFFh
004000h
WRT2,EBTR2 = 11
005FFFh
006000h
WRT3,EBTR3 = 11
007FFFh
Results: Table Reads permitted within Blockn, even when EBTRBn = ‘0’.
TABLAT register returns the value of the data at the location TBLPTR.
© 2006 Microchip Technology Inc.
DS39564C-page 209
PIC18FXX2
19.4.2
DATA EEPROM
CODE PROTECTION
The entire Data EEPROM is protected from external
reads and writes by two bits: CPD and WRTD. CPD
inhibits external reads and writes of Data EEPROM.
WRTD inhibits external writes to Data EEPROM. The
CPU can continue to read and write Data EEPROM
regardless of the protection bit settings.
19.4.3
CONFIGURATION REGISTER
PROTECTION
The configuration registers can be write protected. The
WRTC bit controls protection of the configuration registers. In User mode, the WRTC bit is readable only. WRTC
can only be written via ICSP or an external programmer.
19.5
ID Locations
Eight memory locations (200000h - 200007h) are designated as ID locations, where the user can store
checksum or other code identification numbers. These
locations are accessible during normal execution
through the TBLRD and TBLWT instructions, or during
program/verify. The ID locations can be read when the
device is code protected.
The sequence for programming the ID locations is similar to programming the FLASH memory (see
Section 5.5.1).
19.6
In-Circuit Serial Programming
PIC18FXXX 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.
19.7
In-Circuit Debugger
When the DEBUG bit in configuration register
CONFIG4L 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 of the resources are not available for
general use. Table 19-4 shows which features are
consumed by the background debugger.
TABLE 19-4:
DEBUGGER RESOURCES
I/O pins
Stack
RB6, RB7
19.8
Low Voltage ICSP Programming
The LVP bit configuration register CONFIG4L enables
low voltage ICSP programming. This mode allows the
microcontroller to be programmed via ICSP using a
VDD source in the operating voltage range. This only
means that VPP does not have to be brought to VIHH,
but can instead be left at the normal operating voltage.
In this mode, the RB5/PGM pin is dedicated to the programming function and ceases to be a general purpose
I/O pin. During programming, VDD is applied to the
MCLR/VPP pin. To enter Programming mode, VDD must
be applied to the RB5/PGM, provided the LVP bit is set.
The LVP bit defaults to a (‘1’) from the factory.
Note 1: The High Voltage Programming mode is
always available, regardless of the state
of the LVP bit, by applying VIHH to the
MCLR pin.
2: While in low voltage ICSP mode, the RB5
pin can no longer be used as a general
purpose I/O pin, and should be held low
during normal operation to protect
against inadvertent ICSP mode entry.
3: When using low voltage ICSP programming (LVP), the pull-up on RB5 becomes
disabled. If TRISB bit 5 is cleared,
thereby setting RB5 as an output, LATB
bit 5 must also be cleared for proper
operation.
If Low Voltage Programming mode is not used, the LVP
bit can be programmed to a '0' and RB5/PGM becomes
a digital I/O pin. However, the LVP bit may only be programmed when programming is entered with VIHH on
MCLR/VPP.
It should be noted that once the LVP bit is programmed
to 0, only the High Voltage Programming mode is available and only High Voltage Programming mode can be
used to program the device.
When using low voltage ICSP, the part must be supplied 4.5V to 5.5V, if a bulk erase will be executed. This
includes reprogramming of the code protect bits from
an on-state to off-state. For all other cases of low voltage ICSP, the part may be programmed at the normal
operating voltage. This means unique user IDs, or user
code can be reprogrammed or added.
2 levels
Program Memory
512 bytes
Data Memory
10 bytes
DS39564C-page 210
To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial
Programming connections to MCLR/VPP, VDD, GND,
RB7 and RB6. This will interface to the In-Circuit
Debugger module available from Microchip or one of
the third party development tool companies.
© 2006 Microchip Technology Inc.
PIC18FXX2
20.0
INSTRUCTION SET SUMMARY
The PIC18FXXX instruction set adds many enhancements to the previous PICmicro instruction sets, while
maintaining an easy migration from these PICmicro
instruction sets.
Most instructions are a single program memory word
(16-bits), but there are three 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 PIC18FXXX instruction set summary in Table 20-2
lists byte-oriented, bit-oriented, literal and control
operations. Table 20-1 shows the opcode field
descriptions.
Most byte-oriented instructions have three operands:
1.
2.
3.
The file register (specified by ‘f’)
The destination of the result
(specified by ‘d’)
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 zero, the
result is placed in the WREG register. If 'd' is one, the
result is placed in the file register specified in the
instruction.
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 three double-word instructions. These three instructions were
made double-word instructions so that all the required
information is available in these 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 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.
All bit-oriented instructions have three operands:
One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 μs. If a conditional test is
true or the program counter is changed as a result of an
instruction, the instruction execution time is 2 μs.
Two-word branch instructions (if true) would take 3 μs.
1.
2.
Figure 20-1 shows the general formats that the
instructions can have.
3.
The file register (specified by ‘f’)
The bit in the file register
(specified by ‘b’)
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 designator 'f' represents the number of the file in which the
bit is located.
© 2006 Microchip Technology Inc.
All examples use the format ‘nnh’ to represent a
hexadecimal number, where ‘h’ signifies a
hexadecimal digit.
The Instruction Set Summary, shown in Table 20-2,
lists the instructions recognized by the Microchip
Assembler (MPASMTM).
Section 20.1 provides a description of each instruction.
DS39564C-page 211
PIC18FXX2
TABLE 20-1:
OPCODE FIELD DESCRIPTIONS
Field
Description
a
RAM 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.
d
Destination 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
f
8-bit Register file address (0x00 to 0xFF)
fs
12-bit Register file address (0x000 to 0xFFF). This is the source address.
fd
12-bit Register file address (0x000 to 0xFFF). This is the destination address.
k
Literal 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.
Only used 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)
n
The relative address (2’s complement number) for relative branch instructions, or the direct address for
Call/Branch and Return instructions
PRODH
Product of Multiply high byte
PRODL
Product of Multiply low byte
s
Fast 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)
u
Unused or Unchanged
WREG
Working register (accumulator)
x
Don'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.
TBLPTR
21-bit Table Pointer (points to a Program Memory location)
TABLAT
8-bit Table Latch
TOS
Top-of-Stack
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
GIE
Global Interrupt Enable bit
WDT
Watchdog Timer
TO
Time-out bit
PD
Power-down bit
C, DC, Z, OV, N ALU status bits Carry, Digit Carry, Zero, Overflow, Negative
[
]
Optional
(
)
Contents
→
Assigned to
< >
Register bit field
∈
In the set of
italics
User defined term (font is courier)
DS39564C-page 212
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 20-1:
GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations
15
10
9 8 7
OPCODE d
a
Example Instruction
0
ADDWF MYREG, W, B
f (FILE #)
d = 0 for result destination to be WREG register
d = 1 for result destination to be file register (f)
a = 0 to force Access Bank
a = 1 for BSR to select bank
f = 8-bit file register address
Byte to Byte move operations (2-word)
15
12 11
OPCODE
15
0
f (Source FILE #)
12 11
MOVFF MYREG1, MYREG2
0
f (Destination FILE #)
1111
f = 12-bit file register address
Bit-oriented file register operations
15
12 11
9 8 7
OPCODE b (BIT #) a
0
BSF MYREG, bit, B
f (FILE #)
b = 3-bit position of bit in file register (f)
a = 0 to force Access Bank
a = 1 for BSR to select bank
f = 8-bit file register address
Literal operations
15
8
7
OPCODE
0
MOVLW 0x7F
k (literal)
k = 8-bit immediate value
Control operations
CALL, GOTO and Branch operations
15
8 7
OPCODE
15
0
GOTO Label
n<7:0> (literal)
12 11
0
n<19:8> (literal)
1111
n = 20-bit immediate value
15
8 7
OPCODE
15
S
0
CALL MYFUNC
n<7:0> (literal)
12 11
0
n<19:8> (literal)
S = Fast bit
15
OPCODE
15
OPCODE
© 2006 Microchip Technology Inc.
11 10
0
BRA MYFUNC
n<10:0> (literal)
8 7
n<7:0> (literal)
0
BC MYFUNC
DS39564C-page 213
PIC18FXX2
TABLE 20-2:
PIC18FXXX INSTRUCTION SET
Mnemonic,
Operands
16-Bit Instruction Word
Description
Cycles
MSb
LSb
Status
Affected
Notes
BYTE-ORIENTED FILE REGISTER OPERATIONS
ADDWF
ADDWFC
ANDWF
CLRF
COMF
CPFSEQ
CPFSGT
CPFSLT
DECF
DECFSZ
DCFSNZ
INCF
INCFSZ
INFSNZ
IORWF
MOVF
MOVFF
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
MOVWF
MULWF
NEGF
RLCF
RLNCF
RRCF
RRNCF
SETF
SUBFWB
f, a
f, a
f, a
f, d, a
f, d, a
f, d, a
f, d, a
f, a
f, d, a
SUBWF
SUBWFB
f, d, a
f, d, a
SWAPF
TSTFSZ
XORWF
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
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
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
1
1
1
1
1
1
1
1
0010 01da0
0010
0da
0001 01da
0110 101a
0001 11da
0110 001a
0110 010a
0110 000a
0000 01da
0010 11da
0100 11da
0010 10da
0011 11da
0100 10da
0001 00da
0101 00da
1100 ffff
1111 ffff
0110 111a
0000 001a
0110 110a
0011 01da
0100 01da
0011 00da
0100 00da
0110 100a
0101 01da
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
1
1
0101
0101
11da
10da
ffff
ffff
ffff C, DC, Z, OV, N
ffff C, DC, Z, OV, N
1
1 (2 or 3)
1
0011
0110
0001
10da
011a
10da
ffff
ffff
ffff
ffff None
ffff None
ffff Z, N
4
1, 2
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
None
None
C, DC, Z, OV, N
C, Z, N
Z, N
C, Z, N
Z, N
None
C, DC, Z, OV, N
1, 2
1, 2
1, 2
1, 2
BIT-ORIENTED FILE REGISTER OPERATIONS
BCF
BSF
BTFSC
BTFSS
BTG
f, b, a
f, b, a
f, b, a
f, b, a
f, d, a
Bit Clear f
Bit Set f
Bit Test f, Skip if Clear
Bit Test f, Skip if Set
Bit Toggle f
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 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 2-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.
5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.
DS39564C-page 214
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 20-2:
PIC18FXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word
Mnemonic,
Operands
Description
Cycles
MSb
LSb
Status
Affected
Notes
CONTROL OPERATIONS
BC
BN
BNC
BNN
BNOV
BNZ
BOV
BRA
BZ
CALL
n
n
n
n
n
n
n
n
n
n, s
CLRWDT
DAW
GOTO
—
—
n
NOP
NOP
POP
PUSH
RCALL
RESET
RETFIE
—
—
—
—
n
RETLW
RETURN
SLEEP
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
2
1 (2)
1 (2)
1 (2)
2
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 subroutine1st word
2nd word
Clear Watchdog Timer
Decimal Adjust WREG
Go to address1st 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
k
s
—
Return with literal in WREG
Return from Subroutine
Go into Standby mode
1
1
1
1
2
1
2
1110
1110
1110
1110
1110
1110
1110
1101
1110
1110
1111
0000
0000
1110
1111
0000
1111
0000
0000
1101
0000
0000
0010
0110
0011
0111
0101
0001
0100
0nnn
0000
110s
kkkk
0000
0000
1111
kkkk
0000
xxxx
0000
0000
1nnn
0000
0000
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0000
0000
kkkk
kkkk
0000
xxxx
0000
0000
nnnn
1111
0001
2
2
1
0000
0000
0000
1100
0000
0000
kkkk
0001
0000
1
1
2
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
nnnn
kkkk
kkkk
0100
0111
kkkk
kkkk
0000
xxxx
0110
0101
nnnn
1111
000s
None
None
None
None
None
None
None
None
None
None
TO, PD
C
None
None
None
None
None
None
All
GIE/GIEH,
PEIE/GIEL
kkkk None
001s None
0011 TO, PD
4
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 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 2-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.
5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.
© 2006 Microchip Technology Inc.
DS39564C-page 215
PIC18FXX2
TABLE 20-2:
PIC18FXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word
Mnemonic,
Operands
Description
Cycles
MSb
LSb
Status
Affected
Notes
LITERAL OPERATIONS
ADDLW
ANDLW
IORLW
LFSR
k
k
k
f, k
MOVLB
MOVLW
MULLW
RETLW
SUBLW
XORLW
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 FSRx 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
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
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 (5)
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 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 2-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.
5: If the Table Write starts the write cycle to internal memory, the write will continue until terminated.
DS39564C-page 216
© 2006 Microchip Technology Inc.
PIC18FXX2
20.1
Instruction Set
ADDLW
ADD literal to W
Syntax:
[ label ] ADDLW
Operands:
0 ≤ k ≤ 255
Operation:
(W) + k → W
Status Affected:
N, OV, C, DC, Z
Encoding:
0000
Description:
1111
kkkk
kkkk
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
Decode
Example:
Q2
Q3
Q4
Read
literal 'k'
Process
Data
Write to W
ADDLW
0x15
Before Instruction
W
k
=
0x10
ADDWF
ADD W to f
Syntax:
[ label ] ADDWF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) + (f) → dest
Status Affected:
N, OV, C, DC, Z
Encoding:
0010
01da
f [,d [,a]
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 will be selected. If ‘a’ is 1, the
BSR is used.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
ADDWF
REG, 0, 0
After Instruction
W
=
0x25
Example:
Before Instruction
W
REG
=
=
0x17
0xC2
After Instruction
W
REG
© 2006 Microchip Technology Inc.
=
=
0xD9
0xC2
DS39564C-page 217
PIC18FXX2
ADDWFC
ADD W and Carry bit to f
ANDLW
AND literal with W
Syntax:
[ label ] ADDWFC
Syntax:
[ label ] ANDLW
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
f [,d [,a]
Operation:
(W) + (f) + (C) → dest
Status Affected:
N,OV, C, DC, Z
Encoding:
0010
Description:
1
Cycles:
1
0 ≤ k ≤ 255
Operation:
(W) .AND. k → W
Status Affected:
N,Z
Encoding:
ffff
ffff
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
will be selected. If ‘a’ is 1, the BSR
will not be overridden.
Words:
0000
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
ADDWFC
kkkk
kkkk
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
Decode
Q2
Q3
Q4
Read literal
'k'
Process
Data
Write to W
ANDLW
0x5F
Before Instruction
W
=
0xA3
After Instruction
W
Example:
1011
Description:
Example:
Q Cycle Activity:
Q1
Decode
00da
Operands:
k
=
0x03
REG, 0, 1
Before Instruction
Carry bit =
REG
=
W
=
1
0x02
0x4D
After Instruction
Carry bit =
REG
=
W
=
DS39564C-page 218
0
0x02
0x50
© 2006 Microchip Technology Inc.
PIC18FXX2
ANDWF
AND W with f
Syntax:
[ label ] ANDWF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
f [,d [,a]
Operation:
(W) .AND. (f) → dest
Status Affected:
N,Z
Encoding:
0001
ffff
ffff
-128 ≤ n ≤ 127
Operation:
if carry bit is ’1’
(PC) + 2 + 2n → PC
Status Affected:
None
1110
0010
nnnn
nnnn
Words:
1
1
Cycles:
1(2)
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
ANDWF
REG, 0, 0
Before Instruction
=
=
0x17
0xC2
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
Decode
After Instruction
=
=
Operands:
n
1
Cycles:
W
REG
[ label ] BC
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:
W
REG
Syntax:
Description:
The contents of W are AND’ed 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 will be
selected. If ‘a’ is 1, the BSR will not
be overridden (default).
Example:
Branch if Carry
Encoding:
01da
Description:
Decode
BC
0x02
0xC2
Example:
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
HERE
BC
5
Before Instruction
PC
=
address (HERE)
=
=
=
=
1;
address (HERE+12)
0;
address (HERE+2)
After Instruction
If Carry
PC
If Carry
PC
© 2006 Microchip Technology Inc.
DS39564C-page 219
PIC18FXX2
BCF
Bit Clear f
Syntax:
[ label ] BCF
Operands:
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
Operation:
0 → f<b>
Status Affected:
None
Encoding:
1001
Description:
Branch if Negative
Syntax:
[ label ] BN
Operands:
-128 ≤ n ≤ 127
Operation:
if negative bit is ’1’
(PC) + 2 + 2n → PC
Status Affected:
None
Encoding:
bbba
ffff
ffff
1110
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
Example:
BCF
Before Instruction
FLAG_REG = 0xC7
After Instruction
FLAG_REG = 0x47
FLAG_REG,
n
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)
Bit 'b' in register 'f' is cleared. If ‘a’
is 0, the Access Bank will be
selected, overriding the BSR value.
If ‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
Decode
f,b[,a]
BN
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
7, 0
If No Jump:
Q1
Decode
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
Example:
HERE
BN
Jump
Before Instruction
PC
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE+2)
After Instruction
If Negative
PC
If Negative
PC
DS39564C-page 220
© 2006 Microchip Technology Inc.
PIC18FXX2
BNC
Branch if Not Carry
BNN
Branch if Not Negative
Syntax:
[ label ] BNC
Syntax:
[ label ] BNN
Operands:
-128 ≤ n ≤ 127
Operands:
-128 ≤ n ≤ 127
Operation:
if carry bit is ’0’
(PC) + 2 + 2n → PC
Operation:
if negative bit is ’0’
(PC) + 2 + 2n → PC
Status Affected:
None
Status Affected:
None
Encoding:
1110
n
0011
nnnn
nnnn
Encoding:
1110
n
0111
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.
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
Words:
1
Cycles:
1(2)
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read literal
'n'
Process
Data
Write to PC
Decode
Read literal
'n'
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
If No Jump:
Q1
Decode
Example:
HERE
BNC
Jump
Before Instruction
PC
Decode
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
Example:
HERE
BNN
Jump
Before Instruction
=
address (HERE)
After Instruction
If Carry
PC
If Carry
PC
If No Jump:
Q1
PC
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE+2)
After Instruction
=
=
=
=
0;
address (Jump)
1;
address (HERE+2)
© 2006 Microchip Technology Inc.
If Negative
PC
If Negative
PC
DS39564C-page 221
PIC18FXX2
BNOV
Branch if Not Overflow
BNZ
Branch if Not Zero
Syntax:
[ label ] BNOV
Syntax:
[ label ] BNZ
Operands:
-128 ≤ n ≤ 127
Operands:
-128 ≤ n ≤ 127
Operation:
if overflow bit is ’0’
(PC) + 2 + 2n → PC
Operation:
if zero bit is ’0’
(PC) + 2 + 2n → PC
Status Affected:
None
Status Affected:
None
Encoding:
1110
n
0101
nnnn
nnnn
Encoding:
1110
n
0001
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.
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
Words:
1
Cycles:
1(2)
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read literal
'n'
Process
Data
Write to PC
Decode
Read literal
'n'
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
If No Jump:
Q1
Decode
Example:
HERE
BNOV Jump
Before Instruction
PC
DS39564C-page 222
Decode
Example:
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
HERE
BNZ
Jump
Before Instruction
=
address (HERE)
After Instruction
If Overflow
PC
If Overflow
PC
If No Jump:
Q1
PC
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE+2)
After Instruction
=
=
=
=
0;
address (Jump)
1;
address (HERE+2)
If Zero
PC
If Zero
PC
© 2006 Microchip Technology Inc.
PIC18FXX2
BRA
Unconditional Branch
BSF
Bit Set f
Syntax:
[ label ] BRA
Syntax:
[ label ] BSF
Operands:
-1024 ≤ n ≤ 1023
Operands:
Operation:
(PC) + 2 + 2n → PC
Status Affected:
None
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
Operation:
1 → f<b>
Status Affected:
None
Encoding:
Description:
1101
1
Cycles:
2
Q Cycle Activity:
Q1
No
operation
0nnn
nnnn
nnnn
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:
Decode
n
Q2
Q3
Q4
Read literal
'n'
Process
Data
Write to PC
No
operation
No
operation
No
operation
Encoding:
HERE
BRA
Jump
PC
=
address (HERE)
=
address (Jump)
After Instruction
PC
© 2006 Microchip Technology Inc.
ffff
ffff
Bit 'b' in register 'f' is set. If ‘a’ is 0
Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then
the bank will be selected as per the
BSR value.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
BSF
FLAG_REG, 7, 1
Before Instruction
FLAG_REG
Before Instruction
bbba
Description:
Example:
Example:
1000
f,b[,a]
=
0x0A
=
0x8A
After Instruction
FLAG_REG
DS39564C-page 223
PIC18FXX2
BTFSC
Bit Test File, Skip if Clear
BTFSS
Bit Test File, Skip if Set
Syntax:
[ label ] BTFSC f,b[,a]
Syntax:
[ label ] BTFSS f,b[,a]
Operands:
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
Operation:
skip if (f<b>) = 0
Operation:
skip if (f<b>) = 1
Status Affected:
None
Status Affected:
None
Encoding:
1011
bbba
ffff
ffff
Encoding:
1010
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
execution is discarded, and a NOP is
executed instead, making this a twocycle instruction. If ‘a’ is 0, the
Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then
the bank will be selected as per the
BSR value (default).
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 execution, is discarded and a
NOP is executed instead, making this
a two-cycle instruction. If ‘a’ is 0, the
Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then
the bank will be selected as per the
BSR value (default).
Words:
1
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Cycles:
1(2)
Note:
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
3 cycles if skip and followed
by a 2-word instruction.
Q2
Q3
Q4
Decode
Read
register 'f'
Process Data
No
operation
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
If skip:
Decode
Q2
Q3
Q4
Read
register 'f'
Process Data
No
operation
If skip:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
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
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
DS39564C-page 224
HERE
FALSE
TRUE
BTFSS
:
:
FLAG, 1, 0
Before Instruction
=
address (HERE)
After Instruction
If FLAG<1>
PC
If FLAG<1>
PC
Example:
PC
=
address (HERE)
=
=
=
=
0;
address (FALSE)
1;
address (TRUE)
After Instruction
=
=
=
=
0;
address (TRUE)
1;
address (FALSE)
If FLAG<1>
PC
If FLAG<1>
PC
© 2006 Microchip Technology Inc.
PIC18FXX2
BTG
Bit Toggle f
BOV
Branch if Overflow
Syntax:
[ label ] BTG f,b[,a]
Syntax:
[ label ] BOV
Operands:
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
Operands:
-128 ≤ n ≤ 127
Operation:
if overflow bit is ’1’
(PC) + 2 + 2n → PC
Status Affected:
None
Operation:
(f<b>) → f<b>
Status Affected:
None
Encoding:
Description:
bbba
ffff
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
Example:
BTG
PORTC,
=
0111 0101 [0x75]
After Instruction:
PORTC
1110
=
0110 0101 [0x65]
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
4, 0
Before Instruction:
PORTC
ffff
Bit 'b' in data memory location 'f' is
inverted. If ‘a’ is 0, the Access Bank
will be selected, overriding the BSR
value. If ‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
Decode
Encoding:
0111
n
If No Jump:
Q1
Decode
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
Example:
HERE
BOV
Jump
Before Instruction
PC
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE+2)
After Instruction
If Overflow
PC
If Overflow
PC
© 2006 Microchip Technology Inc.
DS39564C-page 225
PIC18FXX2
BZ
Branch if Zero
CALL
Subroutine Call
Syntax:
[ label ] BZ
Syntax:
[ label ] CALL k [,s]
Operands:
-128 ≤ n ≤ 127
Operands:
Operation:
if Zero bit is ’1’
(PC) + 2 + 2n → PC
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
Status Affected:
n
None
Encoding:
1110
Description:
0000
nnnn
nnnn
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
Decode
Q2
Q3
Q4
Read literal
'n'
Process
Data
No
operation
Example:
HERE
BZ
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
1111
110s
k19kkk
k7kkk
kkkk
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
Jump
Before Instruction
PC
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE+2)
After Instruction
If Zero
PC
If Zero
PC
kkkk0
kkkk8
Example:
HERE
CALL
THERE,1
Before Instruction
PC
=
address (HERE)
After Instruction
PC
=
TOS
=
WS
=
BSRS
=
STATUSS=
DS39564C-page 226
address (THERE)
address (HERE + 4)
W
BSR
STATUS
© 2006 Microchip Technology Inc.
PIC18FXX2
CLRF
Clear f
Syntax:
[ label ] CLRF
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
000h → f
1→Z
Status Affected:
Z
Encoding:
Description:
0110
f [,a]
101a
ffff
ffff
CLRWDT
Clear Watchdog Timer
Syntax:
[ label ] CLRWDT
Operands:
None
Operation:
000h → WDT,
000h → WDT postscaler,
1 → TO,
1 → PD
Status Affected:
TO, PD
Encoding:
0000
0000
0000
0100
Clears the contents of the specified
register. If ‘a’ is 0, the Access Bank
will be selected, overriding the BSR
value. If ‘a’ = 1, then the bank will
be selected as per the BSR value
(default).
Description:
CLRWDT instruction resets the
Watchdog Timer. It also resets the
postscaler of the WDT. Status bits
TO and PD are set.
Words:
1
Words:
1
Cycles:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
Decode
Example:
Example:
CLRF
FLAG_REG,1
Before Instruction
FLAG_REG
Q3
Q4
Process
Data
No
operation
CLRWDT
Before Instruction
WDT Counter
=
0x5A
=
0x00
After Instruction
FLAG_REG
Q2
No
operation
© 2006 Microchip Technology Inc.
=
?
=
=
=
=
0x00
0
1
1
After Instruction
WDT Counter
WDT Postscaler
TO
PD
DS39564C-page 227
PIC18FXX2
COMF
Complement f
Syntax:
[ label ] COMF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
( f ) → dest
Status Affected:
N, Z
Encoding:
0001
Description:
1
Cycles:
1
Q Cycle Activity:
Q1
Syntax:
[ label ] CPFSEQ
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(f) – (W),
skip if (f) = (W)
(unsigned comparison)
Status Affected:
None
Encoding:
0110
001a
f [,a]
ffff
ffff
Description:
Compares the contents of data
memory 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 twocycle instruction. If ‘a’ is 0, the
Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then
the bank will be selected as per the
BSR value (default).
Q2
Q3
Q4
Words:
1
Process
Data
Write to
destination
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
COMF
Before Instruction
=
0x13
After Instruction
REG
W
ffff
Compare f with W, skip if f = W
Read
register 'f'
Example:
REG
ffff
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 will be
selected, overriding the BSR value.
If ‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
Decode
11da
f [,d [,a]
CPFSEQ
=
=
0x13
0xEC
REG, 0, 0
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
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
NEQUAL
EQUAL
CPFSEQ REG, 0
:
:
Before Instruction
PC Address
W
REG
=
=
=
HERE
?
?
=
=
≠
=
W;
Address (EQUAL)
W;
Address (NEQUAL)
After Instruction
If REG
PC
If REG
PC
DS39564C-page 228
© 2006 Microchip Technology Inc.
PIC18FXX2
CPFSGT
Compare f with W, skip if f > W
CPFSLT
Compare f with W, skip if f < W
Syntax:
[ label ] CPFSGT
Syntax:
[ label ] CPFSLT
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(f) − (W),
skip if (f) > (W)
(unsigned comparison)
Operation:
(f) – (W),
skip if (f) < (W)
(unsigned comparison)
Status Affected:
None
Status Affected:
None
Encoding:
Description:
0110
010a
f [,a]
ffff
ffff
Compares the contents of data
memory 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 will be
selected, overriding the BSR value.
If ‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Decode
Encoding:
Q2
Q3
Q4
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
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
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
HERE
NGREATER
GREATER
CPFSGT REG, 0
:
:
>
=
≤
=
W;
Address (GREATER)
W;
Address (NGREATER)
After Instruction
If REG
PC
If REG
PC
© 2006 Microchip Technology Inc.
Q4
No
operation
Q1
No
operation
Address (HERE)
?
Q3
Process
Data
No
operation
No
operation
=
=
Q2
Read
register 'f'
If skip:
No
operation
PC
W
ffff
Words:
No
operation
Before Instruction
ffff
Compares the contents of data
memory 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 will be selected. If ’a’
is 1, the BSR will not be overridden
(default).
No
operation
Example:
000a
Description:
Decode
Read
register 'f'
0110
f [,a]
Example:
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
HERE
NLESS
LESS
CPFSLT REG, 1
:
:
Before Instruction
PC
W
=
=
Address (HERE)
?
<
=
≥
=
W;
Address (LESS)
W;
Address (NLESS)
After Instruction
If REG
PC
If REG
PC
DS39564C-page 229
PIC18FXX2
DAW
Decimal Adjust W Register
DECF
Decrement f
Syntax:
[ label ] DAW
Syntax:
[ label ] DECF f [,d [,a]
Operands:
None
Operands:
Operation:
If [W<3:0> >9] or [DC = 1] then
(W<3:0>) + 6 → W<3:0>;
else
(W<3:0>) → W<3:0>;
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – 1 → dest
Status Affected:
C, DC, N, OV, Z
If [W<7:4> >9] or [C = 1] then
(W<7:4>) + 6 → W<7:4>;
else
(W<7:4>) → W<7:4>;
Status Affected:
Encoding:
0000
0000
0000
1
Cycles:
1
Q Cycle Activity:
Q1
Q3
Q4
Process
Data
Write
W
Example1:
DAW
Before Instruction
=
=
=
0xA5
0
0
ffff
Words:
1
Cycles:
1
Decode
Q2
ffff
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 will be selected, overriding
the BSR value. If ’a’ = 1, then the
bank will be selected as per the
BSR value (default).
Q Cycle Activity:
Q1
Read
register W
01da
Description:
0111
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:
W
C
DC
0000
C
Description:
Decode
Encoding:
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example:
DECF
CNT,
1, 0
Before Instruction
CNT
Z
=
=
0x01
0
After Instruction
CNT
Z
=
=
0x00
1
After Instruction
W
C
DC
=
=
=
0x05
1
0
Example 2:
Before Instruction
W
C
DC
=
=
=
0xCE
0
0
After Instruction
W
C
DC
=
=
=
DS39564C-page 230
0x34
1
0
© 2006 Microchip Technology Inc.
PIC18FXX2
DECFSZ
Decrement f, skip if 0
DCFSNZ
Decrement f, skip if not 0
Syntax:
[ label ] DECFSZ f [,d [,a]]
Syntax:
[ label ] DCFSNZ
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – 1 → dest,
skip if result = 0
Operation:
(f) – 1 → dest,
skip if result ≠ 0
Status Affected:
None
Status Affected:
None
Encoding:
0010
11da
ffff
ffff
Encoding:
0100
11da
f [,d [,a]
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 will be selected, overriding
the BSR value. If ’a’ = 1, then the
bank will be selected as per the
BSR value (default).
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 not 0, the next
instruction, which is already
fetched, is discarded, and a NOP is
executed instead, making it a twocycle instruction. If ’a’ is 0, the
Access Bank will be selected,
overriding the BSR value. If ’a’ = 1,
then the bank will be selected as
per the BSR value (default).
Words:
1
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Decode
If skip:
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
If skip:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
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
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
DECFSZ
GOTO
CNT, 1, 1
LOOP
Example:
HERE
Example:
CONTINUE
Before Instruction
PC
=
=
=
=
≠
=
DCFSNZ
:
:
TEMP, 1, 0
Before Instruction
Address (HERE)
After Instruction
CNT
If CNT
PC
If CNT
PC
HERE
ZERO
NZERO
TEMP
=
?
=
=
=
≠
=
TEMP - 1,
0;
Address (ZERO)
0;
Address (NZERO)
After Instruction
CNT - 1
0;
Address (CONTINUE)
0;
Address (HERE+2)
© 2006 Microchip Technology Inc.
TEMP
If TEMP
PC
If TEMP
PC
DS39564C-page 231
PIC18FXX2
GOTO
Unconditional Branch
INCF
Increment f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ k ≤ 1048575
Operands:
Operation:
k → PC<20:1>
Status Affected:
None
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) + 1 → dest
Status Affected:
C, DC, N, OV, Z
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
Description:
1110
1111
GOTO k
1111
k19kkk
k7kkk
kkkk
kkkk0
kkkk8
GOTO allows an unconditional
branch anywhere within entire
2 Mbyte memory 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)
Encoding:
0010
INCF
f [,d [,a]
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 will be
selected, overriding the BSR value.
If ’a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example:
INCF
CNT, 1, 0
Before Instruction
CNT
Z
C
DC
=
=
=
=
0xFF
0
?
?
After Instruction
CNT
Z
C
DC
DS39564C-page 232
=
=
=
=
0x00
1
1
1
© 2006 Microchip Technology Inc.
PIC18FXX2
INCFSZ
Increment f, skip if 0
INFSNZ
Increment f, skip if not 0
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) + 1 → dest,
skip if result = 0
Operation:
(f) + 1 → dest,
skip if result ≠ 0
Status Affected:
None
Status Affected:
None
Encoding:
0011
INCFSZ
11da
f [,d [,a]
ffff
ffff
Encoding:
0100
INFSNZ
10da
f [,d [,a]
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 will be selected, overriding
the BSR value. If ’a’ = 1, then the
bank will be selected as per the
BSR value (default).
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 not 0, the next
instruction, which is already
fetched, is discarded, and a NOP is
executed instead, making it a twocycle instruction. If ’a’ is 0, the
Access Bank will be selected, overriding the BSR value. If ’a’ = 1, then
the bank will be selected as per the
BSR value (default).
Words:
1
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Decode
If skip:
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
If skip:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
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
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE
NZERO
ZERO
INCFSZ
:
:
Before Instruction
PC
=
=
=
=
≠
=
Example:
HERE
ZERO
NZERO
INFSNZ
REG, 1, 0
Before Instruction
Address (HERE)
After Instruction
CNT
If CNT
PC
If CNT
PC
CNT, 1, 0
PC
=
Address (HERE)
After Instruction
CNT + 1
0;
Address (ZERO)
0;
Address (NZERO)
© 2006 Microchip Technology Inc.
REG
If REG
PC
If REG
PC
=
≠
=
=
=
REG + 1
0;
Address (NZERO)
0;
Address (ZERO)
DS39564C-page 233
PIC18FXX2
IORLW
Inclusive OR literal with W
IORWF
Inclusive OR W with f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) .OR. (f) → dest
Status Affected:
N, Z
IORLW k
Operands:
0 ≤ k ≤ 255
Operation:
(W) .OR. k → W
Status Affected:
N, Z
Encoding:
0000
Description:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Example:
kkkk
Q2
Q3
Q4
Read
literal 'k'
Process
Data
Write to W
IORLW
Before Instruction
=
0x9A
After Instruction
W
kkkk
The contents of W are OR’ed with
the eight-bit literal 'k'. The result is
placed in W.
Words:
W
1001
=
0x35
Encoding:
0001
IORWF
00da
f [,d [,a]
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 will be selected, overriding the BSR value. If ’a’ = 1, then
the bank will be selected as per the
BSR value (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
0xBF
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
IORWF
RESULT, 0, 1
Example:
Before Instruction
RESULT =
W
=
0x13
0x91
After Instruction
RESULT =
W
=
DS39564C-page 234
0x13
0x93
© 2006 Microchip Technology Inc.
PIC18FXX2
LFSR
Load FSR
MOVF
Move f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0≤f≤2
0 ≤ k ≤ 4095
Operands:
Operation:
k → FSRf
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Status Affected:
None
Operation:
f → dest
Status Affected:
N, Z
Encoding:
LFSR f,k
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
FSR2L
=
=
0x03
0xAB
Encoding:
MOVF
0101
f [,d [,a]
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' is 1, 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 will be
selected, overriding the BSR value.
If ‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Example:
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write W
MOVF
REG, 0, 0
Before Instruction
REG
W
=
=
0x22
0xFF
=
=
0x22
0x22
After Instruction
REG
W
© 2006 Microchip Technology Inc.
DS39564C-page 235
PIC18FXX2
MOVFF
Move f to f
MOVLB
Move literal to low nibble in BSR
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ fs ≤ 4095
0 ≤ fd ≤ 4095
Operands:
0 ≤ k ≤ 255
Operation:
k → BSR
None
MOVFF fs,fd
Operation:
(fs) → fd
Status Affected:
Status Affected:
None
Encoding:
Encoding:
1st word (source)
2nd word (destin.)
1100
1111
Description:
ffff
ffff
ffff
ffff
ffffs
ffffd
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.
Note:
Words:
2
Cycles:
2 (3)
Q Cycle Activity:
Q1
Q2
Q3
Q4
Read
register 'f'
(src)
Process
Data
No
operation
Decode
No
operation
No
operation
Write
register 'f'
(dest)
No dummy
read
MOVFF
0000
0001
kkkk
kkkk
Description:
The 8-bit literal 'k' is loaded into
the Bank Select Register (BSR).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Example:
Q2
Q3
Q4
Read literal
'k'
Process
Data
Write
literal 'k' to
BSR
MOVLB
5
Before Instruction
BSR register
=
0x02
=
0x05
After Instruction
BSR register
The MOVFF instruction
should not be used to modify interrupt settings while
any interrupt is enabled.
See Section 8.0 for more
information.
Decode
Example:
MOVLB k
REG1, REG2
Before Instruction
REG1
REG2
=
=
0x33
0x11
=
=
0x33,
0x33
After Instruction
REG1
REG2
DS39564C-page 236
© 2006 Microchip Technology Inc.
PIC18FXX2
MOVLW
Move literal to W
MOVWF
Move W to f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ k ≤ 255
Operands:
Operation:
k→W
0 ≤ f ≤ 255
a ∈ [0,1]
Status Affected:
None
Operation:
(W) → f
Status Affected:
None
Encoding:
0000
Description:
MOVLW k
1110
kkkk
The eight-bit literal 'k' is loaded
into W.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Example:
Q2
Q3
Q4
Read
literal 'k'
Process
Data
Write to W
MOVLW
0x5A
After Instruction
W
kkkk
=
0x5A
Encoding:
0110
Description:
111a
f [,a]
ffff
ffff
Move data from W to register 'f'.
Location 'f' can be anywhere in the
256 byte bank. If ‘a’ is 0, the
Access Bank will be selected, overriding the BSR value. If ‘a’ = 1, then
the bank will be selected as per the
BSR value (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
MOVWF
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
Example:
MOVWF
REG, 0
Before Instruction
W
REG
=
=
0x4F
0xFF
After Instruction
W
REG
© 2006 Microchip Technology Inc.
=
=
0x4F
0x4F
DS39564C-page 237
PIC18FXX2
MULLW
Multiply Literal with W
MULWF
Multiply W with f
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(W) x (f) → PRODH:PRODL
Status Affected:
None
MULLW
k
Operands:
0 ≤ k ≤ 255
Operation:
(W) x k → PRODH:PRODL
Status Affected:
None
Encoding:
Description:
0000
1
Cycles:
1
Q Cycle Activity:
Q1
Example:
kkkk
Q2
Q3
Q4
Read
literal 'k'
Process
Data
Write
registers
PRODH:
PRODL
MULLW
0xC4
W
PRODH
PRODL
Encoding:
=
=
=
0xE2
?
?
=
=
=
0xE2
0xAD
0x08
After Instruction
0000
001a
f [,a]
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’ is 0, the
Access Bank will be selected,
overriding the BSR value. If
‘a’ = 1, then the bank will be
selected as per the BSR value
(default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Before Instruction
W
PRODH
PRODL
kkkk
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:
Decode
1101
MULWF
Example:
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
registers
PRODH:
PRODL
MULWF
REG, 1
Before Instruction
W
REG
PRODH
PRODL
=
=
=
=
0xC4
0xB5
?
?
=
=
=
=
0xC4
0xB5
0x8A
0x94
After Instruction
W
REG
PRODH
PRODL
DS39564C-page 238
© 2006 Microchip Technology Inc.
PIC18FXX2
NEGF
Negate f
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
NEGF
Operation:
(f)+1→f
Status Affected:
N, OV, C, DC, Z
Encoding:
0110
Description:
1
Cycles:
1
Q Cycle Activity:
Q1
Syntax:
[ label ]
NOP
Operands:
None
Operation:
No operation
Status Affected:
None
0000
1111
ffff
Description:
1
Cycles:
1
Decode
0000
xxxx
0000
xxxx
No operation.
Words:
Q Cycle Activity:
Q1
0000
xxxx
Q2
Q3
Q4
No
operation
No
operation
No
operation
Example:
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
Example:
No Operation
Encoding:
ffff
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 will be
selected, overriding the BSR value.
If ’a’ = 1, then the bank will be
selected as per the BSR value.
Words:
Decode
110a
f [,a]
NOP
NEGF
None.
REG, 1
Before Instruction
REG
=
0011 1010 [0x3A]
After Instruction
REG
=
1100 0110 [0xC6]
© 2006 Microchip Technology Inc.
DS39564C-page 239
PIC18FXX2
POP
Pop Top of Return Stack
PUSH
Push Top of Return Stack
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
None
Operands:
None
Operation:
(TOS) → bit bucket
Operation:
(PC+2) → TOS
Status Affected:
None
Status Affected:
None
Encoding:
0000
Description:
0000
0000
0110
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
Decode
POP
Encoding:
Q2
Q3
Q4
POP TOS
value
No
operation
1
Cycles:
1
=
=
DS39564C-page 240
=
=
Q3
Q4
No
operation
No
operation
PUSH
TOS
PC
0031A2h
014332h
After Instruction
TOS
PC
Q2
PUSH PC+2
onto return
stack
Before Instruction
NEW
Before Instruction
TOS
Stack (1 level down)
0101
Words:
Example:
POP
GOTO
0000
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 to implement
a software stack by modifying TOS,
and then push it onto the return
stack.
Q Cycle Activity:
Q1
No
operation
0000
Description:
Decode
Example:
0000
PUSH
014332h
NEW
=
=
00345Ah
000124h
=
=
=
000126h
000126h
00345Ah
After Instruction
PC
TOS
Stack (1 level down)
© 2006 Microchip Technology Inc.
PIC18FXX2
RCALL
Relative Call
RESET
Reset
Syntax:
[ label ] RCALL
Syntax:
[ label ]
Operands:
Operation:
-1024 ≤ n ≤ 1023
Operands:
None
(PC) + 2 → TOS,
(PC) + 2 + 2n → PC
Operation:
Reset all registers and flags that
are affected by a MCLR Reset.
Status Affected:
None
Status Affected:
All
Encoding:
Description:
1101
nnnn
nnnn
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
Decode
1nnn
n
Encoding:
0000
RESET
0000
1111
1111
Description:
This instruction provides a way to
execute a MCLR Reset in software.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Example:
Q2
Q3
Q4
Start
reset
No
operation
No
operation
RESET
After Instruction
Q2
Q3
Q4
Read literal
'n'
Process
Data
Write to PC
No
operation
No
operation
Registers =
Flags*
=
Reset Value
Reset Value
Push PC to
stack
No
operation
Example:
No
operation
HERE
RCALL Jump
Before Instruction
PC =
Address (HERE)
After Instruction
PC =
TOS =
Address (Jump)
Address (HERE+2)
© 2006 Microchip Technology Inc.
DS39564C-page 241
PIC18FXX2
RETFIE
Return from Interrupt
RETLW
Return Literal to W
Syntax:
[ label ]
Syntax:
[ label ]
RETFIE [s]
RETLW k
Operands:
s ∈ [0,1]
Operands:
0 ≤ k ≤ 255
Operation:
(TOS) → PC,
1 → GIE/GIEH or PEIE/GIEL,
if s = 1
(WS) → W,
(STATUSS) → STATUS,
(BSRS) → BSR,
PCLATU, PCLATH are unchanged.
Operation:
k → W,
(TOS) → PC,
PCLATU, PCLATH are unchanged
Status Affected:
None
Status Affected:
0000
Description:
0000
0001
1
Cycles:
2
Q Cycle Activity:
Q1
kkkk
kkkk
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:
Q2
Q3
Q4
No
operation
No
operation
pop PC from
stack
Set GIEH or
GIEL
No
operation
Example:
1100
Description:
000s
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:
No
operation
0000
GIE/GIEH, PEIE/GIEL.
Encoding:
Decode
Encoding:
RETFIE
No
operation
No
operation
1
CALL TABLE ;
;
;
;
:
TABLE
ADDWF PCL ;
RETLW k0
;
RETLW k1
;
:
:
RETLW kn
;
W contains table
offset value
W now has
table value
W = offset
Begin table
End of table
After Interrupt
PC
W
BSR
STATUS
GIE/GIEH, PEIE/GIEL
DS39564C-page 242
=
=
=
=
=
TOS
WS
BSRS
STATUSS
1
Before Instruction
W
=
0x07
After Instruction
W
=
value of kn
© 2006 Microchip Technology Inc.
PIC18FXX2
RETURN
Return from Subroutine
RLCF
Rotate Left f through Carry
Syntax:
[ label ]
Syntax:
[ label ]
RETURN [s]
RLCF
f [,d [,a]
Operands:
s ∈ [0,1]
Operands:
Operation:
(TOS) → PC,
if s = 1
(WS) → W,
(STATUSS) → STATUS,
(BSRS) → BSR,
PCLATU, PCLATH are unchanged
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
None
Encoding:
Status Affected:
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
0011
Description:
Q2
Q3
Q4
No
operation
Process
Data
pop PC from
stack
No
operation
No
operation
No
operation
No
operation
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
After Interrupt
PC = TOS
ffff
register f
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example:
RETURN
ffff
The contents of register 'f' are
rotated one bit to the left through
the Carry Flag. 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’ is 0, the Access
Bank will be selected, overriding
the BSR value. If ’a’ = 1, then the
bank will be selected as per the
BSR value (default).
C
Decode
Example:
01da
RLCF
REG, 0, 0
Before Instruction
REG
C
=
=
1110 0110
0
After Instruction
REG
W
C
© 2006 Microchip Technology Inc.
=
=
=
1110 0110
1100 1100
1
DS39564C-page 243
PIC18FXX2
RLNCF
Rotate Left f (no carry)
RRCF
Rotate Right f through Carry
Syntax:
[ label ]
Syntax:
[ label ]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f<n>) → dest<n+1>,
(f<7>) → dest<0>
Operation:
Status Affected:
N, Z
(f<n>) → dest<n-1>,
(f<0>) → C,
(C) → dest<7>
Status Affected:
C, N, Z
Encoding:
0100
Description:
RLNCF
01da
f [,d [,a]
ffff
ffff
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’ 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).
Encoding:
0011
Description:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
RLNCF
REG, 1, 0
ffff
ffff
register f
C
Q2
Example:
00da
f [,d [,a]
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 will be selected, overriding
the BSR value. If ’a’ is 1, then the
bank will be selected as per the
BSR value (default).
register f
Words:
RRCF
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Before Instruction
REG
=
1010 1011
After Instruction
REG
=
Example:
RRCF
REG, 0, 0
Before Instruction
0101 0111
REG
C
=
=
1110 0110
0
After Instruction
REG
W
C
DS39564C-page 244
=
=
=
1110 0110
0111 0011
0
© 2006 Microchip Technology Inc.
PIC18FXX2
RRNCF
Rotate Right f (no carry)
SETF
Set f
Syntax:
[ label ]
Syntax:
[ label ] SETF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(f<n>) → dest<n-1>,
(f<0>) → dest<7>
FFh → f
Operation:
Status Affected:
None
Status Affected:
N, Z
Encoding:
0100
Description:
RRNCF
00da
f [,d [,a]
Encoding:
ffff
ffff
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).
register f
Words:
1
Cycles:
1
100a
ffff
ffff
Description:
The contents of the specified register are set to FFh. 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).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Example:
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write
register 'f'
SETF
REG,1
Before Instruction
Q Cycle Activity:
Q1
Decode
0110
f [,a]
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example 1:
RRNCF
REG
=
0x5A
=
0xFF
After Instruction
REG
REG, 1, 0
Before Instruction
REG
=
1101 0111
After Instruction
REG
=
Example 2:
1110 1011
RRNCF
REG, 0, 0
Before Instruction
W
REG
=
=
?
1101 0111
After Instruction
W
REG
=
=
1110 1011
1101 0111
© 2006 Microchip Technology Inc.
DS39564C-page 245
PIC18FXX2
SLEEP
Enter SLEEP mode
SUBFWB
Subtract f from W with borrow
Syntax:
[ label ] SLEEP
Syntax:
[ label ] SUBFWB
Operands:
None
Operands:
Operation:
00h → WDT,
0 → WDT postscaler,
1 → TO,
0 → PD
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) – (f) – (C) → dest
Status Affected:
N, OV, C, DC, Z
TO, PD
Encoding:
Status Affected:
Encoding:
0000
0000
0000
0011
Description:
The power-down status bit (PD) is
cleared. The time-out status bit
(TO) is set. 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
Decode
Q2
No
operation
Q3
Process
Data
Q4
Go to
sleep
TO =
PD =
?
?
After Instruction
TO =
PD =
1†
0
† If WDT causes wake-up, this bit is cleared.
ffff
ffff
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’ 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).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
SLEEP
Before Instruction
01da
Description:
Decode
Example:
0101
f [,d [,a]
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example 1:
SUBFWB
REG, 1, 0
Before Instruction
REG
W
C
=
=
=
3
2
1
After Instruction
REG
W
C
Z
N
=
=
=
=
=
Example 2:
FF
2
0
0
1 ; result is negative
SUBFWB
REG, 0, 0
Before Instruction
REG
W
C
=
=
=
2
5
1
After Instruction
REG
W
C
Z
N
=
=
=
=
=
Example 3:
2
3
1
0
0
; result is positive
SUBFWB
REG, 1, 0
Before Instruction
REG
W
C
=
=
=
1
2
0
After Instruction
REG
W
C
Z
N
DS39564C-page 246
=
=
=
=
=
0
2
1
1
0
; result is zero
© 2006 Microchip Technology Inc.
PIC18FXX2
SUBLW
Subtract W from literal
SUBWF
Subtract W from f
Syntax:
[ label ] SUBLW k
Syntax:
[ label ] SUBWF
Operands:
0 ≤ k ≤ 255
Operands:
Operation:
k – (W) → W
Status Affected:
N, OV, C, DC, Z
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – (W) → dest
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
Decode
Q2
Q3
Q4
Read
literal 'k'
Process
Data
Write to W
Example 1:
SUBLW
0x02
Before Instruction
W
C
=
=
1
?
=
=
=
=
Example 2:
1
1
0
0
SUBLW
=
=
=
=
=
=
Example 3:
0
1
1
0
SUBLW
=
=
; result is zero
0x02
=
=
=
=
1
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
SUBWF
REG, 1, 0
Before Instruction
=
=
=
3
2
?
REG
W
C
Z
N
=
=
=
=
=
Example 2:
1
2
1
0
0
SUBWF
; result is positive
REG, 0, 0
Before Instruction
3
?
After Instruction
W
C
Z
N
Cycles:
After Instruction
Before Instruction
W
C
1
REG
W
C
After Instruction
W
C
Z
N
ffff
Words:
Example 1:
2
?
ffff
Subtract W 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 will be selected,
overriding the BSR value. If ’a’ is
1, then the bank will be selected
as per the BSR value (default).
; result is positive
0x02
11da
Description:
Decode
Before Instruction
W
C
0101
Q Cycle Activity:
Q1
After Instruction
W
C
Z
N
Encoding:
f [,d [,a]
REG
W
C
=
=
=
2
2
?
After Instruction
FF ; (2’s complement)
0 ; result is negative
0
1
REG
W
C
Z
N
=
=
=
=
=
Example 3:
2
0
1
1
0
SUBWF
; result is zero
REG, 1, 0
Before Instruction
REG
W
C
=
=
=
1
2
?
After Instruction
REG
W
C
Z
N
© 2006 Microchip Technology Inc.
=
=
=
=
=
FFh ;(2’s complement)
2
0 ; result is negative
0
1
DS39564C-page 247
PIC18FXX2
SUBWFB
Subtract W from f with Borrow
SWAPF
Swap f
Syntax:
[ label ] SUBWFB
Syntax:
[ label ] SWAPF f [,d [,a]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – (W) – (C) → dest
Operation:
Status Affected:
N, OV, C, DC, Z
(f<3:0>) → dest<7:4>,
(f<7:4>) → dest<3:0>
Status Affected:
None
Encoding:
Description:
0101
ffff
ffff
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 will be selected,
overriding the BSR value. If ’a’ is 1,
then the bank will be selected as per
the BSR value (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
10da
f [,d [,a]
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example 1:
SUBWFB
=
=
=
ffff
ffff
The upper and lower nibbles of register '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 will be selected, overriding
the BSR value. If ’a’ is 1, then the
bank will be selected as per the
BSR value (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
(0001 1001)
(0000 1101)
SWAPF
REG, 1, 0
Before Instruction
REG
=
0x53
After Instruction
=
=
=
=
=
Example 2:
10da
Description:
Example:
0x19
0x0D
1
After Instruction
REG
W
C
Z
N
0011
REG, 1, 0
Before Instruction
REG
W
C
Encoding:
0x0C
0x0D
1
0
0
(0000 1011)
(0000 1101)
REG
=
0x35
; result is positive
SUBWFB REG, 0, 0
Before Instruction
REG
W
C
=
=
=
0x1B
0x1A
0
(0001 1011)
(0001 1010)
0x1B
0x00
1
1
0
(0001 1011)
After Instruction
REG
W
C
Z
N
=
=
=
=
=
Example 3:
SUBWFB
; result is zero
REG, 1, 0
Before Instruction
REG
W
C
=
=
=
0x03
0x0E
1
(0000 0011)
(0000 1101)
(1111 0100)
; [2’s comp]
(0000 1101)
After Instruction
REG
=
0xF5
W
C
Z
N
=
=
=
=
0x0E
0
0
1
DS39564C-page 248
; result is negative
© 2006 Microchip Technology Inc.
PIC18FXX2
TBLRD
Table Read
TBLRD
Table Read (cont’d)
Syntax:
[ label ]
Example1:
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;
TBLRD ( *; *+; *-; +*)
Before Instruction
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)
© 2006 Microchip Technology Inc.
TABLAT
TBLPTR
MEMORY(0x00A356)
=
=
=
0x55
0x00A356
0x34
=
=
0x34
0x00A357
After Instruction
TABLAT
TBLPTR
Example2:
TBLRD
+* ;
Before Instruction
TABLAT
TBLPTR
MEMORY(0x01A357)
MEMORY(0x01A358)
=
=
=
=
0xAA
0x01A357
0x12
0x34
=
=
0x34
0x01A358
After Instruction
TABLAT
TBLPTR
No
No operation
operation (Write TABLAT)
DS39564C-page 249
PIC18FXX2
TBLWT
Table Write
TBLWT
Table Write (Continued)
Syntax:
[ label ]
Example1:
TBLWT
TBLWT ( *; *+; *-; +*)
Before Instruction
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:
Description:
0000
0000
0000
11nn
nn=0 *
=1 *+
=2 *=3 +*
This instruction uses the 3 LSbs of the
TBLPTR to determine which of the 8
holding registers the TABLAT data is
written to. The 8 holding registers are
used to program the contents of Program Memory (P.M.). See Section 5.0
for information on writing to FLASH
memory.
The TBLPTR (a 21-bit pointer) points
to each byte in the program memory.
TBLPTR has a 2 MBtye 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 or Memory)
DS39564C-page 250
*+;
TABLAT
TBLPTR
HOLDING REGISTER
(0x00A356)
=
=
0x55
0x00A356
=
0xFF
After Instructions (table write completion)
TABLAT
TBLPTR
HOLDING REGISTER
(0x00A356)
Example 2:
TBLWT
=
=
0x55
0x00A357
=
0x55
+*;
Before Instruction
TABLAT
TBLPTR
HOLDING REGISTER
(0x01389A)
HOLDING REGISTER
(0x01389B)
=
=
0x34
0x01389A
=
0xFF
=
0xFF
After Instruction (table write completion)
TABLAT
TBLPTR
HOLDING REGISTER
(0x01389A)
HOLDING REGISTER
(0x01389B)
=
=
0x34
0x01389B
=
0xFF
=
0x34
© 2006 Microchip Technology Inc.
PIC18FXX2
TSTFSZ
Test f, skip if 0
XORLW
Exclusive OR literal with W
Syntax:
[ label ] TSTFSZ f [,a]
Syntax:
[ label ] XORLW k
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
0 ≤ k ≤ 255
Operation:
Operation:
skip if f = 0
(W) .XOR. k → W
Status Affected:
N, Z
Status Affected:
None
Encoding:
Description:
Encoding:
0110
011a
ffff
ffff
If 'f' = 0, the next instruction,
fetched during the current instruction execution, is discarded and a
NOP is executed, making this a twocycle instruction. 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).
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
No
operation
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
Decode
Q2
Q3
Q4
Read
literal 'k'
Process
Data
Write to W
Example:
XORLW 0xAF
Before Instruction
W
=
0xB5
After Instruction
W
=
0x1A
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
NZERO
ZERO
TSTFSZ
:
CNT, 1
:
Before Instruction
PC = Address (HERE)
After Instruction
If CNT
PC
If CNT
PC
=
=
≠
=
0x00,
Address (ZERO)
0x00,
Address (NZERO)
© 2006 Microchip Technology Inc.
DS39564C-page 251
PIC18FXX2
XORWF
Exclusive OR W with f
Syntax:
[ label ] XORWF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) .XOR. (f) → dest
Status Affected:
N, Z
Encoding:
0001
10da
f [,d [,a]
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 will be selected, overriding
the BSR value. If ’a’ is 1, then the
bank will be selected as per the
BSR value (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
Read
register 'f'
Process
Data
Write to
destination
Example:
XORWF
REG, 1, 0
Before Instruction
REG
W
=
=
0xAF
0xB5
After Instruction
REG
W
=
=
DS39564C-page 252
0x1A
0xB5
© 2006 Microchip Technology Inc.
PIC18FXX2
21.0
DEVELOPMENT SUPPORT
The PICmicro® microcontrollers are supported with a
full range of hardware and software development tools:
• Integrated Development Environment
- MPLAB® IDE Software
• Assemblers/Compilers/Linkers
- MPASMTM Assembler
- MPLAB C17 and MPLAB C18 C Compilers
- MPLINKTM Object Linker/
MPLIBTM Object Librarian
• Simulators
- MPLAB SIM Software Simulator
• Emulators
- MPLAB ICE 2000 In-Circuit Emulator
- ICEPIC™ In-Circuit Emulator
• In-Circuit Debugger
- MPLAB ICD
• Device Programmers
- PRO MATE® II Universal Device Programmer
- PICSTART® Plus Entry-Level Development
Programmer
• Low Cost Demonstration Boards
- PICDEMTM 1 Demonstration Board
- PICDEM 2 Demonstration Board
- PICDEM 3 Demonstration Board
- PICDEM 17 Demonstration Board
- KEELOQ® Demonstration Board
21.1
MPLAB Integrated Development
Environment Software
The MPLAB IDE software brings an ease of software
development previously unseen in the 8-bit microcontroller market. The MPLAB IDE is a Windows® based
application that contains:
• An interface to debugging tools
- simulator
- programmer (sold separately)
- emulator (sold separately)
- in-circuit debugger (sold separately)
• A full-featured editor
• A project manager
• Customizable toolbar and key mapping
• A status bar
• On-line help
© 2006 Microchip Technology Inc.
The MPLAB IDE allows you to:
• Edit your source files (either assembly or ‘C’)
• One touch assemble (or compile) and download
to PICmicro emulator and simulator tools (automatically updates all project information)
• Debug using:
- source files
- absolute listing file
- machine code
The ability to use MPLAB IDE with multiple debugging
tools allows users to easily switch from the costeffective simulator to a full-featured emulator with
minimal retraining.
21.2
MPASM Assembler
The MPASM assembler is a full-featured universal
macro assembler for all PICmicro MCU’s.
The MPASM assembler has a command line interface
and a Windows shell. It can be used as a stand-alone
application on a Windows 3.x or greater system, or it
can be used through MPLAB IDE. 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, an absolute LST file that contains source lines and generated
machine code, and a COD file 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.
21.3
MPLAB C17 and MPLAB C18
C Compilers
The MPLAB C17 and MPLAB C18 Code Development
Systems are complete ANSI ‘C’ compilers for
Microchip’s PIC17CXXX and PIC18CXXX family of
microcontrollers, respectively. These compilers provide
powerful integration capabilities and ease of use not
found with other compilers.
For easier source level debugging, the compilers provide symbol information that is compatible with the
MPLAB IDE memory display.
DS39564C-page 253
PIC18FXX2
21.4
MPLINK Object Linker/
MPLIB Object Librarian
The MPLINK object linker combines relocatable
objects created by the MPASM assembler and the
MPLAB C17 and MPLAB C18 C compilers. It can also
link relocatable objects from pre-compiled libraries,
using directives from a linker script.
The MPLIB object librarian is a librarian for precompiled code to be used with the MPLINK object
linker. When a routine from a library is called from
another 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 MPLIB object librarian manages the
creation and modification of library files.
The MPLINK object linker features include:
• Integration with MPASM assembler and MPLAB
C17 and MPLAB C18 C compilers.
• Allows all memory areas to be defined as sections
to provide link-time flexibility.
The MPLIB object librarian features include:
• Easier linking because single libraries can be
included instead of many smaller files.
• Helps keep code maintainable by grouping
related modules together.
• Allows libraries to be created and modules to be
added, listed, replaced, deleted or extracted.
21.5
MPLAB SIM Software Simulator
The MPLAB SIM software simulator allows code development in a PC-hosted environment by simulating the
PICmicro series microcontrollers on an instruction
level. On any given instruction, the data areas can be
examined or modified and stimuli can be applied from
a file, or user-defined key press, to any of the pins. The
execution can be performed in single step, execute
until break, or trace mode.
21.6
MPLAB ICE High Performance
Universal In-Circuit Emulator with
MPLAB IDE
The MPLAB ICE universal in-circuit emulator is intended
to provide the product development engineer with a
complete microcontroller design tool set for PICmicro
microcontrollers (MCUs). Software control of the
MPLAB ICE in-circuit emulator is provided by the
MPLAB Integrated Development Environment (IDE),
which allows editing, building, downloading and source
debugging from a single environment.
The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring
features. Interchangeable processor modules allow the
system to be easily reconfigured for emulation of different processors. The universal architecture of the
MPLAB ICE in-circuit emulator allows expansion to
support new PICmicro microcontrollers.
The MPLAB ICE in-circuit emulator system has been
designed as a real-time emulation system, with
advanced features that are generally found on more
expensive development tools. The PC platform and
Microsoft® Windows environment were chosen to best
make these features available to you, the end user.
21.7
ICEPIC In-Circuit Emulator
The ICEPIC low cost, in-circuit emulator is a solution
for the Microchip Technology PIC16C5X, PIC16C6X,
PIC16C7X and PIC16CXXX families of 8-bit OneTime-Programmable (OTP) microcontrollers. The modular system can support different subsets of PIC16C5X
or PIC16CXXX products through the use of interchangeable personality modules, or daughter boards.
The emulator is capable of emulating without target
application circuitry being present.
The MPLAB SIM simulator fully supports symbolic debugging using the MPLAB C17 and the MPLAB C18 C compilers and the MPASM assembler. The software simulator
offers the flexibility to develop and debug code outside of
the laboratory environment, making it an excellent multiproject software development tool.
DS39564C-page 254
© 2006 Microchip Technology Inc.
PIC18FXX2
21.8
MPLAB ICD In-Circuit Debugger
Microchip's In-Circuit Debugger, MPLAB ICD, is a powerful, low cost, run-time development tool. This tool is
based on the FLASH PICmicro MCUs and can be used
to develop for this and other PICmicro microcontrollers.
The MPLAB ICD utilizes the in-circuit debugging capability built into the FLASH devices. This feature, along
with Microchip's In-Circuit Serial ProgrammingTM protocol, offers cost-effective in-circuit FLASH debugging
from the graphical user interface of the MPLAB
Integrated Development Environment. This enables a
designer to develop and debug source code by watching variables, single-stepping and setting break points.
Running at full speed enables testing hardware in realtime.
21.9
PRO MATE II Universal Device
Programmer
The PRO MATE II universal device programmer is a
full-featured programmer, capable of operating in
stand-alone mode, as well as PC-hosted mode. The
PRO MATE II device programmer is CE compliant.
The PRO MATE II device programmer has programmable VDD and VPP supplies, which allow it to verify
programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for instructions
and error messages, keys to enter commands and a
modular detachable socket assembly to support various
package types. In stand-alone mode, the PRO MATE II
device programmer can read, verify, or program
PICmicro devices. It can also set code protection in this
mode.
21.10 PICSTART Plus Entry Level
Development Programmer
The PICSTART Plus development programmer is an
easy-to-use, low cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB
Integrated Development Environment software makes
using the programmer simple and efficient.
The PICSTART Plus development programmer supports all PICmicro devices with up to 40 pins. Larger pin
count devices, such as the PIC16C92X and
PIC17C76X, may be supported with an adapter socket.
The PICSTART Plus development programmer is CE
compliant.
© 2006 Microchip Technology Inc.
21.11 PICDEM 1 Low Cost PICmicro
Demonstration Board
The PICDEM 1 demonstration board is a simple board
which demonstrates the capabilities of several of
Microchip’s microcontrollers. The microcontrollers supported are: PIC16C5X (PIC16C54 to PIC16C58A),
PIC16C61, PIC16C62X, PIC16C71, PIC16C8X,
PIC17C42, PIC17C43 and PIC17C44. All necessary
hardware and software is included to run basic demo
programs. The user can program the sample microcontrollers provided with the PICDEM 1 demonstration
board on a PRO MATE II device programmer, or a
PICSTART Plus development programmer, and easily
test firmware. The user can also connect the
PICDEM 1 demonstration board to the MPLAB ICE incircuit emulator and download the firmware to the emulator for testing. A prototype area is available for the
user to build some additional hardware and connect it
to the microcontroller socket(s). Some of the features
include an RS-232 interface, a potentiometer for simulated analog input, push button switches and eight
LEDs connected to PORTB.
21.12 PICDEM 2 Low Cost PIC16CXX
Demonstration Board
The PICDEM 2 demonstration board is a simple demonstration board that supports the PIC16C62,
PIC16C64, PIC16C65, PIC16C73 and PIC16C74
microcontrollers. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample
microcontrollers provided with the PICDEM 2 demonstration board on a PRO MATE II device programmer,
or a PICSTART Plus development programmer, and
easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 2 demonstration
board to test firmware. A prototype area has been provided to the user for adding additional hardware and
connecting it to the microcontroller socket(s). Some of
the features include a RS-232 interface, push button
switches, a potentiometer for simulated analog input, a
serial EEPROM to demonstrate usage of the I2CTM bus
and separate headers for connection to an LCD
module and a keypad.
DS39564C-page 255
PIC18FXX2
21.13 PICDEM 3 Low Cost PIC16CXXX
Demonstration Board
The PICDEM 3 demonstration board is a simple demonstration board that supports the PIC16C923 and
PIC16C924 in the PLCC package. It will also support
future 44-pin PLCC microcontrollers with an LCD Module. All the necessary hardware and software is
included to run the basic demonstration programs. The
user can program the sample microcontrollers provided with the PICDEM 3 demonstration board on a
PRO MATE II device programmer, or a PICSTART Plus
development programmer with an adapter socket, and
easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 3 demonstration
board to test firmware. A prototype area has been provided to the user for adding hardware and connecting it
to the microcontroller socket(s). Some of the features
include a RS-232 interface, push button switches, a
potentiometer for simulated analog input, a thermistor
and separate headers for connection to an external
LCD module and a keypad. Also provided on the
PICDEM 3 demonstration board is a LCD panel, with 4
commons and 12 segments, that is capable of displaying time, temperature and day of the week. The
PICDEM 3 demonstration board provides an additional
RS-232 interface and Windows software for showing
the demultiplexed LCD signals on a PC. A simple serial
interface allows the user to construct a hardware
demultiplexer for the LCD signals.
DS39564C-page 256
21.14 PICDEM 17 Demonstration Board
The PICDEM 17 demonstration board is an evaluation
board that demonstrates the capabilities of several
Microchip microcontrollers, including PIC17C752,
PIC17C756A, PIC17C762 and PIC17C766. All necessary hardware is included to run basic demo programs,
which are supplied on a 3.5-inch disk. A programmed
sample is included and the user may erase it and
program it with the other sample programs using the
PRO MATE II device programmer, or the PICSTART
Plus development programmer, and easily debug and
test the sample code. In addition, the PICDEM 17 demonstration board supports downloading of programs to
and executing out of external FLASH memory on board.
The PICDEM 17 demonstration board is also usable
with the MPLAB ICE in-circuit emulator, or the
PICMASTER emulator and all of the sample programs
can be run and modified using either emulator. Additionally, a generous prototype area is available for user
hardware.
21.15 KEELOQ Evaluation and
Programming Tools
KEELOQ evaluation and programming tools support
Microchip’s HCS Secure Data Products. The HCS evaluation kit includes a LCD display to show changing
codes, a decoder to decode transmissions and a
programming interface to program test transmitters.
© 2006 Microchip Technology Inc.
Software Tools
Programmers Debugger Emulators
PIC12CXXX
PIC14000
PIC16C5X
PIC16C6X
PIC16CXXX
PIC16F62X
PIC16C7X
!
!
!
!
!
!
© 2006 Microchip Technology Inc.
!
!
!
†
†
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
MCP2510
* Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB® ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77.
** Contact Microchip Technology Inc. for availability date.
† Development tool is available on select devices.
MCP2510 CAN Developer’s Kit
!
13.56 MHz Anticollision
microIDTM Developer’s Kit
!
125 kHz Anticollision microIDTM
Developer’s Kit
!
125 kHz microIDTM
Developer’s Kit
MCRFXXX
microIDTM Programmer’s Kit
!
†
!**
!
!*
!
!
!
!
!
!
!
!
!**
!**
PIC18FXXX
!
24CXX/
25CXX/
93CXX
KEELOQ® Transponder Kit
!
!
!
!
!
!
!
!
!
HCSXXX
KEELOQ® Evaluation Kit
PICDEMTM 17 Demonstration
Board
PICDEMTM 14A Demonstration
Board
PICDEMTM 3 Demonstration
Board
PICDEMTM 2 Demonstration
Board
PICDEMTM 1 Demonstration
Board
!
!
PRO MATE® II
Universal Device Programmer
!
!
!
!
PICSTART® Plus Entry Level
Development Programmer
!
!
!*
!
!
MPLAB® ICD In-Circuit
Debugger
!
!
!
!
!
!
!
!
ICEPICTM In-Circuit Emulator
!
!
PIC16C7XX
!
!
!
PIC16C8X/
PIC16F8X
!
!
!
PIC16F8XX
!
!
!
PIC16C9XX
MPLAB® ICE In-Circuit Emulator
!
!
PIC17C4X
!
!
!
PIC17C7XX
MPASMTM Assembler/
MPLINKTM Object Linker
!
PIC18CXX2
MPLAB® C18 C Compiler
MPLAB® C17 C Compiler
TABLE 21-1:
Demo Boards and Eval Kits
MPLAB® Integrated
Development Environment
PIC18FXX2
DEVELOPMENT TOOLS FROM MICROCHIP
DS39564C-page 257
PIC18FXX2
NOTES:
DS39564C-page 258
© 2006 Microchip Technology Inc.
PIC18FXX2
22.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings (†)
Ambient temperature under bias.............................................................................................................-55°C to +125°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on any pin with respect to VSS (except VDD, MCLR, and RA4) ......................................... -0.3V to (VDD + 0.3V)
Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V
Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V
Voltage on RA4 with respect to Vss ............................................................................................................... 0V to +8.5V
Total power dissipation (Note 1) ...............................................................................................................................1.0W
Maximum current out of VSS pin ...........................................................................................................................300 mA
Maximum current into VDD pin ..............................................................................................................................250 mA
Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA
Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. ±20 mA
Maximum output current sunk by any I/O pin..........................................................................................................25 mA
Maximum output current sourced by any I/O pin ....................................................................................................25 mA
Maximum current sunk by PORTA, PORTB, and PORTE (Note 3) (combined) ...................................................200 mA
Maximum current sourced by PORTA, PORTB, and PORTE (Note 3) (combined)..............................................200 mA
Maximum current sunk by PORTC and PORTD (Note 3) (combined)..................................................................200 mA
Maximum current sourced by PORTC and PORTD (Note 3) (combined).............................................................200 mA
Note 1: Power dissipation is calculated as follows:
Pdis = VDD x {IDD - ∑ IOH} + ∑ {(VDD-VOH) x IOH} + ∑(VOl x IOL)
2: Voltage spikes below VSS at the MCLR/VPP pin, inducing currents greater than 80 mA, may cause latchup.
Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/VPP pin, rather
than pulling this pin directly to VSS.
3: PORTD and PORTE not available on the PIC18F2X2 devices.
† 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.
© 2006 Microchip Technology Inc.
DS39564C-page 259
PIC18FXX2
FIGURE 22-1:
PIC18FXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V
5.5V
5.0V
PIC18FXXX
Voltage
4.5V
4.2V
4.0V
3.5V
3.0V
2.5V
2.0V
40 MHz
Frequency
FIGURE 22-2:
PIC18LFXX2 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V
5.5V
Voltage
5.0V
PIC18LFXXX
4.5V
4.2V
4.0V
3.5V
3.0V
2.5V
2.0V
40 MHz
4 MHz
Frequency
FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz
Note: VDDAPPMIN is the minimum voltage of the PICmicro® device in the application.
DS39564C-page 260
© 2006 Microchip Technology Inc.
PIC18FXX2
22.1
DC Characteristics: PIC18FXX2 (Industrial, Extended)
PIC18LFXX2 (Industrial)
PIC18LFXX2
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18FXX2
(Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
Param
Symbol
No.
VDD
D001
Characteristic
Min
Typ
Max Units
PIC18LFXX2
2.0
—
5.5
V
PIC18FXX2
Supply Voltage
D001
4.2
—
5.5
V
D002
VDR
RAM Data Retention
Voltage(1)
1.5
—
—
V
D003
VPOR
VDD Start Voltage
to ensure internal
Power-on Reset signal
—
—
0.7
V
D004
SVDD
VDD Rise Rate
to ensure internal
Power-on Reset signal
0.05
—
—
VBOR
Brown-out Reset Voltage
D005
Conditions
HS, XT, RC and LP Osc mode
See Section 3.1 (Power-on Reset) for details
V/ms See Section 3.1 (Power-on Reset) for details
PIC18LFXX2
BORV1:BORV0 = 11
1.98
—
2.14
V
BORV1:BORV0 = 10
2.67
—
2.89
V
BORV1:BORV0 = 01
4.16
—
4.5
V
BORV1:BORV0 = 00
4.45
—
4.83
V
BORV1:BORV0 = 1x
N.A.
—
N.A.
V
BORV1:BORV0 = 01
4.16
—
4.5
V
BORV1:BORV0 = 00
4.45
—
4.83
V
D005
85°C ≥ T ≥ 25°C
PIC18FXX2
Not in operating voltage range of device
Legend: Shading of rows is to assist in readability of the table.
Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an
impact on the current consumption.
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
MCLR = VDD; WDT enabled/disabled as specified.
3: 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 hi-impedance state and tied to VDD or VSS, and all
features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).
4: For RC osc configuration, current through REXT is not included. The current through the resistor can be
estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.
5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.
Once one of these modules is enabled, the other may also be enabled without further penalty.
© 2006 Microchip Technology Inc.
DS39564C-page 261
PIC18FXX2
22.1
DC Characteristics: PIC18FXX2 (Industrial, Extended)
PIC18LFXX2 (Industrial) (Continued)
PIC18LFXX2
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18FXX2
(Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
Param
Symbol
No.
IDD
Characteristic
Min
Typ
Max Units
Conditions
—
—
—
.5
.5
1.2
1
1.25
2
mA
mA
mA
—
—
—
.3
.3
1.5
1
1
3
mA
mA
mA
—
—
—
.3
.3
.75
1
1
3
mA
mA
mA
—
—
—
1.2
1.2
1.2
1.5
2
3
mA
mA
mA
—
—
—
1.5
1.5
1.6
3
4
4
mA
mA
mA
—
—
—
.75
.75
.8
2
3
3
mA
mA
mA
XT osc configuration
VDD = 4.2V, +25°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz
RC osc configuration
VDD = 4.2V, +25°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz
RCIO osc configuration
VDD = 4.2V, +25°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +125°C, FOSC = 4 MHz
—
14
30
μA
LP osc, FOSC = 32 kHz, WDT disabled
VDD = 2.0V, -40°C to +85°C
—
—
40
50
70
100
μA
μA
LP osc, FOSC = 32 kHz, WDT disabled
VDD = 4.2V, -40°C to +85°C
VDD = 4.2V, -40°C to +125°C
Supply Current(2,4)
D010
D010
D010A
D010A
PIC18LFXX2
PIC18FXX2
PIC18LFXX2
PIC18FXX2
XT osc configuration
VDD = 2.0V, +25°C, FOSC = 4 MHz
VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz
RC osc configuration
VDD = 2.0V, +25°C, FOSC = 4 MHz
VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz
RCIO osc configuration
VDD = 2.0V, +25°C, FOSC = 4 MHz
VDD = 2.0V, -40°C to +85°C, FOSC = 4 MHz
VDD = 4.2V, -40°C to +85°C, FOSC = 4 MHz
Legend: Shading of rows is to assist in readability of the table.
Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an
impact on the current consumption.
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
MCLR = VDD; WDT enabled/disabled as specified.
3: 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 hi-impedance state and tied to VDD or VSS, and all
features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).
4: For RC osc configuration, current through REXT is not included. The current through the resistor can be
estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.
5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.
Once one of these modules is enabled, the other may also be enabled without further penalty.
DS39564C-page 262
© 2006 Microchip Technology Inc.
PIC18FXX2
22.1
DC Characteristics: PIC18FXX2 (Industrial, Extended)
PIC18LFXX2 (Industrial) (Continued)
PIC18LFXX2
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18FXX2
(Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
Param
Symbol
No.
IDD
D010C
Characteristic
Min
Typ
Max Units
Supply Current(2,4) (Continued)
PIC18LFXX2
D010C
—
10
25
mA
EC, ECIO osc configurations
VDD = 4.2V, -40°C to +85°C
—
10
25
mA
EC, ECIO osc configurations
VDD = 4.2V, -40°C to +125°C
—
—
.6
10
2
15
mA
mA
—
15
25
mA
—
10
15
mA
—
15
25
mA
HS osc configuration
FOSC = 25 MHz, VDD = 5.5V
HS + PLL osc configurations
FOSC = 10 MHz, VDD = 5.5V
—
15
55
μA
Timer1 osc configuration
FOSC = 32 kHz, VDD = 2.0V
—
—
—
—
200
250
μA
μA
Timer1 osc configuration
FOSC = 32 kHz, VDD = 4.2V, -40°C to +85°C
FOSC = 32 kHz, VDD = 4.2V, -40°C to +125°C
PIC18FXX2
D013
PIC18LFXX2
D013
PIC18FXX2
D014
PIC18LFXX2
D014
PIC18FXX2
IPD
Conditions
HS osc configuration
FOSC = 4 MHz, VDD = 2.0V
FOSC = 25 MHz, VDD = 5.5V
HS + PLL osc configurations
FOSC = 10 MHz, VDD = 5.5V
Power-down Current(3)
D020
PIC18LFXX2
—
—
—
.08
.1
3
.9
4
10
μA
μA
μA
VDD = 2.0V, +25°C
VDD = 2.0V, -40°C to +85°C
VDD = 4.2V, -40°C to +85°C
D020
PIC18FXX2
—
—
—
.1
3
15
.9
10
25
μA
μA
μA
VDD = 4.2V, +25°C
VDD = 4.2V, -40°C to +85°C
VDD = 4.2V, -40°C to +125°C
D021B
Legend: Shading of rows is to assist in readability of the table.
Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an
impact on the current consumption.
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
MCLR = VDD; WDT enabled/disabled as specified.
3: 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 hi-impedance state and tied to VDD or VSS, and all
features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).
4: For RC osc configuration, current through REXT is not included. The current through the resistor can be
estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.
5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.
Once one of these modules is enabled, the other may also be enabled without further penalty.
© 2006 Microchip Technology Inc.
DS39564C-page 263
PIC18FXX2
22.1
DC Characteristics: PIC18FXX2 (Industrial, Extended)
PIC18LFXX2 (Industrial) (Continued)
PIC18LFXX2
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18FXX2
(Industrial, Extended)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
Param
Symbol
No.
Characteristic
Min
Typ
Max Units
Conditions
Module Differential Current
ΔIWDT
Watchdog Timer
PIC18LFXX2
—
—
—
.75
2
10
1.5
8
25
μA
μA
μA
VDD = 2.0V, +25°C
VDD = 2.0V, -40°C to +85°C
VDD = 4.2V, -40°C to +85°C
Watchdog Timer
PIC18FXX2
—
—
—
7
10
25
15
25
40
μA
μA
μA
VDD = 4.2V, +25°C
VDD = 4.2V, -40°C to +85°C
VDD = 4.2V, -40°C to +125°C
D022A ΔIBOR
Brown-out Reset(5)
PIC18LFXX2
—
—
—
29
29
33
35
45
50
μA
μA
μA
VDD = 2.0V, +25°C
VDD = 2.0V, -40°C to +85°C
VDD = 4.2V, -40°C to +85°C
D022A
Brown-out Reset(5)
PIC18FXX2
—
—
—
36
36
36
40
50
65
μA
μA
μA
VDD = 4.2V, +25°C
VDD = 4.2V, -40°C to +85°C
VDD = 4.2V, -40°C to +125°C
D022B ΔILVD
Low Voltage Detect(5)
PIC18LFXX2
—
—
—
29
29
33
35
45
50
μA
μA
μA
VDD = 2.0V, +25°C
VDD = 2.0V, -40°C to +85°C
VDD = 4.2V, -40°C to +85°C
D022B
Low Voltage Detect(5)
PIC18FXX2
—
—
—
33
33
33
40
50
65
μA
μA
μA
VDD = 4.2V, +25°C
VDD = 4.2V, -40°C to +85°C
VDD = 4.2V, -40°C to +125°C
Timer1 Oscillator
PIC18LFXX2
—
—
—
5.2
5.2
6.5
30
40
50
μA
μA
μA
VDD = 2.0V, +25°C
VDD = 2.0V, -40°C to +85°C
VDD = 4.2V, -40°C to +85°C
Timer1 Oscillator
PIC18FXX2
—
—
—
6.5
6.5
6.5
40
50
65
μA
μA
μA
VDD = 4.2V, +25°C
VDD = 4.2V, -40°C to +85°C
VDD = 4.2V, -40°C to +125°C
D022
D022
D025
ΔITMR1
D025
Legend: Shading of rows is to assist in readability of the table.
Note 1: This is the limit to which VDD can be lowered in SLEEP mode, or during a device RESET, without losing RAM data.
2: The supply current is mainly a function of the operating voltage and frequency. Other factors, such as I/O pin
loading and switching rate, oscillator type, internal code execution pattern and temperature, also have an
impact on the current consumption.
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
MCLR = VDD; WDT enabled/disabled as specified.
3: 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 hi-impedance state and tied to VDD or VSS, and all
features that add delta current disabled (such as WDT, Timer1 Oscillator, BOR,...).
4: For RC osc configuration, current through REXT is not included. The current through the resistor can be
estimated by the formula Ir = VDD/2REXT (mA) with REXT in kOhm.
5: The LVD and BOR modules share a large portion of circuitry. The ΔIBOR and ΔILVD currents are not additive.
Once one of these modules is enabled, the other may also be enabled without further penalty.
DS39564C-page 264
© 2006 Microchip Technology Inc.
PIC18FXX2
22.2
DC Characteristics: PIC18FXX2 (Industrial, Extended)
PIC18LFXX2 (Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
DC CHARACTERISTICS
Param
Symbol
No.
VIL
Characteristic
Min
Max
Units
Conditions
with TTL buffer
Vss
0.15 VDD
V
VDD < 4.5V
—
0.8
V
4.5V ≤ VDD ≤ 5.5V
with Schmitt Trigger buffer
RC3 and RC4
Vss
Vss
0.2 VDD
0.3 VDD
V
V
Input Low Voltage
I/O ports:
D030
D030A
D031
D032
MCLR
VSS
0.2 VDD
V
D032A
OSC1 (in XT, HS and LP modes)
and T1OSI
VSS
0.3 VDD
V
D033
OSC1 (in RC and EC mode)(1)
VSS
0.2 VDD
V
0.25 VDD +
0.8V
VDD
V
VDD < 4.5V
4.5V ≤ VDD ≤ 5.5V
VIH
Input High Voltage
I/O ports:
D040
with TTL buffer
D040A
D041
with Schmitt Trigger buffer
RC3 and RC4
2.0
VDD
V
0.8 VDD
0.7 VDD
VDD
VDD
V
V
D042
MCLR, OSC1 (EC mode)
0.8 VDD
VDD
V
D042A
OSC1 (in XT, HS and LP modes)
and T1OSI
0.7 VDD
VDD
V
D043
OSC1 (RC mode)(1)
0.9 VDD
VDD
V
I/O ports
.02
±1
μA
VSS ≤ VPIN ≤ VDD,
Pin at hi-impedance
D061
MCLR
—
±1
μA
Vss ≤ VPIN ≤ VDD
D063
OSC1
—
±1
μA
Vss ≤ VPIN ≤ VDD
50
450
μA
VDD = 5V, VPIN = VSS
IIL
D060
D070
Input Leakage
Current(2,3)
IPU
Weak Pull-up Current
IPURB
PORTB weak pull-up current
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PICmicro device be driven with an external clock while in RC mode.
2: 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.
3: Negative current is defined as current sourced by the pin.
4: Parameter is characterized but not tested.
© 2006 Microchip Technology Inc.
DS39564C-page 265
PIC18FXX2
22.2
DC Characteristics: PIC18FXX2 (Industrial, Extended)
PIC18LFXX2 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
DC CHARACTERISTICS
Param
Symbol
No.
VOL
D080
Characteristic
D080A
OSC2/CLKO
(RC mode)
D083A
VOH
D090
D090A
OSC2/CLKO
(RC mode)
D092A
D150
VOD
Units
Conditions
—
0.6
V
IOL = 8.5 mA, VDD = 4.5V,
-40°C to +85°C
—
0.6
V
IOL = 7.0 mA, VDD = 4.5V,
-40°C to +125°C
—
0.6
V
IOL = 1.6 mA, VDD = 4.5V,
-40°C to +85°C
—
0.6
V
IOL = 1.2 mA, VDD = 4.5V,
-40°C to +125°C
VDD – 0.7
—
V
IOH = -3.0 mA, VDD = 4.5V,
-40°C to +85°C
VDD – 0.7
—
V
IOH = -2.5 mA, VDD = 4.5V,
-40°C to +125°C
VDD – 0.7
—
V
IOH = -1.3 mA, VDD = 4.5V,
-40°C to +85°C
VDD – 0.7
—
V
IOH = -1.0 mA, VDD = 4.5V,
-40°C to +125°C
—
8.5
V
RA4 pin
Output High Voltage(3)
I/O ports
D092
Max
Output Low Voltage
I/O ports
D083
Min
Open Drain High Voltage
Capacitive Loading Specs
on Output Pins
D100(4) COSC2
OSC2 pin
—
15
pF
In XT, HS and LP modes
when external clock is used
to drive OSC1
D101
CIO
All I/O pins and OSC2
(in RC mode)
—
50
pF
To meet the AC Timing
Specifications
D102
CB
SCL, SDA
—
400
pF
In I2C mode
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PICmicro device be driven with an external clock while in RC mode.
2: 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.
3: Negative current is defined as current sourced by the pin.
4: Parameter is characterized but not tested.
DS39564C-page 266
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-3:
LOW VOLTAGE DETECT CHARACTERISTICS
VDD
(LVDIF can be
cleared in software)
VLVD
(LVDIF set by hardware)
37
LVDIF
TABLE 22-1:
LOW VOLTAGE DETECT CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
Param
Symbol
No.
D420
VLVD
Characteristic
Min
Typ
Max
Units
Conditions
LVD Voltage on VDD LVV = 0001
transition high to
LVV = 0010
low
LVV = 0011
1.98
2.06
2.14
V
T ≥ 25°C
2.18
2.27
2.36
V
T ≥ 25°C
2.37
2.47
2.57
V
T ≥ 25°C
LVV = 0100
2.48
2.58
2.68
V
LVV = 0101
2.67
2.78
2.89
V
LVV = 0110
2.77
2.89
3.01
V
LVV = 0111
2.98
3.1
3.22
V
LVV = 1000
3.27
3.41
3.55
V
LVV = 1001
3.47
3.61
3.75
V
LVV = 1010
3.57
3.72
3.87
V
LVV = 1011
3.76
3.92
4.08
V
LVV = 1100
3.96
4.13
4.3
V
LVV = 1101
4.16
4.33
4.5
V
LVV = 1110
4.45
4.64
4.83
V
© 2006 Microchip Technology Inc.
DS39564C-page 267
PIC18FXX2
TABLE 22-2:
MEMORY PROGRAMMING REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
DC Characteristics
Param
No.
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
9.00
—
13.25
V
—
—
10
mA
E/W -40°C to +85°C
Internal Program Memory
Programming Specifications
D110
VPP
Voltage on MCLR/VPP pin
D113
IDDP
Supply Current during
Programming
D120
ED
Cell Endurance
100K
1M
—
D121
VDRW
VDD for Read/Write
VMIN
—
5.5
D122
TDEW
Erase/Write Cycle Time
—
4
—
D123
TRETD Characteristic Retention
40
—
—
Year Provided no other
specifications are violated
D124
TREF
1M
10M
—
E/W -40°C to +85°C
D130
EP
Cell Endurance
10K
100K
—
E/W -40°C to +85°C
D131
VPR
VDD for Read
VMIN
—
5.5
V
VMIN = Minimum operating
voltage
D132
VIE
Data EEPROM Memory
Number of Total Erase/Write
Cycles before Refresh(1)
V
Using EECON to read/write
VMIN = Minimum operating
voltage
ms
Program FLASH Memory
VDD for Block Erase
4.5
—
5.5
V
Using ICSP port
D132A VIW
VDD for Externally Timed Erase
or Write
4.5
—
5.5
V
Using ICSP port
D132B VPEW
VDD for Self-timed Write
VMIN
—
5.5
V
VMIN = Minimum operating
voltage
D133
ICSP Block Erase Cycle Time
—
4
—
ms
VDD ≥ 4.5V
D133A TIW
ICSP Erase or Write Cycle Time
(externally timed)
1
—
—
ms
VDD ≥ 4.5V
D133A TIW
Self-timed Write Cycle Time
—
2
—
40
—
—
D134
TIE
TRETD Characteristic Retention
ms
Year Provided no other
specifications are violated
† Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: Refer to Section 6.8 for a more detailed discussion on data EEPROM endurance.
DS39564C-page 268
© 2006 Microchip Technology Inc.
PIC18FXX2
22.3
22.3.1
AC (Timing) Characteristics
TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created
following one of the following formats:
1. TppS2ppS
2. TppS
T
F
Frequency
Lowercase letters (pp) and their meanings:
pp
cc
CCP1
ck
CLKO
cs
CS
di
SDI
do
SDO
dt
Data in
io
I/O port
mc
MCLR
Uppercase letters and their meanings:
S
F
Fall
H
High
I
Invalid (Hi-impedance)
L
Low
I2C only
AA
output access
BUF
Bus free
TCC:ST (I2C specifications only)
CC
HD
Hold
ST
DAT
DATA input hold
STA
START condition
© 2006 Microchip Technology Inc.
3. TCC:ST
4. Ts
(I2C specifications only)
(I2C specifications only)
T
Time
osc
rd
rw
sc
ss
t0
t1
wr
OSC1
RD
RD or WR
SCK
SS
T0CKI
T1CKI
WR
P
R
V
Z
Period
Rise
Valid
Hi-impedance
High
Low
High
Low
SU
Setup
STO
STOP condition
DS39564C-page 269
PIC18FXX2
22.3.2
TIMING CONDITIONS
The temperature and voltages specified in Table 22-3
apply to all timing specifications unless otherwise
noted. Figure 22-4 specifies the load conditions for the
timing specifications.
TABLE 22-3:
TEMPERATURE AND VOLTAGE SPECIFICATIONS - AC
AC CHARACTERISTICS
FIGURE 22-4:
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
Operating voltage VDD range as described in DC spec Section 22.1 and
Section 22.2.
LC parts operate for industrial temperatures only.
LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS
Load condition 1
Load condition 2
VDD/2
RL
CL
Pin
VSS
CL
Pin
RL = 464Ω
VSS
DS39564C-page 270
CL = 50 pF
for all pins except OSC2/CLKO
and including D and E outputs as ports
© 2006 Microchip Technology Inc.
PIC18FXX2
22.3.3
TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 22-5:
EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)
Q4
Q1
Q2
Q3
Q4
Q1
OSC1
1
3
4
3
4
2
CLKO
TABLE 22-4:
Param.
No.
1A
EXTERNAL CLOCK TIMING REQUIREMENTS
Symbol
FOSC
Characteristic
Min
Max
Units
External CLKI Frequency(1)
DC
40
MHz
DC
25
MHz
EC, ECIO, +85°C to +125°C
DC
4
MHz
RC osc
Oscillator
1
TOSC
Frequency(1)
External CLKI
Oscillator
Period(1)
Period(1)
Time(1)
2
TCY
Instruction Cycle
3
TosL,
TosH
External Clock in (OSC1)
High or Low Time
4
TosR,
TosF
External Clock in (OSC1)
Rise or Fall Time
Conditions
EC, ECIO, -40°C to +85°C
0.1
4
MHz
XT osc
4
25
MHz
HS osc
4
10
MHz
HS + PLL osc, -40°C to +85°C
4
6.25
MHz
HS + PLL osc, +85°C to +125°C
5
200
kHz
LP Osc mode
25
—
ns
EC, ECIO, -40°C to +85°C
40
—
ns
EC, ECIO, +85°C to +125°C
250
—
ns
RC osc
250
10,000
ns
XT osc
40
250
ns
HS osc
100
250
ns
HS + PLL osc, -40°C to +85°C
160
250
ns
HS + PLL osc, +85°C to +125°C
25
—
μs
LP osc
100
—
ns
TCY = 4/FOSC, -40°C to +85°C
160
—
ns
TCY = 4/FOSC, +85°C to +125°C
30
—
ns
XT osc
2.5
—
μs
LP osc
10
—
ns
HS osc
—
20
ns
XT osc
—
50
ns
LP osc
—
7.5
ns
HS osc
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time-base period for all configurations
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.
© 2006 Microchip Technology Inc.
DS39564C-page 271
PIC18FXX2
TABLE 22-5:
Param
No.
PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2 TO 5.5V)
Sym
Characteristic
Min
Typ†
Max
4
16
—
—
10
40
Units
—
—
FOSC Oscillator Frequency Range
FSYS On-chip VCO System Frequency
—
trc
PLL Start-up Time (Lock Time)
—
—
2
ms
—
ΔCLK
CLKO Stability (Jitter)
-2
—
+2
%
Conditions
MHz HS mode only
MHz HS mode only
† Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only
and are not tested.
FIGURE 22-6:
CLKO AND I/O TIMING
Q1
Q4
Q2
Q3
OSC1
11
10
CLKO
13
14
19
12
18
16
I/O Pin
(input)
15
17
I/O Pin
(output)
New Value
Old Value
20, 21
Note:
Refer to Figure 22-4 for load conditions.
DS39564C-page 272
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 22-6:
CLKO AND I/O TIMING REQUIREMENTS
Param.
Symbol
No.
Characteristic
Min
Typ
Max
Units Conditions
10
TosH2ckL OSC1↑ to CLKO↓
—
75
200
ns
(Note 1)
11
TosH2ckH OSC1↑ to CLKO↑
—
75
200
ns
(Note 1)
12
TckR
CLKO rise time
—
35
100
ns
(Note 1)
13
TckF
CLKO fall time
—
35
100
ns
(Note 1)
14
TckL2ioV CLKO↓ to Port out valid
—
—
0.5 TCY + 20
ns
(Note 1)
15
TioV2ckH Port in valid before CLKO ↑
16
TckH2ioI
17
TosH2ioV OSC1↑ (Q1 cycle) to Port out valid
18
TosH2ioI
18A
0.25 TCY + 25
—
—
ns
(Note 1)
0
—
—
ns
(Note 1)
—
50
150
ns
100
—
—
ns
Port in hold after CLKO ↑
OSC1↑ (Q2 cycle) to Port
PIC18FXXX
input invalid (I/O in hold time) PIC18LFXXX
200
—
—
ns
19
TioV2osH Port input valid to OSC1↑ (I/O in setup time)
0
—
—
ns
20
TioR
PIC18FXXX
—
10
25
ns
PIC18LFXXX
—
—
60
ns
PIC18FXXX
—
10
25
ns
PIC18LFXXX
—
—
60
ns
Port output rise time
20A
21
TioF
Port output fall time
21A
22††
TINP
INT pin high or low time
TCY
—
—
ns
23††
TRBP
RB7:RB4 change INT high or low time
TCY
—
—
ns
24††
TRCP
RC7:RC4 change INT high or low time
20
VDD = 2V
VDD = 2V
ns
†† These parameters are asynchronous events not related to any internal clock edges.
Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.
FIGURE 22-7:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP
TIMER TIMING
VDD
MCLR
30
Internal
POR
33
PWRT
Time-out
32
OSC
Time-out
Internal
Reset
Watchdog
Timer
Reset
34
31
34
I/O Pins
Note:
Refer to Figure 22-4 for load conditions.
© 2006 Microchip Technology Inc.
DS39564C-page 273
PIC18FXX2
FIGURE 22-8:
BROWN-OUT RESET TIMING
BVDD
VDD
35
VBGAP = 1.2V
Typical
VIRVST
Enable Internal Reference Voltage
Internal Reference Voltage stable
TABLE 22-7:
36
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
Symbol
No.
Characteristic
Min
Typ
Max
Units
30
TmcL
MCLR Pulse Width (low)
2
—
—
μs
31
TWDT
Watchdog Timer Time-out Period
(No Postscaler)
7
18
33
ms
32
TOST
Oscillation Start-up Timer Period
1024 TOSC
—
1024 TOSC
—
33
TPWRT
Power up Timer Period
28
72
132
ms
34
TIOZ
I/O Hi-impedance from MCLR Low
or Watchdog Timer Reset
—
2
—
μs
35
TBOR
Brown-out Reset Pulse Width
200
—
—
μs
36
TIVRST
Time for Internal Reference
Voltage to become stable
—
20
500
μs
37
TLVD
Low Voltage Detect Pulse Width
200
—
—
μs
DS39564C-page 274
Conditions
TOSC = OSC1 period
VDD ≤ BVDD (see
D005)
VDD ≤ VLVD (see
D420)
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-9:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
41
40
42
T1OSO/T1CKI
46
45
47
48
TMR0 or
TMR1
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-8:
TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
Symbol
No.
40
Tt0H
Characteristic
T0CKI High Pulse Width
Min
Max
Units
0.5TCY + 20
—
ns
10
—
ns
0.5TCY + 20
—
ns
10
—
ns
TCY + 10
—
ns
Greater of:
20 nS or TCY + 40
N
—
ns
0.5TCY + 20
—
ns
PIC18FXXX
10
—
ns
PIC18LFXXX
25
—
ns
PIC18FXXX
30
—
ns
PIC18LFXXX
50
—
ns
0.5TCY + 5
—
ns
No Prescaler
With Prescaler
41
Tt0L
T0CKI Low Pulse Width
No Prescaler
With Prescaler
42
Tt0P
T0CKI Period
No Prescaler
With Prescaler
45
Tt1H
T1CKI High
Time
Synchronous, no prescaler
Synchronous,
with prescaler
Asynchronous
46
Tt1L
T1CKI Low
Time
Synchronous, no prescaler
Synchronous,
with prescaler
PIC18FXXX
10
—
ns
PIC18LFXXX
25
—
ns
Asynchronous
PIC18FXXX
30
—
ns
50
—
ns
Greater of:
20 nS or TCY + 40
N
—
ns
PIC18LFXXX
47
Tt1P
T1CKI input
period
Synchronous
Ft1
T1CKI oscillator input frequency range
Asynchronous
48
Tcke2tmrI Delay from external T1CKI clock edge to timer
increment
© 2006 Microchip Technology Inc.
Conditions
N = prescale
value
(1, 2, 4,..., 256)
N = prescale
value
(1, 2, 4, 8)
60
—
ns
DC
50
kHz
2 TOSC
7 TOSC
—
DS39564C-page 275
PIC18FXX2
FIGURE 22-10:
CAPTURE/COMPARE/PWM TIMINGS (CCP1 AND CCP2)
CCPx
(Capture Mode)
50
51
52
CCPx
(Compare or PWM Mode)
53
Note:
TABLE 22-9:
Refer to Figure 22-4 for load conditions.
CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1 AND CCP2)
Param.
Symbol
No.
50
51
TccL
TccH
Characteristic
Min
Max
Units
CCPx input low No Prescaler
time
With
PIC18FXXX
Prescaler PIC18LFXXX
0.5 TCY + 20
—
ns
10
—
ns
20
—
ns
CCPx input
high time
0.5 TCY + 20
—
ns
10
—
ns
20
—
ns
3 TCY + 40
N
—
ns
No Prescaler
With
Prescaler
52
TccP
CCPx input period
53
TccR
CCPx output fall time
54
54
TccF
DS39564C-page 276
CCPx output fall time
PIC18FXXX
PIC18LFXXX
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
Conditions
N = prescale
value (1,4 or 16)
VDD = 2V
VDD = 2V
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-11:
PARALLEL SLAVE PORT TIMING (PIC18F4X2)
RE2/CS
RE0/RD
RE1/WR
65
RD7:RD0
62
64
63
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-10: PARALLEL SLAVE PORT REQUIREMENTS (PIC18F4X2)
Param.
No.
62
63
64
Symbol
TdtV2wrH
TwrH2dtI
TrdL2dtV
Characteristic
Min
Max
Units
Conditions
Data in valid before WR↑ or CS↑
(setup time)
20
25
—
—
ns
ns
Extended Temp. Range
WR↑ or CS↑ to data–in invalid PIC18FXXX
(hold time)
PIC18LFXXX
20
—
ns
35
—
ns
VDD = 2V
—
—
80
90
ns
ns
Extended Temp. Range
ns
RD↓ and CS↓ to data–out valid
65
TrdH2dtI
RD↑ or CS↓ to data–out invalid
10
30
66
TibfINH
Inhibit of the IBF flag bit being cleared from
WR↑ or CS↑
—
3 TCY
© 2006 Microchip Technology Inc.
DS39564C-page 277
PIC18FXX2
FIGURE 22-12:
EXAMPLE SPI MASTER MODE TIMING (CKE = 0)
SS
70
SCK
(CKP = 0)
71
72
78
79
79
78
SCK
(CKP = 1)
80
bit6 - - - - - -1
MSb
SDO
LSb
75, 76
SDI
MSb In
bit6 - - - -1
LSb In
74
73
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-11: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Param.
No.
Symbol
Characteristic
70
TssL2scH, SS↓ to SCK↓ or SCK↑ input
TssL2scL
71
TscH
SCK input high time
(Slave mode)
TscL
SCK input low time
(Slave mode)
71A
72
72A
Min
Continuous
Max Units Conditions
TCY
—
ns
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
Continuous
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
100
—
ns
1.5 TCY + 40
—
ns
100
—
ns
—
25
ns
73
TdiV2scH, Setup time of SDI data input to SCK edge
TdiV2scL
73A
TB2B
74
TscH2diL, Hold time of SDI data input to SCK edge
TscL2diL
75
TdoR
SDO data output rise time
PIC18FXXX
PIC18LFXXX
—
60
ns
76
TdoF
SDO data output fall time
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
—
25
ns
PIC18LFXXX
—
60
ns
PIC18FXXX
—
50
ns
PIC18LFXXX
—
150
ns
78
TscR
Last clock edge of Byte1 to the 1st clock edge of Byte2
SCK output rise time
(Master mode)
79
TscF
SCK output fall time (Master mode) PIC18FXXX
80
TscH2doV, SDO data output valid after SCK
TscL2doV edge
(Note 1)
(Note 1)
(Note 2)
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
Note 1: Requires the use of Parameter # 73A.
2: Only if Parameter # 71A and # 72A are used.
DS39564C-page 278
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-13:
EXAMPLE SPI MASTER MODE TIMING (CKE = 1)
SS
81
SCK
(CKP = 0)
71
72
79
73
SCK
(CKP = 1)
80
78
MSb
SDO
bit6 - - - - - -1
LSb
bit6 - - - -1
LSb In
75, 76
SDI
MSb In
74
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-12: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Param.
No.
71
Symbol
TscH
SCK input high time
(Slave mode)
TscL
SCK input low time
(Slave mode)
71A
72
Characteristic
72A
Min
Max Units Conditions
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
Continuous
1.25 TCY + 30
—
ns
Continuous
Single Byte
73
TdiV2scH, Setup time of SDI data input to SCK edge
TdiV2scL
40
—
ns
100
—
ns
1.5 TCY + 40
—
ns
100
—
ns
73A
TB2B
Last clock edge of Byte1 to the 1st clock edge of Byte2
74
TscH2diL,
TscL2diL
Hold time of SDI data input to SCK edge
75
TdoR
SDO data output rise time
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
76
TdoF
SDO data output fall time
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
78
TscR
SCK output rise time (Master mode) PIC18FXXX
—
25
ns
—
60
ns
79
TscF
SCK output fall time (Master mode) PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
80
TscH2doV, SDO data output valid after SCK
TscL2doV edge
PIC18FXXX
—
50
ns
—
150
ns
81
TdoV2scH, SDO data output setup to SCK edge
TdoV2scL
TCY
—
ns
PIC18LFXXX
PIC18LFXXX
(Note 1)
(Note 1)
(Note 2)
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
Note 1: Requires the use of Parameter # 73A.
2: Only if Parameter # 71A and # 72A are used.
© 2006 Microchip Technology Inc.
DS39564C-page 279
PIC18FXX2
FIGURE 22-14:
EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)
SS
70
SCK
(CKP = 0)
83
71
72
78
79
79
78
SCK
(CKP = 1)
80
MSb
SDO
bit6 - - - - - -1
LSb
77
75, 76
SDI
MSb In
bit6 - - - -1
LSb In
74
73
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-13: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING (CKE = 0))
Param. No.
Symbol
Characteristic
70
TssL2scH,
TssL2scL
SS↓ to SCK↓ or SCK↑ input
71
TscH
SCK input high time (Slave mode)
71A
72
73
ns
—
ns
40
—
ns
Continuous
1.25 TCY + 30
—
ns
TdiV2scH,
TdiV2scL
Setup time of SDI data input to SCK edge
Single Byte
40
—
ns
100
—
ns
1.5 TCY + 40
—
ns
100
—
ns
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
73A
TB 2 B
Last clock edge of Byte1 to the first clock edge of Byte2
TscH2diL,
TscL2diL
Hold time of SDI data input to SCK edge
75
TdoR
SDO data output rise time
SDO data output fall time
—
1.25 TCY + 30
SCK input low time (Slave mode)
TdoF
TCY
Units Conditions
Single Byte
74
76
Max
Continuous
TscL
72A
Min
77
TssH2doZ
SS↑ to SDO output hi-impedance
78
TscR
SCK output rise time (Master mode)
79
TscF
SCK output fall time (Master mode)
PIC18LFXXX
—
60
ns
80
TscH2doV, SDO data output valid after SCK edge PIC18FXXX
TscL2doV
PIC18LFXXX
—
50
ns
—
150
ns
83
TscH2ssH, SS ↑ after SCK edge
TscL2ssH
1.5 TCY + 40
—
ns
PIC18FXXX
10
50
ns
—
25
ns
PIC18LFXXX
—
60
ns
PIC18FXXX
—
25
ns
(Note 1)
(Note 1)
(Note 2)
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
Note 1: Requires the use of Parameter # 73A.
2: Only if Parameter # 71A and # 72A are used.
DS39564C-page 280
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 22-15:
EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)
82
SS
70
SCK
(CKP = 0)
83
71
72
SCK
(CKP = 1)
80
MSb
SDO
bit6 - - - - - -1
LSb
75, 76
SDI
MSb In
77
bit6 - - - -1
LSb In
74
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-14: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param. No.
Symbol
Characteristic
70
TssL2scH, SS↓ to SCK↓ or SCK↑ input
TssL2scL
71
TscH
71A
72
SCK input high time
(Slave mode)
Min
Max
Units Conditions
TCY
—
ns
ns
Continuous
1.25 TCY + 30
—
Single Byte
40
—
ns
Continuous
1.25 TCY + 30
—
ns
Single Byte
40
(Note 1)
TscL
SCK input low time
(Slave mode)
—
ns
(Note 1)
73A
TB 2 B
Last clock edge of Byte1 to the first clock edge of Byte2 1.5 TCY + 40
—
ns
(Note 2)
74
TscH2diL,
TscL2diL
Hold time of SDI data input to SCK edge
100
—
ns
75
TdoR
SDO data output rise time
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
76
TdoF
SDO data output fall time
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
10
50
ns
—
25
ns
72A
77
TssH2doZ
SS↑ to SDO output hi-impedance
78
TscR
SCK output rise time (Master mode)
PIC18FXXX
PIC18LFXXX
—
60
ns
79
TscF
SCK output fall time (Master mode)
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
80
TscH2doV, SDO data output valid after SCK
TscL2doV edge
PIC18FXXX
—
50
ns
82
TssL2doV
83
TscH2ssH, SS ↑ after SCK edge
TscL2ssH
PIC18LFXXX
SDO data output valid after SS↓ edge PIC18FXXX
PIC18LFXXX
—
150
ns
—
50
ns
—
150
ns
1.5 TCY + 40
—
ns
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
VDD = 2V
Note 1: Requires the use of Parameter # 73A.
2: Only if Parameter # 71A and # 72A are used.
© 2006 Microchip Technology Inc.
DS39564C-page 281
PIC18FXX2
FIGURE 22-16:
I2C BUS START/STOP BITS TIMING
SCL
91
93
90
92
SDA
STOP
Condition
START
Condition
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-15: I2C BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
Param.
Symbol
No.
90
91
92
93
TSU:STA
THD:STA
TSU:STO
Characteristic
Max
Units
Conditions
ns
Only relevant for Repeated
START condition
ns
After this period, the first
clock pulse is generated
START condition
100 kHz mode
4700
—
Setup time
400 kHz mode
600
—
START condition
100 kHz mode
4000
—
Hold time
400 kHz mode
600
—
STOP condition
100 kHz mode
4700
—
Setup time
400 kHz mode
600
—
100 kHz mode
4000
—
400 kHz mode
600
—
THD:STO STOP condition
Hold time
FIGURE 22-17:
Min
ns
ns
I2C BUS DATA TIMING
103
102
100
101
SCL
90
106
107
91
92
SDA
In
110
109
109
SDA
Out
Note:
Refer to Figure 22-4 for load conditions.
DS39564C-page 282
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 22-16: I2C BUS DATA REQUIREMENTS (SLAVE MODE)
Param.
No.
100
Symbol
THIGH
Characteristic
Clock high time
Min
Max
Units
Conditions
100 kHz mode
4.0
—
μs
PIC18FXXX must operate at a
minimum of 1.5 MHz
400 kHz mode
0.6
—
μs
PIC18FXXX must operate at a
minimum of 10 MHz
1.5 TCY
—
100 kHz mode
4.7
—
μs
PIC18FXXX must operate at a
minimum of 1.5 MHz
400 kHz mode
1.3
—
μs
PIC18FXXX must operate at a
minimum of 10 MHz
SSP Module
101
TLOW
Clock low time
1.5 TCY
—
SDA and SCL rise
time
100 kHz mode
—
1000
ns
400 kHz mode
20 + 0.1 CB
300
ns
CB is specified to be from
10 to 400 pF
ns
VDD ≥ 4.2V
SSP Module
102
TR
103
TF
SDA and SCL fall
time
100 kHz mode
—
1000
400 kHz mode
20 + 0.1 CB
300
ns
VDD ≥ 4.2V
90
TSU:STA
START condition
setup time
100 kHz mode
4.7
—
μs
400 kHz mode
0.6
—
μs
Only relevant for Repeated
START condition
91
THD:STA
START condition hold 100 kHz mode
time
400 kHz mode
4.0
—
μs
μs
106
THD:DAT
Data input hold time
0.6
—
100 kHz mode
0
—
ns
400 kHz mode
0
0.9
μs
ns
107
TSU:DAT
Data input setup time 100 kHz mode
250
—
400 kHz mode
100
—
ns
92
TSU:STO
STOP condition
setup time
100 kHz mode
4.7
—
μs
400 kHz mode
0.6
—
μs
109
TAA
Output valid from
clock
100 kHz mode
—
3500
ns
400 kHz mode
—
—
ns
110
TBUF
Bus free time
100 kHz mode
4.7
—
μs
400 kHz mode
1.3
—
μs
—
400
pF
D102
CB
Bus capacitive loading
After this period, the first clock
pulse is generated
(Note 2)
(Note 1)
Time the bus must be free
before a new transmission can
start
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 SCL 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 SCL signal. If
such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line.
TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification) before the SCL line is
released.
© 2006 Microchip Technology Inc.
DS39564C-page 283
PIC18FXX2
FIGURE 22-18:
MASTER SSP I2C BUS START/STOP BITS TIMING WAVEFORMS
SCL
93
91
90
92
SDA
STOP
Condition
START
Condition
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-17: MASTER SSP I2C BUS START/STOP BITS REQUIREMENTS
Param.
Symbol
No.
90
91
TSU:STA
Characteristic
Units
ns
Only relevant for
Repeated START
condition
ns
After this period, the
first clock pulse is
generated
100 kHz mode
2(TOSC)(BRG + 1)
—
Setup time
400 kHz mode
2(TOSC)(BRG + 1)
—
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
100 kHz mode
2(TOSC)(BRG + 1)
—
THD:STA START condition
TSU:STO STOP condition
Setup time
93
Max
START condition
Hold time
92
Min
THD:STO STOP condition
Hold time
400 kHz mode
2(TOSC)(BRG + 1)
—
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
100 kHz mode
2(TOSC)(BRG + 1)
—
400 kHz mode
2(TOSC)(BRG + 1)
—
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
100 kHz mode
2(TOSC)(BRG + 1)
—
400 kHz mode
2(TOSC)(BRG + 1)
—
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
Conditions
ns
ns
2
Note 1: Maximum pin capacitance = 10 pF for all I C pins.
FIGURE 22-19:
MASTER SSP I2C BUS DATA TIMING
103
102
100
101
SCL
90
106
91
107
92
SDA
In
109
109
110
SDA
Out
Note:
DS39564C-page 284
Refer to Figure 22-4 for load conditions.
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 22-18: MASTER SSP I2C BUS DATA REQUIREMENTS
Param.
Symbol
No.
100
THIGH
Characteristic
Clock high time
Min
Max
Units
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
(1)
2(TOSC)(BRG + 1)
—
ms
1 MHz mode
101
TLOW
Clock low time
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
(1)
2(TOSC)(BRG + 1)
—
ms
100 kHz mode
—
1000
ns
400 kHz mode
20 + 0.1 CB
300
ns
1 MHz mode
102
TR
SDA and SCL
rise time
Conditions
CB is specified to be from
10 to 400 pF
(1)
1 MHz mode
—
300
ns
100 kHz mode
—
1000
ns
VDD ≥ 4.2V
103
TF
SDA and SCL
fall time
20 + 0.1 CB
300
ns
VDD ≥ 4.2V
90
TSU:STA
START condition 100 kHz mode
setup time
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
Only relevant for
Repeated START
condition
THD:STA START condition 100 kHz mode
hold time
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
91
106
107
92
THD:DAT Data input
hold time
TSU:DAT
Data input
setup time
TSU:STO STOP condition
setup time
400 kHz mode
100 kHz mode
0
—
ns
400 kHz mode
0
0.9
ms
100 kHz mode
250
—
ns
400 kHz mode
100
—
ns
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
(1)
2(TOSC)(BRG + 1)
—
ms
—
3500
ns
ns
1 MHz mode
109
110
D102
TAA
TBUF
CB
Output valid from 100 kHz mode
clock
400 kHz mode
Bus free time
—
1000
(1)
1 MHz mode
—
—
ns
100 kHz mode
4.7
—
ms
400 kHz mode
1.3
—
ms
—
400
pF
Bus capacitive loading
After this period, the first
clock pulse is generated
(Note 2)
Time the bus must be free
before a new transmission
can start
I2C
pins.
Note 1: Maximum pin capacitance = 10 pF for all
2: 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 SCL
signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the
SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line
is released.
© 2006 Microchip Technology Inc.
DS39564C-page 285
PIC18FXX2
FIGURE 22-20:
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
RC6/TX/CK
pin
121
121
RC7/RX/DT
pin
120
Note:
122
Refer to Figure 22-4 for load conditions.
TABLE 22-19: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Param.
No.
120
Symbol
Characteristic
Min
Max
Units
—
50
ns
TckH2dtV SYNC XMIT (MASTER & SLAVE)
Clock high to data out valid
PIC18FXXX
PIC18LFXXX
—
150
ns
121
Tckr
Clock out rise time and fall time
(Master mode)
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
122
Tdtr
Data out rise time and fall time
PIC18FXXX
—
25
ns
PIC18LFXXX
—
60
ns
FIGURE 22-21:
RC6/TX/CK
pin
Conditions
VDD = 2V
VDD = 2V
VDD = 2V
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
125
RC7/RX/DT
pin
126
Note:
Refer to Figure 22-4 for load conditions.
TABLE 22-20: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Param.
Symbol
No.
Characteristic
125
TdtV2ckl SYNC RCV (MASTER & SLAVE)
Data hold before CK ↓ (DT hold time)
126
TckL2dtl
DS39564C-page 286
Data hold after CK ↓ (DT hold time)
Min
Max
Units
10
—
ns
PIC18FXXX
15
—
ns
PIC18LFXXX
20
—
ns
Conditions
VDD = 2V
© 2006 Microchip Technology Inc.
PIC18FXX2
TABLE 22-21: A/D CONVERTER CHARACTERISTICS: PIC18FXX2 (INDUSTRIAL, EXTENDED)
PIC18LFXX2 (INDUSTRIAL)
Param
Symbol
No.
Characteristic
Min
Typ
Max
Units
Conditions
A01
NR
Resolution
—
—
10
A03
EIL
Integral linearity error
—
—
<±1
A04
EDL
Differential linearity error
—
—
<±1
LSb VREF = VDD = 5.0V
A05
EG
Gain error
—
—
<±1
LSb VREF = VDD = 5.0V
A06
EOFF
Offset error
—
—
<±1.5
LSb VREF = VDD = 5.0V
A10
—
Monotonicity
A20
A20A
VREF
Reference Voltage
(VREFH – VREFL)
A21
VREFH
Reference voltage High
A22
VREFL
Reference voltage Low
A25
VAIN
Analog input voltage
A30
ZAIN
A50
IREF
Note 1:
2:
3:
4:
guaranteed
1.8V
3V
(2)
bit
LSb VREF = VDD = 5.0V
—
VSS ≤ VAIN ≤ VREF
VDD < 3.0V
VDD ≥ 3.0V
—
—
—
—
V
V
AVSS
—
AVDD + 0.3V
V
AVSS – 0.3V
—
VREFH
V
AVSS – 0.3V
—
AVDD + 0.3V
V
VDD ≥ 2.5V (Note 3)
Recommended impedance of
analog voltage source
—
—
2.5
kΩ
(Note 4)
VREF input current (Note 1)
—
—
—
—
5
150
μA
μA
During VAIN acquisition
During A/D conversion cycle
Vss ≤ VAIN ≤ VREF
The A/D conversion result never decreases with an increase in the Input Voltage, and has no missing codes.
For VDD < 2.5V, VAIN should be limited to < .5 VDD.
Maximum allowed impedance for analog voltage source is 10 kΩ. This requires higher acquisition times.
FIGURE 22-22:
A/D CONVERSION TIMING
BSF ADCON0, GO
(Note 2)
131
Q4
130
A/D CLK
132
A/D DATA
ADRES
9
8
7
...
...
2
1
OLD_DATA
0
NEW_DATA
TCY
ADIF
GO
SAMPLE
DONE
SAMPLING STOPPED
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.
© 2006 Microchip Technology Inc.
DS39564C-page 287
PIC18FXX2
TABLE 22-22: A/D CONVERSION REQUIREMENTS
Param
Symbol
No.
130
TAD
Characteristic
A/D clock period
Min
Max
Units
PIC18FXXX
1.6
20(4)
μs
TOSC based
PIC18FXXX
2.0
6.0
μs
A/D RC mode
131
TCNV
Conversion time
(not including acquisition time) (Note 1)
11
12
TAD
132
TACQ
Acquisition time (Note 2)
5
10
—
—
μs
μs
135
TSWC
Switching Time from convert → sample
—
(Note 3)
Conditions
VREF = VDD = 5.0V
VREF = VDD = 2.5V
Note 1: ADRES register may be read on the following TCY cycle.
2: The time for the holding capacitor to acquire the “New” input voltage, when the new input value has not
changed by more than 1 LSB from the last sampled voltage. The source impedance (RS) on the input channels
is 50Ω. See Section 17.0 for more information on acquisition time consideration.
3: On the next Q4 cycle of the device clock.
4: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
DS39564C-page 288
© 2006 Microchip Technology Inc.
PIC18FXX2
23.0
DC AND AC CHARACTERISTICS GRAPHS AND TABLES
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein are
not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore, outside the warranted range.
“Typical” represents the mean of the distribution at 25°C. “Maximum” or “minimum” represents (mean + 3σ) or (mean - 3σ)
respectively, where σ is a standard deviation, over the whole temperature range.
FIGURE 23-1:
TYPICAL IDD vs. FOSC OVER VDD (HS MODE)
12
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
10
5.5V
5.0V
IDD (mA)
8
4.5V
4.0V
6
3.5V
4
3.0V
2
2.5V
2.0V
0
4
6
8
10
12
14
16
18
20
22
24
26
F O S C (M H z)
FIGURE 23-2:
MAXIMUM IDD vs. FOSC OVER VDD (HS MODE)
12
5.5V
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
10
5.0V
4.5V
8
IDD (mA)
4.0V
3.5V
6
3.0V
4
2.5V
2
2.0V
0
4
6
8
10
12
14
16
18
20
22
24
26
F O S C (M H z)
© 2006 Microchip Technology Inc.
DS39564C-page 289
PIC18FXX2
FIGURE 23-3:
TYPICAL IDD vs. FOSC OVER VDD (HS/PLL MODE)
20
18
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
16
5.5V
14
5.0V
4.5V
IDD (mA)
12
10
4.2V
8
6
4
2
0
4
5
6
7
8
9
10
FOSC (MHz)
FIGURE 23-4:
MAXIMUM IDD vs. FOSC OVER VDD (HS/PLL MODE)
20
18
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
16
5.5V
5.0V
14
4.5V
IDD (mA)
12
4.2V
10
8
6
4
2
0
4
5
6
7
8
9
10
FOSC (MHz)
DS39564C-page 290
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-5:
TYPICAL IDD vs. FOSC OVER VDD (XT MODE)
2,000
1,800
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
5.5V
1,600
5.0V
1,400
4.5V
IIDD
μA)
DD ((uA)
1,200
4.0V
1,000
3.5V
3.0V
800
2.5V
600
2.0V
400
200
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
FOSC (MHz)
FIGURE 23-6:
MAXIMUM IDD vs. FOSC OVER VDD (XT MODE)
2,000
5.5V
1,800
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
5.0V
1,600
4.5V
1,400
4.0V
IDD (μA)
1,200
3.5V
1,000
3.0V
800
2.5V
600
2.0V
400
200
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
FOSC (MHz)
© 2006 Microchip Technology Inc.
DS39564C-page 291
PIC18FXX2
FIGURE 23-7:
TYPICAL IDD vs. FOSC OVER VDD (LP MODE)
100
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
90
80
5.5V
70
5.0V
IDD (uA)
60
4.5V
50
4.0V
40
3.5V
3.0V
30
2.5V
20
2.0V
10
0
20
30
40
50
60
70
80
90
100
90
100
FOSC (kHz)
FIGURE 23-8:
MAXIMUM IDD vs. FOSC OVER VDD (LP MODE)
140
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
120
5.5V
5.0V
100
4.5V
IDD (uA)
80
4.0V
3.5V
60
3.0V
2.5V
40
2.0V
20
0
20
30
40
50
60
70
80
FOSC (kHz)
DS39564C-page 292
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-9:
TYPICAL IDD vs. FOSC OVER VDD (EC MODE)
16
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
14
5.5V
5.0V
12
4.5V
4.2V
IDD (mA)
10
4.0V
8
6
3.5V
4
3.0V
2
2.5V
2.0V
0
4
8
12
16
20
24
28
32
36
40
FOSC (MHz)
FIGURE 23-10:
MAXIMUM IDD vs. FOSC OVER VDD (EC MODE)
16
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
14
5.5V
5.0V
12
4.5V
4.2V
IDD (mA)
10
4.0V
8
3.5V
6
4
3.0V
2
2.5V
2.0V
0
4
8
12
16
20
24
28
32
36
40
FOSC (MHz)
© 2006 Microchip Technology Inc.
DS39564C-page 293
PIC18FXX2
FIGURE 23-11:
TYPICAL AND MAXIMUM IDD vs. VDD
(TIMER1 AS MAIN OSCILLATOR, 32.768 kHz, C1 AND C2 = 47 pF)
180
160
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-10°C to 70°C)
Minimum: mean – 3σ (-10°C to 70°C)
140
IDD
(μA)
PD (uA)
120
100
Max
Max(+70°C)
(70C)
80
60
Typ
Typ(+25°C)
(25C)
40
20
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
FIGURE 23-12:
AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R
(RC MODE, C = 20 pF, +25°C)
4,500
Operation above 4 MHz is not recommended.
4,000
3.3kΩ
3,500
3,000
Freq (kHz)
5.1kΩ
2,500
2,000
1,500
10k Ω
1,000
500
100kΩ
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
DS39564C-page 294
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-13:
AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R
(RC MODE, C = 100 pF, +25°C)
2,000
1,800
1,600
3.3kΩ
1,400
Freq (kHz)
1,200
5.1kΩ
1,000
800
10k Ω
600
400
200
100kΩ
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
5.0
5.5
VDD (V)
FIGURE 23-14:
AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R
(RC MODE, C = 300 pF, +25°C)
800
700
3.3kΩ
600
Freq (MHz)
500
5.1kΩ
400
300
10kΩ
200
100
100kΩ
0
2.0
2.5
3.0
3.5
4.0
4.5
VDD (V)
© 2006 Microchip Technology Inc.
DS39564C-page 295
PIC18FXX2
FIGURE 23-15:
IPD vs. VDD, -40°C TO +125°C (SLEEP MODE, ALL PERIPHERALS DISABLED)
100
Max
(-40°C to +125°C)
10
IPD (uA)
Max
(+85°C)
1
Typ (+25°C)
0.1
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
0.01
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
FIGURE 23-16:
ΔIBOR vs. VDD OVER TEMPERATURE (BOR ENABLED, VBOR = 2.00 - 2.16V)
90
80
70
60
IDD (μA)
Max
Max(+125°C)
(125C)
Device
Device
Heldinin
Held
RESET
Reset
Max
Max (+85°C)
(85C)
50
40
Typ
Typ(+25°C)
(25C)
30
Device
Device
inin
SLEEP
Sleep
20
10
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
DS39564C-page 296
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-17:
TYPICAL AND MAXIMUM ΔITMR1 vs. VDD OVER TEMPERATURE (-10°C TO +70°C,
TIMER1 WITH OSCILLATOR, XTAL = 32 kHz, C1 AND C2 = 47 pF)
14
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-10°C to 70°C)
Minimum: mean – 3σ (-10°C to 70°C)
12
Max(+70°C)
(70C)
Max
10
IPD (uA)
(μA)
8
Typ
Typ(+25°C)
(25C)
6
4
2
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
FIGURE 23-18:
TYPICAL AND MAXIMUM ΔIWDT vs. VDD OVER TEMPERATURE (WDT ENABLED)
70
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
60
50
40
IPD (μA)
Max
(+125°C)
Max
(125C)
30
Max
Max(+85°C)
(85C)
20
Typ
(+25°C)
Typ
(25C)
10
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
© 2006 Microchip Technology Inc.
DS39564C-page 297
PIC18FXX2
FIGURE 23-19:
TYPICAL, MINIMUM AND MAXIMUM WDT PERIOD vs. VDD (-40°C TO +125°C)
50
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
45
40
Max
Max
(+125°C)
(125C)
35
WDT Period (ms)
Max
MAX
(+85°C)
(85C)
30
25
Typ
(+25°C)
(25C)
20
15
Min
Min
(-40°C)
(-40C)
10
5
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
FIGURE 23-20:
ΔILVD vs. VDD OVER TEMPERATURE (LVD ENABLED, VLVD = 4.5 - 4.78V)
90
80
Max
Max(+125°C)
(125C)
70
60
IDD (μA)
Max
Max (+125°C)
(125C)
50
Typ
Typ(+25°C)
(25C)
40
Typ
Typ(+25°C)
(25C)
30
LVDIF can be
cleared by
firmware
20
LVDIF state
is unknown
10
LVDIF is set
by hardware
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
DS39564C-page 298
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-21:
TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 5V, -40°C TO +125°C)
5.5
5.0
4.5
Max
Max
4.0
Typ
Typ(+25°C)
(25C)
VOH (V)
3.5
3.0
Min
Min
2.5
2.0
1.5
1.0
0.5
0.0
0
5
10
15
20
25
IOH (-mA)
FIGURE 23-22:
TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 3V, -40°C TO +125°C)
3.0
2.5
2.0
VOH (V)
Max
Max
1.5
Typ
Typ(+25°C)
(25C)
1.0
Min
Min
0.5
0.0
0
5
10
15
20
25
IOH (-mA)
© 2006 Microchip Technology Inc.
DS39564C-page 299
PIC18FXX2
FIGURE 23-23:
TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 5V, -40°C TO +125°C)
1.8
1.6
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
1.4
VOL (V)
1.2
1.0
Max
Max
0.8
0.6
0.4
Typ
(+25°C)
Typ
(25C)
0.2
0.0
0
5
10
15
20
25
IOL (-mA)
FIGURE 23-24:
TYPICAL AND MAXIMUM VOL vs. IOL (VDD = 3V, -40°C TO +125°C)
2.5
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
2.0
VOL (V)
1.5
1.0
Max
Max
Typ
Typ(+25°C)
(25C)
0.5
0.0
0
5
10
15
20
25
IOL (-mA)
DS39564C-page 300
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-25:
MINIMUM AND MAXIMUM VIN vs. VDD (ST INPUT, -40°C TO +125°C)
4.0
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
3.5
VIH Max
3.0
2.5
VIN (V)
VIH Min
2.0
VIL Max
1.5
1.0
VIL Min
0.5
0.0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
FIGURE 23-26:
MINIMUM AND MAXIMUM VIN vs. VDD (TTL INPUT, -40°C TO +125°C)
1.6
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
1.4
VTH (Max)
1.2
VTH (Min)
VIN (V)
1.0
0.8
0.6
0.4
0.2
0.0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
© 2006 Microchip Technology Inc.
DS39564C-page 301
PIC18FXX2
MINIMUM AND MAXIMUM VIN vs. VDD (I2C INPUT, -40°C TO +125°C)
FIGURE 23-27:
3.5
VIH Max
Typical:
statistical mean @ 25°C
Maximum: mean + 3σ (-40°C to 125°C)
Minimum: mean – 3σ (-40°C to 125°C)
3.0
2.5
2.0
VIN (V)
VILMax
VIH Min
1.5
1.0
VIL Min
0.5
0.0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VDD (V)
A/D NON-LINEARITY vs. VREFH (VDD = VREFH, -40°C TO +125°C)
FIGURE 23-28:
4
3.5
Differential or Integral Nonlinearity (LSB)
-40°C
-40C
3
+25°C
25C
2.5
+85°C
85C
2
1.5
1
0.5
+125°C
125C
0
2
2.5
3
3.5
4
4.5
5
5.5
VDD and VREFH (V)
DS39564C-page 302
© 2006 Microchip Technology Inc.
PIC18FXX2
FIGURE 23-29:
A/D NON-LINEARITY vs. VREFH (VDD = 5V, -40°C TO +125°C)
3
Differential or Integral Nonlinearilty (LSB)
2.5
2
1.5
Max
+125°C)
Max (-40°C
(-40C toto125C)
1
Typ
Typ (+25°C)
(25C)
0.5
0
2
2.5
3
3.5
4
4.5
5
5.5
VREFH (V)
© 2006 Microchip Technology Inc.
DS39564C-page 303
PIC18FXX2
NOTES:
DS39564C-page 304
© 2006 Microchip Technology Inc.
PIC18FXX2
24.0
PACKAGING INFORMATION
24.1
Package Marking Information
28-Lead SPDIP
Example
PIC18F242-I/SP e3
0610017
XXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXX
YYWWNNN
28-Lead SOIC
Example
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXX
YYWWNNN
40-Lead PDIP
Example
XXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXX
YYWWNNN
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
PIC18F242-E/SO e3
0610017
PIC18F442-I/P e3
0610017
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
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.
© 2006 Microchip Technology Inc.
DS39564C-page 305
PIC18FXX2
Package Marking Information (Cont’d)
44-Lead TQFP
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
44-Lead PLCC
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
DS39564C-page 306
Example
PIC18F452
-E/PT e3
0610017
Example
PIC18F442
-I/L e3
0610017
© 2006 Microchip Technology Inc.
PIC18FXX2
24.2
Package Details
The following sections give the technical details of the packages.
28-Lead Skinny Plastic Dual In-line (SP) – 300 mil Body (PDIP)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
E1
D
2
n
1
α
E
A2
A
L
c
β
B1
A1
eB
Units
Number of Pins
Pitch
p
B
Dimension Limits
n
p
INCHES*
MIN
NOM
MILLIMETERS
MAX
MIN
28
NOM
MAX
28
.100
2.54
Top to Seating Plane
A
.140
.150
.160
3.56
3.81
4.06
Molded Package Thickness
A2
.125
.130
.135
3.18
3.30
3.43
Base to Seating Plane
A1
.015
8.26
0.38
Shoulder to Shoulder Width
E
.300
.310
.325
7.62
7.87
Molded Package Width
E1
.275
.285
.295
6.99
7.24
7.49
Overall Length
D
1.345
1.365
1.385
34.16
34.67
35.18
Tip to Seating Plane
L
c
.125
.130
.135
3.18
3.30
3.43
.008
.012
.015
0.20
0.29
0.38
Upper Lead Width
B1
.040
.053
.065
1.02
1.33
1.65
Lower Lead Width
B
.016
.019
.022
0.41
0.48
0.56
eB
α
.320
.350
.430
8.13
8.89
10.92
Lead Thickness
Overall Row Spacing
Mold Draft Angle Top
§
5
10
15
5
10
15
β
Mold Draft Angle Bottom
5
10
15
5
10
15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimension D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.
JEDEC Equivalent: MO-095
Drawing No. C04-070
© 2006 Microchip Technology Inc.
DS39564C-page 307
PIC18FXX2
28-Lead Plastic Small Outline (SO) – Wide, 300 mil Body (SOIC)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
E
E1
p
D
B
2
1
n
h
α
45°
c
A2
A
φ
β
L
Units
Dimension Limits
n
p
A1
INCHES*
NOM
28
.050
.099
.091
.008
.407
.295
.704
.020
.033
4
.011
.017
12
12
MAX
MILLIMETERS
NOM
28
1.27
2.36
2.50
2.24
2.31
0.10
0.20
10.01
10.34
7.32
7.49
17.65
17.87
0.25
0.50
0.41
0.84
0
4
0.23
0.28
0.36
0.42
0
12
0
12
MAX
Number of Pins
Pitch
Overall Height
A
.093
.104
2.64
Molded Package Thickness
A2
.088
.094
2.39
Standoff
§
A1
.004
.012
0.30
Overall Width
E
.394
.420
10.67
Molded Package Width
.288
.299
7.59
E1
Overall Length
D
.695
.712
18.08
Chamfer Distance
h
.010
.029
0.74
Foot Length
L
.016
.050
1.27
φ
Foot Angle Top
0
8
8
c
Lead Thickness
.009
.013
0.33
Lead Width
B
.014
.020
0.51
α
Mold Draft Angle Top
0
15
15
β
Mold Draft Angle Bottom
0
15
15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.
JEDEC Equivalent: MS-013
Drawing No. C04-052
DS39564C-page 308
MIN
MIN
© 2006 Microchip Technology Inc.
PIC18FXX2
40-Lead Plastic Dual In-line (P) – 600 mil Body (PDIP)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
E1
D
α
2
1
n
E
A2
A
L
c
β
B1
A1
eB
p
B
Units
Dimension Limits
n
p
INCHES*
NOM
40
.100
.175
.150
MAX
MILLIMETERS
NOM
40
2.54
4.06
4.45
3.56
3.81
0.38
15.11
15.24
13.46
13.84
51.94
52.26
3.05
3.30
0.20
0.29
0.76
1.27
0.36
0.46
15.75
16.51
5
10
5
10
MAX
Number of Pins
Pitch
Top to Seating Plane
A
.160
.190
4.83
Molded Package Thickness
A2
.140
.160
4.06
Base to Seating Plane
A1
.015
Shoulder to Shoulder Width
E
.595
.600
.625
15.88
Molded Package Width
E1
.530
.545
.560
14.22
Overall Length
D
2.045
2.058
2.065
52.45
Tip to Seating Plane
L
.120
.130
.135
3.43
c
Lead Thickness
.008
.012
.015
0.38
Upper Lead Width
B1
.030
.050
.070
1.78
Lower Lead Width
B
.014
.018
.022
0.56
Overall Row Spacing
§
eB
.620
.650
.680
17.27
α
Mold Draft Angle Top
5
10
15
15
β
Mold Draft Angle Bottom
5
10
15
15
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.
JEDEC Equivalent: MO-011
Drawing No. C04-016
© 2006 Microchip Technology Inc.
MIN
MIN
DS39564C-page 309
PIC18FXX2
44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
E
E1
#leads=n1
p
D1
D
2
1
B
n
CH x 45°
α
A
c
φ
β
A1
L
Units
Dimension Limits
n
p
Number of Pins
Pitch
Pins per Side
Overall Height
Molded Package Thickness
Standoff
Foot Length
Footprint (Reference)
n1
A
A2
A1
L
F
φ
MIN
.039
.037
.002
.018
INCHES
NOM
44
.031
11
.043
.039
.004
.024
.039 REF.
A2
F
MAX
.047
.041
.006
.030
MILLIMETERS*
NOM
MAX
44
0.80
11
1.00
1.10
1.20
0.95
1.00
1.05
0.05
0.10
0.15
0.45
0.60
0.75
1.00 REF.
MIN
0
3.5
7
0
3.5
7
Foot Angle
Overall Width
E
.463
.472
.482
11.75
12.00
12.25
Overall Length
D
.463
.472
.482
11.75
12.00
12.25
Molded Package Width
E1
.390
.394
.398
9.90
10.00
10.10
Molded Package Length
D1
.390
.394
.398
9.90
10.00
10.10
c
Lead Thickness
.004
.006
.008
0.09
0.15
0.20
Lead Width
B
.012
.015
.017
0.30
0.38
0.44
CH
.025
.035
.045
0.64
0.89
1.14
Pin 1 Corner Chamfer
α
5
10
15
5
10
15
Mold Draft Angle Top
β
5
10
15
5
10
15
Mold Draft Angle Bottom
* Controlling Parameter
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side.
REF: Reference Dimension, usually without tolerance, for information purposes only.
See ASME Y14.5M
JEDEC Equivalent: MS-026
Revised 07-22-05
Drawing No. C04-076
DS39564C-page 310
© 2006 Microchip Technology Inc.
PIC18FXX2
44-Lead Plastic Leaded Chip Carrier (L) – Square (PLCC)
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
E
E1
#leads=n1
D1 D
n 1 2
CH2 x 45 °
CH1 x 45 °
α
A3
A2
35°
A
B1
B
c
β
E2
Units
Dimension Limits
n
p
A1
p
D2
INCHES*
MIN
NOM
44
.050
11
.165
.173
.145
.153
.028
.020
.024
.029
.040
.045
.000
.005
.685
.690
.685
.690
.650
.653
.650
.653
.590
.620
.590
.620
.008
.011
.026
.029
.013
.020
0
5
0
5
MILLIMETERS
NOM
44
1.27
11
4.19
4.39
3.68
3.87
0.71
0.51
0.61
0.74
1.02
1.14
0.00
0.13
17.40
17.53
17.40
17.53
16.51
16.59
16.51
16.59
14.99
15.75
14.99
15.75
0.20
0.27
0.66
0.74
0.33
0.51
0
5
0
5
MAX
Number of Pins
Pitch
Pins per Side
n1
Overall Height
A
.180
4.57
.160
4.06
Molded Package Thickness
A2
.035
0.89
Standoff
§
A1
Side 1 Chamfer Height
A3
.034
0.86
Corner Chamfer 1
CH1
.050
1.27
Corner Chamfer (others)
CH2
.010
0.25
Overall Width
E
.695
17.65
Overall Length
D
.695
17.65
Molded Package Width
E1
.656
16.66
Molded Package Length
D1
.656
16.66
Footprint Width
.630
16.00
E2
Footprint Length
D2
.630
16.00
c
Lead Thickness
.013
0.33
Upper Lead Width
B1
.032
0.81
B
.021
0.53
Lower Lead Width
α
Mold Draft Angle Top
10
10
β
Mold Draft Angle Bottom
10
10
* Controlling Parameter
§ Significant Characteristic
Notes:
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side.
JEDEC Equivalent: MO-047
Drawing No. C04-048
© 2006 Microchip Technology Inc.
MAX
MIN
DS39564C-page 311
PIC18FXX2
NOTES:
DS39564C-page 312
© 2006 Microchip Technology Inc.
PIC18FXX2
APPENDIX A:
REVISION HISTORY
APPENDIX B:
Revision A (June 2001)
DEVICE
DIFFERENCES
The differences between the devices listed in this data
sheet are shown in Table B-1.
Original data sheet for the PIC18FXX2 family.
Revision B (August 2002)
This revision includes the DC and AC Characteristics
Graphs and Tables. The Electrical Specifications in
Section 22.0 have been updated and there have been
minor corrections to the data sheet text.
Revision C (October 2006)
Packaging diagrams updated.
TABLE B-1:
DEVICE DIFFERENCES
Feature
PIC18F242
PIC18F252
PIC18F442
PIC18F452
Program Memory (Kbytes)
16
32
16
32
Data Memory (Bytes)
768
1536
768
1536
5
5
8
8
No
No
Yes
Yes
28-pin DIP
28-pin SOIC
40-pin DIP
44-pin PLCC
44-pin TQFP
40-pin DIP
44-pin PLCC
44-pin TQFP
A/D Channels
Parallel Slave Port (PSP)
Package Types
© 2006 Microchip Technology Inc.
28-pin DIP
28-pin SOIC
DS39564C-page 313
PIC18FXX2
APPENDIX C:
CONVERSION
CONSIDERATIONS
This appendix discusses the considerations for converting from previous versions of a device to the ones
listed in this data sheet. Typically, these changes are
due to the differences in the process technology used.
An example of this type of conversion is from a
PIC16C74A to a PIC16C74B.
Not Applicable
DS39564C-page 314
APPENDIX D:
MIGRATION FROM
BASELINE TO
ENHANCED DEVICES
This section discusses how to migrate from a Baseline
device (i.e., PIC16C5X) to an Enhanced MCU device
(i.e., PIC18FXXX).
The following are the list of modifications over the
PIC16C5X microcontroller family:
Not Currently Available
© 2006 Microchip Technology Inc.
PIC18FXX2
APPENDIX E:
MIGRATION FROM
MID-RANGE TO
ENHANCED DEVICES
A detailed discussion of the differences between the
mid-range MCU devices (i.e., PIC16CXXX) and the
enhanced devices (i.e., PIC18FXXX) is provided in
AN716, “Migrating Designs from PIC16C74A/74B to
PIC18F442”. The changes discussed, while device
specific, are generally applicable to all mid-range to
enhanced device migrations.
APPENDIX F:
MIGRATION FROM
HIGH-END TO
ENHANCED DEVICES
A detailed discussion of the migration pathway and differences between the high-end MCU devices (i.e.,
PIC17CXXX) and the enhanced devices (i.e.,
PIC18FXXX) is provided in AN726, “PIC17CXXX to
PIC18FXXX Migration”. This Application Note is
available as Literature Number DS00726.
This Application Note is available as Literature Number
DS00716.
© 2006 Microchip Technology Inc.
DS39564C-page 315
PIC18FXX2
NOTES:
DS39564C-page 316
© 2006 Microchip Technology Inc.
PIC18FXX2
INDEX
A
A/D ................................................................................... 181
A/D Converter Flag (ADIF Bit) ................................. 183
A/D Converter Interrupt, Configuring ....................... 184
Acquisition Requirements ........................................ 184
ADCON0 Register .................................................... 181
ADCON1 Register .................................................... 181
ADRESH Register .................................................... 181
ADRESH/ADRESL Registers .................................. 183
ADRESL Register .................................................... 181
Analog Port Pins ................................................ 99, 100
Analog Port Pins, Configuring .................................. 186
Associated Registers ............................................... 188
Configuring the Module ............................................ 184
Conversion Clock (TAD) ........................................... 186
Conversion Status (GO/DONE Bit) .......................... 183
Conversions ............................................................. 187
Converter Characteristics ........................................ 287
Equations
Acquisition Time ............................................... 185
Minimum Charging Time .................................. 185
Examples
Calculating the Minimum Required
Acquisition Time ...................................... 185
Result Registers ....................................................... 187
Special Event Trigger (CCP) ............................ 120, 188
TAD vs. Device Operating Frequencies .................... 186
Use of the CCP2 Trigger .......................................... 188
Absolute Maximum Ratings ............................................. 259
AC (Timing) Characteristics ............................................. 269
Load Conditions for Device Timing
Specifications ................................................... 270
Parameter Symbology ............................................. 269
Temperature and Voltage Specifications - AC ......... 270
Timing Conditions .................................................... 270
ACKSTAT Status Flag ..................................................... 155
ADCON0 Register ............................................................ 181
GO/DONE Bit ........................................................... 183
ADCON1 Register ............................................................ 181
ADDLW ............................................................................ 217
ADDWF ............................................................................ 217
ADDWFC ......................................................................... 218
ADRESH Register ............................................................ 181
ADRESH/ADRESL Registers ........................................... 183
ADRESL Register ............................................................ 181
Analog-to-Digital Converter. See A/D
ANDLW ............................................................................ 218
ANDWF ............................................................................ 219
Assembler
MPASM Assembler .................................................. 253
B
Baud Rate Generator ....................................................... 151
BC .................................................................................... 219
BCF .................................................................................. 220
BF Status Flag ................................................................. 155
© 2006 Microchip Technology Inc.
Block Diagrams
A/D Converter .......................................................... 183
Analog Input Model .................................................. 184
Baud Rate Generator .............................................. 151
Capture Mode Operation ......................................... 119
Compare Mode Operation ....................................... 120
Low Voltage Detect
External Reference Source ............................. 190
Internal Reference Source ............................... 190
MSSP
I2C Mode ......................................................... 134
MSSP (SPI Mode) ................................................... 125
On-Chip Reset Circuit ................................................ 25
Parallel Slave Port (PORTD and PORTE) ............... 100
PIC18F2X2 .................................................................. 8
PIC18F4X2 .................................................................. 9
PLL ............................................................................ 19
PORTC (Peripheral Output Override) ........................ 93
PORTD (I/O Mode) .................................................... 95
PORTE (I/O Mode) .................................................... 97
PWM Operation (Simplified) .................................... 122
RA3:RA0 and RA5 Port Pins ..................................... 87
RA4/T0CKI Pin .......................................................... 88
RA6 Pin ..................................................................... 88
RB2:RB0 Port Pins .................................................... 91
RB3 Pin ..................................................................... 91
RB7:RB4 Port Pins .................................................... 90
Table Read Operation ............................................... 55
Table Write Operation ................................................ 56
Table Writes to FLASH Program Memory ................. 61
Timer0 in 16-bit Mode .............................................. 104
Timer0 in 8-bit Mode ................................................ 104
Timer1 ..................................................................... 108
Timer1 (16-bit R/W Mode) ....................................... 108
Timer2 ..................................................................... 112
Timer3 ..................................................................... 114
Timer3 (16-bit R/W Mode) ....................................... 114
USART
Asynchronous Receive .................................... 174
Asynchronous Transmit ................................... 172
Watchdog Timer ...................................................... 204
BN .................................................................................... 220
BNC ................................................................................. 221
BNN ................................................................................. 221
BNOV ............................................................................... 222
BNZ .................................................................................. 222
BOR. See Brown-out Reset
BOV ................................................................................. 225
BRA ................................................................................. 223
BRG. See Baud Rate Generator
Brown-out Reset (BOR) ..................................................... 26
BSF .................................................................................. 223
BTFSC ............................................................................. 224
BTFSS ............................................................................. 224
BTG ................................................................................. 225
Bus Collision During a STOP Condition .......................... 163
BZ .................................................................................... 226
DS39564C-page 317
PIC18FXX2
C
D
CALL ................................................................................ 226
Capture (CCP Module) ..................................................... 119
Associated Registers ............................................... 121
CCP Pin Configuration ............................................. 119
CCPR1H:CCPR1L Registers ................................... 119
Software Interrupt ..................................................... 119
Timer1/Timer3 Mode Selection ................................ 119
Capture/Compare/PWM (CCP) ........................................ 117
Capture Mode. See Capture
CCP1 ........................................................................ 118
CCPR1H Register ............................................ 118
CCPR1L Register ............................................ 118
CCP2 ........................................................................ 118
CCPR2H Register ............................................ 118
CCPR2L Register ............................................ 118
Compare Mode. See Compare
Interaction of Two CCP Modules ............................. 118
PWM Mode. See PWM
Timer Resources ...................................................... 118
Clocking Scheme/Instruction Cycle .................................... 39
CLRF ................................................................................ 227
CLRWDT .......................................................................... 227
Code Examples
16 x 16 Signed Multiply Routine ................................. 72
16 x 16 Unsigned Multiply Routine ............................. 72
8 x 8 Signed Multiply Routine ..................................... 71
8 x 8 Unsigned Multiply Routine ................................. 71
Changing Between Capture Prescalers ................... 119
Data EEPROM Read ................................................. 67
Data EEPROM Refresh Routine ................................ 68
Data EEPROM Write .................................................. 67
Erasing a FLASH Program Memory Row .................. 60
Fast Register Stack .................................................... 39
How to Clear RAM (Bank1) Using
Indirect Addressing ............................................ 50
Initializing PORTA ...................................................... 87
Initializing PORTB ...................................................... 90
Initializing PORTC ...................................................... 93
Initializing PORTD ...................................................... 95
Initializing PORTE ...................................................... 97
Loading the SSPBUF (SSPSR) Register ................. 128
Reading a FLASH Program Memory Word ................ 59
Saving STATUS, WREG and BSR
Registers in RAM ............................................... 85
Writing to FLASH Program Memory ..................... 62–63
Code Protection ............................................................... 195
COMF ............................................................................... 228
Compare (CCP Module) ................................................... 120
Associated Registers ............................................... 121
CCP Pin Configuration ............................................. 120
CCPR1 Register ....................................................... 120
Software Interrupt ..................................................... 120
Special Event Trigger ........................109, 115, 120, 188
Timer1/Timer3 Mode Selection ................................ 120
Configuration Bits ............................................................. 195
Context Saving During Interrupts ....................................... 85
Conversion Considerations .............................................. 314
CPFSEQ .......................................................................... 228
CPFSGT ........................................................................... 229
CPFSLT ........................................................................... 229
Data EEPROM Memory
Associated Registers ................................................. 69
EEADR Register ........................................................ 65
EECON1 Register ...................................................... 65
EECON2 Register ...................................................... 65
Operation During Code Protect ................................. 68
Protection Against Spurious Write ............................. 68
Reading ..................................................................... 67
Using .......................................................................... 68
Write Verify ................................................................ 68
Writing ........................................................................ 67
Data Memory ..................................................................... 42
General Purpose Registers ....................................... 42
Map for PIC18F242/442 ............................................ 43
Map for PIC18F252/452 ............................................ 44
Special Function Registers ........................................ 42
DAW ................................................................................ 230
DC and AC Characteristics
Graphs and Tables .................................................. 289
DC Characteristics ....................................................261, 265
DCFSNZ .......................................................................... 231
DECF ............................................................................... 230
DECFSZ .......................................................................... 231
Development Support ...................................................... 253
Device Differences ........................................................... 313
Device Overview .................................................................. 7
Features ....................................................................... 7
Direct Addressing ............................................................... 51
Example ..................................................................... 49
DS39564C-page 318
E
Electrical Characteristics .................................................. 259
Errata ................................................................................... 5
F
Firmware Instructions ....................................................... 211
FLASH Program Memory ................................................... 55
Associated Registers ................................................. 63
Control Registers ....................................................... 56
Erase Sequence ........................................................ 60
Erasing ....................................................................... 60
Operation During Code Protect ................................. 63
Reading ..................................................................... 59
TABLAT Register ....................................................... 58
Table Pointer ............................................................. 58
Boundaries Based on Operation ........................ 58
Table Pointer Boundaries .......................................... 58
Table Reads and Table Writes .................................. 55
Block Diagrams
Reads from FLASH Program Memory ....... 59
Writing to .................................................................... 61
Protection Against Spurious Writes ................... 63
Unexpected Termination .................................... 63
Write Verify ........................................................ 63
G
General Call Address Support ......................................... 148
GOTO .............................................................................. 232
© 2006 Microchip Technology Inc.
PIC18FXX2
I
I/O Ports ............................................................................. 87
I2C (MSSP Module)
ACK Pulse ................................................................ 139
Read/Write Bit Information (R/W Bit) ....................... 139
I2C (SSP Module)
ACK Pulse ................................................................ 138
I2C Master Mode Reception ............................................. 155
I2C Mode
Clock Stretching ....................................................... 144
I2C Mode (MSSP Module) ................................................ 134
Registers .................................................................. 134
I2C Module
ACK Pulse ........................................................ 138, 139
Acknowledge Sequence Timing ............................... 158
Baud Rate Generator ............................................... 151
Bus Collision
Repeated START Condition ............................ 162
START Condition ............................................. 160
Clock Arbitration ....................................................... 152
Effect of a RESET .................................................... 159
General Call Address Support ................................. 148
Master Mode ............................................................ 149
Operation ......................................................... 150
Repeated START Condition Timing ................. 154
Master Mode START Condition ............................... 153
Master Mode Transmission ...................................... 155
Multi-Master Communication, Bus Collision
and Arbitration .................................................. 159
Multi-Master Mode ................................................... 159
Operation ................................................................. 138
Read/Write Bit Information (R/W Bit) ............... 138, 139
Serial Clock (RC3/SCK/SCL) ................................... 139
Slave Mode .............................................................. 138
Addressing ....................................................... 138
Reception ......................................................... 139
Transmission .................................................... 139
Slave Mode Timing (10-bit Reception,
SEN = 0) .......................................................... 142
Slave Mode Timing (10-bit Reception,
SEN = 1) .......................................................... 147
Slave Mode Timing (10-bit Transmission) ................ 143
Slave Mode Timing (7-bit Reception,
SEN = 0) .......................................................... 140
Slave Mode Timing (7-bit Reception,
SEN = 1) .......................................................... 146
Slave Mode Timing (7-bit Transmission) .................. 141
SLEEP Operation ..................................................... 159
STOP Condition Timing ........................................... 158
ICEPIC In-Circuit Emulator .............................................. 254
ID Locations ............................................................. 195, 210
INCF ................................................................................. 232
INCFSZ ............................................................................ 233
In-Circuit Debugger .......................................................... 210
In-Circuit Serial Programming (ICSP) ...................... 195, 210
Indirect Addressing ............................................................ 51
INDF and FSR Registers ........................................... 50
Indirect Addressing Operation ............................................ 51
Indirect File Operand .......................................................... 42
INFSNZ ............................................................................ 233
Instruction Cycle ................................................................. 39
Instruction Flow/Pipelining ................................................. 40
Instruction Format ............................................................ 213
© 2006 Microchip Technology Inc.
Instruction Set .................................................................. 211
ADDLW .................................................................... 217
ADDWF .................................................................... 217
ADDWFC ................................................................. 218
ANDLW .................................................................... 218
ANDWF .................................................................... 219
BC ............................................................................ 219
BCF ......................................................................... 220
BN ............................................................................ 220
BNC ......................................................................... 221
BNN ......................................................................... 221
BNOV ...................................................................... 222
BNZ ......................................................................... 222
BOV ......................................................................... 225
BRA ......................................................................... 223
BSF .......................................................................... 223
BTFSC ..................................................................... 224
BTFSS ..................................................................... 224
BTG ......................................................................... 225
BZ ............................................................................ 226
CALL ........................................................................ 226
CLRF ....................................................................... 227
CLRWDT ................................................................. 227
COMF ...................................................................... 228
CPFSEQ .................................................................. 228
CPFSGT .................................................................. 229
CPFSLT ................................................................... 229
DAW ........................................................................ 230
DCFSNZ .................................................................. 231
DECF ....................................................................... 230
DECFSZ .................................................................. 231
GOTO ...................................................................... 232
INCF ........................................................................ 232
INCFSZ .................................................................... 233
INFSNZ .................................................................... 233
IORLW ..................................................................... 234
IORWF ..................................................................... 234
LFSR ....................................................................... 235
MOVF ...................................................................... 235
MOVFF .................................................................... 236
MOVLB .................................................................... 236
MOVLW ................................................................... 237
MOVWF ................................................................... 237
MULLW .................................................................... 238
MULWF .................................................................... 238
NEGF ....................................................................... 239
NOP ......................................................................... 239
POP ......................................................................... 240
PUSH ....................................................................... 240
RCALL ..................................................................... 241
RESET ..................................................................... 241
RETFIE .................................................................... 242
RETLW .................................................................... 242
RETURN .................................................................. 243
RLCF ....................................................................... 243
RLNCF ..................................................................... 244
RRCF ....................................................................... 244
RRNCF .................................................................... 245
SETF ....................................................................... 245
SLEEP ..................................................................... 246
SUBFWB ................................................................. 246
SUBLW .................................................................... 247
SUBWF .................................................................... 247
SUBWFB ................................................................. 248
SWAPF .................................................................... 248
DS39564C-page 319
PIC18FXX2
TBLRD ..................................................................... 249
TBLWT ..................................................................... 250
TSTFSZ .................................................................... 251
XORLW .................................................................... 251
XORWF .................................................................... 252
Summary Table ........................................................ 214
Instructions in Program Memory ........................................ 40
Two-Word Instructions ............................................... 41
INT Interrupt (RB0/INT). See Interrupt Sources
INTCON Register
RBIF Bit ...................................................................... 90
INTCON Registers ....................................................... 75–77
Inter-Integrated Circuit. See I2C
Interrupt Sources .............................................................. 195
A/D Conversion Complete ........................................ 184
Capture Complete (CCP) ......................................... 119
Compare Complete (CCP) ....................................... 120
INT0 ........................................................................... 85
Interrupt-on-Change (RB7:RB4 ) ............................... 90
PORTB, Interrupt-on-Change .................................... 85
RB0/INT Pin, External ................................................ 85
TMR0 ......................................................................... 85
TMR0 Overflow ........................................................ 105
TMR1 Overflow ................................................ 107, 109
TMR2 to PR2 Match ................................................. 112
TMR2 to PR2 Match (PWM) ............................ 111, 122
TMR3 Overflow ................................................ 113, 115
USART Receive/Transmit Complete ........................ 165
Interrupts ............................................................................ 73
Logic ........................................................................... 74
Interrupts, Enable Bits
CCP1 Enable (CCP1IE Bit) ...................................... 119
Interrupts, Flag Bits
A/D Converter Flag (ADIF Bit) .................................. 183
CCP1 Flag (CCP1IF Bit) .......................................... 119
CCP1IF Flag (CCP1IF Bit) ....................................... 120
Interrupt-on-Change (RB7:RB4) Flag
(RBIF Bit) ........................................................... 90
IORLW ............................................................................. 234
IORWF ............................................................................. 234
IPR Registers ............................................................... 82–83
K
KEELOQ Evaluation and Programming Tools ................... 256
L
LFSR ................................................................................ 235
Lookup Tables
Computed GOTO ....................................................... 41
Table Reads, Table Writes ......................................... 41
Low Voltage Detect .......................................................... 189
Converter Characteristics ......................................... 267
Effects of a RESET .................................................. 193
Operation ................................................................. 192
Current Consumption ....................................... 193
During SLEEP .................................................. 193
Reference Voltage Set Point ............................ 193
Typical Application ................................................... 189
LVD. See Low Voltage Detect. ......................................... 189
DS39564C-page 320
M
Master SSP (MSSP) Module Overview ........................... 125
Master Synchronous Serial Port (MSSP). See MSSP.
Master Synchronous Serial Port. See MSSP
Memory Organization
Data Memory ............................................................. 42
Program Memory ....................................................... 35
Memory Programming Requirements .............................. 268
Migration from Baseline to Enhanced Devices ................ 314
Migration from High-End to Enhanced Devices ............... 315
Migration from Mid-Range to Enhanced Devices ............ 315
MOVF .............................................................................. 235
MOVFF ............................................................................ 236
MOVLB ............................................................................ 236
MOVLW ........................................................................... 237
MOVWF ........................................................................... 237
MPLAB C17 and MPLAB C18 C Compilers ..................... 253
MPLAB ICD In-Circuit Debugger ..................................... 255
MPLAB ICE High Performance Universal In-Circuit
Emulator with MPLAB IDE ....................................... 254
MPLAB Integrated Development
Environment Software ............................................. 253
MPLINK Object Linker/MPLIB Object Librarian ............... 254
MSSP ............................................................................... 125
Control Registers (general) ...................................... 125
Enabling SPI I/O ...................................................... 129
Operation ................................................................. 128
Typical Connection .................................................. 129
MSSP Module
SPI Master Mode ..................................................... 130
SPI Master./Slave Connection ................................. 129
SPI Slave Mode ....................................................... 131
MULLW ............................................................................ 238
MULWF ............................................................................ 238
N
NEGF ............................................................................... 239
NOP ................................................................................. 239
O
Opcode Field Descriptions ............................................... 212
OPTION_REG Register
PSA Bit .................................................................... 105
T0CS Bit .................................................................. 105
T0PS2:T0PS0 Bits ................................................... 105
T0SE Bit ................................................................... 105
Oscillator Configuration ...................................................... 17
EC .............................................................................. 17
ECIO .......................................................................... 17
HS .............................................................................. 17
HS + PLL ................................................................... 17
LP .............................................................................. 17
RC .............................................................................. 17
RCIO .......................................................................... 17
XT .............................................................................. 17
Oscillator Selection .......................................................... 195
Oscillator, Timer1 ..............................................107, 109, 115
Oscillator, Timer3 ............................................................. 113
Oscillator, WDT ................................................................ 203
© 2006 Microchip Technology Inc.
PIC18FXX2
P
Packaging ........................................................................ 305
Details ...................................................................... 307
Marking Information ................................................. 305
Parallel Slave Port
PORTD .................................................................... 100
Parallel Slave Port (PSP) ........................................... 95, 100
Associated Registers ............................................... 101
RE0/RD/AN5 Pin ................................................ 99, 100
RE1/WR/AN6 Pin ............................................... 99, 100
RE2/CS/AN7 Pin ................................................ 99, 100
Select (PSPMODE Bit) ...................................... 95, 100
PIC18F2X2 Pin Functions
MCLR/VPP .................................................................. 10
OSC1/CLKI ................................................................ 10
OSC2/CLKO/RA6 ...................................................... 10
RA0/AN0 .................................................................... 10
RA1/AN1 .................................................................... 10
RA2/AN2/VREF- .......................................................... 10
RA3/AN3/VREF+ ......................................................... 10
RA4/T0CKI ................................................................. 10
RA5/AN4/SS/LVDIN ................................................... 10
RB0/INT0 ................................................................... 11
RB1/INT1 ................................................................... 11
RB2/INT2 ................................................................... 11
RB3/CCP2 ................................................................. 11
RB4 ............................................................................ 11
RB5/PGM ................................................................... 11
RB6/PGC ................................................................... 11
RB7/PGD ................................................................... 11
RC0/T1OSO/T1CKI ................................................... 12
RC1/T1OSI/CCP2 ...................................................... 12
RC2/CCP1 ................................................................. 12
RC3/SCK/SCL ........................................................... 12
RC4/SDI/SDA ............................................................ 12
RC5/SDO ................................................................... 12
RC6/TX/CK ................................................................ 12
RC7/RX/DT ................................................................ 12
VDD ............................................................................. 12
VSS ............................................................................. 12
PIC18F4X2 Pin Functions
MCLR/VPP .................................................................. 13
OSC1/CLKI ................................................................ 13
OSC2/CLKO .............................................................. 13
RA0/AN0 .................................................................... 13
RA1/AN1 .................................................................... 13
RA2/AN2/VREF- .......................................................... 13
RA3/AN3/VREF+ ......................................................... 13
RA4/T0CKI ................................................................. 13
RA5/AN4/SS/LVDIN ................................................... 13
RB0/INT ..................................................................... 14
RB1 ............................................................................ 14
RB2 ............................................................................ 14
RB3 ............................................................................ 14
RB4 ............................................................................ 14
RB5/PGM ................................................................... 14
RB6/PGC ................................................................... 14
RB7/PGD ................................................................... 14
RC0/T1OSO/T1CKI ................................................... 15
RC1/T1OSI/CCP2 ...................................................... 15
RC2/CCP1 ................................................................. 15
RC3/SCK/SCL ........................................................... 15
RC4/SDI/SDA ............................................................ 15
RC5/SDO ................................................................... 15
RC6/TX/CK ................................................................ 15
© 2006 Microchip Technology Inc.
RC7/RX/DT ................................................................ 15
RD0/PSP0 ................................................................. 16
RD1/PSP1 ................................................................. 16
RD2/PSP2 ................................................................. 16
RD3/PSP3 ................................................................. 16
RD4/PSP4 ................................................................. 16
RD5/PSP5 ................................................................. 16
RD6/PSP6 ................................................................. 16
RD7/PSP7 ................................................................. 16
RE0/RD/AN5 .............................................................. 16
RE1/WR/AN6 ............................................................. 16
RE2/CS/AN7 .............................................................. 16
VDD ............................................................................ 16
VSS ............................................................................ 16
PIC18FXX2 Voltage-Frequency Graph
(Industrial) ................................................................ 260
PIC18LFXX2 Voltage-Frequency Graph
(Industrial) ................................................................ 260
PICDEM 1 Low Cost PICmicro
Demonstration Board ............................................... 255
PICDEM 17 Demonstration Board ................................... 256
PICDEM 2 Low Cost PIC16CXX
Demonstration Board ............................................... 255
PICDEM 3 Low Cost PIC16CXXX
Demonstration Board ............................................... 256
PICSTART Plus Entry Level Development
Programmer ............................................................. 255
PIE Registers ................................................................80–81
Pinout I/O Descriptions
PIC18F2X2 ................................................................ 10
PIR Registers ................................................................78–79
PLL Lock Time-out ............................................................. 26
Pointer, FSR ...................................................................... 50
POP ................................................................................. 240
POR. See Power-on Reset
PORTA
Associated Registers ................................................. 89
LATA Register ........................................................... 87
PORTA Register ........................................................ 87
TRISA Register .......................................................... 87
PORTB
Associated Registers ................................................. 92
LATB Register ........................................................... 90
PORTB Register ........................................................ 90
RB0/INT Pin, External ................................................ 85
RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) .......... 90
TRISB Register .......................................................... 90
PORTC
Associated Registers ................................................. 94
LATC Register ........................................................... 93
PORTC Register ........................................................ 93
RC3/SCK/SCL Pin ................................................... 139
RC7/RX/DT Pin ........................................................ 168
TRISC Register ...................................................93, 165
PORTD
Associated Registers ................................................. 96
LATD Register ........................................................... 95
Parallel Slave Port (PSP) Function ............................ 95
PORTD Register ........................................................ 95
TRISD Register .......................................................... 95
DS39564C-page 321
PIC18FXX2
PORTE
Analog Port Pins ................................................ 99, 100
Associated Registers ................................................. 99
LATE Register ............................................................ 97
PORTE Register ........................................................ 97
PSP Mode Select (PSPMODE Bit) .................... 95, 100
RE0/RD/AN5 Pin ................................................ 99, 100
RE1/WR/AN6 Pin ............................................... 99, 100
RE2/CS/AN7 Pin ................................................ 99, 100
TRISE Register .......................................................... 97
Postscaler, WDT
Assignment (PSA Bit) ............................................... 105
Rate Select (T0PS2:T0PS0 Bits) ............................. 105
Switching Between Timer0 and WDT ...................... 105
Power-down Mode. See SLEEP
Power-on Reset (POR) ...................................................... 26
Oscillator Start-up Timer (OST) ................................. 26
Power-up Timer (PWRT) ............................................ 26
Prescaler, Capture ........................................................... 119
Prescaler, Timer0 ............................................................. 105
Assignment (PSA Bit) ............................................... 105
Rate Select (T0PS2:T0PS0 Bits) ............................. 105
Switching Between Timer0 and WDT ...................... 105
Prescaler, Timer2 ............................................................. 122
PRO MATE II Universal Device Programmer ................... 255
Product Identification System ........................................... 327
Program Counter
PCL Register .............................................................. 39
PCLATH Register ....................................................... 39
PCLATU Register ....................................................... 39
Program Memory
Interrupt Vector .......................................................... 35
Map and Stack for PIC18F442/242 ............................ 36
Map and Stack for PIC18F452/252 ............................ 36
RESET Vector ............................................................ 35
Program Verification and Code Protection ....................... 207
Associated Registers ............................................... 207
Programming, Device Instructions ................................... 211
PSP.See Parallel Slave Port.
Pulse Width Modulation. See PWM (CCP Module).
PUSH ............................................................................... 240
PWM (CCP Module) ......................................................... 122
Associated Registers ............................................... 123
CCPR1H:CCPR1L Registers ................................... 122
Duty Cycle ................................................................ 122
Example Frequencies/Resolutions ........................... 123
Period ....................................................................... 122
Setup for PWM Operation ........................................ 123
TMR2 to PR2 Match ......................................... 111, 122
Q
Q Clock ............................................................................ 122
R
RAM. See Data Memory
RC Oscillator ...................................................................... 18
RCALL .............................................................................. 241
RCSTA Register
SPEN Bit .................................................................. 165
Register File ....................................................................... 42
DS39564C-page 322
Registers
ADCON0 (A/D Control 0) ......................................... 181
ADCON1 (A/D Control 1) ......................................... 182
CCP1CON and CCP2CON
(Capture/Compare/PWM Control) ................... 117
CONFIG1H (Configuration 1 High) .......................... 196
CONFIG2H (Configuration 2 High) .......................... 197
CONFIG2L (Configuration 2 Low) ........................... 197
CONFIG3H (Configuration 3 High) .......................... 198
CONFIG4L (Configuration 4 Low) ........................... 198
CONFIG5H (Configuration 5 High) .......................... 199
CONFIG5L (Configuration 5 Low) ........................... 199
CONFIG6H (Configuration 6 High) .......................... 200
CONFIG6L (Configuration 6 Low) ........................... 200
CONFIG7H (Configuration 7 High) .......................... 201
CONFIG7L (Configuration 7 Low) ........................... 201
DEVID1 (Device ID Register 1) ............................... 202
DEVID2 (Device ID Register 2) ............................... 202
EECON1 (Data EEPROM Control 1) ....................57, 66
File Summary ........................................................46–48
INTCON (Interrupt Control) ........................................ 75
INTCON2 (Interrupt Control 2) ................................... 76
INTCON3 (Interrupt Control 3) ................................... 77
IPR1 (Peripheral Interrupt Priority 1) ......................... 82
IPR2 (Peripheral Interrupt Priority 2) ......................... 83
LVDCON (LVD Control) ........................................... 191
OSCCON (Oscillator Control) .................................... 21
PIE1 (Peripheral Interrupt Enable 1) .......................... 80
PIE2 (Peripheral Interrupt Enable 2) .......................... 81
PIR1 (Peripheral Interrupt Request 1) ....................... 78
PIR2 (Peripheral Interrupt Request 2) ....................... 79
RCON (Register Control) ........................................... 84
RCON (RESET Control) ............................................ 53
RCSTA (Receive Status and Control) ..................... 167
SSPCON1 (MSSP Control 1)
I2C Mode ......................................................... 136
SPI Mode ......................................................... 127
SSPCON2 (MSSP Control 2)
I2C Mode ......................................................... 137
SSPSTAT (MSSP Status)
I2C Mode ......................................................... 135
SPI Mode ......................................................... 126
STATUS ..................................................................... 52
STKPTR (Stack Pointer) ............................................ 38
T0CON (Timer0 Control) ......................................... 103
T1CON (Timer 1 Control) ........................................ 107
T2CON (Timer 2 Control) ........................................ 111
T3CON (Timer3 Control) ......................................... 113
TRISE ........................................................................ 98
TXSTA (Transmit Status and Control) ..................... 166
WDTCON (Watchdog Timer Control) ...................... 203
RESET ................................................................25, 195, 241
Brown-out Reset (BOR) ........................................... 195
MCLR Reset (During SLEEP) .................................... 25
MCLR Reset (Normal Operation) .............................. 25
Oscillator Start-up Timer (OST) ............................... 195
Power-on Reset (POR) .......................................25, 195
Power-up Timer (PWRT) ......................................... 195
Programmable Brown-out Reset (BOR) .................... 25
RESET Instruction ..................................................... 25
Stack Full Reset ......................................................... 25
Stack Underflow Reset .............................................. 25
Watchdog Timer (WDT) Reset .................................. 25
© 2006 Microchip Technology Inc.
PIC18FXX2
RETFIE ............................................................................ 242
RETLW ............................................................................. 242
RETURN .......................................................................... 243
Revision History ............................................................... 313
RLCF ................................................................................ 243
RLNCF ............................................................................. 244
RRCF ............................................................................... 244
RRNCF ............................................................................. 245
S
SCI. See USART
SCK .................................................................................. 125
SDI ................................................................................... 125
SDO ................................................................................. 125
Serial Clock, SCK ............................................................. 125
Serial Communication Interface. See USART
Serial Data In, SDI ........................................................... 125
Serial Data Out, SDO ....................................................... 125
Serial Peripheral Interface. See SPI
SETF ................................................................................ 245
Slave Select Synchronization ........................................... 131
Slave Select, SS .............................................................. 125
SLEEP ...............................................................195, 205, 246
Software Simulator (MPLAB SIM) .................................... 254
Special Event Trigger. See Compare
Special Features of the CPU ............................................ 195
Configuration Registers ................................... 196–201
Special Function Registers ................................................ 42
Map ............................................................................ 45
SPI
Master Mode ............................................................ 130
Serial Clock .............................................................. 125
Serial Data In ........................................................... 125
Serial Data Out ........................................................ 125
Slave Select ............................................................. 125
SPI Clock ................................................................. 130
SPI Mode ................................................................. 125
SPI Master/Slave Connection .......................................... 129
SPI Module
Associated Registers ............................................... 133
Bus Mode Compatibility ........................................... 133
Effects of a RESET .................................................. 133
Master/Slave Connection ......................................... 129
Slave Mode .............................................................. 131
Slave Select Synchronization .................................. 131
Slave Synch Timing ................................................. 131
SLEEP Operation ..................................................... 133
SS .................................................................................... 125
SSP
I2C Mode. See I2C
SPI Mode ................................................................. 125
SPI Mode. See SPI
SSPBUF Register .................................................... 130
SSPSR Register ...................................................... 130
TMR2 Output for Clock Shift ............................ 111, 112
SSPOV Status Flag .......................................................... 155
SSPSTAT Register
R/W Bit ............................................................. 138, 139
Status Bits
Significance and the Initialization Condition
for RCON Register ............................................. 27
SUBFWB .......................................................................... 246
SUBLW ............................................................................ 247
SUBWF ............................................................................ 247
SUBWFB .......................................................................... 248
SWAPF ............................................................................ 248
© 2006 Microchip Technology Inc.
T
TABLAT Register ............................................................... 58
Table Pointer Operations (table) ........................................ 58
TBLPTR Register ............................................................... 58
TBLRD ............................................................................. 249
TBLWT ............................................................................. 250
Time-out Sequence ........................................................... 26
Time-out in Various Situations ................................... 27
Timer0 .............................................................................. 103
16-bit Mode Timer Reads and Writes ...................... 105
Associated Registers ............................................... 105
Clock Source Edge Select (T0SE Bit) ..................... 105
Clock Source Select (T0CS Bit) ............................... 105
Operation ................................................................. 105
Overflow Interrupt .................................................... 105
Prescaler. See Prescaler, Timer0
Timer1 .............................................................................. 107
16-bit Read/Write Mode ........................................... 109
Associated Registers ............................................... 110
Operation ................................................................. 108
Oscillator ...........................................................107, 109
Overflow Interrupt .............................................107, 109
Special Event Trigger (CCP) ............................109, 120
TMR1H Register ...................................................... 107
TMR1L Register ....................................................... 107
Timer2 .............................................................................. 111
Associated Registers ............................................... 112
Operation ................................................................. 111
Postscaler. See Postscaler, Timer2
PR2 Register ....................................................111, 122
Prescaler. See Prescaler, Timer2
SSP Clock Shift ................................................111, 112
TMR2 Register ......................................................... 111
TMR2 to PR2 Match Interrupt ................... 111, 112, 122
Timer3 .............................................................................. 113
Associated Registers ............................................... 115
Operation ................................................................. 114
Oscillator ...........................................................113, 115
Overflow Interrupt .............................................113, 115
Special Event Trigger (CCP) ................................... 115
TMR3H Register ...................................................... 113
TMR3L Register ....................................................... 113
Timing Diagrams
Bus Collision
Transmit and Acknowledge ..................... 159
A/D Conversion ........................................................ 287
Acknowledge Sequence .......................................... 158
Baud Rate Generator with Clock Arbitration ............ 152
BRG Reset Due to SDA Arbitration During
START Condition ............................................. 161
Brown-out Reset (BOR) ........................................... 274
Bus Collision
Start Condition (SDA Only) .............................. 160
Bus Collision During a Repeated
START Condition (Case 1) .............................. 162
Bus Collision During a Repeated
START Condition (Case 2) .............................. 162
Bus Collision During a START Condition
(SCL = 0) ......................................................... 161
Bus Collision During a STOP Condition
(Case 1) ........................................................... 163
Bus Collision During a STOP Condition
(Case 2) ........................................................... 163
Capture/Compare/PWM (CCP1 and CCP2) ............ 276
CLKO and I/O .......................................................... 272
Clock Synchronization ............................................. 145
DS39564C-page 323
PIC18FXX2
Example SPI Master Mode (CKE = 0) ..................... 278
Example SPI Master Mode (CKE = 1) ..................... 279
Example SPI Slave Mode (CKE = 0) ....................... 280
Example SPI Slave Mode (CKE = 1) ....................... 281
External Clock (All Modes except PLL) .................... 271
First START Bit Timing ............................................ 153
I2C Bus Data ............................................................ 282
I2C Bus START/STOP Bits ...................................... 282
I2C Master Mode (Reception, 7-bit Address) ........... 157
I2C Master Mode (Transmission,
7 or 10-bit Address) ......................................... 156
I2C Slave Mode Timing (10-bit Reception,
SEN = 0) .......................................................... 142
I2C Slave Mode Timing (10-bit Transmission) ......... 143
I2C Slave Mode Timing (7-bit Reception,
SEN = 0) .......................................................... 140
I2C Slave Mode Timing (7-bit Reception,
SEN = 1) .................................................. 146, 147
I2C Slave Mode Timing (7-bit Transmission) ........... 141
Low Voltage Detect .................................................. 192
Master SSP I2C Bus Data ........................................ 284
Master SSP I2C Bus START/STOP Bits .................. 284
Parallel Slave Port (PIC18F4X2) .............................. 277
Parallel Slave Port (Read) ........................................ 101
Parallel Slave Port (Write) ........................................ 100
PWM Output ............................................................. 122
Repeat START Condition ......................................... 154
RESET, Watchdog Timer (WDT),
Oscillator Start-up Timer (OST) and
Power-up Timer (PWRT) ................................. 273
Slave Synchronization .............................................. 131
Slaver Mode General Call Address Sequence
(7 or 10-bit Address Mode) .............................. 148
Slow Rise Time (MCLR Tied to VDD) ......................... 33
SPI Mode (Master Mode) ......................................... 130
SPI Mode (Slave Mode with CKE = 0) ..................... 132
SPI Mode (Slave Mode with CKE = 1) ..................... 132
Stop Condition Receive or Transmit Mode .............. 158
Time-out Sequence on POR w/PLL Enabled
(MCLR Tied to VDD) ........................................... 33
Time-out Sequence on Power-up
(MCLR Not Tied to VDD)
Case 1 ................................................................ 32
Case 2 ................................................................ 32
Time-out Sequence on Power-up
(MCLR Tied to VDD) ........................................... 32
Timer0 and Timer1 External Clock ........................... 275
Timing for Transition Between Timer1 and
OSC1 (HS with PLL) .......................................... 23
Transition Between Timer1 and OSC1
(HS, XT, LP) ....................................................... 22
Transition Between Timer1 and OSC1
(RC, EC) ............................................................ 23
Transition from OSC1 to Timer1 Oscillator ................ 22
USART Asynchronous Master Transmission ........... 173
USART Asynchronous Master Transmission
(Back to Back) .................................................. 173
USART Asynchronous Reception ............................ 175
USART Synchronous Receive (Master/Slave) ......... 286
USART Synchronous Reception
(Master Mode, SREN) ...................................... 178
USART Synchronous Transmission ......................... 177
USART Synchronous Transmission
(Master/Slave) .................................................. 286
DS39564C-page 324
USART Synchronous Transmission
(Through TXEN) .............................................. 177
Wake-up from SLEEP via Interrupt .......................... 206
Timing Diagrams Requirements
Master SSP I2C Bus START/STOP Bits .................. 284
Timing Requirements
A/D Conversion ........................................................ 288
Capture/Compare/PWM (CCP1 and CCP2) ............ 276
CLKO and I/O .......................................................... 273
Example SPI Mode (Master Mode, CKE = 0) .......... 278
Example SPI Mode (Master Mode, CKE = 1) .......... 279
Example SPI Mode (Slave Mode, CKE = 0) ............ 280
Example SPI Slave Mode (CKE = 1) ....................... 281
External Clock .......................................................... 271
I2C Bus Data (Slave Mode) ..................................... 283
Master SSP I2C Bus Data ........................................ 285
Parallel Slave Port (PIC18F4X2) ............................. 277
RESET, Watchdog Timer, Oscillator Start-up
Timer, Power-up Timer and
Brown-out Reset Requirements ....................... 274
Timer0 and Timer1 External Clock .......................... 275
USART Synchronous Receive ................................. 286
USART Synchronous Transmission ........................ 286
Timing Specifications
PLL Clock ................................................................ 272
TRISE Register
PSPMODE Bit .....................................................95, 100
TSTFSZ ........................................................................... 251
Two-Word Instructions
Example Cases .......................................................... 41
TXSTA Register
BRGH Bit ................................................................. 168
U
Universal Synchronous Asynchronous
Receiver Transmitter. See USART
USART ............................................................................. 165
Asynchronous Mode ................................................ 172
Associated Registers, Receive ........................ 175
Associated Registers, Transmit ....................... 173
Receiver .......................................................... 174
Transmitter ....................................................... 172
Baud Rate Generator (BRG) ................................... 168
Associated Registers ....................................... 168
Baud Rate Error, Calculating ........................... 168
Baud Rate Formula .......................................... 168
Baud Rates for Asynchronous Mode
(BRGH = 0) .............................................. 170
Baud Rates for Asynchronous Mode
(BRGH = 1) .............................................. 171
Baud Rates for Synchronous Mode ................. 169
High Baud Rate Select (BRGH Bit) ................. 168
Sampling .......................................................... 168
Serial Port Enable (SPEN Bit) ................................. 165
Synchronous Master Mode ...................................... 176
Associated Registers, Reception ..................... 178
Associated Registers, Transmit ....................... 176
Reception ........................................................ 178
Transmission ................................................... 176
Synchronous Slave Mode ........................................ 179
Associated Registers, Receive ........................ 180
Associated Registers, Transmit ....................... 179
Reception ........................................................ 180
Transmission ................................................... 179
© 2006 Microchip Technology Inc.
PIC18FXX2
W
X
Wake-up from SLEEP .............................................. 195, 205
Using Interrupts ........................................................ 205
Watchdog Timer (WDT) ........................................... 195, 203
Associated Registers ............................................... 204
Control Register ....................................................... 203
Postscaler ........................................................ 203, 204
Programming Considerations .................................. 203
RC Oscillator ............................................................ 203
Time-out Period ....................................................... 203
WCOL .............................................................................. 153
WCOL Status Flag ............................................153, 155, 158
WWW, On-Line Support ....................................................... 5
XORLW ............................................................................ 251
XORWF ........................................................................... 252
© 2006 Microchip Technology Inc.
DS39564C-page 325
PIC18FXX2
NOTES:
DS39564C-page 326
© 2006 Microchip Technology Inc.
PIC18FXX2
THE MICROCHIP WEB SITE
CUSTOMER SUPPORT
Microchip provides online support via our WWW site at
www.microchip.com. This web site is used as a means
to make files and information easily available to
customers. Accessible by using your favorite Internet
browser, the web site contains the following
information:
Users of Microchip products can receive assistance
through several channels:
• Product Support – Data sheets and errata,
application notes and sample programs, design
resources, user’s guides and hardware support
documents, latest software releases and archived
software
• General Technical Support – Frequently Asked
Questions (FAQ), technical support requests,
online discussion groups, Microchip consultant
program member listing
• Business of Microchip – Product selector and
ordering guides, latest Microchip press releases,
listing of seminars and events, listings of
Microchip sales offices, distributors and factory
representatives
•
•
•
•
•
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Development Systems Information Line
Customers
should
contact
their
distributor,
representative or field application engineer (FAE) for
support. Local sales offices are also available to help
customers. A listing of sales offices and locations is
included in the back of this document.
Technical support is available through the web site
at: http://support.microchip.com
CUSTOMER CHANGE NOTIFICATION
SERVICE
Microchip’s customer notification service helps keep
customers current on Microchip products. Subscribers
will receive e-mail notification whenever there are
changes, updates, revisions or errata related to a
specified product family or development tool of interest.
To register, access the Microchip web site at
www.microchip.com, click on Customer Change
Notification and follow the registration instructions.
© 2006 Microchip Technology Inc.
DS39564C-page 327
PIC18FXX2
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation
can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150.
Please list the following information, and use this outline to provide us with your comments about this document.
To:
Technical Publications Manager
RE:
Reader Response
Total Pages Sent ________
From: Name
Company
Address
City / State / ZIP / Country
Telephone: (_______) _________ - _________
FAX: (______) _________ - _________
Application (optional):
Would you like a reply?
Device: PIC18FXX2
Y
N
Literature Number: DS39564C
Questions:
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?
5. What deletions from the document could be made without affecting the overall usefulness?
6. Is there any incorrect or misleading information (what and where)?
7. How would you improve this document?
DS39564C-page 328
Advance Information
© 2006 Microchip Technology Inc.
PIC18FXX2
PIC18FXX2 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.
Device
Device
X
Temperature
Range
/XX
XXX
Package
Pattern
PIC18FXX2(1), PIC18FXX2T(2);
VDD range 4.2V to 5.5V
PIC18LFXX2(1), PIC18LFXX2T(2);
VDD range 2.5V to 5.5V
Temperature
Range
I
E
=
=
-40°C to +85°C (Industrial)
-40°C to +125°C (Extended)
Package
PT
SO
SP
P
L
=
=
=
=
=
TQFP (Thin Quad Flatpack)
SOIC
Skinny Plastic DIP
PDIP
PLCC
Pattern
Examples:
a)
b)
c)
PIC18LF452 - I/P 301 = Industrial temp.,
PDIP package, Extended VDD limits,
QTP pattern #301.
PIC18LF242 - I/SO = Industrial temp.,
SOIC package, Extended VDD limits.
PIC18F442 - E/P = Extended temp.,
PDIP package, normal VDD limits.
Note 1: F
LF
2: T
= Standard Voltage range
= Wide Voltage Range
= in tape and reel - SOIC,
PLCC, and TQFP
packages only.
QTP, SQTP, Code or Special Requirements
(blank otherwise)
© 2006 Microchip Technology Inc.
DS39564C-page 329
WORLDWIDE SALES AND SERVICE
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://support.microchip.com
Web Address:
www.microchip.com
Asia Pacific Office
Suites 3707-14, 37th Floor
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Tel: 852-2401-1200
Fax: 852-2401-3431
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Tel: 91-80-4182-8400
Fax: 91-80-4182-8422
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Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
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Tel: 43-7242-2244-3910
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Tel: 45-4450-2828
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Tel: 49-89-627-144-0
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Tel: 770-640-0034
Fax: 770-640-0307
Boston
Westborough, MA
Tel: 774-760-0087
Fax: 774-760-0088
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Tel: 630-285-0071
Fax: 630-285-0075
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Toronto
Mississauga, Ontario,
Canada
Tel: 905-673-0699
Fax: 905-673-6509
Australia - Sydney
Tel: 61-2-9868-6733
Fax: 61-2-9868-6755
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Tel: 86-10-8528-2100
Fax: 86-10-8528-2104
China - Chengdu
Tel: 86-28-8665-5511
Fax: 86-28-8665-7889
Korea - Gumi
Tel: 82-54-473-4301
Fax: 82-54-473-4302
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Tel: 86-591-8750-3506
Fax: 86-591-8750-3521
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Tel: 82-2-554-7200
Fax: 82-2-558-5932 or
82-2-558-5934
China - Hong Kong SAR
Tel: 852-2401-1200
Fax: 852-2401-3431
Malaysia - Penang
Tel: 60-4-646-8870
Fax: 60-4-646-5086
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Tel: 86-532-8502-7355
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Tel: 63-2-634-9065
Fax: 63-2-634-9069
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Tel: 86-21-5407-5533
Fax: 86-21-5407-5066
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Tel: 65-6334-8870
Fax: 65-6334-8850
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Tel: 86-24-2334-2829
Fax: 86-24-2334-2393
Taiwan - Hsin Chu
Tel: 886-3-572-9526
Fax: 886-3-572-6459
China - Shenzhen
Tel: 86-755-8203-2660
Fax: 86-755-8203-1760
Taiwan - Kaohsiung
Tel: 886-7-536-4818
Fax: 886-7-536-4803
China - Shunde
Tel: 86-757-2839-5507
Fax: 86-757-2839-5571
Taiwan - Taipei
Tel: 886-2-2500-6610
Fax: 886-2-2508-0102
China - Wuhan
Tel: 86-27-5980-5300
Fax: 86-27-5980-5118
Thailand - Bangkok
Tel: 66-2-694-1351
Fax: 66-2-694-1350
Italy - Milan
Tel: 39-0331-742611
Fax: 39-0331-466781
Netherlands - Drunen
Tel: 31-416-690399
Fax: 31-416-690340
Spain - Madrid
Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
UK - Wokingham
Tel: 44-118-921-5869
Fax: 44-118-921-5820
China - Xian
Tel: 86-29-8833-7250
Fax: 86-29-8833-7256
08/29/06
DS39564C-page 330
© 2006 Microchip Technology Inc.