MICROCHIP PIC18F6490-E/PT

PIC18F6390/6490/8390/8490
Data Sheet
64/80-Pin Flash Microcontrollers
with LCD Driver and nanoWatt Technology
© 2007 Microchip Technology Inc.
DS39629C
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•
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•
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•
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•
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Trademarks
The Microchip name and logo, the Microchip logo, Accuron,
dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC,
PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt are
registered trademarks of Microchip Technology Incorporated
in the U.S.A. and other countries.
AmpLab, FilterLab, Linear Active Thermistor, 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, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, FlexROM, fuzzyLAB,
In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi,
MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit,
PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal,
PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, 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.
© 2007, 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 design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, 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.
DS39629C-page ii
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
64/80-Pin Flash Microcontrollers with LCD Driver
and nanoWatt Technology
LCD Driver Module Features:
Peripheral Highlights:
• Direct Driving of LCD Panel
• Up to 48 Segments: Software Selectable
• Programmable LCD Timing module:
- Multiple LCD timing sources available
- Up to 4 commons: Static, 1/2, 1/3 or 1/4 multiplex
- Static, 1/2 or 1/3 bias configuration
• Can drive LCD Panel while in Sleep mode
•
•
•
•
•
Power-Managed Modes:
•
•
Run: CPU On, Peripherals On
Idle: CPU Off, Peripherals On
Sleep: CPU Off, Peripherals Off
Run mode Currents Down to 14.0 μA Typical
Idle mode Currents Down to 5.8 μA Typical
Sleep Current Down to 0.1 μA Typical
Timer1 Oscillator: 1.8 μA, 32 kHz, 2V
Watchdog Timer: 2.1 μA
Two-Speed Oscillator Start-up
•
•
•
Flexible Oscillator Structure:
• Four Crystal modes:
- LP: up to 200 kHz
- XT: up to 4 MHz
- HS: up to 40 MHz
- HSPLL: 4-10 MHz (16-40 MHz internal)
• 4x Phase Lock Loop (available for crystal and
internal oscillators)
• Two External RC modes, up to 4 MHz
• Two External Clock modes, up to 40 MHz
• Internal Oscillator Block:
- 8 user-selectable frequencies, from 31 kHz to 8 MHz
- Provides a complete range of clock speeds
from 31 kHz to 32 MHz when used with PLL
- User-tunable to compensate for frequency drift
• Secondary Oscillator using Timer1 @ 32 kHz
• Fail-Safe Clock Monitor:
- Allows for safe shut down of device if primary
or secondary clock fails
Program Memory
Device
Data
Memory
Flash # Single-Word SRAM
(bytes) Instructions (bytes)
I/O
•
Special Microcontroller Features:
• C Compiler Optimized Architecture:
- Optional extended instruction set designed to
optimize re-entrant code
• 1000 Erase/Write Cycle Flash Program Memory Typical
• Flash Retention: 100 Years Typical
• Priority Levels for Interrupts
• 8 x 8 Single-Cycle Hardware Multiplier
• Extended Watchdog Timer (WDT):
- Programmable period from 4 ms to 132s
- 2% stability over VDD and temperature
• In-Circuit Serial Programming™ (ICSP™) via Two Pins
• In-Circuit Debug (ICD) via Two Pins
• Wide Operating Voltage Range: 2.0V to 5.5V
LCD
10-Bit
(pixel) A/D (ch)
CCP
(PWM)
MSSP
SPI
Master
I2C™
EUSART/
AUSART
•
•
•
•
•
•
•
•
•
High-Current Sink/Source 25 mA/25 mA
Four External Interrupts
Four Input Change Interrupts
Four 8-Bit/16-Bit Timer/Counter modules
Real-Time Clock (RTC) Software module:
- Configurable 24-hour clock, calendar, automatic
100-year or 12800-year, day-of-week calculator
- Uses Timer1
Up to 2 Capture/Compare/PWM (CCP) modules
Master Synchronous Serial Port (MSSP) module
supporting 3-Wire SPI (all 4 modes) and I2C™
Master and Slave modes
Addressable USART module:
- Supports RS-485 and RS-232
Enhanced Addressable USART module:
- Supports RS-485, RS-232 and LIN 1.2
- Auto-wake-up on Start bit
- Auto-Baud Detect
10-Bit, up to 12-Channel Analog-to-Digital (A/D)
Converter module:
- Auto-acquisition capability
- Conversion available during Sleep
Dual Analog Comparators with Input Multiplexing
Comparators
Timers
8/16-Bit
PIC18F6390
8K
4096
768
50
128
12
2
Y
Y
1/1
2
1/3
PIC18F6490
16K
8192
768
50
128
12
2
Y
Y
1/1
2
1/3
PIC18F8390
8K
4096
768
66
192
12
2
Y
Y
1/1
2
1/3
PIC18F8490
16K
8192
768
66
192
12
2
Y
Y
1/1
2
1/3
© 2007 Microchip Technology Inc.
DS39629C-page 1
PIC18F6390/6490/8390/8490
Pin Diagrams
RD7/SEG7
RD6/SEG6
RD5/SEG5
RD4/SEG4
RD3/SEG3
RD2/SEG2
RD1/SEG1
VSS
VDD
RE7/CCP2(1)/SEG31
RD0/SEG0
RE6/COM3
RE5/COM2
RE4/COM1
COM0
LCDBIAS3
64-Pin TQFP
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
LCDBIAS2
LCDBIAS1
RG0/SEG30
RG1/TX2/CK2/SEG29
RF7/SS/SEG25
RF6/AN11/SEG24
RF5/AN10/CVREF/SEG23
RF4/AN9/SEG22
1
2
3
4
5
6
7
8
9
10
11
12
13
14
RF3/AN8/SEG21
RF2/AN7/C1OUT/SEG20
15
16
RG2/RX2/DT2/SEG28
RG3/SEG27
MCLR/VPP/RG5
RG4/SEG26
VSS
VDD
48
47
46
45
44
PIC18F6390
43
42
PIC18F6490
41
40
39
38
37
36
35
34
33
RB0/INT0
RB1/INT1/SEG8
RB2/INT2/SEG9
RB3/INT3/SEG10
RB4/KBI0/SEG11
RB5/KBI1
RB6/KBI2/PGC
VSS
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VDD
RB7/KBI3/PGD
RC5/SDO/SEG12
RC4/SDI/SDA
RC3/SCK/SCL
RC2/CCP1/SEG13
RC7/RX1/DT1
RC6/TX1/CK1
RC0/T1OSO/T13CKI
RA4/T0CKI/SEG14
RC1/T1OSI/CCP2(1)
RA5/AN4/HLVDIN/SEG15
VDD
VSS
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/SEG16
AVSS
RA3/AN3/VREF+/SEG17
AVDD
RF0/AN5/SEG18
RF1/AN6/C2OUT/SEG19
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
Note 1: RE7 is the alternate pin for CCP2 multiplexing.
DS39629C-page 2
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
Pin Diagrams (Continued)
RJ1/SEG33
RJ0/SEG32
RD7/SEG7
RD6/SEG6
RD5/SEG5
RD4/SEG4
RD3/SEG3
RD2/SEG2
RD1/SEG1
VDD
VSS
RD0/SEG0
RE7/CCP2(1)/SEG31
RE6/COM3
RE5/COM2
RE4/COM1
COM0
LCDBIAS3
RH0/SEG47
RH1/SEG46
80-Pin TQFP
80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61
RH2/SEG45
RH3/SEG44
LCDBIAS2
LCDBIAS1
RG0/SEG30
RG1/TX2/CK2/SEG29
RG2/RX2/DT2/SEG28
RG3/SEG27
MCLR/VPP/RG5
RG4/SEG26
VSS
VDD
RF7/SS/SEG25
RF6/AN11/SEG24
RF5/AN10/CVREF/SEG23
RF4/AN9/SEG22
RF3/AN8/SEG21
RF2/AN7/C1OUT/SEG20
RH7/SEG43
RH6/SEG42
1
2
60
59
58
57
56
55
3
4
5
6
7
8
9
10
11
12
13
14
15
16
54
53
52
51
50
PIC18F8390
PIC18F8490
49
48
47
46
45
44
43
17
18
19
20
42
41
RJ2/SEG34
RJ3/SEG35
RB0/INT0
RB1/INT1/SEG8
RB2/INT2/SEG9
RB3/INT3/SEG10
RB4/KBI0/SEG11
RB5/KBI1
RB6/KBI2/PGC
VSS
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VDD
RB7/KBI3/PGD
RC5/SDO/SEG12
RC4/SDI/SDA
RC3/SCK/SCL
RC2/CCP1/SEG13
RJ7/SEG36
RJ6/SEG37
RJ5/SEG38
RJ4/SEG39
RC7/RX1/DT1
RC6/TX1/CK1
RC0/T1OSO/T13CKI
RA4/T0CKI/SEG14
RC1/T1OSI/CCP2(1)
VDD
RA5/AN4/HLVDIN/SEG15
VSS
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/SEG16
AVSS
RA3/AN3/VREF+/SEG17
AVDD
RF0/AN5/SEG18
RF1/AN6/C2OUT/SEG19
RH4/SEG40
RH5/SEG41
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Note 1: RE7 is the alternate pin for CCP2 multiplexing.
© 2007 Microchip Technology Inc.
DS39629C-page 3
PIC18F6390/6490/8390/8490
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7
2.0 Oscillator Configurations ............................................................................................................................................................ 31
3.0 Power-Managed Modes ............................................................................................................................................................. 41
4.0 Reset .......................................................................................................................................................................................... 51
5.0 Memory Organization ................................................................................................................................................................. 65
6.0 Flash Program Memory .............................................................................................................................................................. 87
7.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 91
8.0 Interrupts .................................................................................................................................................................................... 93
9.0 I/O Ports ................................................................................................................................................................................... 109
10.0 Timer0 Module ......................................................................................................................................................................... 131
11.0 Timer1 Module ......................................................................................................................................................................... 135
12.0 Timer2 Module ......................................................................................................................................................................... 141
13.0 Timer3 Module ......................................................................................................................................................................... 143
14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 147
15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 157
16.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 197
17.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) ........................................................... 217
18.0 10-Bit Analog-to-Digital Converter (A/D) Module ..................................................................................................................... 231
19.0 Comparator Module.................................................................................................................................................................. 241
20.0 Comparator Voltage Reference Module ................................................................................................................................... 247
21.0 High/Low-Voltage Detect (HLVD)............................................................................................................................................. 251
22.0 Liquid Crystal Display (LCD) Driver Module ............................................................................................................................. 257
23.0 Special Features of the CPU .................................................................................................................................................... 281
24.0 Instruction Set Summary .......................................................................................................................................................... 295
25.0 Development Support............................................................................................................................................................... 345
26.0 Electrical Characteristics .......................................................................................................................................................... 349
27.0 DC and AC Characteristics Graphs and Tables ....................................................................................................................... 387
28.0 Packaging Information.............................................................................................................................................................. 389
Appendix A: Revision History............................................................................................................................................................. 395
Appendix B: Device Differences......................................................................................................................................................... 395
Appendix C: Conversion Considerations ........................................................................................................................................... 396
Appendix D: Migration from Baseline to Enhanced Devices.............................................................................................................. 396
Appendix E: migration from Mid-Range to Enhanced Devices .......................................................................................................... 397
Appendix F: Migration from High-End to Enhanced Devices ............................................................................................................. 397
Index .................................................................................................................................................................................................. 399
The Microchip Web Site ..................................................................................................................................................................... 409
Customer Change Notification Service .............................................................................................................................................. 409
Customer Support .............................................................................................................................................................................. 409
Reader Response .............................................................................................................................................................................. 410
PIC18F6390/6490/8390/8490 Product Identification System ............................................................................................................ 411
DS39629C-page 4
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TO OUR VALUED CUSTOMERS
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If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
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We welcome your feedback.
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You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
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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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© 2007 Microchip Technology Inc.
DS39629C-page 5
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 6
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
1.0
DEVICE OVERVIEW
This document contains device-specific information for
the following devices:
• PIC18F6390
• PIC18F8390
• PIC18F6490
• PIC18F8490
This family offers the advantages of all PIC18
microcontrollers – namely, high computational
performance at an economical price. In addition to
these features, the PIC18F6390/6490/8390/8490
family introduces design enhancements that make
these microcontrollers a logical choice for many
high-performance, power-sensitive applications.
1.1
1.1.1
New Core Features
nanoWatt TECHNOLOGY
All of the devices in the PIC18F6390/6490/8390/8490
family incorporate a range of features that can
significantly reduce power consumption during
operation. Key items include:
• Alternate Run Modes: By clocking the controller
from the Timer1 source or the internal oscillator
block, power consumption during code execution
can be reduced by as much as 90%.
• Multiple Idle Modes: The controller can also run
with its CPU core disabled, but the peripherals still
active. In these states, power consumption can be
reduced even further – to as little as 4% of normal
operation requirements.
• On-the-Fly Mode Switching: The
power-managed modes are invoked by user code
during operation, allowing the user to incorporate
power-saving ideas into their application’s
software design.
• Lower Consumption in Key Modules: The
power requirements for both Timer1 and the
Watchdog Timer have been reduced by up to
80%, with typical values of 1.1 μA and 2.1 μA,
respectively.
© 2007 Microchip Technology Inc.
1.1.2
MULTIPLE OSCILLATOR OPTIONS
AND FEATURES
All of the devices in the PIC18F6390/6490/8390/8490
family offer ten different oscillator options, allowing
users a wide range of choices in developing application
hardware. These include:
• Four Crystal modes using crystals or ceramic
resonators.
• Two External Clock modes offering the option of
using two pins (oscillator input and a divide-by-4
clock output) or one pin (oscillator input, with the
second pin reassigned as general I/O).
• Two External RC Oscillator modes with the same
pin options as the External Clock modes.
• An internal oscillator block which provides an
8 MHz clock (±2% accuracy) and an INTRC
source (approximately 31 kHz, stable over
temperature and VDD), as well as a range of six
user-selectable clock frequencies between
125 kHz to 4 MHz for a total of eight clock
frequencies. This option frees the two oscillator
pins for use as additional general purpose I/O.
• A Phase Lock Loop (PLL) frequency multiplier,
available to both the High-Speed Crystal and
Internal Oscillator modes, which allows clock
speeds of up to 40 MHz. Used with the internal
oscillator, the PLL gives users a complete
selection of clock speeds from 31 kHz to
32 MHz – all without using an external crystal or
clock circuit.
Besides its availability as a clock source, the internal
oscillator block provides a stable reference source that
gives the family additional features for robust
operation:
• Fail-Safe Clock Monitor: This option constantly
monitors the main clock source against a
reference signal provided by the internal
oscillator. If a clock failure occurs, the controller is
switched to the internal oscillator block, allowing
for continued low-speed operation or a safe
application shutdown.
• Two-Speed Start-up: This option allows the
internal oscillator to serve as the clock source
from Power-on Reset or wake-up from Sleep
mode until the primary clock source is available.
DS39629C-page 7
PIC18F6390/6490/8390/8490
1.2
Other Special Features
• Memory Endurance: The Flash cells for program
memory are rated to last for approximately a
thousand erase/write cycles. Data retention
without refresh is conservatively estimated to be
greater than 100 years.
• Extended Instruction Set: The
PIC18F6390/6490/8390/8490 family introduces
an optional extension to the PIC18 instruction set,
which adds 8 new instructions and an Indexed
Addressing mode. This extension, enabled as a
device configuration option, has been specifically
designed to optimize re-entrant application code
originally developed in high-level languages such
as C.
• Enhanced Addressable USART: This serial
communication module is capable of standard
RS-232 operation and provides support for the LIN
bus protocol. Other enhancements include
Automatic Baud Rate Detection and a 16-bit Baud
Rate Generator for improved resolution. When the
microcontroller is using the internal oscillator
block, the EUSART provides stable operation for
applications that talk to the outside world, without
using an external crystal (or its accompanying
power requirement).
• 10-Bit A/D Converter: This module incorporates
programmable acquisition time, allowing for a
channel to be selected and a conversion to be
initiated without waiting for a sampling period and
thus, reduces code overhead.
• Extended Watchdog Timer (WDT): This
enhanced version incorporates a 16-bit prescaler,
allowing a time-out range from 4 ms to over
10 minutes that is stable across operating voltage
and temperature.
DS39629C-page 8
1.3
Details on Individual Family
Members
Devices in the PIC18F6390/6490/8390/8490 family are
available in 64-pin (PIC18F6X90) and 80-pin
(PIC18F8X90) packages. Block diagrams for the two
groups are shown in Figure 1-1 and Figure 1-2,
respectively.
The devices are differentiated from each other in three
ways:
1.
2.
3.
I/O Ports: 7 bidirectional ports on 64-pin
devices; 9 bidirectional ports on 80-pin devices.
LCD Pixels: 128 (32 SEGs x 4 COMs) pixels can
be driven by 64-pin devices; 192 (48 SEGs x
4 COMs) pixels can be driven by 80-pin devices.
Flash Program Memory: 8 Kbytes for
PIC18FX390 devices; 16 Kbytes for PIC18FX490.
All other features for devices in this family are identical.
These are summarized in Table 1-1.
The pinouts for all devices are listed in Table 1-2 and
Table 1-3.
Like all Microchip PIC18 devices, members of the
PIC18F6390/6490/8390/8490 family are available as
both standard and low-voltage devices. Standard
devices with Flash memory, designated with an “F” in
the part number (such as PIC18F6390), accommodate
an operating VDD range of 4.2V to 5.5V. Low-voltage
parts, designated by “LF” (such as PIC18LF6490),
function over an extended VDD range of 2.0V to 5.5V.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-1:
DEVICE FEATURES
Features
PIC18F6390
PIC18F6490
PIC18F8390
PIC18F8490
DC – 40 MHz
DC – 40 MHz
DC – 40 MHz
DC – 40 MHz
8K
16K
8K
16K
Program Memory (Instructions)
4096
8192
4096
8192
Data Memory (Bytes)
768
768
768
768
22
22
22
22
Operating Frequency
Program Memory (Bytes)
Interrupt Sources
I/O Ports
Number of Pixels the LCD Driver
can Drive
Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E,
F, G
F, G
F, G, H, J
F, G, H, J
128 (32 SEGs x
4 COMs)
128 (32 SEGs x
4 COMs)
192 (48 SEGs x
4 COMs)
192 (48 SEGs x
4 COMs)
Timers
4
4
4
4
Capture/Compare/PWM Modules
2
2
2
2
Serial Communications
MSSP, AUSART
MSSP, AUSART
MSSP, AUSART
MSSP, AUSART
Enhanced USART Enhanced USART Enhanced USART Enhanced USART
10-Bit Analog-to-Digital Module
12 Input Channels 12 Input Channels 12 Input Channels 12 Input Channels
Resets (and Delays)
POR, BOR,
POR, BOR,
POR, BOR,
POR, BOR,
RESET Instruction, RESET Instruction, RESET Instruction, RESET Instruction,
Stack Full,
Stack Full,
Stack Full,
Stack Full,
Stack Underflow
Stack Underflow
Stack Underflow
Stack Underflow
(PWRT, OST),
(PWRT, OST),
(PWRT, OST),
(PWRT, OST),
MCLR (optional), MCLR (optional), MCLR (optional), MCLR (optional),
WDT
WDT
WDT
WDT
Programmable Low-Voltage Detect
Programmable Brown-out Reset
Instruction Set
Packages
© 2007 Microchip Technology Inc.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
75 Instructions;
83 with Extended
Instruction Set
Enabled
75 Instructions;
83 with Extended
Instruction Set
Enabled
75 Instructions;
83 with Extended
Instruction Set
Enabled
75 Instructions;
83 with Extended
Instruction Set
Enabled
64-Pin TQFP
64-Pin TQFP
80-Pin TQFP
80-Pin TQFP
DS39629C-page 9
PIC18F6390/6490/8390/8490
FIGURE 1-1:
PIC18F6X90 (64-PIN) BLOCK DIAGRAM
Data Bus<8>
Table Pointer<21>
Data Latch
8
8
inc/dec logic
PORTA
Data Memory
(3.9 Kbytes)
PCLATU PCLATH
21
20
Address Latch
PCU PCH PCL
Program Counter
12
Data Address<12>
31 Level Stack
4
BSR
Address Latch
Program Memory
(48/64 Kbytes)
STKPTR
8
Instruction Bus <16>
4
Access
Bank
12
FSR0
FSR1
FSR2
Data Latch
PORTB
12
inc/dec
logic
Table Latch
PORTC
Address
Decode
ROM Latch
IR
Instruction
Decode and
Control
8
State Machine
Control Signals
OSC2
(3)
T1OSI
INTRC
Oscillator
T1OSO
8 MHz
Oscillator
Single-Supply
Programming
In-Circuit
Debugger
MCLR(2)
VDD, VSS
BOR
HLVD
Comparators
Note
ADC
10-Bit
CCP1
RD7/SEG7:RD0/SEG0
8
W
Power-up
Timer
8
Oscillator
Start-up Timer
Power-on
Reset
PORTE
8
8
8
Internal
Oscillator
Block
8
ALU<8>
8
Watchdog
Timer
PORTF
Precision
Band Gap
Reference
Brown-out
Reset
Fail-Safe
Clock Monitor
PORTG
Timer0
CCP2
Timer1
MSSP
Timer2
EUSART1
RC0/T1OSO/T13CKI
RC1/T1OSI/CCP2(1)
RC2/CCP1/SEG13
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO/SEG12
RC6/TX1/CK1
RC7/RX1/DT1
8 x 8 Multiply
BITOP
OSC1(3)
RB0/INT0
RB1/INT1/SEG8
RB2/INT2/SEG9
RB3/INT3/SEG10
RB4/KBI0/SEG11
RB5/KBI1
RB6/KBI2/PGC
RB7/KBI3/PGD
PORTD
PRODH PRODL
3
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/SEG16
RA3/AN3/VREF+/SEG17
RA4/T0CKI/SEG14
RA5/AN4/HLVDIN/SEG15
OSC2/CLKO(3)/RA6
OSC1/CLKI(3)/RA7
Timer3
AUSART2
LCDBIAS1
LCDBIAS2
LCDBIAS3
COM0
RE4/COM1
RE5/COM2
RE6/COM3
RE7/CCP2(1)/SEG31
RF0/AN5/SEG18
RF1/AN6/C2OUT/SEG19
RF2/AN7/C1OUT/SEG20
RF3/AN8/SEG21
RF4/AN9/SEG22
RF5/AN10/CVREF/SEG23
RF6/AN11/SEG24
RF7/SS/SEG25
RG0/SEG30
RG1/TX2/CK2/SEG29
RG2/RX2/DT2/SEG28
RG3/SEG27
RG4/SEG26
MCLR/VPP/RG5(2)
LCD
Driver
1:
CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set, or RE7 when CCP2MX is not set.
2:
RG5 is only available when MCLR functionality is disabled.
3:
OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O.
Refer to Section 2.0 “Oscillator Configurations” for additional information.
DS39629C-page 10
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 1-2:
PIC18F8X90 (80-PIN) BLOCK DIAGRAM
PORTA
Data Bus<8>
Table Pointer<21>
Data Latch
8
8
inc/dec logic
Data Memory
(3.9 Kbytes)
PCLATU PCLATH
21
20
Address Latch
PCU PCH PCL
Program Counter
PORTB
12
Data Address<12>
31 Level Stack
4
BSR
Address Latch
Program Memory
(48/64 Kbytes)
STKPTR
Data Latch
8
Instruction Bus <16>
12
4
Access
Bank
FSR0
FSR1
FSR2
12
PORTC
inc/dec
logic
Table Latch
Address
Decode
ROM Latch
8
OSC2
(3)
T1OSI
INTRC
Oscillator
T1OSO
8 MHz
Oscillator
MCLR(2)
VDD, VSS
Single-Supply
Programming
In-Circuit
Debugger
RD7/SEG7:RD0/SEG0
PORTE
PRODH PRODL
8 x 8 Multiply
8
W
BITOP
8
Internal
Oscillator
Block
RC0/T1OSO/T13CKI
RC1/T1OSI/CCP2(1)
RC2/CCP1/SEG13
RC3/SCK/SCL
RC4/SDI/SDA
RC5/SDO/SEG12
RC6/TX1/CK1
RC7/RX1/DT1
State Machine
Control Signals
3
OSC1(3)
RB0/INT0
RB1/INT1/SEG8
RB2/INT2/SEG9
RB3/INT3/SEG10
RB4/KBI0/SEG11
RB5/KBI1
RB6/KBI2/PGC
RB7/KBI3/PGD
PORTD
IR
Instruction
Decode and
Control
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/SEG16
RA3/AN3/VREF+/SEG17
RA4/T0CKI/SEG14
RA5/AN4/HLVDIN/SEG15
OSC2/CLKO(3)/RA6
OSC1/CLKI(3)/RA7
Power-up
Timer
8
8
8
Oscillator
Start-up Timer
Power-on
Reset
8
PORTF
ALU<8>
8
Watchdog
Timer
Precision
Band Gap
Reference
Brown-out
Reset
Fail-Safe
Clock Monitor
PORTG
LCDBIAS1
LCDBIAS2
LCDBIAS3
COM0
RE4/COM1
RE5/COM2
RE6/COM3
RE7/CCP2(1)/SEG31
RF0/AN5/SEG18
RF1/AN6/C2OUT/SEG19
RF2/AN7/C1OUT/SEG20
RF3/AN8/SEG21
RF4/AN9/SEG22
RF5/AN10/CVREF/SEG23
RF6/AN11/SEG24
RF7/SS/SEG25
RG0/SEG30
RG1/TX2/CK2/SEG29
RG2/RX2/DT2/SEG28
RG3/SEG27
RG4/SEG26
MCLR/VPP/RG5(2)
PORTH
BOR
HLVD
ADC
10-Bit
Timer0
Timer1
Timer2
Timer3
RH3/SEG47:RH0/SEG44
RH7/SEG40:RH4/SEG43
PORTJ
RJ3/SEG35:RJ0/SEG32
Comparators
Note
CCP1
CCP2
LCD
Driver
MSSP
EUSART1
AUSART2
RJ7/SEG36:RJ4/SEG39
1:
CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set and RE7 when CCP2MX is not set.
2:
RG5 is only available when MCLR functionality is disabled.
3:
OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as digital I/O.
Refer to Section 2.0 “Oscillator Configurations” for additional information.
© 2007 Microchip Technology Inc.
DS39629C-page 11
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS
Pin Name
MCLR/VPP/RG5
MCLR
Pin Number
TQFP
7
VPP
RG5
OSC1/CLKI/RA7
OSC1
I
ST
P
I
ST
39
I
CLKI
I
RA7
OSC2/CLKO/RA6
OSC2
Pin Buffer
Type Type
I/O
Description
Master Clear (input) or programming voltage (input).
Master Clear (Reset) input. This pin is an active-low
Reset to the device.
Programming voltage input.
Digital input.
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode, CMOS
otherwise.
CMOS
External clock source input. Always associated
with pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
TTL
General purpose I/O pin.
ST
40
O
—
CLKO
O
—
RA6
I/O
TTL
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.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 12
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTA is a bidirectional I/O port.
RA0/AN0
RA0
AN0
24
RA1/AN1
RA1
AN1
23
RA2/AN2/VREF-/SEG16
RA2
AN2
VREFSEG16
22
RA3/AN3/VREF+/SEG17
RA3
AN3
VREF+
SEG17
21
RA4/T0CKI/SEG14
RA4
T0CKI
SEG14
28
RA5/AN4/HLVDIN/SEG15
RA5
AN4
HLVDIN
SEG15
27
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
O
TTL
Analog
Analog
Analog
Digital I/O.
Analog input 2.
A/D reference voltage (Low) input.
SEG16 output for LCD.
I/O
I
I
O
TTL
Analog
Analog
Analog
Digital I/O.
Analog input 3.
A/D reference voltage (High) input.
SEG17 output for LCD.
I/O
I
O
ST/OD
ST
Analog
Digital I/O. Open-drain when configured as output.
Timer0 external clock input.
SEG14 output for LCD.
I/O
I
I
O
TTL
Analog
Analog
Analog
Digital I/O.
Analog input 4.
Low-Voltage Detect input.
SEG15 output for LCD.
RA6
See the OSC2/CLKO/RA6 pin.
RA7
See the OSC1/CLKI/RA7 pin.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 13
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTB is a bidirectional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/INT0
RB0
INT0
48
RB1/INT1/SEG8
RB1
INT1
SEG8
47
RB2/INT2/SEG9
RB2
INT2
SEG9
46
RB3/INT3/SEG10
RB3
INT3
SEG10
45
RB4/KBI0/SEG11
RB4
KBI0
SEG11
44
RB5/KBI1
RB5
KBI1
43
RB6/KBI2/PGC
RB6
KBI2
PGC
42
RB7/KBI3/PGD
RB7
KBI3
PGD
37
I/O
I
TTL
ST
Digital I/O.
External interrupt 0.
I/O
I
O
TTL
ST
Analog
Digital I/O.
External interrupt 1.
SEG8 output for LCD.
I/O
I
O
TTL
ST
Analog
Digital I/O.
External interrupt 2.
SEG9 output for LCD.
I/O
I
O
TTL
ST
Analog
Digital I/O.
External interrupt 3.
SEG10 output for LCD.
I/O
I
O
TTL
TTL
Analog
Digital I/O.
Interrupt-on-change pin.
SEG11 output for LCD.
I/O
I
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP™ programming clock pin.
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 14
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
T1OSO
T13CKI
30
RC1/T1OSI/CCP2
RC1
T1OSI
CCP2(1)
29
RC2/CCP1/SEG13
RC2
CCP1
SEG13
33
RC3/SCK/SCL
RC3
SCK
SCL
34
RC4/SDI/SDA
RC4
SDI
SDA
35
RC5/SDO/SEG12
RC5
SDO
SEG12
36
RC6/TX1/CK1
RC6
TX1
CK1
31
RC7/RX1/DT1
RC7
RX1
DT1
32
I/O
O
I
ST
—
ST
I/O
I
I/O
ST
CMOS
ST
Digital I/O.
Timer1 oscillator input.
Capture 2 input/Compare 2 output/PWM2 output.
I/O
I/O
O
ST
ST
Analog
Digital I/O.
Capture 1 input/Compare 1 output/PWM1 output.
SEG13 output for LCD.
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
O
ST
—
Analog
I/O
O
I/O
ST
—
ST
Digital I/O.
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related RX1/DT1).
I/O
I
I/O
ST
ST
ST
Digital I/O.
EUSART1 asynchronous receive.
EUSART1 synchronous data (see related TX1/CK1).
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
Digital I/O.
SPI data out.
SEG12 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 15
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTD is a bidirectional I/O port.
RD0/SEG0
RD0
SEG0
58
RD1/SEG1
RD1
SEG1
55
RD2/SEG2
RD2
SEG2
54
RD3/SEG3
RD3
SEG3
53
RD4/SEG4
RD4
SEG4
52
RD5/SEG5
RD5
SEG5
51
RD6/SEG6
RD6
SEG6
50
RD7/SEG7
RD7
SEG7
49
I/O
O
ST
Analog
Digital I/O.
SEG0 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG1 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG2 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG3 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG4 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG5 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG6 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG7 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 16
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTE is a bidirectional I/O port.
LCDBIAS1
LCDBIAS1
2
LCDBIAS2
LCDBIAS2
1
LCDBIAS3
LCDBIAS3
64
COM0
COM0
63
RE4/COM1
RE4
COM1
62
RE5/COM2
RE5
COM2
61
RE6/COM3
RE6
COM3
60
RE7/CCP2/SEG31
RE7
CCP2(2)
SEG31
59
I
Analog
BIAS1 input for LCD.
I
Analog
BIAS2 input for LCD.
I
Analog
BIAS3 input for LCD.
O
Analog
COM0 output for LCD.
I/O
O
ST
Analog
Digital I/O.
COM1 output for LCD.
I/O
O
ST
Analog
Digital I/O.
COM2 output for LCD.
I/O
O
ST
Analog
Digital I/O.
COM3 output for LCD.
I/O
I/O
O
ST
ST
Analog
Digital I/O.
Capture 2 input/Compare 2 output/PWM2 output.
SEG31 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 17
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTF is a bidirectional I/O port.
RF0/AN5/SEG18
RF0
AN5
SEG18
18
RF1/AN6/C2OUT/SEG19
RF1
AN6
C2OUT
SEG19
17
RF2/AN7/C1OUT/SEG20
RF2
AN7
C1OUT
SEG20
16
RF3/AN8/SEG21
RF3
AN8
SEG21
15
RF4/AN9/SEG22
RF4
AN9
SEG22
14
RF5/AN10/CVREF/SEG23
RF5
AN10
CVREF
SEG23
13
RF6/AN11/SEG24
RF6
AN11
SEG24
12
RF7/SS/SEG25
RF7
SS
SEG25
11
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 5.
SEG18 output for LCD.
I/O
I
O
O
ST
Analog
—
Analog
Digital I/O.
Analog input 6.
Comparator 2 output.
SEG19 output for LCD.
I/O
I
O
O
ST
Analog
—
Analog
Digital I/O.
Analog input 7.
Comparator 1 output.
SEG20 output for LCD.
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 8.
SEG21 output for LCD.
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 9.
SEG22 output for LCD.
I/O
I
O
O
ST
Analog
Analog
Analog
Digital I/O.
Analog input 10.
Comparator reference voltage output.
SEG23 output for LCD.
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 11.
SEG24 output for LCD.
I/O
I
O
ST
TTL
Analog
Digital I/O.
SPI slave select input.
SEG25 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 18
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-2:
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTG is a bidirectional I/O port.
RG0/SEG30
RG0
SEG30
3
RG1/TX2/CK2/SEG29
RG1
TX2
CK2
SEG29
4
RG2/RX2/DT2/SEG28
RG2
RX2
DT2
SEG28
5
RG3/SEG27
RG3
SEG27
6
RG4/SEG26
RG4
SEG26
8
I/O
O
ST
Analog
Digital I/O.
SEG30 output for LCD.
I/O
O
I/O
O
ST
—
ST
Analog
Digital I/O.
AUSART2 asynchronous transmit.
AUSART2 synchronous clock (see related RX2/DT2).
SEG29 output for LCD.
I/O
I
I/O
O
ST
ST
ST
Analog
Digital I/O.
AUSART2 asynchronous receive.
AUSART2 synchronous data (see related TX2/CK2).
SEG28 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG27 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG26 output for LCD.
P
—
See MCLR/VPP/RG5 pin.
RG5
VSS
9, 25, 41, 56
Ground reference for logic and I/O pins.
VDD
10, 26, 38, 57
P
—
Positive supply for logic and I/O pins.
AVSS
20
P
—
Ground reference for analog modules.
AVDD
19
P
—
Positive supply for analog modules.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 19
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS
Pin Name
MCLR/VPP/RG5
MCLR
Pin Number
TQFP
9
VPP
RG5
OSC1/CLKI/RA7
OSC1
Pin Buffer
Type Type
I
ST
P
I
ST
49
I
CLKI
I
RA7
I/O
OSC2/CLKO/RA6
OSC2
Description
Master Clear (input) or programming voltage (input).
Master Clear (Reset) input. This pin is an active-low
Reset to the device.
Programming voltage input.
Digital input.
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode, CMOS
otherwise.
CMOS
External clock source input. Always associated with
pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
TTL
General purpose I/O pin.
ST
50
O
—
CLKO
O
—
RA6
I/O
TTL
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.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 20
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTA is a bidirectional I/O port.
RA0/AN0
RA0
AN0
30
RA1/AN1
RA1
AN1
29
RA2/AN2/VREF-/SEG16
RA2
AN2
VREFSEG16
28
RA3/AN3/VREF+/SEG17
RA3
AN3
VREF+
SEG17
27
RA4/T0CKI/SEG14
RA4
T0CKI
SEG14
34
RA5/AN4/HLVDIN/SEG15
RA5
AN4
HLVDIN
SEG15
33
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
O
TTL
Analog
Analog
Analog
Digital I/O.
Analog input 2.
A/D reference voltage (Low) input.
SEG16 output for LCD.
I/O
I
I
O
TTL
Analog
Analog
Analog
Digital I/O.
Analog input 3.
A/D reference voltage (High) input.
SEG17 output for LCD.
I/O
I
O
ST/OD
ST
Analog
Digital I/O. Open-drain when configured as output.
Timer0 external clock input.
SEG14 output for LCD.
I/O
I
I
O
TTL
Analog
Analog
Analog
Digital I/O.
Analog input 4.
Low-Voltage Detect input.
SEG15 output for LCD.
RA6
See the OSC2/CLKO/RA6 pin.
RA7
See the OSC1/CLKI/RA7 pin.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 21
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTB is a bidirectional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/INT0
RB0
INT0
58
RB1/INT1/SEG8
RB1
INT1
SEG8
57
RB2/INT2/SEG9
RB2
INT2
SEG9
56
RB3/INT3/SEG10
RB3
INT3
SEG10
55
RB4/KBI0/SEG11
RB4
KBI0
SEG11
54
RB5/KBI1
RB5
KBI1
53
RB6/KBI2/PGC
RB6
KBI2
PGC
52
RB7/KBI3/PGD
RB7
KBI3
PGD
47
I/O
I
TTL
ST
Digital I/O.
External interrupt 0.
I/O
I
O
TTL
ST
Analog
Digital I/O.
External interrupt 1.
SEG8 output for LCD.
I/O
I
O
TTL
ST
Analog
Digital I/O.
External interrupt 2.
SEG9 output for LCD.
I/O
I
O
TTL
ST
Analog
Digital I/O.
External interrupt 3.
SEG10 output for LCD.
I/O
I
O
TTL
TTL
Analog
Digital I/O.
Interrupt-on-change pin.
SEG11 output for LCD.
I/O
I
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP™ programming clock pin.
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 22
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
T1OSO
T13CKI
36
RC1/T1OSI/CCP2
RC1
T1OSI
CCP2(1)
35
RC2/CCP1/SEG13
RC2
CCP1
SEG13
43
RC3/SCK/SCL
RC3
SCK
SCL
44
RC4/SDI/SDA
RC4
SDI
SDA
45
RC5/SDO/SEG12
RC5
SDO
SEG12
46
RC6/TX1/CK1
RC6
TX1
CK1
37
RC7/RX1/DT1
RC7
RX1
DT1
38
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.
Capture 2 input/Compare 2 output/PWM2 output.
I/O
I/O
O
ST
ST
Analog
Digital I/O.
Capture 1 input/Compare 1 output/PWM1 output.
SEG13 output for LCD.
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
O
ST
—
Analog
I/O
O
I/O
ST
—
ST
Digital I/O.
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related RX1/DT1).
I/O
I
I/O
ST
ST
ST
Digital I/O.
EUSART1 asynchronous receive.
EUSART1 synchronous data (see related TX1/CK1).
Digital I/O.
SPI data out.
SEG12 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 23
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTD is a bidirectional I/O port.
RD0/SEG0
RD0
SEG0
72
RD1/SEG1
RD1
SEG1
69
RD2/SEG2
RD2
SEG2
68
RD3/SEG3
RD3
SEG3
67
RD4/SEG4
RD4
SEG4
66
RD5/SEG5
RD5
SEG5
65
RD6/SEG6
RD6
SEG6
64
RD7/SEG7
RD7
SEG7
63
I/O
O
ST
Analog
Digital I/O.
SEG0 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG1 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG2 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG3 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG4 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG5 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG6 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG7 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 24
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTE is a bidirectional I/O port.
LCDBIAS1
LCDBIAS1
4
LCDBIAS2
LCDBIAS2
3
LCDBIAS3
LCDBIAS3
78
COM0
COM0
77
RE4/COM1
RE4
COM1
76
RE5/COM2
RE5
COM2
75
RE6/COM3
RE6
COM3
74
RE7/CCP2/SEG31
RE7
CCP2(2)
SEG31
73
I
Analog
BIAS1 input for LCD.
I
Analog
BIAS2 input for LCD.
I
Analog
BIAS3 input for LCD.
O
Analog
COM0 output for LCD.
I/O
O
ST
Analog
Digital I/O.
COM1 output for LCD.
I/O
O
ST
Analog
Digital I/O.
COM2 output for LCD.
I/O
O
ST
Analog
Digital I/O.
COM3 output for LCD.
I/O
I/O
O
ST
ST
Analog
Digital I/O.
Capture 2 input/Compare 2 output/PWM2 output.
SEG31 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 25
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTF is a bidirectional I/O port.
RF0/AN5/SEG18
RF0
AN5
SEG18
24
RF1/AN6/C2OUT/SEG19
RF1
AN6
C2OUT
SEG19
23
RF2/AN7/C1OUT/SEG20
RF2
AN7
C1OUT
SEG20
18
RF3/AN8/SEG21
RF3
AN8
SEG21
17
RF4/AN9/SEG22
RF4
AN9
SEG22
16
RF5/AN10/CVREF/SEG23
RF5
AN10
CVREF
SEG23
15
RF6/AN11/SEG24
RF6
AN11
SEG24
14
RF7/SS/SEG25
RF7
SS
SEG25
13
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 5.
SEG18 output for LCD.
I/O
I
O
O
ST
Analog
—
Analog
Digital I/O.
Analog input 6.
Comparator 2 output.
SEG19 output for LCD.
I/O
I
O
O
ST
Analog
—
Analog
Digital I/O.
Analog input 7.
Comparator 1 output.
SEG20 output for LCD.
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 8.
SEG21 output for LCD.
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 9.
SEG22 output for LCD.
I/O
I
O
O
ST
Analog
Analog
Analog
Digital I/O.
Analog input 10.
Comparator reference voltage output.
SEG23 output for LCD.
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 11.
SEG24 output for LCD.
I/O
I
O
ST
TTL
Analog
Digital I/O.
SPI slave select input.
SEG25 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 26
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTG is a bidirectional I/O port.
RG0/SEG30
RG0
SEG30
5
RG1/TX2/CK2/SEG29
RG1
TX2
CK2
SEG29
6
RG2/RX2/DT2/SEG28
RG2
RX2
DT2
SEG28
7
RG3/SEG27
RG3
SEG27
8
RG4/SEG26
RG4
SEG26
10
RG5
I/O
O
ST
Analog
Digital I/O.
SEG30 output for LCD.
I/O
O
I/O
O
ST
—
ST
Analog
Digital I/O.
AUSART2 asynchronous transmit.
AUSART2 synchronous clock (see related RX2/DT2).
SEG29 output for LCD.
I/O
I
I/O
O
ST
ST
ST
Analog
Digital I/O.
AUSART2 asynchronous receive.
AUSART2 synchronous data (see related TX2/CK2).
SEG28 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG27 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG26 output for LCD.
See MCLR/VPP/RG5 pin.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 27
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTH is a bidirectional I/O port.
RH0/SEG47
RH0
SEG47
79
RH1/SEG46
RH1
SEG46
80
RH2/SEG45
RH2
SEG45
1
RH3/SEG44
RH3
SEG44
2
RH4/SEG40
RH4
SEG40
22
RH5/SEG41
RH5
SEG41
21
RH6/SEG42
RH6
SEG42
20
RH7/SEG43
RH7
SEG43
19
I/O
O
ST
Analog
Digital I/O.
SEG47 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG46 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG45 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG44 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG40 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG41 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG42 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG43 output for LCD.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
DS39629C-page 28
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 1-3:
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Name
Pin Number
TQFP
Pin Buffer
Type Type
Description
PORTJ is a bidirectional I/O port.
RJ0/SEG32
RJ0
SEG32
62
RJ1/SEG33
RJ1
SEG33
61
RJ2/SEG34
RJ2
SEG34
60
RJ3/SEG35
RJ3
SEG35
59
RJ4/SEG39
RJ4
SEG39
39
RJ5/SEG38
RJ5
SEG38
40
RJ6/SEG37
RJ6
SEG37
41
RJ7/SEG36
RJ7
SEG36
42
I/O
O
ST
Analog
Digital I/O.
SEG32 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG33 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG34 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG35 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG39 output for LCD.
I/O
O
ST
Analog
Digital I/O
SEG38 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG37 output for LCD.
I/O
O
ST
Analog
Digital I/O.
SEG36 output for LCD.
P
—
VSS
11, 31, 51, 70
VDD
12, 32, 48, 71
P
—
Positive supply for logic and I/O pins.
AVSS
26
P
—
Ground reference for analog modules.
AVDD
25
P
—
Positive supply for analog modules.
Ground reference for logic and I/O pins.
Legend: TTL = TTL compatible input
CMOS = CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels
Analog = Analog input
I
= Input
O
= Output
P
= Power
OD
= Open-Drain (no P diode to VDD)
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 29
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 30
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
2.0
OSCILLATOR
CONFIGURATIONS
2.1
Oscillator Types
PIC18F6390/6490/8390/8490 devices can be operated
in ten different oscillator modes. The user can program
the Configuration bits, FOSC3:FOSC0, in Configuration
Register 1H to select one of these ten modes:
1.
2.
3.
4.
LP
XT
HS
HSPLL
Low-Power Crystal
Crystal/Resonator
High-Speed Crystal/Resonator
High-Speed Crystal/Resonator
with PLL Enabled
5. RC
External Resistor/Capacitor with
FOSC/4 Output on RA6
6. RCIO
External Resistor/Capacitor with I/O
on RA6
7. INTIO1 Internal Oscillator with FOSC/4 Output
on RA6 and I/O on RA7
8. INTIO2 Internal Oscillator with I/O on RA6
and RA7
9. EC
External Clock with FOSC/4 Output
10. ECIO
External Clock with I/O on RA6
2.2
Crystal Oscillator/Ceramic
Resonators
In XT, LP, HS or HSPLL 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 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 manufacturer’s
specifications.
FIGURE 2-1:
CRYSTAL/CERAMIC
RESONATOR OPERATION
(XT, LP, HS OR HSPLL
CONFIGURATION)
C1(1)
OSC1
XTAL
To
Internal
Logic
RF(3)
Sleep
RS(2)
C2(1)
PIC18FXXXX
OSC2
Note 1:
See Table 2-1 and Table 2-2 for initial values of
C1 and C2.
2:
A series resistor (RS) may be required for AT
strip cut crystals.
3:
RF varies with the oscillator mode chosen.
TABLE 2-1:
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
Typical Capacitor Values Used:
Mode
Freq
OSC1
OSC2
XT
455 kHz
2.0 MHz
4.0 MHz
56 pF
47 pF
33 pF
56 pF
47 pF
33 pF
HS
8.0 MHz
16.0 MHz
27 pF
22 pF
27 pF
22 pF
Capacitor values are for design guidance only.
These capacitors were tested with the resonators
listed below for basic start-up and operation. These
values are not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application.
See the notes following Table 2-2 for additional
information.
Resonators Used:
455 kHz
4.0 MHz
2.0 MHz
8.0 MHz
16.0 MHz
© 2007 Microchip Technology Inc.
DS39629C-page 31
PIC18F6390/6490/8390/8490
TABLE 2-2:
Osc Type
LP
XT
HS
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Crystal
Freq
Typical Capacitor Values
Tested:
C1
C2
32 kHz
33 pF
33 pF
200 kHz
15 pF
15 pF
1 MHz
33 pF
33 pF
4 MHz
27 pF
27 pF
4 MHz
27 pF
27 pF
8 MHz
22 pF
22 pF
20 MHz
15 pF
15 pF
Capacitor values are for design guidance only.
These capacitors were tested with the crystals listed
below for basic start-up and operation. These values
are not optimized.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application.
See the notes following this table for additional
information.
An external clock source may also be connected to the
OSC1 pin in the HS mode, as shown in Figure 2-2.
FIGURE 2-2:
EXTERNAL CLOCK
INPUT OPERATION
(HS CONFIGURATION)
OSC1
Clock from
Ext. System
PIC18FXXXX
Open
2.3
External Clock Input
The EC and ECIO Oscillator modes require an external
clock source to be connected to the OSC1 pin. There is
no oscillator start-up time required after a Power-on
Reset or after an exit from Sleep mode.
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 2-3 shows the pin connections for the EC
Oscillator mode.
FIGURE 2-3:
EXTERNAL CLOCK
INPUT OPERATION
(EC CONFIGURATION)
Crystals Used:
32 kHz
4 MHz
200 kHz
8 MHz
1 MHz
20 MHz
Note 1: Higher capacitance increases the stability
of 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 the
HS mode 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.
4: Rs may be required to avoid overdriving
crystals with low drive level specification.
5: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
DS39629C-page 32
(HS Mode)
OSC2
OSC1/CLKI
Clock from
Ext. System
PIC18FXXXX
FOSC/4
OSC2/CLKO
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 2-4 shows the pin connections
for the ECIO Oscillator mode.
FIGURE 2-4:
EXTERNAL CLOCK
INPUT OPERATION
(ECIO CONFIGURATION)
OSC1/CLKI
Clock from
Ext. System
PIC18FXXXX
RA6
I/O (OSC2)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
2.4
RC Oscillator
2.5
For timing insensitive applications, the “RC” and
“RCIO” device options offer additional cost savings.
The actual oscillator frequency is a function of several
factors:
• Supply voltage
• Values of the external resistor (REXT) and
capacitor (CEXT)
• Operating temperature
PLL Frequency Multiplier
A Phase Locked Loop (PLL) circuit is provided as an
option for users who want to use a lower frequency
oscillator circuit, or to clock the device up to its highest
rated frequency from a crystal oscillator. This may be
useful for customers who are concerned with EMI due
to high-frequency crystals, or users who require higher
clock speeds from an internal oscillator.
2.5.1
HSPLL OSCILLATOR MODE
Given the same device, operating voltage and
temperature and component values, there will also be
unit-to-unit frequency variations. These are due to
factors such as:
The HSPLL mode makes use of the HS mode oscillator
for frequencies up to 10 MHz. A PLL then multiplies the
oscillator output frequency by 4 to produce an internal
clock frequency up to 40 MHz.
• Normal manufacturing variation
• Difference in lead frame capacitance between
package types (especially for low CEXT values)
• Variations within the tolerance of limits of REXT
and CEXT
The PLL is only available to the crystal oscillator when
the FOSC3:FOSC0 Configuration bits are programmed
for HSPLL mode (= 0110).
FIGURE 2-7:
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. Figure 2-5 shows how the R/C combination is
connected.
FIGURE 2-5:
RC OSCILLATOR MODE
VDD
REXT
OSC1
PLL BLOCK DIAGRAM
(HS MODE)
HS Oscillator Enable
PLL Enable
(from Configuration Register 1H)
OSC2
HS Mode
OSC1 Crystal
Oscillator
FIN
Phase
Comparator
FOUT
Internal
Clock
Loop
Filter
CEXT
PIC18FXXXX
VSS
÷4
VCO
Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ
CEXT > 20 pF
The RCIO Oscillator mode (Figure 2-6) 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).
FIGURE 2-6:
RCIO OSCILLATOR MODE
VDD
REXT
OSC1
SYSCLK
MUX
FOSC/4
OSC2/CLKO
2.5.2
PLL AND INTOSC
The PLL is also available to the internal oscillator block
in selected oscillator modes. In this configuration, the
PLL is enabled in software and generates a clock
output of up to 32 MHz. The operation of INTOSC with
the PLL is described in Section 2.6.4 “PLL in INTOSC
Modes”.
Internal
Clock
CEXT
PIC18FXXXX
VSS
RA6
I/O (OSC2)
Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ
CEXT > 20 pF
© 2007 Microchip Technology Inc.
DS39629C-page 33
PIC18F6390/6490/8390/8490
2.6
Internal Oscillator Block
The PIC18F6390/6490/8390/8490 devices include an
internal oscillator block, which generates two different
clock signals; either can be used as the microcontroller’s clock source. This may eliminate the need
for external oscillator circuits on the OSC1 and/or
OSC2 pins.
The main output (INTOSC) is an 8 MHz clock source,
which can be used to directly drive the device clock. It
also drives a postscaler, which can provide a range of
clock frequencies from 31 kHz to 4 MHz. The INTOSC
output is enabled when a clock frequency from 125 kHz
to 8 MHz is selected.
The other clock source is the internal RC oscillator
(INTRC), which provides a nominal 31 kHz output.
INTRC is enabled if it is selected as the device clock
source; it is also enabled automatically when any of the
following are enabled:
•
•
•
•
•
Power-up Timer
Fail-Safe Clock Monitor
Watchdog Timer
Two-Speed Start-up
LCD with INTRC as its clock source
These features are discussed in greater detail in
Section 23.0 “Special Features of the CPU”.
The clock source frequency (INTOSC direct, INTRC
direct or INTOSC postscaler) is selected by configuring
the IRCF bits of the OSCCON register (Register 2-2).
2.6.1
INTIO MODES
Using the internal oscillator as the clock source eliminates the need for up to two external oscillator pins,
which can then be used for digital I/O. Two distinct
configurations are available:
• In INTIO1 mode, the OSC2 pin outputs FOSC/4,
while OSC1 functions as RA7 for digital input and
output.
• In INTIO2 mode, OSC1 functions as RA7 and
OSC2 functions as RA6, both for digital input and
output.
2.6.2
INTOSC OUTPUT FREQUENCY
The internal oscillator block is calibrated at the factory
to produce an INTOSC output frequency of 8.0 MHz.
The INTRC oscillator operates independently of the
INTOSC source. Any changes in INTOSC across
voltage and temperature are not necessarily reflected
by changes in INTRC and vice versa.
2.6.3
OSCTUNE REGISTER
The internal oscillator’s output has been calibrated at
the factory, but can be adjusted in the user’s application. This is done by writing to the OSCTUNE register
(Register 2-1). The tuning sensitivity is constant
throughout the tuning range.
DS39629C-page 34
When the OSCTUNE register is modified, the INTOSC
and INTRC frequencies will begin shifting to the new
frequency. The INTRC clock will reach the new
frequency within 8 clock cycles (approximately
8 * 32 μs = 256 μs). The INTOSC clock will stabilize
within 1 ms. Code execution continues during this shift.
There is no indication that the shift has occurred.
The OSCTUNE register also implements the INTSRC
and PLLEN bits, which control certain features of the
internal oscillator block. The INTSRC bit allows users
to select which internal oscillator provides the clock
source when the 31 kHz frequency option is selected.
This is covered in greater detail in Section 2.7.1
“Oscillator Control Register”.
The PLLEN bit controls the operation of the frequency
multiplier, PLL, in internal oscillator modes.
2.6.4
PLL IN INTOSC MODES
The 4x frequency multiplier can be used with the internal oscillator block to produce faster device clock
speeds than are normally possible with an internal
oscillator. When enabled, the PLL produces a clock
speed of up to 32 MHz.
Unlike HSPLL mode, the PLL is controlled through
software. The control bit, PLLEN (OSCTUNE<6>), is
used to enable or disable its operation.
The PLL is available when the device is configured to use
the internal oscillator block as its primary clock source
(FOSC3:FOSC0 = 1001 or 1000). Additionally, the PLL
will only function when the selected output frequency is
either 4 MHz or 8 MHz (OSCCON<6:4> = 111 or 110). If
both of these conditions are not met, the PLL is disabled.
The PLLEN control bit is only functional in those internal oscillator modes where the PLL is available. In all
other modes, it is forced to ‘0’ and is effectively
unavailable.
2.6.5
INTOSC FREQUENCY DRIFT
The factory calibrates the internal oscillator block
output (INTOSC) for 8 MHz. However, this frequency
may drift as VDD or temperature changes, which can
affect the controller operation in a variety of ways. It is
possible to adjust the INTOSC frequency by modifying
the value in the OSTUNE register. This has no effect on
the INTRC clock source frequency.
Tuning the INTOSC source requires knowing when to
make the adjustment, in which direction it should be
made and in some cases, how large a change is
needed. Three compensation techniques are
discussed in Section 2.6.5.1 “Compensating with
the AUSART”, Section 2.6.5.2 “Compensating with
the Timers” and Section 2.6.5.3 “Compensating
with the Timers”, but other techniques may be used.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
2.6.5.1
Compensating with the AUSART
An adjustment may be required when the AUSART
begins to generate framing errors or receives data with
errors while in Asynchronous mode. Framing errors
indicate that the device clock frequency is too high. To
adjust for this, decrement the value in OSTUNE to
reduce the clock frequency. On the other hand, errors
in data may suggest that the clock speed is too low. To
compensate, increment OSTUNE to increase the clock
frequency.
2.6.5.2
Compensating with the Timers
This technique compares device clock speed to some
reference clock. Two timers may be used; one timer is
clocked by the peripheral clock, while the other is
clocked by a fixed reference source, such as the
Timer1 oscillator.
Both timers are cleared, but the timer clocked by the
reference generates interrupts. When an interrupt
occurs, the internally clocked timer is read and both
timers are cleared. If the internally clocked timer value
REGISTER 2-1:
is greater than expected, then the internal oscillator
block is running too fast. To adjust for this, decrement
the OSCTUNE register.
2.6.5.3
Compensating with the Timers
A CCP module can use free-running Timer1 (or
Timer3), clocked by the internal oscillator block and an
external event with a known period (i.e., AC power
frequency). The time of the first event is captured in the
CCPRxH:CCPRxL registers and is recorded. When the
second event causes a capture, the time of the first
event is subtracted from the time of the second event.
Since the period of the external event is known, the
time difference between events can be calculated.
If the measured time is much greater than the
calculated time, then the internal oscillator block is
running too fast. To compensate, decrement the
OSTUNE register. If the measured time is much less
than the calculated time, then the internal oscillator
block is running too slow. To compensate, increment
the OSTUNE register.
OSCTUNE: OSCILLATOR TUNING REGISTER
R/W-0
R/W-0(1)
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
INTSRC
PLLEN(1)
—
TUN4
TUN3
TUN2
TUN1
TUN0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
INTSRC: Internal Oscillator Low-Frequency Source Select bit
1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)
0 = 31 kHz device clock derived directly from INTRC internal oscillator
bit 6
PLLEN: Frequency Multiplier PLL for INTOSC Enable bit(1)
1 = PLL enabled for INTOSC (4 MHz and 8 MHz only)
0 = PLL disabled
bit 5
Unimplemented: Read as ‘0’
bit 4-0
TUN4:TUN0: Frequency Tuning bits
01111 = Maximum frequency
•
•
•
•
00001
00000 = Center frequency. Oscillator module is running at the calibrated frequency.
11111
•
•
•
•
10000 = Minimum frequency
Note 1:
Available only in certain oscillator configurations; otherwise, this bit is unavailable and read as ‘0’. See
Section 2.6.4 “PLL in INTOSC Modes” for details.
© 2007 Microchip Technology Inc.
DS39629C-page 35
PIC18F6390/6490/8390/8490
2.7
Clock Sources and
Oscillator Switching
Like
previous
PIC18
devices,
the
PIC18F6390/6490/8390/8490 family includes a feature
that allows the device clock source to be switched from
the main oscillator to an alternate low-frequency clock
source. PIC18F6390/6490/8390/8490 devices offer
two alternate clock sources. When an alternate clock
source is enabled, the various power-managed
operating modes are available.
Essentially, there are three clock sources for these
devices:
• Primary oscillators
• Secondary oscillators
• Internal oscillator block
The primary oscillators include the External Crystal
and Resonator modes, the External RC modes, the
External Clock modes and the internal oscillator block.
The particular mode is defined by the FOSC3:FOSC0
Configuration bits. The details of these modes are
covered earlier in this chapter.
FIGURE 2-8:
The secondary oscillators are those external sources
not connected to the OSC1 or OSC2 pins. These
sources may continue to operate even after the
controller is placed in a power-managed mode.
PIC18F6390/6490/8390/8490 devices offer the Timer1
oscillator as a secondary oscillator. This oscillator, in all
power-managed modes, is often the time base for
functions such as a Real-Time Clock.
Most often, a 32.768 kHz watch crystal is connected
between the RC0/T1OSO/T13CKI and RC1/T1OSI
pins. Like the LP Oscillator mode circuit, loading
capacitors are also connected from each pin to ground.
The Timer1 oscillator is discussed in greater detail in
Section 11.3 “Timer1 Oscillator”.
In addition to being a primary clock source, the internal
oscillator block is available as a power-managed
mode clock source. The INTRC source is also used as
the clock source for several special features, such as
the WDT and Fail-Safe Clock Monitor.
The clock sources for the PIC18F6390/6490/8390/8490
devices are shown in Figure 2-8. See Section 23.0
“Special Features of the CPU” for Configuration
register details.
PIC18F6390/6490/8390/8490 CLOCK DIAGRAM
PIC18F6X90/8X90
Primary Oscillator
LP, XT, HS, RC, EC
OSC2
Sleep
4 x PLL
OSC1
HSPLL, INTOSC/PLL
OSCTUNE<6>
T1OSC
T1OSO
OSCCON<6:4>
8 MHz
OSCCON<6:4>
INTRC
Source
4 MHz
2 MHz
8 MHz
(INTOSC)
31 kHz (INTRC)
Postscaler
Internal
Oscillator
Block
8 MHz
Source
1 MHz
500 kHz
250 kHz
125 kHz
Internal Oscillator
CPU
111
110
IDLEN
101
100
011
MUX
T1OSI
T1OSCEN
Enable
Oscillator
Peripherals
MUX
Secondary Oscillator
010
001
1 31 kHz
000
0
Clock
Control
FOSC3:FOSC0
OSCCON<1:0>
Clock Source Option
for Other Modules
OSCTUNE<7>
WDT, PWRT, FSCM
and Two-Speed Start-up
DS39629C-page 36
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
2.7.1
OSCILLATOR CONTROL REGISTER
The OSCCON register (Register 2-2) controls several
aspects of the device clock’s operation, both in
full-power operation and in power-managed modes.
The System Clock Select bits, SCS1:SCS0, select the
clock source. The available clock sources are the primary clock (defined by the FOSC:FOSC0 Configuration
bits), the secondary clock (Timer1 oscillator) and the
internal oscillator block. The clock source changes
immediately after one or more of the bits is written to,
following a brief clock transition interval. The SCS bits
are cleared on all forms of Reset.
The Internal Oscillator Frequency Select bits,
IRCF2:IRCF0, select the frequency output of the
internal oscillator block to drive the device clock. The
choices are the INTRC source, the INTOSC source
(8 MHz) or one of the frequencies derived from the
INTOSC postscaler (31.25 kHz to 4 MHz). If the
internal oscillator block is supplying the device clock,
changing the states of these bits will have an
immediate change on the internal oscillator’s output.
When an output frequency of 31 kHz is selected
(IRCF2:IRCF0 = 000), users may choose which internal oscillator acts as the source. This is done with the
INTSRC bit in the OSCTUNE register (OSCTUNE<7>).
Setting this bit selects INTOSC as a 31.25 kHz clock
source by enabling the divide-by-256 output of the
INTOSC postscaler. Clearing INTSRC selects INTRC
(nominally 31 kHz) as the clock source.
This option allows users to select the tunable and more
precise INTOSC as a clock source, while maintaining
power savings with a very low clock speed. Regardless
of the setting of INTSRC, INTRC always remains the
clock source for features such as the Watchdog Timer
and the Fail-Safe Clock Monitor.
The IDLEN bit determines if the device goes into Sleep
mode or one of the Idle modes when the SLEEP
instruction is executed.
The use of the flag and control bits in the OSCCON
register is discussed in more detail in Section 3.0
“Power-Managed Modes”.
Note 1: The Timer1 oscillator must be enabled to
select the secondary clock source. The
Timer1 oscillator is enabled by setting the
T1OSCEN bit in the Timer1 Control register (T1CON<3>). If the Timer1 oscillator is
not enabled, then any attempt to select a
secondary clock source when executing a
SLEEP instruction will be ignored.
2: It is recommended that the Timer1
oscillator be operating and stable before
executing the SLEEP instruction, or a very
long delay may occur while the Timer1
oscillator starts.
2.7.2
OSCILLATOR TRANSITIONS
PIC18F6390/6490/8390/8490 devices contain circuitry
to prevent clock “glitches” when switching between
clock sources. A short pause in the device clock occurs
during the clock switch. The length of this pause is the
sum of two cycles of the old clock source and three to
four cycles of the new clock source. This formula
assumes that the new clock source is stable.
Clock transitions are discussed in greater detail in
Section 3.1.2 “Entering Power-Managed Modes”.
The OSTS, IOFS and T1RUN bits indicate which clock
source is currently providing the device clock. The
OSTS bit indicates that the Oscillator Start-up Timer
has timed out and the primary clock is providing the
device clock in primary clock modes. The IOFS bit
indicates when the internal oscillator block has
stabilized and is providing the device clock in RC Clock
modes. The T1RUN bit (T1CON<6>) indicates when
the Timer1 oscillator is providing the device clock in
secondary clock modes. In power-managed modes,
only one of these three bits will be set at any time. If
none of these bits are set, the INTRC is providing the
clock, or the internal oscillator block has just started
and is not yet stable.
© 2007 Microchip Technology Inc.
DS39629C-page 37
PIC18F6390/6490/8390/8490
REGISTER 2-2:
OSCCON: OSCILLATOR CONTROL REGISTER
R/W-0
R/W-1
R/W-0
R/W-0
R(1)
R-0
R/W-0
R/W-0
IDLEN
IRCF2
IRCF1
IRCF0
OSTS
IOFS
SCS1
SCS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
IDLEN: Idle Enable bit
1 = Device enters Idle mode on SLEEP instruction
0 = Device enters Sleep mode on SLEEP instruction
bit 6-4
IRCF2:IRCF0: Internal Oscillator Frequency Select bits
111 = 8 MHz (INTOSC drives clock directly)
110 = 4 MHz
101 = 2 MHz
100 = 1 MHz(3)
011 = 500 kHz
010 = 250 kHz
001 = 125 kHz
000 = 31 kHz (from either INTOSC/256 or INTRC directly)(2)
bit 3
OSTS: Oscillator Start-up Timer Time-out Status bit(1)
1 = Oscillator Start-up Timer time-out has expired; primary oscillator is running
0 = Oscillator Start-up Timer time-out is running; primary oscillator is not ready
bit 2
IOFS: INTOSC Frequency Stable bit
1 = INTOSC frequency is stable
0 = INTOSC frequency is not stable
bit 1-0
SCS1:SCS0: System Clock Select bits
1x = Internal oscillator block
01 = Timer1 oscillator
00 = Primary oscillator
Note 1:
2:
3:
Depends on state of the IESO Configuration bit.
Source selected by the INTSRC bit (OSCTUNE<7>), see Section 2.6.3 “OSCTUNE Register”.
Default output frequency of INTOSC on Reset.
DS39629C-page 38
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
2.8
Effects of Power-Managed Modes
on the Various Clock Sources
When PRI_IDLE mode is selected, the designated primary oscillator continues to run without interruption.
For all other power-managed modes, the oscillator
using the OSC1 pin is disabled. The OSC1 pin (and
OSC2 pin, if used by the oscillator) will stop oscillating.
In secondary clock modes (SEC_RUN and
SEC_IDLE), the Timer1 oscillator is operating and
providing the device clock. The Timer1 oscillator may
also run in all power-managed modes if required to
clock Timer1 or Timer3.
In internal oscillator modes (RC_RUN and RC_IDLE),
the internal oscillator block provides the device clock
source. The 31 kHz INTRC output can be used directly
to provide the clock and may be enabled to support various special features, regardless of the power-managed
mode (see Section 23.2 “Watchdog Timer (WDT)”
through Section 23.4 “Fail-Safe Clock Monitor” for
more information on WDT, Fail-Safe Clock Monitor and
Two-Speed Start-up). The INTOSC output at 8 MHz may
be used directly to clock the device, or may be divided
down by the postscaler. The INTOSC output is disabled
if the clock is provided directly from the INTRC output.
If the Sleep mode is selected, all clock sources are
stopped. Since all the transistor switching currents
have been stopped, Sleep mode achieves the lowest
current consumption of the device (only leakage
currents).
2.9
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 is stable under normal circumstances and the primary clock is operating and stable.
For additional information on power-up delays, see
Section 4.5 “Device Reset Timers”.
The first timer is the Power-up Timer (PWRT), which
provides a fixed delay on power-up (parameter 33,
Table 26-10). It is enabled by clearing (= 0) the
PWRTEN Configuration bit.
The second timer is the Oscillator Start-up Timer
(OST), intended to keep the chip in Reset until the
crystal oscillator is stable (LP, XT and HS modes). The
OST does this by counting 1024 oscillator cycles
before allowing the oscillator to clock the device.
When the HSPLL Oscillator mode is selected, the
device is kept in Reset for an additional 2 ms, following
the HS mode OST delay, so the PLL can lock to the
incoming clock frequency.
There is a delay of interval TCSD (parameter 38,
Table 26-10) following POR while the controller
becomes ready to execute instructions. This delay runs
concurrently with any other delays. This may be the
only delay that occurs when any of the EC, RC or INTIO
modes are used as the primary clock source.
Enabling any on-chip feature that will operate during
Sleep will increase the current consumed during Sleep.
The INTRC is required to support WDT operation. The
Timer1 oscillator may be operating to support a
Real-Time Clock. Other features may be operating that
do not require a device clock source (i.e., MSSP slave,
INTx pins and others). Peripherals that may add significant current consumption are listed in Section 26.2
“DC Characteristics: Power-Down and Supply
Current”.
TABLE 2-3:
OSC1 AND OSC2 PIN STATES IN SLEEP MODE
Oscillator Mode
OSC1 Pin
OSC2 Pin
RC, INTIO1
Floating, external resistor should pull high
RCIO, INTIO2
Floating, external resistor should pull high
Configured as PORTA, bit 6
ECIO
Floating, pulled by external clock
Configured as PORTA, bit 6
EC
Floating, pulled by external clock
At logic low (clock/4 output)
LP, XT and HS
Feedback inverter disabled at quiescent
voltage level
Feedback inverter disabled at quiescent
voltage level
Note:
At logic low (clock/4 output)
See Table 4-2 in Section 4.0 “Reset” for time-outs due to Sleep and MCLR Reset.
© 2007 Microchip Technology Inc.
DS39629C-page 39
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 40
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
3.0
POWER-MANAGED MODES
3.1.1
The SCS1:SCS0 bits allow the selection of one of three
clock sources for power-managed modes. They are:
PIC18F6390/6490/8390/8490 devices offer a total of
seven operating modes for more efficient power
management. These modes provide a variety of
options for selective power conservation in applications
where resources may be limited (i.e., battery-powered
devices).
• the primary clock, as defined by the
FOSC3:FOSC0 Configuration bits
• the secondary clock (the Timer1 oscillator)
• the internal oscillator block (for RC modes)
There are three categories of power-managed modes:
3.1.2
• Sleep mode
• Idle modes
• Run modes
The power-managed modes include several
power-saving features. One of these is the clock
switching feature, offered in other PIC18 devices,
allowing the controller to use the Timer1 oscillator in
place of the primary oscillator. Also included is the
Sleep mode, offered by all PIC® devices, where all
device clocks are stopped.
Entry to the power-managed Idle or Sleep modes is
triggered by the execution of a SLEEP instruction. The
actual mode that results depends on the status of the
IDLEN bit.
Depending on the current mode and the mode being
switched to, a change to a power-managed mode does
not always require setting all of these bits. Many transitions may be done by changing the oscillator select
bits, or changing the IDLEN bit prior to issuing a SLEEP
instruction. If the IDLEN bit is already configured
correctly, it may only be necessary to perform a SLEEP
instruction to switch to the desired mode.
Selecting Power-Managed Modes
Selecting a power-managed mode requires deciding if
the CPU is to be clocked or not and selecting a clock
source. The IDLEN bit controls CPU clocking, while the
SCS1:SCS0 bits select a clock source. The individual
modes, bit settings, clock sources and affected
modules are summarized in Table 3-1.
TABLE 3-1:
POWER-MANAGED MODES
OSCCON<7,1:0>
Mode
Sleep
ENTERING POWER-MANAGED
MODES
Entering power-managed Run mode, or switching from
one power-managed mode to another, begins by
loading the OSCCON register. The SCS1:SCS0 bits
select the clock source and determine which Run or
Idle mode is being used. Changing these bits causes
an immediate switch to the new clock source,
assuming that it is running. The switch may also be
subject to clock transition delays. These are discussed
in Section 3.1.3 “Clock Transitions and Status
Indicators” and subsequent sections.
These categories define which portions of the device
are clocked and sometimes, what speed. The Run and
Idle modes may use any of the three available clock
sources (primary, secondary or INTOSC multiplexer);
the Sleep mode does not use a clock source.
3.1
CLOCK SOURCES
IDLEN(1)
SCS1:SCS0
Module Clocking
CPU
Peripherals
Available Clock and Oscillator Source
0
N/A
Off
Off
PRI_RUN
N/A
00
Clocked
Clocked
None – All clocks are disabled
SEC_RUN
N/A
01
Clocked
Clocked
Secondary – Timer1 Oscillator
RC_RUN
N/A
1x
Clocked
Clocked
Internal Oscillator Block(2)
Primary – LP, XT, HS, HSPLL, RC, EC
Primary – LP, XT, HS, HSPLL, RC, EC, INTRC(2):
This is the normal, full-power execution mode.
PRI_IDLE
1
00
Off
Clocked
SEC_IDLE
1
01
Off
Clocked
Secondary – Timer1 Oscillator
RC_IDLE
1
1x
Off
Clocked
Internal Oscillator Block(2)
Note 1:
2:
IDLEN reflects its value when the SLEEP instruction is executed.
Includes INTOSC and INTOSC postscaler, as well as the INTRC source.
© 2007 Microchip Technology Inc.
DS39629C-page 41
PIC18F6390/6490/8390/8490
3.1.3
CLOCK TRANSITIONS AND
STATUS INDICATORS
The length of the transition between clock sources is
the sum of two cycles of the old clock source and three
to four cycles of the new clock source. This formula
assumes that the new clock source is stable.
Three bits indicate the current clock source and its
status. They are:
• OSTS (OSCCON<3>)
• IOFS (OSCCON<2>)
• T1RUN (T1CON<6>)
In general, only one of these bits will be set while in a
given power-managed mode. When the OSTS bit is
set, the primary clock is providing the device clock.
When the IOFS bit is set, the INTOSC output provides
a stable, 8 MHz clock source to a divider that actually
drives the device clock. When the T1RUN bit is set, the
Timer1 oscillator provides the clock. If none of these
bits are set, then either the INTRC clock source clocks
the device, or the INTOSC source is not yet stable.
If the internal oscillator block is configured as the
primary clock source by the FOSC3:FOSC0
Configuration bits, then both the OSTS and IOFS bits
may be set when in PRI_RUN or PRI_IDLE modes.
This indicates that the primary clock (INTOSC output)
is generating a stable 8 MHz output. Entering another
power-managed RC mode at the same frequency
would clear the OSTS bit.
Note 1: Caution should be used when modifying a
single IRCF bit. If VDD is less than 3V, it is
possible to select a higher clock speed
than is supported by the low VDD.
Improper device operation may result if
the VDD/FOSC specifications are violated.
2: Executing a SLEEP instruction does not
necessarily place the device into Sleep
mode. It acts as the trigger to place the
controller into either the Sleep mode or
one of the Idle modes, depending on the
setting of the IDLEN bit.
3.1.4
MULTIPLE SLEEP COMMANDS
The power-managed mode that is invoked with the
SLEEP instruction is determined by the setting of the
IDLEN bit at the time the instruction is executed. If
another SLEEP instruction is executed, the device will
enter the power-managed mode specified by IDLEN at
that time. If IDLEN has changed, the device will enter
the new power-managed mode specified by the new
setting.
DS39629C-page 42
3.2
Run Modes
In the Run modes, clocks to both the core and
peripherals are active. The difference between these
modes is the clock source.
3.2.1
PRI_RUN MODE
The PRI_RUN mode is the normal, full-power
execution mode of the microcontroller. This is also the
default mode upon a device Reset unless Two-Speed
Start-up is enabled (see Section 23.3 “Two-Speed
Start-up” for details). In this mode, the OSTS bit is set.
The IOFS bit may be set if the internal oscillator block
is the primary clock source (see Section 2.7.1
“Oscillator Control Register”).
3.2.2
SEC_RUN MODE
The SEC_RUN mode is the compatible mode to the
“clock switching” feature offered in other PIC18
devices. In this mode, the CPU and peripherals are
clocked from the Timer1 oscillator. This gives users the
option of lower power consumption while still using a
high-accuracy clock source.
SEC_RUN mode is entered by setting the SCS1:SCS0
bits to ‘01’. The device clock source is switched to the
Timer1 oscillator (see Figure 3-1), the primary
oscillator is shut down, the T1RUN bit (T1CON<6>) is
set and the OSTS bit is cleared.
Note:
The Timer1 oscillator should already be
running prior to entering SEC_RUN mode.
If the T1OSCEN bit is not set when the
SCS1:SCS0 bits are set to ‘01’, entry to
SEC_RUN mode will not occur. If the
Timer1 oscillator is enabled, but not yet
running, peripheral clocks will be delayed
until the oscillator has started. In such
situations, initial oscillator operation is far
from stable and unpredictable operation
may result.
On transitions from SEC_RUN mode to PRI_RUN, the
peripherals and CPU continue to be clocked from the
Timer1 oscillator while the primary clock is started.
When the primary clock becomes ready, a clock switch
back to the primary clock occurs (see Figure 3-2).
When the clock switch is complete, the T1RUN bit is
cleared, the OSTS bit is set and the primary clock
provides the clock. The IDLEN and SCS bits are not
affected by the wake-up; the Timer1 oscillator
continues to run.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 3-1:
TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE
Q1 Q2 Q3 Q4 Q1
Q2
1
T1OSI
2
3
n-1
Q3
Q4
Q1
Q2
Q3
n
Clock Transition
OSC1
CPU
Clock
Peripheral
Clock
Program
Counter
PC
FIGURE 3-2:
PC + 2
PC + 4
TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL)
Q1
Q2
Q3
Q4
Q1
Q2 Q3 Q4 Q1 Q2 Q3
T1OSI
OSC1
TOST(1)
TPLL(1)
PLL Clock
Output
1
CPU Clock
2
n-1
Clock
Transition
n
Peripheral
Clock
Program
Counter
SCS1:SCS0 bits Changed
PC + 2
PC
PC + 4
OSTS bit Set
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
© 2007 Microchip Technology Inc.
DS39629C-page 43
PIC18F6390/6490/8390/8490
3.2.3
RC_RUN MODE
If the IRCF bits and the INTSRC bit are all clear, the
INTOSC output is not enabled and the IOFS bit will
remain clear; there will be no indication of the current
clock source. The INTRC source provides the device
clocks.
In RC_RUN mode, the CPU and peripherals are
clocked from the internal oscillator block using the
INTOSC multiplexer and the primary clock is shut
down. When using the INTRC source, this mode
provides the best power conservation of all the Run
modes, while still executing code. It works well for user
applications which are not highly timing-sensitive, or do
not require high-speed clocks at all times.
If the IRCF bits are changed from all clear (thus
enabling the INTOSC output), or if INTSRC is set, the
IOFS bit becomes set after the INTOSC output
becomes stable. Clocks to the device continue while
the INTOSC source stabilizes after an interval of
TIOBST.
If the primary clock source is the internal oscillator block
(either INTRC or INTOSC), there are no distinguishable
differences between PRI_RUN and RC_RUN modes
during execution. However, a clock switch delay will occur
during entry to and exit from RC_RUN mode. Therefore,
if the primary clock source is the internal oscillator block,
the use of RC_RUN mode is not recommended.
If the IRCF bits were previously at a non-zero value, or
if INTSRC was set before setting SCS1 and the
INTOSC source was already stable, the IOFS bit will
remain set.
On transitions from RC_RUN mode to PRI_RUN, the
device continues to be clocked from the INTOSC
multiplexer while the primary clock is started. When the
primary clock becomes ready, a clock switch to the
primary clock occurs (see Figure 3-4). When the clock
switch is complete, the IOFS bit is cleared, the OSTS
bit is set and the primary clock provides the device
clock. The IDLEN and SCS bits are not affected by the
switch. The INTRC source will continue to run if either
the WDT or the Fail-Safe Clock Monitor is enabled.
This mode is entered by setting the SCS1 bit to ‘1’.
Although it is ignored, it is recommended that the SCS0
bit also be cleared; this is to maintain software
compatibility with future devices. When the clock
source is switched to the INTOSC multiplexer (see
Figure 3-3), the primary oscillator is shut down and the
OSTS bit is cleared. The IRCF bits may be modified at
any time to immediately change the clock speed.
Note:
Caution should be used when modifying a
single IRCF bit. If VDD is less than 3V, it is
possible to select a higher clock speed
than is supported by the low VDD.
Improper device operation may result if
the VDD/FOSC specifications are violated.
FIGURE 3-3:
TRANSITION TIMING TO RC_RUN MODE
Q1 Q2 Q3 Q4 Q1
Q2
1
INTRC
2
3
n-1
Q3
Q4
Q1
Q2
Q3
n
Clock Transition
OSC1
CPU
Clock
Peripheral
Clock
Program
Counter
PC
FIGURE 3-4:
PC + 2
PC + 4
TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE
Q1
Q2
Q3
Q4
Q2 Q3 Q4 Q1 Q2 Q3
Q1
INTOSC
Multiplexer
OSC1
TOST(1)
TPLL(1)
PLL Clock
Output
1
2
n-1 n
Clock
Transition
CPU Clock
Peripheral
Clock
Program
Counter
SCS1:SCS0 bits Changed
PC + 2
PC
PC + 4
OSTS bit Set
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
DS39629C-page 44
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
3.3
Sleep Mode
3.4
The
power-managed
Sleep
mode
in
the
PIC18F6390/6490/8390/8490 devices is identical to
the legacy Sleep mode offered in all other PIC devices.
It is entered by clearing the IDLEN bit (the default state
on device Reset) and executing the SLEEP instruction.
This shuts down the selected oscillator (see
Figure 3-5). All clock source status bits are cleared.
Entering the Sleep mode from any other mode does not
require a clock switch. This is because no clocks are
needed once the controller has entered Sleep. If the
WDT is selected, the INTRC source will continue to
operate. If the Timer1 oscillator is enabled, it will also
continue to run.
When a wake event occurs in Sleep mode (by interrupt,
Reset or WDT time-out), the device will not be clocked
until the primary clock source becomes ready (see
Figure 3-6), or it will be clocked from the internal oscillator block if either the Two-Speed Start-up or the
Fail-Safe Clock Monitor are enabled (see Section 23.0
“Special Features of the CPU”). In either case, the
OSTS bit is set when the primary clock provides the
device clocks. The IDLEN and SCS bits are not
affected by the wake-up.
Idle Modes
The Idle modes allow the controller’s CPU to be
selectively shut down while the peripherals continue to
operate. Selecting a particular Idle mode allows users
to further manage power consumption.
If the IDLEN bit is set to a ‘1’ when a SLEEP instruction
is executed, the peripherals will be clocked from the
clock source selected using the SCS1:SCS0 bits;
however, the CPU will not be clocked. The clock source
status bits are not affected. Setting IDLEN and executing SLEEP provides a quick method of switching from a
given Run mode to its corresponding Idle mode.
If the WDT is selected, the INTRC source will continue
to operate. If the Timer1 oscillator is enabled, it will also
continue to run.
Since the CPU is not executing instructions, the only
exits from any of the Idle modes are by interrupt, WDT
time-out or a Reset. When a wake event occurs, CPU
execution is delayed by an interval of TCSD
(parameter 38, Table 26-10) while it becomes ready to
execute code. When the CPU begins executing code,
it resumes with the same clock source for the current
Idle mode. For example, when waking from RC_IDLE
mode, the internal oscillator block will clock the CPU
and peripherals (in other words, RC_RUN mode). The
IDLEN and SCS bits are not affected by the wake-up.
While in any Idle mode or the Sleep mode, a WDT
time-out will result in a WDT wake-up to the Run mode
currently specified by the SCS1:SCS0 bits.
FIGURE 3-5:
TRANSITION TIMING FOR ENTRY TO SLEEP MODE
Q1 Q2 Q3 Q4 Q1
OSC1
CPU
Clock
Peripheral
Clock
Sleep
Program
Counter
PC
FIGURE 3-6:
PC + 2
TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1
OSC1
TOST(1)
PLL Clock
Output
TPLL(1)
CPU Clock
Peripheral
Clock
Program
Counter
PC
Wake Event
PC + 2
PC + 4
PC + 6
OSTS bit Set
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
© 2007 Microchip Technology Inc.
DS39629C-page 45
PIC18F6390/6490/8390/8490
3.4.1
PRI_IDLE MODE
This mode is unique among the three low-power Idle
modes, in that it does not disable the primary device
clock. For timing-sensitive applications, this allows for
the fastest resumption of device operation with its more
accurate primary clock source, since the clock source
does not have to “warm up” or transition from another
oscillator.
When a wake event occurs, the CPU is clocked from the
primary clock source. A delay of interval TCSD is
required between the wake event and when code
execution starts. This is required to allow the CPU to
become ready to execute instructions. After the
wake-up, the OSTS bit remains set. The IDLEN and
SCS bits are not affected by the wake-up (see
Figure 3-8).
PRI_IDLE mode is entered from PRI_RUN mode by
setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN
first, then clear the SCS bits and execute SLEEP.
Although the CPU is disabled, the peripherals continue
to be clocked from the primary clock source specified
by the FOSC3:FOSC0 Configuration bits. The OSTS
bit remains set (see Figure 3-7).
FIGURE 3-7:
TRANSITION TIMING FOR ENTRY TO PRI_IDLE MODE
Q1
Q4
Q3
Q2
Q1
OSC1
CPU Clock
Peripheral
Clock
Program
Counter
PC
FIGURE 3-8:
PC + 2
TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE
Q1
Q2
Q3
Q4
OSC1
TCSD
CPU Clock
Peripheral
Clock
Program
Counter
PC
Wake Event
DS39629C-page 46
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
3.4.2
SEC_IDLE MODE
In SEC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the Timer1
oscillator. This mode is entered from SEC_RUN by setting the IDLEN bit and executing a SLEEP instruction. If
the device is in another Run mode, set IDLEN first, then
set SCS1:SCS0 to ‘01’ and execute SLEEP. When the
clock source is switched to the Timer1 oscillator, the
primary oscillator is shut down, the OSTS bit is cleared
and the T1RUN bit is set.
When a wake event occurs, the peripherals continue to
be clocked from the Timer1 oscillator. After an interval
of TCSD following the wake event, the CPU begins
executing code being clocked by the Timer1 oscillator.
The IDLEN and SCS bits are not affected by the
wake-up; the Timer1 oscillator continues to run (see
Figure 3-8).
Note:
The Timer1 oscillator should already be
running prior to entering SEC_IDLE mode.
If the T1OSCEN bit is not set when the
SLEEP instruction is executed, the SLEEP
instruction will be ignored and entry to
SEC_IDLE mode will not occur. If the
Timer1 oscillator is enabled, but not yet
running, peripheral clocks will be delayed
until the oscillator has started. In such
situations, initial oscillator operation is far
from stable and unpredictable operation
may result.
3.4.3
RC_IDLE MODE
In RC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the internal oscillator
block using the INTOSC multiplexer. This mode allows
for controllable power conservation during Idle periods.
From RC_RUN, this mode is entered by setting the
IDLEN bit and executing a SLEEP instruction. If the
device is in another Run mode, first set IDLEN, then set
the SCS1 bit and execute SLEEP. Although its value is
ignored, it is recommended that SCS0 also be cleared;
this is to maintain software compatibility with future
devices. The INTOSC multiplexer may be used to
select a higher clock frequency by modifying the IRCF
bits before executing the SLEEP instruction. When the
clock source is switched to the INTOSC multiplexer, the
primary oscillator is shut down and the OSTS bit is
cleared.
If the IRCF bits are set to any non-zero value, or the
INTSRC bit is set, the INTOSC output is enabled. The
IOFS bit becomes set after the INTOSC output
becomes stable after an interval of TIOBST
(parameter 39, Table 26-10). Clocks to the peripherals
continue while the INTOSC source stabilizes. If the
IRCF bits were previously at a non-zero value, or
INTSRC was set before the SLEEP instruction was
executed and the INTOSC source was already stable,
the IOFS bit will remain set. If the IRCF bits and
INTSRC are all clear, the INTOSC output will not be
enabled; the IOFS bit will remain clear and there will be
no indication of the current clock source.
When a wake event occurs, the peripherals continue to
be clocked from the INTOSC multiplexer. After a delay
of TCSD following the wake event, the CPU begins
executing code being clocked by the INTOSC multiplexer. The IDLEN and SCS bits are not affected by the
wake-up. The INTRC source will continue to run if
either the WDT or the Fail-Safe Clock Monitor is
enabled.
© 2007 Microchip Technology Inc.
DS39629C-page 47
PIC18F6390/6490/8390/8490
3.5
Exiting Idle and Sleep Modes
An exit from Sleep mode or any of the Idle modes is
triggered by an interrupt, a Reset or a WDT time-out.
This section discusses the triggers that cause exits
from power-managed modes. The clocking subsystem
actions are discussed in each of the power-managed
modes (see Section 3.2 “Run Modes” through
Section 3.4 “Idle Modes”).
3.5.1
EXIT BY INTERRUPT
Any of the available interrupt sources can cause the
device to exit from an Idle or Sleep mode to a Run
mode. To enable this functionality, an interrupt source
must be enabled by setting its enable bit in one of the
INTCON or PIE registers. The exit sequence is initiated
when the corresponding interrupt flag bit is set.
On all exits from Idle or Sleep modes by interrupt, code
execution branches to the interrupt vector if the
GIE/GIEH bit (INTCON<7>) is set. Otherwise, code
execution continues or resumes without branching
(see Section 8.0 “Interrupts”).
A fixed delay of interval, TCSD, following the wake
event, is required when leaving Sleep and Idle modes.
This delay is required for the CPU to prepare for
execution. Instruction execution resumes on the first
clock cycle following this delay.
3.5.2
EXIT BY WDT TIME-OUT
A WDT time-out will cause different actions depending
on which power-managed mode the device is in when
the time-out occurs.
If the device is not executing code (all Idle modes and
Sleep mode), the time-out will result in an exit from the
power-managed mode (see Section 3.2 “Run
Modes” and Section 3.3 “Sleep Mode”). If the device
is executing code (all Run modes), the time-out will
result in a WDT Reset (see Section 23.2 “Watchdog
Timer (WDT)”).
The WDT timer and postscaler are cleared by executing a SLEEP or CLRWDT instruction, losing a currently
selected clock source (if the Fail-Safe Clock Monitor is
enabled) and modifying the IRCF bits in the OSCCON
register if the internal oscillator block is the device clock
source.
DS39629C-page 48
3.5.3
EXIT BY RESET
Normally, the device is held in Reset by the Oscillator
Start-up Timer (OST) until the primary clock becomes
ready. At that time, the OSTS bit is set and the device
begins executing code. If the internal oscillator block is
the new clock source, the IOFS bit is set instead.
The exit delay time from Reset to the start of code
execution depends on both the clock sources before
and after the wake-up and the type of oscillator if the
new clock source is the primary clock. Exit delays are
summarized in Table 3-2.
Code execution can begin before the primary clock
becomes ready. If either the Two-Speed Start-up (see
Section 23.3 “Two-Speed Start-up”) or Fail-Safe
Clock Monitor (see Section 23.4 “Fail-Safe Clock
Monitor”) is enabled, the device may begin execution
as soon as the Reset source has cleared. Execution is
clocked by the INTOSC multiplexer driven by the
internal oscillator block. Execution is clocked by the
internal oscillator block until either the primary clock
becomes ready, or a power-managed mode is entered
before the primary clock becomes ready; the primary
clock is then shut down.
3.5.4
EXIT WITHOUT AN OSCILLATOR
START-UP DELAY
Certain exits from power-managed modes do not
invoke the OST at all. There are two cases:
• PRI_IDLE mode, where the primary clock source
is not stopped; and
• the primary clock source is not any of the LP, XT,
HS or HSPLL modes.
In these instances, the primary clock source either
does not require an oscillator start-up delay since it is
already running (PRI_IDLE), or normally does not
require an oscillator start-up delay (RC, EC and INTIO
Oscillator modes). However, a fixed delay of interval,
TCSD, following the wake event, is still required when
leaving Sleep and Idle modes to allow the CPU to
prepare for execution. Instruction execution resumes
on the first clock cycle following this delay.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 3-2:
EXIT DELAY ON WAKE-UP BY RESET FROM SLEEP MODE OR ANY IDLE MODE
(BY CLOCK SOURCES)
Clock Source
before Wake-up
Clock Source
after Wake-up
Exit Delay
LP, XT, HS
Primary Device Clock
(PRI_IDLE mode)
HSPLL
EC, RC, INTRC(1)
OSTS
TCSD(2)
INTOSC(3)
T1OSC or
INTRC(1)
HSPLL
TOST + trc(4)
EC, RC, INTRC(1)
TCSD(2)
—
TIOBST(5)
TOST(5)
TOST + trc(4)
TCSD(2)
IOFS
OSTS
None
IOFS
(3)
HSPLL
EC, RC, INTRC(1)
INTOSC
Note 1:
2:
3:
4:
5:
IOFS
TOST(4)
INTOSC
None
(Sleep mode)
—
LP, XT, HS
LP, XT, HS
INTOSC(3)
Clock Ready Status
Bit (OSCCON)
(3)
OSTS
—
LP, XT, HS
TOST(4)
HSPLL
TOST + trc(4)
EC, RC, INTRC(1)
TCSD(2)
—
INTOSC(3)
TIOBST(5)
IOFS
OSTS
In this instance, refers specifically to the 31 kHz INTRC clock source.
TCSD (parameter 38) is a required delay when waking from Sleep and all Idle modes and runs concurrently
with any other required delays (see Section 3.4 “Idle Modes”).
Includes both the INTOSC 8 MHz source and postscaler derived frequencies.
TOST is the Oscillator Start-up Timer (parameter 32). trc is the PLL Lock-out Timer (parameter F12); it is
also designated as TPLL.
Execution continues during TIOBST (parameter 39), the INTOSC stabilization period.
© 2007 Microchip Technology Inc.
DS39629C-page 49
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 50
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
4.0
RESET
4.1
The PIC18F6390/6490/8390/8490 devices differentiate
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 power-managed modes
Watchdog Timer (WDT) Reset (during
execution)
Programmable Brown-out Reset (BOR)
RESET Instruction
Stack Full Reset
Stack Underflow Reset
This section discusses Resets generated by MCLR,
POR and BOR and covers the operation of the various
start-up timers. Stack Reset events are covered in
Section 5.1.2.4 “Stack Full and Underflow Resets”.
WDT Resets are covered in Section 23.2 “Watchdog
Timer (WDT)”.
RCON Register
Device Reset events are tracked through the RCON
register (Register 4-1). The lower five bits of the
register indicate that a specific Reset event has
occurred. In most cases, these bits can only be set by
the event and must be cleared by the application after
the event. The state of these flag bits, taken together,
can be read to indicate the type of Reset that just
occurred. This is described in more detail in
Section 4.6 “Reset State of Registers”.
The RCON register also has control bits for setting
interrupt priority (IPEN) and software control of the
BOR (SBOREN). Interrupt priority is discussed in
Section 8.0 “Interrupts”. BOR is covered in
Section 4.4 “Brown-out Reset (BOR)”.
A simplified block diagram of the on-chip Reset circuit
is shown in Figure 4-1.
FIGURE 4-1:
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
RESET
Instruction
Stack Full/Underflow Reset
Stack
Pointer
External Reset
MCLRE
MCLR
( )_IDLE
Sleep
WDT
Time-out
VDD Rise
Detect
VDD
POR Pulse
Brown-out
Reset
BOREN
S
OST/PWRT
OST
1024 Cycles
10-Bit Ripple Counter
Chip_Reset
R
Q
OSC1
32 μs
INTRC(1)
PWRT
65.5 ms
11-Bit Ripple Counter
Enable PWRT
Enable OST(2)
Note 1:
2:
This is the INTRC source from the internal oscillator block and is separate from the RC oscillator of the CLKI pin.
See Table 4-2 for time-out situations.
© 2007 Microchip Technology Inc.
DS39629C-page 51
PIC18F6390/6490/8390/8490
REGISTER 4-1:
R/W-0
IPEN
RCON: RESET CONTROL REGISTER
R/W-1(1)
U-0
R/W-1
R-1
R-1
R/W-0
R/W-0
SBOREN
—
RI
TO
PD
POR
BOR
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6
SBOREN: BOR Software Enable bit(1)
If BOREN1:BOREN0 = 01:
1 = BOR is enabled
0 = BOR is disabled
If BOREN1:BOREN0 = 00, 10 or 11:
Bit is disabled and read as ‘0’.
bit 5
Unimplemented: Read as ‘0’
bit 4
RI: RESET Instruction Flag bit
1 = The RESET instruction was not executed (set by firmware only)
0 = The RESET instruction was executed causing a device Reset (must be set in software after a
Brown-out Reset occurs)
bit 3
TO: Watchdog Time-out Flag bit
1 = Set by power-up, CLRWDT instruction or SLEEP instruction
0 = A WDT time-out occurred
bit 2
PD: Power-Down Detection Flag bit
1 = Set by power-up or by the CLRWDT instruction
0 = Set by execution of the SLEEP instruction
bit 1
POR: Power-on Reset Status bit
1 = A Power-on Reset has not occurred (set by firmware only)
0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
bit 0
BOR: Brown-out Reset Status bit
1 = A Brown-out Reset has not occurred (set by firmware only)
0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)
Note 1:
If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’.
Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent
Power-on Resets may be detected.
2: Brown-out Reset is said to have occurred when BOR is ‘0’ and POR is ‘1’ (assuming that POR was set to
‘1’ by software immediately after a Power-on Reset).
DS39629C-page 52
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
4.2
Master Clear (MCLR)
The MCLR pin provides a method for triggering a hard
external Reset of the device. A Reset is generated by
holding the pin low. PIC18 Extended MCU devices
have a noise filter in the MCLR Reset path which
detects and ignores small pulses.
FIGURE 4-2:
In PIC18F6390/6490/8390/8490 devices, the MCLR
input can be disabled with the MCLRE Configuration
bit. When MCLR is disabled, the pin becomes a digital
input. See Section 9.7 “PORTG, TRISG and LATG
Registers” for more information.
4.3
D
To take advantage of the POR circuitry, tie the MCLR
pin through a resistor (1 kΩ to 10 kΩ) 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 4-2.
R
R1
C
MCLR
PIC18FXXXX
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 ≥ 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).
Power-on Reset (POR)
A Power-on Reset pulse is generated on-chip
whenever VDD rises above a certain threshold. This
allows the device to start in the initialized state when
VDD is adequate for operation.
VDD
VDD
The MCLR pin is not driven low by any internal Resets,
including the WDT.
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW VDD POWER-UP)
When the device starts normal operation (i.e., exits the
Reset condition), device operating parameters
(voltage, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
POR events are captured by the POR bit (RCON<1>).
The state of the bit is set to ‘0’ whenever a Power-on
Reset occurs; it does not change for any other Reset
event. POR is not reset to ‘1’ by any hardware event.
To capture multiple events, the user manually resets
the bit to ‘1’ in software following any Power-on Reset.
© 2007 Microchip Technology Inc.
DS39629C-page 53
PIC18F6390/6490/8390/8490
4.4
Brown-out Reset (BOR)
PIC18F6390/6490/8390/8490 devices implement a
BOR circuit that provides the user with a number of
configuration and power-saving options. The BOR is
controlled
by
the
BORV1:BORV0
and
BOREN1:BOREN0 Configuration bits. There are a total
of four BOR configurations, which are summarized in
Table 4-1.
The BOR threshold is set by the BORV1:BORV0 bits. If
BOR is enabled (any values of BOREN1:BOREN0
except ‘00’), any drop of VDD below VBOR (parameter
D005) for greater than TBOR (parameter 35) will reset
the device. A Reset may or may not occur if VDD falls
below VBOR for less than TBOR. The chip will remain in
Brown-out Reset until VDD rises above VBOR.
If the Power-up Timer is enabled, it will be invoked after
VDD rises above VBOR; it then will keep the chip in
Reset for an additional time delay, TPWRT
(parameter 33). If VDD drops below VBOR 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 VBOR, the Power-up
Timer will execute the additional time delay.
BOR and the Power-up Timer (PWRT) are
independently configured. Enabling the BOR Reset
does not automatically enable the PWRT.
4.4.1
SOFTWARE ENABLED BOR
When BOREN1:BOREN0 = 01, the BOR can be
enabled or disabled by the user in software. This is
done with the control bit, SBOREN (RCON<6>).
Setting SBOREN enables the BOR to function as
previously described. Clearing SBOREN disables the
BOR entirely. The SBOREN bit operates only in this
mode; otherwise it is read as ‘0’.
TABLE 4-1:
Placing the BOR under software control gives the user
the additional flexibility of tailoring the application to its
environment without having to reprogram the device to
change the BOR configuration. It also allows the user
to tailor device power consumption in software by
eliminating the incremental current that the BOR
consumes. While the BOR current is typically very
small, it may have some impact in low-power
applications.
Note:
4.4.2
Even when BOR is under software control,
the BOR Reset voltage level is still set by
the BORV1:BORV0 Configuration bits. It
cannot be changed in software.
DETECTING BOR
When BOR is enabled, the BOR bit always resets to ‘0’
on any BOR or POR event. This makes it difficult to
determine if a BOR event has occurred just by reading
the state of BOR alone. A more reliable method is to
simultaneously check the state of both POR and BOR.
This assumes that the POR bit is reset to ‘1’ in software
immediately after any POR event. IF BOR is ‘0’ while
POR is ‘1’, it can be reliably assumed that a BOR event
has occurred.
4.4.3
DISABLING BOR IN SLEEP MODE
When BOREN1:BOREN0 = 10, the BOR remains
under hardware control and operates as previously
described. Whenever the device enters Sleep mode,
however, the BOR is automatically disabled. When the
device returns to any other operating mode, BOR is
automatically re-enabled.
This mode allows for applications to recover from
brown-out situations while actively executing code,
when the device requires BOR protection the most. At
the same time, it saves additional power in Sleep mode
by eliminating the small incremental BOR current.
BOR CONFIGURATIONS
BOR Configuration
BOREN1
BOREN0
Status of
SBOREN
(RCON<6>)
0
0
Unavailable
0
1
Available
1
0
Unavailable
BOR is enabled in hardware and active during the Run and Idle modes,
disabled during Sleep mode.
1
1
Unavailable
BOR is enabled in hardware; must be disabled by reprogramming the
Configuration bits.
DS39629C-page 54
BOR Operation
BOR is disabled; must be enabled by reprogramming the Configuration
bits.
BOR is enabled in software; operation controlled by SBOREN.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
4.5
Device Reset Timers
4.5.3
PIC18F6390/6490/8390/8490 devices incorporate
three separate on-chip timers that help regulate the
Power-on Reset process. Their main function is to
ensure that the device clock is stable before code is
executed. These timers are:
• Power-up Timer (PWRT)
• Oscillator Start-up Timer (OST)
• PLL Lock Time-out
4.5.1
With the PLL enabled in its PLL mode, the time-out
sequence following a Power-on Reset is slightly
different from other oscillator modes. A separate 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.
4.5.4
TIME-OUT SEQUENCE
On power-up, the time-out sequence is as follows:
POWER-UP TIMER (PWRT)
The
Power-up
Timer
(PWRT)
of
PIC18F6390/6490/8390/8490 devices is an 11-bit
counter which uses the INTRC source as the clock
input. This yields an approximate time interval of
2048 x 32 μs = 65.6 ms. While the PWRT is counting,
the device is held in Reset.
The power-up time delay depends on the INTRC clock
and will vary from chip-to-chip due to temperature and
process variation. See DC parameter 33 for details.
The PWRT is enabled by clearing the PWRTEN
Configuration bit.
4.5.2
PLL LOCK TIME-OUT
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 33). This ensures that
the crystal oscillator or resonator has started and is
stabilized.
1.
2.
After the POR pulse has cleared, PWRT
time-out is invoked (if enabled).
Then, the OST is activated.
The total time-out will vary based on oscillator
configuration and the status of the PWRT. Figure 4-3,
Figure 4-4, Figure 4-5, Figure 4-6 and Figure 4-7 all
depict time-out sequences on power-up, with the
Power-up Timer enabled and the device operating in
HS Oscillator mode. Figures 4-3 through 4-6 also apply
to devices operating in XT or LP modes. For devices in
RC mode and with the PWRT disabled, on the other
hand, there will be no time-out at all.
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, all time-outs will expire.
Bringing MCLR high will begin execution immediately
(Figure 4-5). This is useful for testing purposes, or to
synchronize more than one PIC18FXXXX device
operating in parallel.
The OST time-out is invoked only for XT, LP, HS and
HSPLL modes and only on Power-on Reset, or on exit
from most power-managed modes.
TABLE 4-2:
TIME-OUT IN VARIOUS SITUATIONS
Power-up(2) and Brown-out
Oscillator
Configuration
HSPLL
PWRTEN = 0
66
ms(1)
+ 1024 TOSC + 2
ms(2)
PWRTEN = 1
Exit from
Power-Managed Mode
1024 TOSC + 2 ms(2)
1024 TOSC + 2 ms(2)
HS, XT, LP
66 ms(1) + 1024 TOSC
1024 TOSC
1024 TOSC
EC, ECIO
66 ms(1)
—
—
RC, RCIO
66
ms(1)
—
—
66
ms(1)
—
—
INTIO1, INTIO2
Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay.
2: 2 ms is the nominal time required for the PLL to lock.
© 2007 Microchip Technology Inc.
DS39629C-page 55
PIC18F6390/6490/8390/8490
FIGURE 4-3:
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)
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 4-4:
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 4-5:
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
DS39629C-page 56
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 4-6:
SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)
5V
VDD
1V
0V
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 4-7:
TIME-OUT SEQUENCE ON POR w/PLL ENABLED (MCLR TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
OST TIME-OUT
TOST
TPLL
PLL TIME-OUT
INTERNAL RESET
Note:
TOST = 1024 clock cycles.
TPLL ≈ 2 ms max. First three stages of the PWRT timer.
© 2007 Microchip Technology Inc.
DS39629C-page 57
PIC18F6390/6490/8390/8490
4.6
Reset State of Registers
Most registers are unaffected by a Reset. Their status
is unknown on POR and unchanged by all other
Resets. The other registers are forced to a “Reset
state” depending on the type of Reset that occurred.
Table 4-4 describes the Reset states for all of the
Special Function Registers. These are categorized by
Power-on and Brown-out Resets, Master Clear and
WDT Resets and WDT wake-ups.
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 4-3.
These bits are used in software to determine the nature
of the Reset.
TABLE 4-3:
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR
RCON REGISTER
RCON Register
STKPTR Register
Program
Counter
SBOREN
RI
TO
PD
0000h
1
1
1
1
0
0
0
0
RESET Instruction
0000h
u(2)
0
u
u
u
u
u
u
Brown-out Reset
0000h
u(2)
1
1
1
u
0
u
u
MCLR Reset during
power-managed Run modes
0000h
u(2)
u
1
u
u
u
u
u
MCLR Reset during
power-managed Idle modes and
Sleep
0000h
u(2)
u
1
0
u
u
u
u
WDT time-out during full power
or power-managed Run modes
0000h
u(2)
u
0
u
u
u
u
u
MCLR during full-power
execution
0000h
u(2)
u
u
u
u
u
u
u
Stack Full Reset (STVREN = 1)
0000h
u(2)
u
u
u
u
u
1
u
Stack Underflow Reset
(STVREN = 1)
0000h
u(2)
u
u
u
u
u
u
1
Stack Underflow Error (not an
actual Reset, STVREN = 0)
0000h
u(2)
u
u
u
u
u
u
1
WDT time-out during
power-managed Idle or
Sleep modes
PC + 2(1)
u(2)
u
0
0
u
u
u
u
Interrupt exit from
power-managed modes
PC + 2(1)
u(2)
u
u
0
u
u
u
u
Condition
Power-on Reset
POR BOR STKFUL
STKUNF
Legend: u = unchanged
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 (008h or 0018h).
2: Reset state is ‘1’ for POR and unchanged for all other Resets when software BOR is enabled
(BOREN1:BOREN0 Configuration bits = 01 and SBOREN = 1); otherwise, the Reset state is ‘0’.
DS39629C-page 58
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 4-4:
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
6X90
8X90
---0 0000
---0 0000
---0 uuuu(3)
TOSH
6X90
8X90
0000 0000
0000 0000
uuuu uuuu(3)
TOSL
6X90
8X90
0000 0000
0000 0000
uuuu uuuu(3)
STKPTR
6X90
8X90
00-0 0000
00-0 0000
uu-u uuuu(3)
PCLATU
6X90
8X90
---0 0000
---0 0000
---u uuuu
PCLATH
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
PCL
6X90
8X90
0000 0000
0000 0000
PC + 2(2)
TBLPTRU
6X90
8X90
--00 0000
--00 0000
--uu uuuu
TBLPTRH
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TBLPTRL
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TABLAT
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
PRODH
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
PRODL
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
INTCON
6X90
8X90
0000 000x
0000 000u
uuuu uuuu(1)
INTCON2
6X90
8X90
1111 1111
1111 1111
uuuu uuuu(1)
INTCON3
6X90
8X90
1100 0000
1100 0000
uuuu uuuu(1)
INDF0
6X90
8X90
N/A
N/A
N/A
POSTINC0
6X90
8X90
N/A
N/A
N/A
POSTDEC0
6X90
8X90
N/A
N/A
N/A
PREINC0
6X90
8X90
N/A
N/A
N/A
PLUSW0
6X90
8X90
N/A
N/A
FSR0H
6X90
8X90
---- xxxx
---- uuuu
---- uuuu
N/A
FSR0L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
WREG
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
INDF1
6X90
8X90
N/A
N/A
N/A
POSTINC1
6X90
8X90
N/A
N/A
N/A
POSTDEC1
6X90
8X90
N/A
N/A
N/A
PREINC1
6X90
8X90
N/A
N/A
N/A
PLUSW1
6X90
8X90
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 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When
not enabled as PORTA pins, they are disabled and read ‘0’.
6: These registers are cleared on POR and unchanged on BOR.
© 2007 Microchip Technology Inc.
DS39629C-page 59
PIC18F6390/6490/8390/8490
TABLE 4-4:
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
6X90
8X90
---- xxxx
---- uuuu
---- uuuu
FSR1L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
BSR
6X90
8X90
---- 0000
---- 0000
---- uuuu
INDF2
6X90
8X90
N/A
N/A
N/A
POSTINC2
6X90
8X90
N/A
N/A
N/A
POSTDEC2
6X90
8X90
N/A
N/A
N/A
PREINC2
6X90
8X90
N/A
N/A
N/A
PLUSW2
6X90
8X90
N/A
N/A
N/A
FSR2H
6X90
8X90
---- xxxx
---- uuuu
---- uuuu
FSR2L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
STATUS
6X90
8X90
---x xxxx
---u uuuu
---u uuuu
TMR0H
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TMR0L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
T0CON
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
OSCCON
6X90
8X90
0100 q000
0100 00q0
uuuu uuqu
HLVDCON
6X90
8X90
0-00 0101
0-00 0101
u-uu uuuu
WDTCON
6X90
8X90
---- ---0
---- ---0
---- ---u
RCON(4)
6X90
8X90
0q-1 11q0
0q-q qquu
uq-u qquu
TMR1H
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR1L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
T1CON
6X90
8X90
0000 0000
u0uu uuuu
uuuu uuuu
TMR2
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
PR2
6X90
8X90
1111 1111
1111 1111
1111 1111
T2CON
6X90
8X90
-000 0000
-000 0000
-uuu uuuu
SSPBUF
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
SSPADD
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
SSPSTAT
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
SSPCON1
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
SSPCON2
6X90
8X90
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 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When
not enabled as PORTA pins, they are disabled and read ‘0’.
6: These registers are cleared on POR and unchanged on BOR.
DS39629C-page 60
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 4-4:
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
ADRESH
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADRESL
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
ADCON0
6X90
8X90
--00 0000
--00 0000
--uu uuuu
ADCON1
6X90
8X90
--00 0000
--00 0000
--uu uuuu
ADCON2
6X90
8X90
0-00 0000
0-00 0000
u-uu uuuu
CCPR1H
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCPR1L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCP1CON
6X90
8X90
--00 0000
--00 0000
--uu uuuu
CCPR2H
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCPR2L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
CCP2CON
6X90
8X90
--00 0000
--00 0000
--uu uuuu
CVRCON
6X90
8X90
000- 0000
000- 0000
uuu- uuuu
CMCON
6X90
8X90
0000 0111
0000 0111
uuuu uuuu
TMR3H
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
TMR3L
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
T3CON
6X90
8X90
0000 0000
uuuu uuuu
uuuu uuuu
SPBRG1
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
RCREG1
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TXREG1
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TXSTA1
6X90
8X90
0000 0010
0000 0010
uuuu uuuu
RCSTA1
6X90
8X90
0000 000x
0000 000x
uuuu uuuu
IPR3
6X90
8X90
-111 ----
-111 ----
-uuu ----
PIR3
6X90
8X90
-000 ----
-000 ----
-uuu ----(1)
PIE3
6X90
8X90
-000 ----
-000 ----
-uuu ----
IPR2
6X90
8X90
11-- 1111
11-- 1111
uu-- uuuu
PIR2
6X90
8X90
00-- 0000
00-- 0000
uu-- uuuu(1)
PIE2
6X90
8X90
00-- 0000
00-- 0000
uu-- uuuu
IPR1
6X90
8X90
-111 1111
-111 1111
-uuu uuuu
PIR1
6X90
8X90
-000 0000
-000 0000
-uuu uuuu(1)
PIE1
6X90
8X90
-000 0000
-000 0000
-uuu uuuu
OSCTUNE
6X90
8X90
00-0 0000
00-0 0000
uu-u 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 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When
not enabled as PORTA pins, they are disabled and read ‘0’.
6: These registers are cleared on POR and unchanged on BOR.
© 2007 Microchip Technology Inc.
DS39629C-page 61
PIC18F6390/6490/8390/8490
TABLE 4-4:
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
TRISJ
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
TRISH
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
TRISG
6X90
8X90
---1 1111
---1 1111
---u uuuu
TRISF
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
TRISE
6X90
8X90
1111 ----
1111 ----
uuuu ----
TRISD
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
TRISC
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
TRISB
6X90
8X90
1111 1111
1111 1111
uuuu uuuu
(5)
1111(5)
1111(5)
uuuu uuuu(5)
TRISA
6X90
8X90
1111
LATJ
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATH
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATG
6X90
8X90
---x xxxx
---u uuuu
---u uuuu
1111
LATF
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATE
6X90
8X90
xxxx ----
uuuu ----
uuuu ----
LATD
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATC
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATB
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
LATA(5)
6X90
8X90
xxxx xxxx(5)
uuuu uuuu(5)
uuuu uuuu(5)
PORTJ
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTH
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTG
6X90
8X90
--xx xxxx
--uu uuuu
--uu uuuu
PORTF
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTE
6X90
8X90
xxxx ----
uuuu ----
uuuu ----
PORTD
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTC
6X90
8X90
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTB
6X90
8X90
xxxx xxxx
uuuu uuuu
(5)
(5)
uuuu uuuu
(5)
uuuu uuuu(5)
PORTA
6X90
8X90
xx0x 0000
SPBRGH1
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
BAUDCON1
6X90
8X90
01-0 0-00
01-0 0-00
uu-u u-uu
uu0u 0000
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 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When
not enabled as PORTA pins, they are disabled and read ‘0’.
6: These registers are cleared on POR and unchanged on BOR.
DS39629C-page 62
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 4-4:
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
LCDDATA23
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA22
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA21
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA20
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA19
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA18
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA17
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA16
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA15
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA14
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA13
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA12
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA11
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
SPBRG2
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
RCREG2
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TXREG2
6X90
8X90
0000 0000
0000 0000
uuuu uuuu
TXSTA2
6X90
8X90
0000 -010
0000 -010
uuuu -uuu
RCSTA2
6X90
8X90
0000 000x
0000 000x
uuuu uuuu
LCDDATA10
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA9
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA8
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA7
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA6
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA5
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA4
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA3
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA2
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA1
6X90
8X90
xxxx xxxx
0000 0000
uuuu uuuu
LCDDATA0
6X90
8X90
xxxx xxxx
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 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When
not enabled as PORTA pins, they are disabled and read ‘0’.
6: These registers are cleared on POR and unchanged on BOR.
© 2007 Microchip Technology Inc.
DS39629C-page 63
PIC18F6390/6490/8390/8490
TABLE 4-4:
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
LCDSE5
6X90
8X90
0000 0000
0000 0000(6)
uuuu uuuu
LCDSE4
6X90
8X90
0000 0000
0000 0000(6)
uuuu uuuu
(6)
uuuu uuuu
LCDSE3
6X90
8X90
0000 0000
0000 0000
LCDSE2
6X90
8X90
0000 0000
0000 0000(6)
uuuu uuuu
0000(6)
uuuu uuuu
LCDSE1
6X90
8X90
0000 0000
0000
LCDSE0
6X90
8X90
0000 0000
0000 0000(6)
uuuu uuuu
LCDCON
6X90
8X90
000- 0000
000- 0000
uuu- uuuu
LCDPS
6X90
8X90
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 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When
not enabled as PORTA pins, they are disabled and read ‘0’.
6: These registers are cleared on POR and unchanged on BOR.
DS39629C-page 64
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
5.0
MEMORY ORGANIZATION
There are two types of memory in PIC18 Flash
microcontroller devices:
• Program Memory
• Data RAM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for
concurrent access of the two memory spaces.
Additional detailed information on the operation of the
Flash program memory is provided in Section 6.0
“Flash Program Memory”.
5.1
Program Memory Organization
PIC18 microcontrollers implement a 21-bit program
counter, which is capable of addressing a 2-Mbyte
program memory space. Accessing a location between
the upper boundary of the physically implemented
memory and the 2-Mbyte address will return all ‘0’s (a
NOP instruction).
The PIC18FX390 have 8 Kbytes of Flash memory and
can store up to 4,096 single-word instructions and the
PIC18FX490 have 16 Kbytes of Flash memory and can
store up to 8,192 single-word instructions.
PIC18 devices have two interrupt vectors. The Reset
vector address is at 0000h and the interrupt vector
addresses are at 0008h and 0018h.
The
program
memory
maps
for
PIC18F6390/6490/8390/8490 devices are shown in
Figure 5-1.
PROGRAM MEMORY MAP AND STACK FOR PIC18F6390/6490/8390/8490 DEVICES
PIC18F6390/8390
PIC18F6490/8490
PC<20:0>
21
CALL,RCALL,RETURN
RETFIE,RETLW
Stack Level 1
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
On-Chip
Program Memory
On-Chip
Program Memory
User Memory Space
1FFFh
2000h
Read ‘0’
1FFFFFh
© 2007 Microchip Technology Inc.
3FFFh
4000h
Read ‘0’
User Memory Space
FIGURE 5-1:
1FFFFFh
DS39629C-page 65
PIC18F6390/6490/8390/8490
5.1.1
PROGRAM COUNTER
The Program Counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 21 bits wide
and is contained in three separate 8-bit registers. The
low byte, known as the PCL register, is both readable
and writable. The high byte, or PCH register, contains
the PC<15:8> bits; it is not directly readable or writable.
Updates to the PCH register are performed through the
PCLATH register. The upper byte is called PCU. This
register contains the PC<20:16> bits; it is also not
directly readable or writable. Updates to the PCU
register are performed through the PCLATU register.
The contents of PCLATH and PCLATU are transferred
to the program counter by any operation that writes
PCL. Similarly, the upper two bytes of the program
counter are transferred to PCLATH and PCLATU by an
operation that reads PCL. This is useful for computed
offsets to the PC (see Section 5.1.4.1 “Computed
GOTO”).
The PC addresses bytes in the program memory. To
prevent the PC from becoming misaligned with word
instructions, the Least Significant bit of PCL is fixed to
a value of ‘0’. The PC increments by 2 to address
sequential instructions in the program memory.
The CALL, RCALL, GOTO and program branch
instructions write to the program counter directly. For
these instructions, the contents of PCLATH and
PCLATU are not transferred to the program counter.
5.1.2
RETURN ADDRESS STACK
The return address stack allows any combination of up
to 31 program calls and interrupts to occur. The PC is
pushed onto the stack when a CALL or RCALL 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.
FIGURE 5-2:
The stack operates as a 31-word by 21-bit RAM and a
5-bit Stack Pointer. The stack space is not part of either
program or data space. The Stack Pointer is readable
and writable and the address on the top of the stack is
readable and writable through the top-of-stack Special
Function Registers. Data can also be pushed to, or
popped from the stack using these registers.
A CALL type instruction causes a push onto the stack;
the Stack Pointer is first incremented and the location
pointed to by the Stack Pointer is written with the
contents of the PC (already pointing to the instruction
following the CALL). A RETURN type instruction causes
a pop from the stack; the contents of the location
pointed to by the STKPTR register are transferred to
the PC and then the Stack Pointer is decremented.
The Stack Pointer is initialized to ‘00000’ after all
Resets. There is no RAM associated with the location
corresponding to a Stack Pointer value of ‘00000’; this
is only a Reset value. Status bits indicate if the stack is
full, has overflowed or has underflowed.
5.1.2.1
Top-of-Stack Access
Only the top of the return address stack (TOS) is readable and writable. A set of three registers,
TOSU:TOSH:TOSL, hold the contents of the stack
location pointed to by the lower five bits of the STKPTR
register (Figure 5-2). 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:TOSL registers. These
values can be placed on a user-defined software stack.
At return time, the software can return these values to
TOSU:TOSH:TOSL and do a return.
The user must disable the global interrupt enable bits
while accessing the stack to prevent inadvertent stack
corruption.
RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
Return Address Stack <20:0>
11111
11110
11101
Top-of-Stack Registers
TOSU
00h
TOSH
1Ah
DS39629C-page 66
STKPTR<4:0>
00010
TOSL
34h
Top-of-Stack
Stack Pointer
001A34h
000D58h
00011
00010
00001
00000
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
5.1.2.2
Return Stack Pointer (STKPTR)
The STKPTR register (Register 5-1) contains the Stack
Pointer value, the STKFUL (Stack Full) status bit and
the STKUNF (Stack Underflow) status bits. The value
of the Stack Pointer can be 0 through 31. The Stack
Pointer increments before values are pushed onto the
stack and decrements after values are popped off the
stack. On Reset, the Stack Pointer value will be zero.
The user may read and write the Stack Pointer value.
This feature can be used by a Real-Time Operating
System (RTOS) for return stack maintenance.
After the PC is pushed onto the stack 31 times (without
popping any values off the stack), the STKFUL bit is
set. The STKFUL bit is cleared by software or by a
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 23.1 “Configuration Bits” 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 zero.
If STVREN is cleared, the STKFUL bit will be set on the
31st push and the Stack Pointer will increment to 31.
Any additional pushes will not overwrite the 31st push
and STKPTR will remain at 31.
REGISTER 5-1:
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 zero. The STKUNF bit will remain
set until cleared by software, or until a POR occurs.
Note:
5.1.2.3
Returning a value of zero to the PC on an
underflow has the effect of vectoring the
program to the Reset vector where the
stack conditions can be verified and
appropriate actions can be taken. This is
not the same as a Reset, as the contents
of the SFRs are not affected.
PUSH and POP Instructions
Since the Top-of-Stack is readable and writable, the
ability to push values onto the stack and pull values off
the stack, without disturbing normal program execution, is a desirable feature. The PIC18 instruction set
includes two instructions, PUSH and POP, that permit
the TOS to be manipulated under software control.
TOSU, TOSH and TOSL can be modified to place data
or a return address on the stack.
The PUSH instruction places the current PC value onto
the stack. This increments the Stack Pointer and loads
the current PC value onto the stack.
The POP instruction discards the current TOS by
decrementing the Stack Pointer. The previous value
pushed onto the stack then becomes the TOS value.
STKPTR: STACK POINTER REGISTER
R/C-0
R/C-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
STKFUL(1)
STKUNF(1)
—
SP4
SP3
SP2
SP1
SP0
bit 7
bit 0
Legend:
C = Clearable only bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
STKFUL: Stack Full Flag bit(1)
1 = Stack became full or overflowed
0 = Stack has not become full or overflowed
bit 6
STKUNF: Stack Underflow Flag bit(1)
1 = Stack underflow occurred
0 = Stack underflow did not occur
bit 5
Unimplemented: Read as ‘0’
bit 4-0
SP4:SP0: Stack Pointer Location bits
Note 1:
x = Bit is unknown
Bit 7 and bit 6 are cleared by user software or by a POR.
© 2007 Microchip Technology Inc.
DS39629C-page 67
PIC18F6390/6490/8390/8490
5.1.2.4
Stack Full and Underflow Resets
Device Resets on stack overflow and stack underflow
conditions are enabled by setting the STVREN bit in
Configuration Register 4L. When STVREN is set, a full
or underflow will set the appropriate STKFUL or
STKUNF bit and then cause a device Reset. When
STVREN is cleared, a full or underflow condition will set
the appropriate STKFUL or STKUNF bit, but not cause
a device Reset. The STKFUL or STKUNF bits are
cleared by the user software or a Power-on Reset.
5.1.3
FAST REGISTER STACK
A Fast Register Stack is provided for the STATUS,
WREG and BSR registers, to provide a “fast return”
option for interrupts. This stack is only one level deep
and is neither readable nor writable. It is loaded with the
current value of the corresponding register when the
processor vectors for an interrupt. All interrupt sources
will push values into the stack registers. The values in
the registers are then loaded back into the working
registers if the RETFIE, FAST instruction is used to
return from the interrupt.
5.1.4
LOOK-UP TABLES IN PROGRAM
MEMORY
There may be programming situations that require the
creation of data structures, or look-up tables, in
program memory. For PIC18 devices, look-up tables
can be implemented in two ways:
• Computed GOTO
• Table Reads
5.1.4.1
Computed GOTO
A computed GOTO is accomplished by adding an offset
to the program counter. An example is shown in
Example 5-2.
A look-up table can be formed with an ADDWF PCL
instruction and a group of RETLW nn instructions. The
W register is loaded with an offset into the table before
executing a call to that table. The first instruction of the
called routine is the ADDWF PCL instruction. The next
instruction executed will be one of the RETLW nn
instructions that returns the value ‘nn’ to the calling
function.
If both low and high-priority interrupts are enabled, the
stack registers cannot be used reliably to return from
low-priority interrupts. If a high-priority interrupt occurs
while servicing a low-priority interrupt, the Stack
register values stored by the low-priority interrupt will
be overwritten. In these cases, users must save the key
registers in software during a low-priority interrupt.
The offset value (in WREG) specifies the number of
bytes that the program counter should advance and
should be multiples of 2 (LSb = 0).
If interrupt priority is not used, all interrupts may use the
Fast Register Stack for returns from interrupt. 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 CALL label, FAST
instruction must be executed to save the STATUS,
WREG and BSR registers to the Fast Register Stack. A
RETURN, FAST instruction is then executed to restore
these registers from the Fast Register Stack.
EXAMPLE 5-2:
Example 5-1 shows a source code example that uses
the Fast Register Stack during a subroutine call and
return.
EXAMPLE 5-1:
CALL SUB1, FAST
•
•
•
•
RETURN FAST
FAST REGISTER STACK
CODE EXAMPLE
;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
SUB1
DS39629C-page 68
;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
In this method, only one data byte may be stored in
each instruction location and room on the return
address stack is required.
ORG
TABLE
5.1.4.2
MOVF
CALL
nn00h
ADDWF
RETLW
RETLW
RETLW
.
.
.
COMPUTED GOTO USING
AN OFFSET VALUE
OFFSET, W
TABLE
PCL
nnh
nnh
nnh
Table Reads
A better method of storing data in program memory
allows two bytes of data to be stored in each instruction
location.
Look-up table data may be stored two bytes per
program word while programming. The Table Pointer
register (TBLPTR) specifies the byte address and the
Table Latch register (TABLAT) contains the data that is
read from the program memory. Data is transferred
from program memory one byte at a time.
Table read operation is
Section 6.1 “Table Reads”.
discussed
further
in
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
5.2
PIC18 Instruction Cycle
5.2.1
5.2.2
An “Instruction Cycle” consists of four Q cycles, Q1
through Q4. The instruction fetch and execute are pipelined in such a manner that a fetch takes one instruction
cycle, while the decode and execute take 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 5-3).
CLOCKING SCHEME
The microcontroller clock input, whether from an
internal or external source, is internally divided by four
to generate four non-overlapping quadrature clocks
(Q1, Q2, Q3 and Q4). Internally, the program counter is
incremented on every Q1; the instruction is fetched
from the program memory and latched into the Instruction Register (IR) during Q4. The instruction is decoded
and executed during the following Q1 through Q4. The
clocks and instruction execution flow are shown in
Figure 5-3.
FIGURE 5-3:
INSTRUCTION FLOW/PIPELINING
A fetch cycle begins with the Program Counter (PC)
incrementing in Q1.
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).
CLOCK/INSTRUCTION CYCLE
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
OSC1
Q1
Q2
Internal
Phase
Clock
Q3
Q4
PC
PC
PC + 2
PC + 4
OSC2/CLKO
(RC mode)
Execute INST (PC – 2)
Fetch INST (PC)
EXAMPLE 5-3:
TCY0
TCY1
Fetch 1
Execute 1
2. MOVWF PORTB
4. BSF
Execute INST (PC + 2)
Fetch INST (PC + 4)
INSTRUCTION PIPELINE FLOW
1. MOVLW 55h
3. BRA
Execute INST (PC)
Fetch INST (PC + 2)
SUB_1
PORTA, BIT3 (Forced NOP)
5. Instruction @ address SUB_1
Fetch 2
TCY2
TCY3
TCY4
TCY5
Execute 2
Fetch 3
Execute 3
Fetch 4
Flush (NOP)
Fetch SUB_1 Execute 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.
© 2007 Microchip Technology Inc.
DS39629C-page 69
PIC18F6390/6490/8390/8490
5.2.3
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). To maintain alignment
with instruction boundaries, the PC increments in steps
of 2 and the LSB will always read ‘0’ (see Section 5.1.1
“Program Counter”).
Figure 5-4 shows an example of how instruction words
are stored in the program memory.
The CALL and GOTO instructions have the absolute program memory address embedded into the 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 5-4 shows how the
instruction, GOTO 0006h, is encoded in the program
memory. Program branch instructions, which encode a
relative address offset, operate in the same manner. The
offset value stored in a branch instruction represents the
FIGURE 5-4:
number of single-word instructions that the PC will be
offset by. Section 24.0 “Instruction Set Summary”
provides further details of the instruction set.
5.2.4
TWO-WORD INSTRUCTIONS
The standard PIC18 instruction set has four two-word
instructions: CALL, MOVFF, GOTO and LSFR. In all
cases, the second word of the instructions always has
‘1111’ as its four Most Significant bits; the other 12 bits
are literal data, usually a data memory address.
The use of ‘1111’ in the 4 MSbs of an instruction
specifies a special form of NOP. If the instruction is
executed in proper sequence – immediately after the
first word – the data in the second word is accessed
and used by the instruction sequence. If the first word
is skipped for some reason and the second word is
executed by itself, a NOP is executed instead. This is
necessary for cases when the two-word instruction is
preceded by a conditional instruction that changes the
PC. Example 5-4 shows how this works.
Note:
See Section 5.5 “Program Memory and
the Extended Instruction Set” for
information on two-word instructions in the
extended instruction set.
INSTRUCTIONS IN PROGRAM MEMORY
LSB = 1
LSB = 0
0Fh
EFh
F0h
C1h
F4h
55h
03h
00h
23h
56h
Program Memory
Byte Locations →
Instruction 1:
Instruction 2:
MOVLW
GOTO
055h
0006h
Instruction 3:
MOVFF
123h, 456h
EXAMPLE 5-4:
Word Address
↓
000000h
000002h
000004h
000006h
000008h
00000Ah
00000Ch
00000Eh
000010h
000012h
000014h
TWO-WORD INSTRUCTIONS
CASE 1:
Object Code
Source Code
0110 0110 0000 0000
TSTFSZ
REG1
; is RAM location 0?
1100 0001 0010 0011
MOVFF
REG1, REG2
; No, skip this word
1111 0100 0101 0110
0010 0100 0000 0000
; Execute this word as a NOP
ADDWF
REG3
; continue code
CASE 2:
Object Code
Source Code
0110 0110 0000 0000
TSTFSZ
REG1
; is RAM location 0?
1100 0001 0010 0011
MOVFF
REG1, REG2
; Yes, execute this word
ADDWF
REG3
; continue code
1111 0100 0101 0110
0010 0100 0000 0000
DS39629C-page 70
; 2nd word of instruction
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
5.3
Note:
Data Memory Organization
The operation of some aspects of data
memory are changed when the PIC18
extended instruction set is enabled. See
Section 5.6 “Data Memory and the
Extended Instruction Set” for more
information.
The data memory in PIC18 devices is implemented as
static RAM. Each register in the data memory has a
12-bit address, allowing up to 4096 bytes of data
memory. The memory space is divided into as many
as 16 banks that contain 256 bytes each;
PIC18F6390/6490/8390/8490 devices implement
only 4 banks. Figure 5-5 shows the data memory
organization for the PIC18F6390/6490/8390/8490
devices.
The data memory contains Special Function Registers
(SFRs) and General Purpose Registers (GPRs). The
SFRs are used for control and status of the controller
and peripheral functions, while GPRs are used for data
storage and scratchpad operations in the user’s
application. Any read of an unimplemented location will
read as ‘0’s.
The instruction set and architecture allow operations
across all banks. The entire data memory may be
accessed by Direct, Indirect or Indexed Addressing
modes. Addressing modes are discussed later in this
section.
To ensure that commonly used registers (SFRs and
select GPRs) can be accessed in a single cycle, PIC18
devices implement an Access Bank. This is a 256-byte
memory space that provides fast access to SFRs and
the lower portion of GPR Bank 0 without using the
BSR. Section 5.3.2 “Access Bank” provides a
detailed description of the Access RAM.
5.3.1
BANK SELECT REGISTER
Large areas of data memory require an efficient
addressing scheme to make rapid access to any
address possible. Ideally, this means that an entire
address does not need to be provided for each read or
write operation. For PIC18 devices, this is accomplished with a RAM banking scheme. This divides the
memory space into 16 contiguous banks of 256 bytes.
Depending on the instruction, each location can be
addressed directly by its full 12-bit address, or an 8-bit
low-order address and a 4-bit Bank Pointer.
Most instructions in the PIC18 instruction set make use
of the Bank Pointer, known as the Bank Select Register
(BSR). This SFR holds the 4 Most Significant bits of a
location’s address; the instruction itself includes the
8 Least Significant bits. Only the four lower bits of the
BSR are implemented (BSR3:BSR0). The upper four
bits are unused; they will always read ‘0’ and cannot be
written to. The BSR can be loaded directly by using the
MOVLB instruction.
The value of the BSR indicates the bank in data
memory; the 8 bits in the instruction show the location
in the bank and can be thought of as an offset from the
bank’s lower boundary. The relationship between the
BSR’s value and the bank division in data memory is
shown in Figure 5-6.
Since up to 16 registers may share the same low-order
address, the user must always be careful to ensure that
the proper bank is selected before performing a data
read or write. For example, writing what should be
program data to an 8-bit address of F9h, while the BSR
is 0Fh will end up resetting the program counter.
While any bank can be selected, only those banks that
are actually implemented can be read or written to.
Writes to unimplemented banks are ignored, while
reads from unimplemented banks will return ‘0’s. Even
so, the STATUS register will still be affected as if the
operation was successful. The data memory map in
Figure 5-5 indicates which banks are implemented.
In the core PIC18 instruction set, only the MOVFF
instruction fully specifies the 12-bit address of the
source and target registers. This instruction ignores the
BSR completely when it executes. All other instructions
include only the low-order address as an operand and
must use either the BSR or the Access Bank to locate
their target registers.
© 2007 Microchip Technology Inc.
DS39629C-page 71
PIC18F6390/6490/8390/8490
FIGURE 5-5:
DATA MEMORY MAP FOR PIC18F6390/6490/8390/8490 DEVICES
BSR<3:0>
00h
= 0000
= 0001
= 0010
Bank 0
FFh
00h
GPR
000h
05Fh
060h
0FFh
100h
GPR
Bank 1
Bank 2
Access RAM
1FFh
200h
FFh
00h
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:
GPR
FFh
= 0011
When a = 0:
Data Memory Map
2FFh
300h
The BSR specifies the bank
used by the instruction.
Bank 3
Access Bank
Access RAM Low
Unused
Read as 00h
to
= 1110
= 1111
DS39629C-page 72
00h
5Fh
Access RAM High 60h
(SFRs)
FFh
Bank 14
00h
Unimplemented
FFh
SFR
Bank 15
EFFh
F00h
F58h
F60h
FFFh
Banked SFRs
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 5-6:
USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)
BSR(1)
7
0
0
0
0
0
0
0
Bank Select(2)
1
0
000h
Data Memory
Bank 0
100h
Bank 1
200h
Bank 2
300h
00h
7
FFh
00h
11
From Opcode(2)
11
11
11
11
1
0
1
1
FFh
00h
FFh
00h
Bank 3
through
Bank 13
E00h
Bank 14
F00h
FFFh
Note 1:
2:
5.3.2
Bank 15
FFh
00h
FFh
00h
FFh
The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to
the registers of the Access Bank.
The MOVFF instruction embeds the entire 12-bit address in the instruction.
ACCESS BANK
While the use of the BSR with an embedded 8-bit
address allows users to address the entire range of
data memory, it also means that the user must always
ensure that the correct bank is selected. Otherwise,
data may be read from or written to the wrong location.
This can be disastrous if a GPR is the intended target
of an operation but an SFR is written to instead.
Verifying and/or changing the BSR for each read or
write to data memory can become very inefficient.
To streamline access for the most commonly used data
memory locations, the data memory is configured with
an Access Bank, which allows users to access a
mapped block of memory without specifying a BSR.
The Access Bank consists of the first 96 bytes of
memory (00h-5Fh) in Bank 0 and the last 160 bytes of
memory (60h-FFh) in Block 15. The lower half is known
as the “Access RAM” and is composed of GPRs. This
upper half is where the device’s SFRs are mapped.
These two areas are mapped contiguously in the
Access Bank and can be addressed in a linear fashion
by an 8-bit address (Figure 5-5).
The Access Bank is used by core PIC18 instructions
that include the Access RAM bit (the ‘a’ parameter in
the instruction). When ‘a’ is equal to ‘1’, the instruction
uses the BSR and the 8-bit address included in the
opcode for the data memory address. When ‘a’ is ‘0’,
however, the instruction is forced to use the Access
Bank address map; the current value of the BSR is
ignored entirely.
© 2007 Microchip Technology Inc.
Using this “forced” addressing allows the instruction to
operate on a data address in a single cycle without
updating the BSR first. For 8-bit addresses of 80h and
above, this means that users can evaluate and operate
on SFRs more efficiently. The Access RAM below 60h
is a good place for data values that the user might need
to access rapidly, such as immediate computational
results or common program variables. Access RAM
also allows for faster and more code efficient context
saving and switching of variables.
The mapping of the Access Bank is slightly different
when the extended instruction set is enabled (XINST
Configuration bit = 1). This is discussed in more detail
in Section 5.6.3 “Mapping the Access Bank in
Indexed Literal Offset Mode”.
5.3.3
GENERAL PURPOSE
REGISTER FILE
PIC18 devices may have banked memory in the GPR
area. This is data RAM, which is available for use by all
instructions. GPRs start at the bottom of Bank 0
(address 000h) and grow upwards towards the bottom
of the SFR area. GPRs are not initialized by a
Power-on Reset and are unchanged on all other
Resets.
DS39629C-page 73
PIC18F6390/6490/8390/8490
5.3.4
SPECIAL FUNCTION REGISTERS
The SFRs can be classified into two sets: those
associated with the “core” device functionality (ALU,
Resets and interrupts) and those related to the
peripheral functions. The Reset and Interrupt registers
are described in their respective chapters, while the
ALU’s STATUS register is described later in this
section. Registers related to the operation of the
peripheral features are described in the chapter for that
peripheral.
The 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. SFRs start at the top of
data memory (FFFh) and extend downward to occupy
three-quarters of Bank 15 (from F40h to FFFh). A list of
these registers is given in Table 5-1 and Table 5-2.
The SFRs are typically distributed among the
peripherals whose functions they control. Unused SFR
locations are unimplemented and read as ‘0’s.
TABLE 5-1:
SPECIAL FUNCTION REGISTER MAP FOR PIC18F6390/6490/8390/8490 DEVICES
Address
Name
FFFh
Address
TOSU
FDFh
Name
Address
INDF2(1)
Name
CCPR1H
Address
Name
F9Fh
IPR1
PIR1
(1)
FBEh
CCPR1L
F9Eh
FBDh
CCP1CON
F9Dh
PIE1
FFEh
TOSH
FDEh
FFDh
TOSL
FDDh POSTDEC2(1)
FFCh
STKPTR
FDCh
PREINC2(1)
FBCh
CCPR2H
F9Ch
MEMCON(3)
FFBh
PCLATU
FDBh
PLUSW2(1)
FBBh
CCPR2L
F9Bh
OSCTUNE
FFAh
PCLATH
FDAh
FSR2H
FBAh
CCP2CON
FF9h
PCL
FD9h
POSTINC2
FBFh
FSR2L
FB9h
F9Ah
TRISJ(3)
—
(2)
F99h
TRISH(3)
(2)
F98h
TRISG
F97h
TRISF
FF8h
TBLPTRU
FD8h
STATUS
FB8h
—
FF7h
TBLPTRH
FD7h
TMR0H
FB7h
—(2)
(2)
FF6h
TBLPTRL
FD6h
TMR0L
FB6h
FF5h
TABLAT
FD5h
T0CON
FB5h
CVRCON
FF4h
PRODH
FD4h
—(2)
FB4h
FF3h
PRODL
FD3h
OSCCON
FB3h
FF2h
INTCON
FD2h
HLVDCON
FB2h
TMR3L
F92h
TRISA
FF1h
INTCON2
FD1h
WDTCON
FB1h
T3CON
F91h
LATJ(3)
FF0h
INTCON3
FD0h
RCON
FB0h
—(2)
F90h
LATH(3)
FEFh
INDF0(1)
FCFh
TMR1H
FAFh
SPBRG1
F8Fh
LATG
FEEh
POSTINC0(1)
FCEh
TMR1L
FAEh
RCREG1
F8Eh
LATF
FEDh POSTDEC0(1)
FCDh
T1CON
FADh
TXREG1
F8Dh
LATE
—
F96h
TRISE
F95h
TRISD
CMCON
F94h
TRISC
TMR3H
F93h
TRISB
FECh
PREINC0(1)
FCCh
TMR2
FACh
TXSTA1
F8Ch
LATD
FEBh
PLUSW0(1)
FCBh
PR2
FABh
RCSTA1
F8Bh
LATC
(2)
F8Ah
LATB
FEAh
FSR0H
FCAh
T2CON
FAAh
—
FE9h
FSR0L
FC9h
SSPBUF
FA9h
—(2)
F89h
LATA
FE8h
WREG
FC8h
SSPADD
FA8h
—(2)
F88h
PORTJ(3)
FE7h
INDF1(1)
FC7h
SSPSTAT
FA7h
—(2)
F87h
PORTH(3)
(2)
F86h
PORTG
(1)
FC6h
SSPCON1
FA6h
—
FE5h POSTDEC1(1)
FC5h
SSPCON2
FA5h
IPR3
F85h
PORTF
FE6h
Note 1:
2:
3:
4:
POSTINC1
FE4h
PREINC1(1)
FC4h
ADRESH
FA4h
PIR3
F84h
PORTE
FE3h
PLUSW1(1)
FC3h
ADRESL
FA3h
PIE3
F83h
PORTD
FE2h
FSR1H
FC2h
ADCON0
FA2h
IPR2
F82h
PORTC
FE1h
FSR1L
FC1h
ADCON1
FA1h
PIR2
F81h
PORTB
FE0h
BSR
FC0h
ADCON2
FA0h
PIE2
F80h
PORTA
This is not a physical register.
Unimplemented registers are read as ‘0’.
This register is not available on 64-pin devices.
This register is implemented but unused on 64-pin devices.
DS39629C-page 74
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 5-1:
Address
SPECIAL FUNCTION REGISTER MAP FOR PIC18F6390/6490/8390/8490 DEVICES
(CONTINUED)
Name
F7Fh
Address
SPBRGH1
F6Fh
Name
Address
SPBRG2
F5Fh
F7Eh
BAUDCON1
F6Eh
RCREG2
F5Eh
F7Dh
—(2)
Address
Name
LCDSE5
(3)
F4Fh
—(2)
LCDSE4
(3)
F4Eh
—(2)
F6Dh
TXREG2
F5Dh
LCDSE3
F4Dh
—(2)
(4)
F6Ch
TXSTA2
F5Ch
LCDSE2
F4Ch
—(2)
LCDDATA22(4)
F6Bh
RCSTA2
F5Bh
LCDSE1
F4Bh
—(2)
F7Ch LCDDATA23
F7Bh
Name
F7Ah
LCDDATA21
F6Ah LCDDATA10
F5Ah
LCDSE0
F4Ah
—(2)
F79h
LCDDATA20
F69h
LCDDATA9
F59h
LCDCON
F49h
—(2)
F78h
LCDDATA19
F68h
LCDDATA8
F58h
LCDPS
F77h
LCDDATA18
F67h
LCDDATA7
F57h
F48h
—(2)
(2)
F47h
—(2)
(2)
—
(4)
F66h
LCDDATA6
F56h
—
F46h
—(2)
F75h LCDDATA16(4)
F65h
LCDDATA5(4)
F55h
—(2)
F45h
—(2)
F64h
(4)
F54h
(2)
F44h
—(2)
F53h
(2)
—
F43h
—(2)
F42h
—(2)
F76h LCDDATA17
F74h
F73h
LCDDATA15
LCDDATA14
F63h
LCDDATA4
LCDDATA3
—
F72h
LCDDATA13
F62h
LCDDATA2
F52h
—(2)
F71h
LCDDATA12
F61h
LCDDATA1
F51h
—(2)
F41h
—(2)
F50h
(2)
F40h
—(2)
F70h LCDDATA11
Note 1:
2:
3:
4:
(4)
(4)
F60h
LCDDATA0
—
This is not a physical register.
Unimplemented registers are read as ‘0’.
This register is not available on 64-pin devices.
This register is implemented but unused on 64-pin devices.
© 2007 Microchip Technology Inc.
DS39629C-page 75
PIC18F6390/6490/8390/8490
TABLE 5-2:
File Name
TOSU
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY
Bit 7
Bit 6
Bit 5
—
—
—
TOSH
Top-of-Stack High Byte (TOS<15:8>)
TOSL
Top-of-Stack Low Byte (TOS<7:0>)
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Top-of-Stack Upper Byte (TOS<20:16>)
Value on
POR, BOR
Details
on page:
---0 0000
59, 66
0000 0000
59, 66
0000 0000
59, 66
STKPTR
STKFUL
STKUNF
—
Return Stack Pointer
00-0 0000
59, 67
PCLATU
—
—
—
Holding Register for PC<20:16>
---0 0000
59, 66
0000 0000
59, 66
PCLATH
Holding Register for PC<15:8>
PCL
PC Low Byte (PC<7:0>)
TBLPTRU
—
—
bit 21
Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
0000 0000
59, 66
--00 0000
59, 88
TBLPTRH
Program Memory Table Pointer High Byte (TBLPTR<15:8>)
0000 0000
59, 88
TBLPTRL
Program Memory Table Pointer Low Byte (TBLPTR<7:0>)
0000 0000
59, 88
TABLAT
Program Memory Table Latch
0000 0000
59, 88
PRODH
Product Register High Byte
xxxx xxxx
59, 91
PRODL
Product Register Low Byte
INTCON
RBIF
xxxx xxxx
59, 91
0000 000x
59, 95
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
INTCON2
RBPU
INTEDG0
INTEDG1
INTEDG2
INTEDG3
TMR0IP
INT3IP
RBIP
1111 1111
59, 96
INTCON3
INT2IP
INT1IP
INT3IE
INT2IE
INT1IE
INT3IF
INT2IF
INT1IF
1100 0000
59, 97
INDF0
Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register)
N/A
59, 82
POSTINC0
Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register)
N/A
59, 83
POSTDEC0
Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register)
N/A
59, 83
PREINC0
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register)
N/A
59, 83
PLUSW0
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register),
value of FSR0 offset by W
N/A
59, 83
FSR0H
---- xxxx
59, 82
FSR0L
Indirect Data Memory Address Pointer 0 Low Byte
—
xxxx xxxx
59, 82
WREG
Working Register
xxxx xxxx
59
INDF1
Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register)
N/A
59, 82
POSTINC1
Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register)
N/A
59, 83
POSTDEC1
Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register)
N/A
59, 83
PREINC1
Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register)
N/A
59, 83
PLUSW1
Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register),
value of FSR1 offset by W
N/A
59, 83
FSR1H
—
FSR1L
—
—
—
—
—
—
Indirect Data Memory Address Pointer 0 High Byte
Indirect Data Memory Address Pointer 1 High Byte
Indirect Data Memory Address Pointer 1 Low Byte
BSR
—
---- 0000
60, 71
Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register)
N/A
60, 82
POSTINC2
Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register)
N/A
60, 83
POSTDEC2
Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register)
N/A
60, 83
PREINC2
Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register)
N/A
60, 83
PLUSW2
Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register),
value of FSR2 offset by W
N/A
60, 83
FSR2H
—
—
—
—
—
—
Bank Select Register
60, 82
60, 82
INDF2
FSR2L
—
---- xxxx
xxxx xxxx
Indirect Data Memory Address Pointer 2 High Byte
Indirect Data Memory Address Pointer 2 Low Byte
STATUS
Legend:
Note 1:
2:
3:
4:
5:
6:
—
—
—
N
OV
Z
DC
C
---- xxxx
60, 82
xxxx xxxx
60, 82
---x xxxx
60, 80
x = unknown, u = unchanged, – = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 4.4 “Brown-out Reset (BOR)”.
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is
read-only.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
DS39629C-page 76
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 5-2:
File Name
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY (CONTINUED)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Details
on page:
TMR0H
Timer0 Register High Byte
0000 0000
60, 132
TMR0L
Timer0 Register Low Byte
xxxx xxxx
60, 132
60, 131
TMR0ON
T08BIT
T0CS
T0SE
PSA
T0PS2
T0PS1
T0PS0
1111 1111
OSCCON
T0CON
IDLEN
IRCF2
IRCF1
IRCF0
OSTS
IOFS
SCS1
SCS0
0100 q000
38, 60
HLVDCON
VDIRMAG
—
IRVST
HLVDEN
HLVDL3
HLVDL2
HLVDL1
HLVDL0
0-00 0101
60, 251
WDTCON
—
—
—
—
—
—
—
SWDTEN
--- ---0
60, 288
—
RI
TO
PD
POR
BOR
0q-1 11q0
52, 60,
107
RCON
IPEN
SBOREN
(1)
TMR1H
Timer1 Register High Byte
xxxx xxxx
60, 137
TMR1L
Timer1 Register Low Byte
xxxx xxxx
60, 137
T1CON
RD16
T1RUN
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
0000 0000
60, 135
TMR2
Timer2 Register
0000 0000
60, 141
PR2
Timer2 Period Register
1111 1111
60, 141
-000 0000
60, 141
xxxx xxxx
60, 158,
166
T2CON
—
T2OUTPS3
T2OUTPS2
T2OUTPS1
T2OUTPS0
TMR2ON
TMR1CS
T2CKPS1
TMR1ON
T2CKPS0
SSPBUF
MSSP Receive Buffer/Transmit Register
SSPADD
MSSP Address Register in I2C™ Slave Mode. MSSP Baud Rate Reload Register in I2C Master Mode.
0000 0000
60, 166
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
0000 0000
60, 158,
167
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
0000 0000
60, 159,
168
GCEN
ACKSTAT
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
SSPCON2
0000 0000
60, 169
ADRESH
A/D Result Register High Byte
xxxx xxxx
61, 240
ADRESL
A/D Result Register Low Byte
xxxx xxxx
61, 240
ADCON0
—
—
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
--00 0000
61, 231
ADCON1
—
—
VCFG1
VCFG0
PCFG3
PCFG2
PCFG1
PCFG0
--00 0000
61, 232
ADCON2
ADFM
—
ACQT2
ACQT1
ACQT0
ADCS2
ADCS1
ADCS0
0-00 0000
61, 233
CCPR1H
Capture/Compare/PWM Register 1 High Byte
xxxx xxxx
61, 152,
155
CCPR1L
Capture/Compare/PWM Register 1 Low Byte
xxxx xxxx
61, 152,
155
CCP1CON
--00 0000
61, 147
CCPR2H
Capture/Compare/PWM Register 2 High Byte
—
—
DC1B1
DC1B0
CCP1M3
CCP1M2
CCP1M1
CCP1M0
xxxx xxxx
61, 152,
155
CCPR2L
Capture/Compare/PWM Register 2 Low Byte
xxxx xxxx
61, 152,
155
61, 147
CCP2CON
—
—
DC2B1
DC2B0
CCP2M3
CCP2M2
CCP2M1
CCP2M0
--00 0000
CVRCON
CVREN
CVROE
CVRR
CVRSS
CVR3
CVR2
CVR1
CVR0
0000 0000
61, 247
CMCON
C2OUT
C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
0000 0111
61, 241
TMR3H
Timer3 Register High Byte
xxxx xxxx
61, 145
TMR3L
Timer3 Register Low Byte
xxxx xxxx
61, 145
0000 0000
61, 143
T3CON
RD16
Legend:
Note 1:
2:
3:
4:
5:
6:
T3CCP2
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON
x = unknown, u = unchanged, – = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 4.4 “Brown-out Reset (BOR)”.
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is
read-only.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
© 2007 Microchip Technology Inc.
DS39629C-page 77
PIC18F6390/6490/8390/8490
TABLE 5-2:
File Name
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY (CONTINUED)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Details
on page:
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
0000 0000
61, 201
RCREG1
EUSART1 Receive Register
0000 0000
61, 208
TXREG1
EUSART1 Transmit Register
0000 0000
61, 206
TXSTA1
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
0000 0010
61, 198
RCSTA1
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
0000 000x
61, 199
IPR3
—
LCDIP
RC2IP
TX2IP
—
—
—
—
-111 ----
61, 106
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
-000 ----
61, 100
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
-000 ----
61, 103
IPR2
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
11-- 1111
61, 105
PIR2
OSCFIF
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
00-- 0000
61, 99
PIE2
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
00-- 0000
61, 102
61, 104
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
-111 1111
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
-000 0000
61, 98
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
-000 0000
61, 101
INTSRC
PLLEN(3)
—
TUN4
TUN3
TUN2
TUN1
TUN0
OSCTUNE
TRISJ(2)
PORTJ Data Direction Register
TRISH(2)
PORTH Data Direction Register
TRISG
—
TRISF
—
—
PORTG Data Direction Register
PORTF Data Direction Register
00-0 0000
35, 61
1111 1111
62, 130
1111 1111
62, 128
---1 1111
62, 126
1111 1111
62, 124
1111 ----
62, 121
TRISE
PORTE Data Direction Register
TRISD
PORTD Data Direction Register
1111 1111
62, 119
TRISC
PORTC Data Direction Register
1111 1111
62, 117
TRISB
PORTB Data Direction Register
1111 1111
62, 114
TRISA7(5)
TRISA
TRISA6(5)
LATJ(2)
LATJ Data Output Register
LATH(2)
LATH Data Output Register
LATG
—
LATF
—
—
—
—
—
PORTA Data Direction Register
—
LATG Data Output Register
LATF Data Output Register
1111 1111
62, 111
xxxx xxxx
62, 130
xxxx xxxx
62, 128
---x xxxx
62, 126
xxxx xxxx
62, 124
xxxx ----
62, 121
LATE
LATE Data Output Register
LATD
LATD Data Output Register
xxxx xxxx
62, 119
LATC
LATC Data Output Register
xxxx xxxx
62, 117
LATB
LATB Data Output Register
xxxx xxxx
62, 114
LATA7(5)
LATA
LATA6(5)
—
Read PORTJ pins, Write PORTJ Data Latch
PORTH(2)
Read PORTH pins, Write PORTH Data Latch
—
—
—
—
LATA Data Output Register
PORTJ(2)
PORTG
—
RG5(4)
Read PORTG pins <4:0>, Write PORTG Data Latch <4:0>
xxxx xxxx
62, 111
xxxx xxxx
62, 130
xxxx xxxx
62, 128
--xx xxxx
62, 126
PORTF
Read PORTF pins, Write PORTF Data Latch
PORTE
Read PORTE pins, Write PORTE Data Latch
PORTD
Read PORTD pins, Write PORTD Data Latch
xxxx xxxx
62, 119
PORTC
Read PORTC pins, Write PORTC Data Latch
xxxx xxxx
62, 117
PORTB
Read PORTB pins, Write PORTB Data Latch
xxxx xxxx
62, 114
xx0x 0000
62, 111
RA7(5)
PORTA
Legend:
Note 1:
2:
3:
4:
5:
6:
RA6(5)
—
Read PORTA pins, Write PORTA Data Latch
—
—
—
xxxx xxxx
62, 124
xxxx ----
62, 121
x = unknown, u = unchanged, – = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 4.4 “Brown-out Reset (BOR)”.
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is
read-only.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
DS39629C-page 78
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 5-2:
File Name
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY (CONTINUED)
Bit 7
SPBRGH1
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
EUSART1 Baud Rate Generator Register High Byte
BAUDCON1
Details
on page:
0000 0000
62, 201
ABDOVF
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
01-0 0-00
62, 200
63, 261
LCDDATA23(6)
S47C3
S46C3
S45C3
S44C3
S43C3
S42C3
S41C3
S40C3
xxxx xxxx
LCDDATA22(6)
S39C3
S38C3
S37C3
S36C3
S35C3
S34C3
S33C3
S32C3
xxxx xxxx
63, 261
LCDDATA21
S31C3
S30C3
S29C3
S28C3
S27C3
S26C3
S25C3
S24C3
xxxx xxxx
63, 261
LCDDATA20
S23C3
S22C3
S21C3
S20C3
S19C3
S18C3
S17C3
S16C3
xxxx xxxx
63, 261
LCDDATA19
S15C3
S14C3
S13C3
S12C3
S11C3
S10C3
S09C3
S08C3
xxxx xxxx
63, 261
LCDDATA18
S07C3
S06C3
S05C3
S04C3
S03C3
S02C3
S01C3
S00C3
xxxx xxxx
63, 261
LCDDATA17(6)
S47C2
S46C2
S45C2
S44C2
S43C2
S42C2
S41C2
S40C2
xxxx xxxx
63, 261
LCDDATA16(6)
S39C2
S38C2
S37C2
S36C2
S35C2
S34C2
S33C2
S32C2
xxxx xxxx
63, 261
LCDDATA15
S31C2
S30C2
S29C2
S28C2
S27C2
S26C2
S25C2
S24C2
xxxx xxxx
63, 261
LCDDATA14
S23C2
S22C2
S21C2
S20C2
S19C2
S18C2
S17C2
S16C2
xxxx xxxx
63, 261
LCDDATA13
S15C2
S14C2
S13C2
S12C2
S11C2
S10C2
S09C2
S08C2
xxxx xxxx
63, 261
LCDDATA12
S07C2
S06C2
S05C2
S04C2
S03C2
S02C2
S01C2
S00C2
xxxx xxxx
63, 261
LCDDATA11(6)
S47C1
S46C1
S45C1
S44C1
S43C1
S42C1
S41C1
S40C1
xxxx xxxx
63, 261
AUSART2 Baud Rate Generator Register
0000 0000
63, 220
RCREG2
AUSART2 Receive Register
0000 0000
63, 224
TXREG2
AUSART2 Transmit Register
0000 0000
63, 222
63, 218
SPBRG2
TXSTA2
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
0000 -010
RCSTA2
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
0000 000x
63, 219
LCDDATA10(6)
S39C1
S38C1
S37C1
S36C1
S35C1
S34C1
S33C1
S32C1
xxxx xxxx
63, 261
LCDDATA9
S31C1
S30C1
S29C1
S28C1
S27C1
S26C1
S25C1
S24C1
xxxx xxxx
63, 261
LCDDATA8
S23C1
S22C1
S21C1
S20C1
S19C1
S18C1
S17C1
S16C1
xxxx xxxx
63, 261
LCDDATA7
S15C1
S14C1
S13C1
S12C1
S11C1
S10C1
S09C1
S08C1
xxxx xxxx
63, 261
LCDDATA6
S07C1
S06C1
S05C1
S04C1
S03C1
S02C1
S01C1
S00C1
xxxx xxxx
63, 261
LCDDATA5(6)
S47C0
S46C0
S45C0
S44C0
S43C0
S42C0
S41C0
S40C0
xxxx xxxx
63, 261
LCDDATA4(6)
S39C0
S38C0
S37C0
S36C0
S35C0
S34C0
S33C0
S32C0
xxxx xxxx
63, 261
LCDDATA3
S31C0
S30C0
S29C0
S28C0
S27C0
S26C0
S25C0
S24C0
xxxx xxxx
63, 261
LCDDATA2
S23C0
S22C0
S21C0
S20C0
S19C0
S18C0
S17C0
S16C0
xxxx xxxx
63, 261
LCDDATA1
S15C0
S14C0
S13C0
S12C0
S11C0
S10C0
S09C0
S08C0
xxxx xxxx
63, 261
LCDDATA0
S07C0
S06C0
S05C0
S04C0
S03C0
S02C0
S01C0
S00C0
xxxx xxxx
63, 261
LCDSE5(2)
SE47
SE46
SE45
SE44
SE43
SE42
SE41
SE40
0000 0000
64, 261
LCDSE4(2)
SE39
SE38
SE37
SE36
SE35
SE34
SE33
SE32
0000 0000
64, 260
LCDSE3
SE31
SE30
SE29
SE28
SE27
SE26
SE25
SE24
0000 0000
64, 260
LCDSE2
SE23
SE22
SE21
SE20
SE19
SE18
SE17
SE16
0000 0000
64, 260
LCDSE1
SE15
SE14
SE13
SE12
SE11
SE10
SE9
SE8
0000 0000
64, 260
LCDSE0
SE7
SE6
SE5
SE4
SE3
SE2
SE1
SE0
0000 0000
64, 260
LCDCON
LCDEN
SLPEN
WERR
—
CS1
CS0
LMUX1
LMUX0
000- 0000
64, 258
WFT
BIASMD
LCDA
WA
LP3
LP2
LP1
LP0
0000 0000
64, 259
LCDPS
Legend:
Note 1:
2:
3:
4:
5:
6:
x = unknown, u = unchanged, – = unimplemented, q = value depends on condition
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See
Section 4.4 “Brown-out Reset (BOR)”.
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is
read-only.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.
© 2007 Microchip Technology Inc.
DS39629C-page 79
PIC18F6390/6490/8390/8490
5.3.5
STATUS REGISTER
The STATUS register, shown in Register 5-2, contains
the arithmetic status of the ALU. As with any other SFR,
it can be the operand for any instruction.
If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV or N bits, the results of
the instruction are not written; instead, the status is
updated according to the instruction performed. Therefore, the result of an instruction with the STATUS register
as its destination may be different than intended. As an
example, CLRF STATUS will set the Z bit and leave the
remaining Status bits unchanged (‘000u u1uu’).
REGISTER 5-2:
U-0
For other instructions that do not affect Status bits, see
the instruction set summaries in Table 24-2 and
Table 24-3.
Note:
The C and DC bits operate as a borrow and
digit borrow bit respectively, in subtraction.
STATUS REGISTER
U-0
—
It is recommended that only BCF, BSF, SWAPF, MOVFF
and MOVWF instructions are used to alter the STATUS
register, because these instructions do not affect the Z,
C, DC, OV or N bits in the STATUS register.
—
U-0
—
R/W-x
N
R/W-x
R/W-x
R/W-x
R/W-x
Z
DC(1)
C(2)
OV
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-5
Unimplemented: Read as ‘0’
bit 4
N: Negative bit
This bit is used for signed arithmetic (2’s complement). It indicates whether the result was negative
(ALU MSB = 1).
1 = Result was negative
0 = Result was positive
bit 3
OV: Overflow bit
This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit magnitude
which causes the sign bit (bit 7) to change state.
1 = Overflow occurred for signed arithmetic (in this arithmetic operation)
0 = No overflow occurred
bit 2
Z: Zero bit
1 = The result of an arithmetic or logic operation is zero
0 = The result of an arithmetic or logic operation is not zero
bit 1
DC: Digit carry/borrow bit(1)
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the 4th low-order bit of the result occurred
0 = No carry-out from the 4th low-order bit of the result
bit 0
C: Carry/borrow bit(2)
For ADDWF, ADDLW, SUBLW and SUBWF instructions:
1 = A carry-out from the Most Significant bit of the result occurred
0 = No carry-out from the Most Significant bit of the result occurred
Note 1:
2:
For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register.
For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the
source register.
DS39629C-page 80
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
5.4
Data Addressing Modes
Note:
The execution of some instructions in the
core PIC18 instruction set are changed
when the PIC18 extended instruction set is
enabled. See Section 5.6 “Data Memory
and the Extended Instruction Set” for
more information.
While the program memory can be addressed in only
one way – through the program counter – information
in the data memory space can be addressed in several
ways. For most instructions, the addressing mode is
fixed. Other instructions may use up to three modes,
depending on which operands are used and whether or
not the extended instruction set is enabled.
The addressing modes are:
•
•
•
•
Inherent
Literal
Direct
Indirect
An additional addressing mode, Indexed Literal Offset,
is available when the extended instruction set is
enabled (XINST Configuration bit = 1). Its operation is
discussed in greater detail in Section 5.6.1 “Indexed
Addressing With Literal Offset”.
5.4.1
INHERENT AND LITERAL
ADDRESSING
Many PIC18 control instructions do not need any
argument at all; they either perform an operation that
globally affects the device, or they operate implicitly on
one register. This addressing mode is known as
Inherent Addressing. Examples include SLEEP, RESET
and DAW.
Other instructions work in a similar way but require an
additional explicit argument in the opcode. This is
known as Literal Addressing mode, because they
require some literal value as an argument. Examples
include ADDLW and MOVLW, which respectively add or
move a literal value to the W register. Other examples
include CALL and GOTO, which include a 20-bit
program memory address.
5.4.2
DIRECT ADDRESSING
Direct Addressing specifies all or part of the source
and/or destination address of the operation within the
opcode itself. The options are specified by the
arguments accompanying the instruction.
In the core PIC18 instruction set, bit-oriented and
byte-oriented instructions use some version of Direct
Addressing by default. All of these instructions include
some 8-bit literal address as their Least Significant
Byte. This address specifies either a register address in
one of the banks of data RAM (Section 5.3.3 “General
© 2007 Microchip Technology Inc.
Purpose Register File”), or a location in the Access
Bank (Section 5.3.2 “Access Bank”) as the data
source for the instruction.
The Access RAM bit ‘a’ determines how the address is
interpreted. When ‘a’ is ‘1’, the contents of the BSR
(Section 5.3.1 “Bank Select Register”) are used with
the address to determine the complete 12-bit address
of the register. When ‘a’ is ‘0’, the address is interpreted
as being a register in the Access Bank. Addressing that
uses the Access RAM is sometimes also known as
Direct Forced Addressing mode.
A few instructions, such as MOVFF, include the entire
12-bit address (either source or destination) in their
op codes. In those cases, the BSR is ignored entirely.
The destination of the operation’s results is determined
by the destination bit ‘d’. When ‘d’ is ‘1’, the results are
stored back in the source register, overwriting its original contents. When ‘d’ is ‘0’, the results are stored in
the W register. Instructions without the ‘d’ argument
have a destination that is implicit in the instruction; their
destination is either the target register being operated
on, or the W register.
5.4.3
INDIRECT ADDRESSING
Indirect Addressing allows the user to access a location
in data memory without giving a fixed address in the
instruction. This is done by using File Select Registers
(FSRs) as pointers to the locations to be read or written
to. Since the FSRs are themselves located in RAM as
Special Function Registers, they can also be directly
manipulated under program control. This makes FSRs
very useful in implementing data structures, such as
tables and arrays in data memory.
The registers for Indirect Addressing are also
implemented with Indirect File Operands (INDFs) that
permit automatic manipulation of the pointer value with
auto-incrementing, auto-decrementing or offsetting
with another value. This allows for efficient code using
loops, such as the example of clearing an entire RAM
bank in Example 5-5. It also enables users to perform
Indexed Addressing and other Stack Pointer
operations for program memory in data memory.
EXAMPLE 5-5:
NEXT
LFSR
CLRF
BTFSS
BRA
CONTINUE
HOW TO CLEAR RAM
(BANK 1) USING
INDIRECT ADDRESSING
FSR0, 100h ;
POSTINC0
; Clear INDF
; register then
; inc pointer
FSR0H, 1
; All done with
; Bank1?
NEXT
; NO, clear next
; YES, continue
DS39629C-page 81
PIC18F6390/6490/8390/8490
5.4.3.1
FSR Registers and the
INDF Operand
mapped in the SFR space but are not physically
implemented. Reading or writing to a particular INDF
register actually accesses its corresponding FSR
register pair. A read from INDF1, for example, reads
the data at the address indicated by FSR1H:FSR1L.
Instructions that use the INDF registers as operands
actually use the contents of their corresponding FSR as
a pointer to the instruction’s target. The INDF operand
is just a convenient way of using the pointer.
At the core of Indirect Addressing are three sets of
registers: FSR0, FSR1 and FSR2. Each represents a
pair of 8-bit registers, FSRnH and FSRnL. The four
upper bits of the FSRnH register are not used, so each
FSR pair holds a 12-bit value. This represents a value
that can address the entire range of the data memory
in a linear fashion. The FSR register pairs, then, serve
as pointers to data memory locations.
Because Indirect Addressing uses a full 12-bit address,
data RAM banking is not necessary. Thus, the current
contents of the BSR and the Access RAM bit have no
effect on determining the target address.
Indirect Addressing is accomplished with a set of
Indirect File Operands, INDF0 through INDF2. These
can be thought of as “virtual” registers: they are
FIGURE 5-7:
INDIRECT ADDRESSING
000h
Using an instruction with one of the
Indirect Addressing registers as the
operand....
Bank 0
ADDWF, INDF1, 1
100h
Bank 1
200h
...uses the 12-bit address stored in
the FSR pair associated with that
register....
300h
FSR1H:FSR1L
7
0
x x x x 1 1 1 1
7
0
Bank 2
Bank 3
through
Bank 13
1 1 0 0 1 1 0 0
...to determine the data memory
location to be used in that operation.
In this case, the FSR1 pair contains
FCCh. This means the contents of
location FCCh will be added to that
of the W register and stored back in
FCCh.
E00h
Bank 14
F00h
FFFh
Bank 15
Data Memory
DS39629C-page 82
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
5.4.3.2
FSR Registers and POSTINC,
POSTDEC, PREINC and PLUSW
In addition to the INDF operand, each FSR register pair
also has four additional indirect operands. Like INDF,
these are “virtual” registers that cannot be indirectly
read or written to. Accessing these registers actually
accesses the associated FSR register pair, but also
performs a specific action on its stored value. They are:
• POSTDEC: accesses the FSR value, then
automatically decrements it by ‘1’ afterwards
• POSTINC: accesses the FSR value, then
automatically increments it by ‘1’ afterwards
• PREINC: increments the FSR value by ‘1’, then
uses it in the operation
• PLUSW: adds the signed value of the W register
(range of -127 to 128) to that of the FSR and uses
the new value in the operation.
In this context, accessing an INDF register uses the
value in the FSR registers without changing them.
Similarly, accessing a PLUSW register gives the FSR
value offset by the value in the W register; neither value
is actually changed in the operation. Accessing the
other virtual registers changes the value of the FSR
registers.
Operations on the FSRs with POSTDEC, POSTINC
and PREINC affect the entire register pair; that is, rollovers of the FSRnL register from FFh to 00h carry over
to the FSRnH register. On the other hand, results of
these operations do not change the value of any flags
in the STATUS register (e.g., Z, N, OV, etc.).
5.4.3.3
Operations by FSRs on FSRs
Indirect Addressing operations that target other FSRs
or virtual registers represent special cases. For example, using an FSR to point to one of the virtual registers
will not result in successful operations. As a specific
case, assume that FSR0H:FSR0L contains FE7h, the
address of INDF1. Attempts to read the value of the
INDF1, using INDF0 as an operand, will return 00h.
Attempts to write to INDF1, using INDF0 as the
operand, will result in a NOP.
On the other hand, using the virtual registers to write to
an FSR pair may not occur as planned. In these cases,
the value will be written to the FSR pair, but without any
incrementing or decrementing. Thus, writing to INDF2
or POSTDEC2 will write the same value to the
FSR2H:FSR2L.
Since the FSRs are physical registers mapped in the
SFR space, they can be manipulated through all direct
operations. Users should proceed cautiously when
working on these registers, particularly if their code
uses Indirect Addressing.
Similarly, operations by Indirect Addressing are generally permitted on all other SFRs. Users should exercise
the appropriate caution that they do not inadvertently
change settings that might affect the operation of the
device.
The PLUSW register can be used to implement a form
of Indexed Addressing in the data memory space. By
manipulating the value in the W register, users can
reach addresses that are fixed offsets from pointer
addresses. In some applications, this can be used to
implement some powerful program control structure,
such as software stacks, inside of data memory.
© 2007 Microchip Technology Inc.
DS39629C-page 83
PIC18F6390/6490/8390/8490
5.5
Program Memory and the
Extended Instruction Set
The operation of program memory is unaffected by the
use of the extended instruction set.
Enabling the extended instruction set adds five additional two-word commands to the existing PIC18
instruction set: ADDFSR, CALLW, MOVSF, MOVSS and
SUBFSR. These instructions are executed as described
in Section 5.2.4 “Two-Word Instructions”.
5.6
Data Memory and the Extended
Instruction Set
Enabling the PIC18 extended instruction set (XINST
Configuration bit = 1) significantly changes certain
aspects of data memory and its addressing.
Specifically, the use of the Access Bank for many of the
core PIC18 instructions is different; this is due to the
introduction of a new addressing mode for the data
memory space. This mode also alters the behavior of
Indirect Addressing using FSR2 and its associated
operands.
What does not change is just as important. The size of
the data memory space is unchanged, as well as its
linear addressing. The SFR map remains the same.
Core PIC18 instructions can still operate in both Direct
and Indirect Addressing mode; inherent and literal
instructions do not change at all. Indirect Addressing
with FSR0 and FSR1 also remains unchanged.
5.6.1
INDEXED ADDRESSING WITH
LITERAL OFFSET
Enabling the PIC18 extended instruction set changes
the behavior of Indirect Addressing using the FSR2
register pair and its associated file operands. Under the
proper conditions, instructions that use the Access
Bank – that is, most bit-oriented and byte-oriented
instructions – can invoke a form of Indexed Addressing
using an offset specified in the instruction. This special
addressing mode is known as Indexed Addressing with
Literal Offset, or Indexed Literal Offset mode.
DS39629C-page 84
When using the extended instruction set, this
addressing mode requires the following:
• The use of the Access Bank is forced (‘a’ = 0);
and
• The file address argument is less than or equal to
5Fh.
Under these conditions, the file address of the
instruction is not interpreted as the lower byte of an
address (used with the BSR in Direct Addressing), or
as an 8-bit address in the Access Bank. Instead, the
value is interpreted as an offset value to an Address
Pointer specified by FSR2. The offset and the contents
of FSR2 are added to obtain the target address of the
operation.
5.6.2
INSTRUCTIONS AFFECTED BY
INDEXED LITERAL OFFSET MODE
Any of the core PIC18 instructions that can use Direct
Addressing are potentially affected by the Indexed
Literal Offset Addressing mode. This includes all
byte-oriented and bit-oriented instructions, or almost
one-half of the standard PIC18 instruction set. Instructions that only use Inherent or Literal Addressing
modes are unaffected.
Additionally, byte-oriented and bit-oriented instructions
are not affected if they use the Access Bank (Access
RAM bit is ‘1’), or include a file address of 60h or above.
Instructions meeting these criteria will continue to
execute as before. A comparison of the different
possible addressing modes when the extended
instruction set is enabled is shown in Figure 5-8.
Those who desire to use byte-oriented or bit-oriented
instructions in the Indexed Literal Offset mode should
note the changes to assembler syntax for this mode.
This is described in more detail in Section 24.2.1
“Extended Instruction Syntax”.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 5-8:
COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND
BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED)
EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff)
When a = 0 and f ≥ 60h:
The instruction executes in
Direct Forced mode. ‘f’ is
interpreted as a location in the
Access RAM between 060h
and FFFh. This is the same as
locations F60h to FFFh
(Bank 15) of data memory.
Locations below 060h are not
available in this addressing
mode.
000h
060h
Bank 0
100h
00h
Bank 1
through
Bank 14
F00h
60h
Valid range
for ‘f’
Access RAM
FFh
Bank 15
F40h
SFRs
FFFh
When a = 0 and f ≤ 5Fh:
The instruction executes in
Indexed Literal Offset mode. ‘f’
is interpreted as an offset to the
address value in FSR2. The
two are added together to
obtain the address of the target
register for the instruction. The
address can be anywhere in
the data memory space.
Note that in this mode, the
correct syntax is now:
ADDWF [k], d
where ‘k’ is the same as ‘f’.
When a = 1 (all values of f):
The instruction executes in
Direct mode (also known as
Direct Long mode). ‘f’ is
interpreted as a location in
one of the 16 banks of the data
memory space. The bank is
designated by the Bank Select
Register (BSR). The address
can be in any implemented
bank in the data memory
space.
Data Memory
000h
Bank 0
060h
100h
001001da ffffffff
Bank 1
through
Bank 14
FSR2H
FSR2L
F00h
Bank 15
F40h
SFRs
FFFh
Data Memory
BSR
00000000
000h
Bank 0
060h
100h
Bank 1
through
Bank 14
001001da ffffffff
F00h
Bank 15
F40h
SFRs
FFFh
© 2007 Microchip Technology Inc.
Data Memory
DS39629C-page 85
PIC18F6390/6490/8390/8490
5.6.3
MAPPING THE ACCESS BANK IN
INDEXED LITERAL OFFSET MODE
The use of Indexed Literal Offset Addressing mode
effectively changes how the lower part of Access RAM
(00h to 5Fh) is mapped. Rather than containing just the
contents of the bottom part of Bank 0, this mode maps
the contents from Bank 0 and a user-defined “window”
that can be located anywhere in the data memory
space. The value of FSR2 establishes the lower boundary of the addresses mapped into the window, while the
upper boundary is defined by FSR2 plus 95 (5Fh).
Addresses in the Access RAM above 5Fh are mapped
as previously described (see Section 5.3.2 “Access
Bank”). An example of Access Bank remapping in this
addressing mode is shown in Figure 5-9.
FIGURE 5-9:
Remapping of the Access Bank applies only to operations using the Indexed Literal Offset mode. Operations
that use the BSR (Access RAM bit is ‘1’) will continue
to use Direct Addressing as before. Any indirect or
indexed operation that explicitly uses any of the indirect
file operands (including FSR2) will continue to operate
as standard Indirect Addressing. Any instruction that
uses the Access Bank, but includes a register address
of greater than 05Fh, will use Direct Addressing and
the normal Access Bank map.
5.6.4
BSR IN INDEXED LITERAL
OFFSET MODE
Although the Access Bank is remapped when the
extended instruction set is enabled, the operation of the
BSR remains unchanged. Direct Addressing, using the
BSR to select the data memory bank, operates in the
same manner as previously described.
REMAPPING THE ACCESS BANK WITH INDEXED LITERAL
OFFSET ADDRESSING
Example Situation:
ADDWF f, d, a
FSR2H:FSR2L = 120h
Locations in the region
from the FSR2 Pointer
(120h) to the pointer plus
05Fh (17Fh) are mapped
to the bottom of the
Access RAM (000h-05Fh).
000h
05Fh
Bank 0
100h
120h
17Fh
200h
Window
Bank 1
00h
Bank 1 “Window”
5Fh
60h
Special File Registers at
F60h through FFFh are
mapped to 60h through
FFh, as usual.
Bank 0 addresses below
5Fh are not available in
this mode. They can still
be addressed by using the
BSR.
Not Accessible
Bank 2
through
Bank 14
SFRs
FFh
Access Bank
F00h
Bank 15
F60h
FFFh
SFRs
Data Memory
DS39629C-page 86
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
6.0
FLASH PROGRAM MEMORY
In PIC18F6390/6490/8390/8490 devices, the program
memory is implemented as read-only Flash memory. It
is readable over the entire VDD range during normal
operation. A read from program memory is executed on
one byte at a time.
6.1
Table Reads
For PIC18 devices, there are two operations that allow
the processor to move bytes between the program
memory space and the data RAM: table read (TBLRD)
and table write (TBLWT).
Table read operations retrieve data from program
memory and place it into the data RAM space.
Figure 6-1 shows the operation of a table read with
program memory and data RAM.
Table reads 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.
Because the program memory cannot be written to or
erased under normal operation, the TBLWT operation is
not discussed here.
Note 1: Although it cannot be used in
PIC18F6390/6490/8390/8490 devices in
normal operation, the TBLWT instruction
is still implemented in the instruction set.
Executing the instruction takes two
instruction cycles, but effectively results
in a NOP.
2: The TBLWT instruction is available only in
programming modes and is used during
In-Circuit Serial Programming™ (ICSP™).
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.
FIGURE 6-1:
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 register points to a byte in program memory.
© 2007 Microchip Technology Inc.
DS39629C-page 87
PIC18F6390/6490/8390/8490
6.2
Control Registers
TABLE 6-1:
TABLE POINTER
OPERATIONS WITH TBLRD
INSTRUCTIONS
Example
Operation on Table Pointer
Two control registers are used in conjunction with the
TBLRD instruction: the TABLAT register and the
TBLPTR register set.
6.2.1
TABLE LATCH REGISTER (TABLAT)
The Table Latch (TABLAT) is an 8-bit register mapped
into the SFR space. The Table Latch register is used to
hold 8-bit data during data transfers between program
memory and data RAM.
6.2.2
TBLRD*
TBLPTR is not modified
TBLRD*+
TBLPTR is incremented after the read
TBLRD*-
TBLPTR is decremented after the read
TBLRD+*
TBLPTR is incremented before the read
6.3
TABLE POINTER REGISTER
(TBLPTR)
The Table Pointer register (TBLPTR) addresses a byte
within the program memory. It is comprised of three
SFR registers: Table Pointer Upper Byte, Table Pointer
High Byte and Table Pointer Low Byte
(TBLPTRU:TBLPTRH:TBLPTRL). Only the lower six
bits of TBLPTRU are used with TBLPTRH and
TBLPTRL to form a 22-bit wide pointer.
The contents of TBLPTR indicates a location in
program memory space. The low-order 21 bits allow
the device to address the full 2 Mbytes of program
memory space. The 22nd bit allows access to the
configuration space, including the device ID, user ID
locations and the Configuration bits.
The TBLPTR register set is updated when executing a
TBLRD in one of four ways, based on the instruction’s
arguments. These are detailed in Table 6-1. These
operations on the TBLPTR only affect the low-order
21 bits.
Reading the Flash Program
Memory
The TBLRD instruction is used to retrieve data from
program memory and places it into data RAM. Table
reads from program memory are performed one byte at
a time.
TBLPTR points to a byte address in program space.
Executing TBLRD places the byte pointed to into
TABLAT. In addition, TBLPTR can be modified
automatically for the next table read operation.
The internal program memory is typically organized by
words. The Least Significant bit of the address selects
between the high and low bytes of the word. Figure 6-2
shows the interface between the internal program
memory and the TABLAT.
A typical method for reading data from program memory
is shown in Example 6-1.
When a TBLRD is executed, all 22 bits of the TBLPTR
determine which byte is read from program memory
into TABLAT.
FIGURE 6-2:
READS FROM FLASH PROGRAM MEMORY
Program Memory
(Even Byte Address)
(Odd Byte Address)
TBLPTR = xxxxx1
Instruction Register
(IR)
DS39629C-page 88
FETCH
TBLRD
TBLPTR = xxxxx0
TABLAT
Read Register
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
EXAMPLE 6-1:
READING A FLASH PROGRAM MEMORY WORD
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 word
READ_WORD
TBLRD*+
MOVF
MOVWF
TBLRD*+
MOVF
MOVWF
TABLE 6-2:
Name
TBLPTRU
; read into TABLAT and increment
; get data
TABLAT, W
WORD_EVEN
; read into TABLAT and increment
; get data
TABLAT, W
WORD_ODD
REGISTERS ASSOCIATED WITH READING PROGRAM FLASH MEMORY
Bit 7
Bit 6
Bit 5
—
—
bit 21
Bit 4
Bit 3
Bit 2
Bit 1
Program Memory Table Pointer Upper Byte
(TBLPTR<20:16>)
Bit 0
Reset
Values on
Page
59
TBLPTRH
Program Memory Table Pointer High Byte (TBLPTR<15:8>)
59
TBLPTRL
Program Memory Table Pointer Low Byte (TBLPTR<7:0>)
59
TABLAT
Program Memory Table Latch
59
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash access.
© 2007 Microchip Technology Inc.
DS39629C-page 89
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 90
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
7.0
8 x 8 HARDWARE MULTIPLIER
7.1
Introduction
EXAMPLE 7-1:
MOVF
MULWF
All PIC18 devices include an 8 x 8 hardware multiplier
as part of the ALU. The multiplier performs an unsigned
operation and yields a 16-bit result that is stored in the
product register pair PRODH:PRODL. The multiplier’s
operation does not affect any flags in the STATUS
register.
ARG1, W
ARG2
EXAMPLE 7-2:
Making multiplication a hardware operation allows it to
be completed in a single instruction cycle. This has the
advantages of higher computational throughput and
reduced code size for multiplication algorithms and
allows the PIC18 devices to be used in many
applications previously reserved for digital signal
processors. A comparison of various hardware and
software multiply operations, along with the savings in
memory and execution time, is shown in Table 7-1.
7.2
8 x 8 UNSIGNED
MULTIPLY ROUTINE
;
; ARG1 * ARG2 ->
; PRODH:PRODL
8 x 8 SIGNED MULTIPLY
ROUTINE
MOVF
MULWF
ARG1, W
ARG2
BTFSC
SUBWF
ARG2, SB
PRODH, F
MOVF
BTFSC
SUBWF
ARG2, W
ARG1, SB
PRODH, F
;
;
;
;
;
ARG1 * ARG2 ->
PRODH:PRODL
Test Sign Bit
PRODH = PRODH
- ARG1
; Test Sign Bit
; PRODH = PRODH
;
- ARG2
Operation
Example 7-1 shows the instruction sequence for an
8 x 8 unsigned multiplication. Only one instruction is
required when one of the arguments is already loaded
in the WREG register.
Example 7-2 shows the sequence to do an 8 x 8 signed
multiplication. To account for the signed bits of the
arguments, each argument’s Most Significant bit (MSb)
is tested and the appropriate subtractions are done.
TABLE 7-1:
PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
Routine
8 x 8 unsigned
8 x 8 signed
16 x 16 unsigned
16 x 16 signed
Multiply Method
Program
Memory
(Words)
Cycles
(Max)
Time
@ 40 MHz
@ 10 MHz
@ 4 MHz
Without hardware multiply
13
69
6.9 μs
27.6 μs
69 μs
Hardware multiply
1
1
100 ns
400 ns
1 μs
Without hardware multiply
33
91
9.1 μs
36.4 μs
91 μs
Hardware multiply
6
6
600 ns
2.4 μs
6 μs
Without hardware multiply
21
242
24.2 μs
96.8 μs
242 μs
Hardware multiply
28
28
2.8 μs
11.2 μs
28 μs
Without hardware multiply
52
254
25.4 μs
102.6 μs
254 μs
Hardware multiply
35
40
4.0 μs
16.0 μs
40 μs
© 2007 Microchip Technology Inc.
DS39629C-page 91
PIC18F6390/6490/8390/8490
Example 7-3 shows the sequence to do a 16 x 16
unsigned multiplication. 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
=
=
EXAMPLE 7-3:
16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
ARG1H:ARG1L • ARG2H:ARG2L
(ARG1H • ARG2H • 216) +
(ARG1H • ARG2L • 28) +
(ARG1L • ARG2H • 28) +
(ARG1L • ARG2L)
EQUATION 7-2:
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)
EXAMPLE 7-4:
16 x 16 UNSIGNED
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, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
MOVF
MULWF
ARG1H, W
ARG2L
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
; ARG1L * ARG2L->
; PRODH:PRODL
;
;
ARG1L * ARG2H->
PRODH:PRODL
Add cross
products
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 signed bits of the
arguments, the MSb for each argument pair is tested
and the appropriate subtractions are done.
DS39629C-page 92
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, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
MOVF
MULWF
ARG1H, W
ARG2L
MOVF
ADDWF
MOVF
ADDWFC
CLRF
ADDWFC
PRODL, W
RES1, F
PRODH, W
RES2, F
WREG
RES3, F
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
;
;
; ARG1H * ARG2H ->
; PRODH:PRODL
;
;
;
;
;
;
;
;
;
;
ARG1L * ARG2H ->
PRODH:PRODL
Add cross
products
;
;
;
;
;
;
;
;
;
;
;
MOVF
MULWF
;
;
;
;
;
;
;
;
;
;
16 x 16 SIGNED
MULTIPLY ROUTINE
;
;
; ARG1H * ARG2H->
; PRODH:PRODL
;
;
16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
;
;
;
;
;
;
;
;
;
ARG1H * ARG2L ->
PRODH:PRODL
Add cross
products
;
;
SIGN_ARG1
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB
;
CONT_CODE
:
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
8.0
INTERRUPTS
The PIC18F6390/6490/8390/8490 devices have
multiple interrupt sources and an interrupt priority feature that allows most interrupt sources to be assigned
a high-priority level or a low-priority level. The highpriority interrupt vector is at 0008h and the low-priority
interrupt vector is at 0018h. High-priority interrupt
events will interrupt any low-priority interrupts that may
be in progress.
There are thirteen registers which are used to control
interrupt operation. These registers are:
•
•
•
•
•
•
•
RCON
INTCON
INTCON2
INTCON3
PIR1, PIR2, PIR3
PIE1, PIE2, PIE3
IPR1, IPR2, IPR3
It is recommended that the Microchip header files
supplied with MPLAB® IDE be used for the symbolic bit
names in these registers. This allows the assembler/
compiler to automatically take care of the placement of
these bits within the specified register.
In general, interrupt sources have three bits to control
their operation. They are:
• Flag bit to indicate that an interrupt event
occurred
• Enable bit that allows program execution to
branch to the interrupt vector address when the
flag bit is set
• Priority bit to select high priority or low priority
The interrupt priority feature is enabled by setting the
IPEN bit (RCON<7>). When interrupt priority is
enabled, there are two bits which enable interrupts
globally. Setting the GIEH bit (INTCON<7>) enables all
interrupts that have the priority bit set (high priority).
Setting the GIEL bit (INTCON<6>) enables all
interrupts that have the priority bit cleared (low priority).
When the interrupt flag, enable bit and appropriate
global interrupt enable bit are set, the interrupt will
vector immediately to address 0008h or 0018h,
depending on the priority bit setting. Individual
interrupts can be disabled through their corresponding
enable bits.
© 2007 Microchip Technology Inc.
When the IPEN bit is cleared (default state), the
interrupt priority feature is disabled and interrupts are
compatible with PIC® mid-range devices. In
Compatibility mode, the interrupt priority bits for each
source have no effect. INTCON<6> is the PEIE bit,
which enables/disables all peripheral interrupt sources.
INTCON<7> is the GIE bit, which enables/disables all
interrupt sources. All interrupts branch to address
0008h in Compatibility mode.
When an interrupt is responded to, the global interrupt
enable bit is 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 lowpriority interrupt. Low-priority interrupts are not
processed while high-priority interrupts are in progress.
The return address is pushed onto the stack and the
PC is loaded with the interrupt vector address (0008h
or 0018h). Once in the Interrupt Service Routine, 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 INTx pins or
the PORTB input change interrupt, the interrupt latency
will be three to four instruction cycles. The exact
latency is the same for one or two-cycle instructions.
Individual interrupt flag bits are set, regardless of the
status of their corresponding enable bit or the GIE bit.
Note:
Do not use the MOVFF instruction to modify
any of the interrupt control registers while
any interrupt is enabled. Doing so may
cause erratic microcontroller behavior.
DS39629C-page 93
PIC18F6390/6490/8390/8490
FIGURE 8-1:
PIC18F6X90/8X90 INTERRUPT LOGIC
Wake-up if in
Idle or Sleep modes
TMR0IF
TMR0IE
TMR0IP
RBIF
RBIE
RBIP
INT0IF
INT0IE
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
INT3IF
INT3IE
INT3IP
PIR1<6:0>
PIE1<6:0>
IPR1<6:0>
PIR2<7:6, 3:0>
PIE2<7:6, 3:0>
IPR2<7:6, 3:0>
Interrupt to CPU
Vector to Location
0008h
GIE/GIEH
IPEN
PIR3<6:4>
PIE3<6:4>
IPR3<6:4>
IPEN
PEIE/GIEL
IPEN
High-Priority Interrupt Generation
Low-Priority Interrupt Generation
PIR1<6:0>
PIE1<6:0>
IPR1<6:0>
PIR2<7:6, 3:0>
PIE2<7:6, 3:0>
IPR2<7:6, 3:0>
PIR3<6:4>
PIE3<6:4>
IPR3<6:4>
TMR0IF
TMR0IE
TMR0IP
RBIF
RBIE
RBIP
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
INT3IF
INT3IE
INT3IP
DS39629C-page 94
Interrupt to CPU
Vector to Location
0018h
IPEN
GIEH/GIE
GIEL/PEIE
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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
interrupt enable bit. User software should
ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt.
This feature allows for software polling.
INTCON: INTERRUPT 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-x
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF(1)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
GIE/GIEH: Global Interrupt Enable bit
When IPEN = 0:
1 = Enables all unmasked interrupts
0 = Disables all interrupts
When IPEN = 1:
1 = Enables all high-priority interrupts
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)
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 1:
A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and
allow the bit to be cleared.
© 2007 Microchip Technology Inc.
DS39629C-page 95
PIC18F6390/6490/8390/8490
REGISTER 8-2:
INTCON2: INTERRUPT CONTROL REGISTER 2
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
RBPU
INTEDG0
INTEDG1
INTEDG2
INTEDG3
TMR0IP
INT3IP
RBIP
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
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 Interrupt 0 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 5
INTEDG1: External Interrupt 1 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 4
INTEDG2: External Interrupt 2 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 3
INTEDG3: External Interrupt 3 Edge Select bit
1 = Interrupt on rising edge
0 = Interrupt on falling edge
bit 2
TMR0IP: TMR0 Overflow Interrupt Priority bit
1 = High priority
0 = Low priority
bit 1
INT3IP: INT3 External Interrupt Priority bit
1 = High priority
0 = Low priority
bit 0
RBIP: RB Port Change Interrupt Priority bit
1 = High priority
0 = Low priority
Note:
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 interrupt enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
DS39629C-page 96
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 8-3:
INTCON3: INTERRUPT CONTROL REGISTER 3
R/W-1
R/W-1
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
INT2IP
INT1IP
INT3IE
INT2IE
INT1IE
INT3IF
INT2IF
INT1IF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
INT2IP: INT2 External Interrupt Priority bit
1 = High priority
0 = Low priority
bit 6
INT1IP: INT1 External Interrupt Priority bit
1 = High priority
0 = Low priority
bit 5
INT3IE: INT3 External Interrupt Enable bit
1 = Enables the INT3 external interrupt
0 = Disables the INT3 external interrupt
bit 4
INT2IE: INT2 External Interrupt Enable bit
1 = Enables the INT2 external interrupt
0 = Disables the INT2 external interrupt
bit 3
INT1IE: INT1 External Interrupt Enable bit
1 = Enables the INT1 external interrupt
0 = Disables the INT1 external interrupt
bit 2
INT3IF: INT3 External Interrupt Flag bit
1 = The INT3 external interrupt occurred (must be cleared in software)
0 = The INT3 external interrupt did not occur
bit 1
INT2IF: INT2 External Interrupt Flag bit
1 = The INT2 external interrupt occurred (must be cleared in software)
0 = The INT2 external interrupt did not occur
bit 0
INT1IF: INT1 External Interrupt Flag bit
1 = The INT1 external interrupt occurred (must be cleared in software)
0 = The INT1 external interrupt did not occur
Note:
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 interrupt enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
© 2007 Microchip Technology Inc.
DS39629C-page 97
PIC18F6390/6490/8390/8490
8.2
PIR Registers
The PIR registers contain the individual flag bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are three Peripheral Interrupt
Request (Flag) registers (PIR1, PIR2, PIR3).
REGISTER 8-4:
Note 1: Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the global
interrupt enable bit, GIE (INTCON<7>).
2: User software should ensure the
appropriate interrupt flag bits are cleared
prior to enabling an interrupt and after
servicing that interrupt.
PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
U-0
R/W-0
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6
ADIF: A/D Converter Interrupt Flag bit
1 = An A/D conversion completed (must be cleared in software)
0 = The A/D conversion is not complete
bit 5
RC1IF: EUSART Receive Interrupt Flag bit
1 = The EUSART receive buffer, RCREG1, is full (cleared when RCREG1 is read)
0 = The EUSART receive buffer is empty
bit 4
TX1IF: EUSART Transmit Interrupt Flag bit
1 = The EUSART transmit buffer, TXREG1, is empty (cleared when TXREG1 is written)
0 = The EUSART 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/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
bit 1
TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1 = TMR2 to PR2 match occurred (must be cleared in software)
0 = No TMR2 to PR2 match occurred
bit 0
TMR1IF: TMR1 Overflow Interrupt Flag bit
1 = TMR1 register overflowed (must be cleared in software)
0 = TMR1 register did not overflow
DS39629C-page 98
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 8-5:
R/W-0
PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
R/W-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
OSCFIF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
OSCFIF: Oscillator Fail Interrupt Flag bit
1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software)
0 = Device clock operating
bit 6
CMIF: Comparator Interrupt Flag bit
1 = Comparator input has changed (must be cleared in software)
0 = Comparator input has not changed
bit 5-4
Unimplemented: Read as ‘0’
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
HLVDIF: High/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: CCP2 Interrupt Flag bit
Capture mode:
1 = A TMR1/TMR3 register capture occurred (must be cleared in software)
0 = No TMR1/TMR3 register capture occurred
Compare mode:
1 = A TMR1/TMR3 register compare match occurred (must be cleared in software)
0 = No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
© 2007 Microchip Technology Inc.
DS39629C-page 99
PIC18F6390/6490/8390/8490
REGISTER 8-6:
PIR3: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 3
U-0
R/W-0
R-0
R/W-0
U-0
U-0
U-0
U-0
—
LCDIF
RC2IF
TX2IF
—
—
—
—
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6
LCDIF: LCD Interrupt Flag bit (valid when Type-B waveform with Non-Static mode is selected)
1 = LCD data of all COMs is output (must be cleared in software)
0 = LCD data of all COMs is not yet output
bit 5
RC2IF: AUSART Receive Interrupt Flag bit
1 = The AUSART receive buffer, RCREG2, is full (cleared when RCREG2 is read)
0 = The AUSART receive buffer is empty
bit 4
TX2IF: AUSART Transmit Interrupt Flag bit
1 = The AUSART transmit buffer, TXREG2, is empty (cleared when TXREG2 is written)
0 = The AUSART transmit buffer is full
bit 3-0
Unimplemented: Read as ‘0’
DS39629C-page 100
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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 three Peripheral
Interrupt Enable registers (PIE1, PIE2, PIE3). When
IPEN = 0, the PEIE bit must be set to enable any of
these peripheral interrupts.
REGISTER 8-7:
PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
Unimplemented: Read as ‘0’
bit 6
ADIE: A/D Converter Interrupt Enable bit
1 = Enables the A/D interrupt
0 = Disables the A/D interrupt
bit 5
RC1IE: EUSART Receive Interrupt Enable bit
1 = Enables the EUSART receive interrupt
0 = Disables the EUSART receive interrupt
bit 4
TX1IE: EUSART Transmit Interrupt Enable bit
1 = Enables the EUSART transmit interrupt
0 = Disables the EUSART 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
© 2007 Microchip Technology Inc.
x = Bit is unknown
DS39629C-page 101
PIC18F6390/6490/8390/8490
REGISTER 8-8:
PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
R/W-0
R/W-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
OSCFIE: Oscillator Fail Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 6
CMIE: Comparator Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 5-4
Unimplemented: Read as ‘0’
bit 3
BCL1IE: Bus Collision Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 2
HLVDIE: High/Low-Voltage Detect Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 1
TMR3IE: TMR3 Overflow Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 0
CCP2IE: CCP2 Interrupt Enable bit
1 = Enabled
0 = Disabled
DS39629C-page 102
x = Bit is unknown
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 8-9:
PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3
U-0
R/W-0
R-0
R-0
U-0
U-0
U-0
U-0
—
LCDIE
RC2IE
TX2IE
—
—
—
—
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6
LCDIE: LCD Interrupt Enable bit (valid when Type-B waveform with Non-Static mode is selected)
1 = Enabled
0 = Disabled
bit 5
RC2IE: AUSART Receive Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 4
TX2IE: AUSART Transmit Interrupt Enable bit
1 = Enabled
0 = Disabled
bit 3-0
Unimplemented: Read as ‘0’
© 2007 Microchip Technology Inc.
DS39629C-page 103
PIC18F6390/6490/8390/8490
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 three Peripheral
Interrupt Priority registers (IPR1, IPR2, IPR3). Using
the priority bits requires that the Interrupt Priority
Enable (IPEN) bit be set.
REGISTER 8-10:
IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
U-0
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
Unimplemented: Read as ‘0’
bit 6
ADIP: A/D Converter Interrupt Priority bit
1 = High priority
0 = Low priority
bit 5
RC1IP: EUSART Receive Interrupt Priority bit
1 = High priority
0 = Low priority
bit 4
TX1IP: EUSART Transmit Interrupt Priority bit
x = Bit is unknown
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
DS39629C-page 104
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 8-11:
IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
R/W-1
R/W-1
U-0
U-0
R/W-1
R/W-1
R/W-1
R/W-1
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
OSCFIP: Oscillator Fail Interrupt Priority bit
1 = High priority
0 = Low priority
bit 6
CMIP: Comparator Interrupt Priority bit
1 = High priority
0 = Low priority
bit 5-4
Unimplemented: Read as ‘0’
bit 3
BCLIP: Bus Collision Interrupt Priority bit
1 = High priority
0 = Low priority
bit 2
HLVDIP: High/Low-Voltage Detect Interrupt Priority bit
1 = High priority
0 = Low priority
bit 1
TMR3IP: TMR3 Overflow Interrupt Priority bit
1 = High priority
0 = Low priority
bit 0
CCP2IP: CCP2 Interrupt Priority bit
1 = High priority
0 = Low priority
© 2007 Microchip Technology Inc.
x = Bit is unknown
DS39629C-page 105
PIC18F6390/6490/8390/8490
REGISTER 8-12:
IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3
U-0
R/W-1
R/W-1
R/W-1
U-0
U-0
U-0
U-0
—
LCDIP
RC2IP
TX2IP
—
—
—
—
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6
LCDIP: LCD Interrupt Priority bit (valid when Type-B waveform with Non-Static mode is selected)
1 = High priority
0 = Low priority
bit 5
RC2IP: AUSART Receive Interrupt Priority bit
1 = High priority
0 = Low priority
bit 4
TX2IP: AUSART Transmit Interrupt Priority bit
1 = High priority
0 = Low priority
bit 3-0
Unimplemented: Read as ‘0’
DS39629C-page 106
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
8.5
RCON Register
The RCON register contains bits used to determine the
cause of the last Reset or wake-up from Idle or Sleep
modes. RCON also contains the bit that enables
interrupt priorities (IPEN).
REGISTER 8-13:
R/W-0
IPEN
RCON: RESET CONTROL REGISTER
R/W-1
U-0
R/W-1
R-1
R-1
R/W-0
R/W-0
SBOREN
—
RI
TO
PD
POR
BOR
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
IPEN: Interrupt Priority Enable bit
1 = Enable priority levels on interrupts
0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
bit 6
SBOREN: Software BOR Enable bit
For details of bit operation and Reset state, see Register 4-1.
bit 5
Unimplemented: Read as ‘0’
bit 4
RI: RESET Instruction Flag bit
For details of bit operation, see Register 4-1.
bit 3
TO: Watchdog Timer Time-out Flag bit
For details of bit operation, see Register 4-1.
bit 2
PD: Power-Down Detection Flag bit
For details of bit operation, see Register 4-1.
bit 1
POR: Power-on Reset Status bit
For details of bit operation, see Register 4-1.
bit 0
BOR: Brown-out Reset Status bit
For details of bit operation, see Register 4-1.
© 2007 Microchip Technology Inc.
x = Bit is unknown
DS39629C-page 107
PIC18F6390/6490/8390/8490
8.6
INTx Pin Interrupts
8.7
TMR0 Interrupt
External interrupts on the RB0/INT0, RB1/INT1, RB2/
INT2 and RB3/INT3 pins are edge-triggered. If the
corresponding INTEDGx bit in the INTCON2 register is
set (= 1), the interrupt is triggered by a rising edge; if the
bit is clear, the trigger is on the falling edge. When a valid
edge appears on the RBx/INTx pin, the corresponding
flag bit INTxIF is set. This interrupt can be disabled by
clearing the corresponding enable bit, INTxIE. The
interrupt flag bit must be cleared in software in the
Interrupt Service Routine before re-enabling the
interrupt.
In 8-bit mode (which is the default), an overflow in the
TMR0 register (FFh → 00h) will set flag bit, TMR0IF. In
16-bit mode, an overflow in the TMR0H:TMR0L register pair (FFFFh → 0000h) will set TMR0IF. The interrupt
can be enabled/disabled by setting/clearing enable bit,
TMR0IE (INTCON<5>). Interrupt priority for Timer0 is
determined by the value contained in the interrupt
priority bit, TMR0IP (INTCON2<2>). See Section 10.0
“Timer0 Module” for further details on the Timer0
module.
All external interrupts (INT0, INT1, INT2 and INT3) can
wake-up the processor from the power-managed
modes if bit INTxIE was set prior to going into the
power-managed modes. If the Global Interrupt Enable
bit, GIE, is set, the processor will branch to the interrupt
vector following wake-up.
8.8
Interrupt priority for INT1, INT2 and INT3 is determined
by the value contained in the interrupt priority bits,
INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and
INT3IP (INTCON2<1>). There is no priority bit
associated with INT0. It is always a high-priority
interrupt source.
EXAMPLE 8-1:
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 interrupts, the return PC address is saved on
the stack. Additionally, the WREG, STATUS and BSR
registers are saved on the fast return stack. If a fast
return from interrupt is not used (see Section 5.3
“Data Memory Organization”), the user may need to
save the WREG, STATUS and BSR registers on entry
to the Interrupt Service Routine. Depending on the
user’s application, other registers may also need to be
saved. Example 8-1 saves and restores the WREG,
STATUS and BSR registers during an Interrupt Service
Routine.
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
MOVWF
W_TEMP
MOVFF
STATUS, STATUS_TEMP
MOVFF
BSR, BSR_TEMP
;
; USER ISR CODE
;
MOVFF
BSR_TEMP, BSR
MOVF
W_TEMP, W
MOVFF
STATUS_TEMP, STATUS
DS39629C-page 108
PORTB Interrupt-on-Change
; W_TEMP is in virtual bank
; STATUS_TEMP located anywhere
; BSR_TMEP located anywhere
; Restore BSR
; Restore WREG
; Restore STATUS
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
9.0
I/O PORTS
9.1
Depending on the device selected and features
enabled, there are up to nine 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-modify-write operations on the value that the I/O
pins are driving.
A simplified model of a generic I/O port, without the
interfaces to other peripherals, is shown in Figure 9-1.
FIGURE 9-1:
GENERIC I/O PORT
OPERATION
RD LAT
Data
Bus
WR LAT
or PORT
D
Q
I/O pin(1)
Data Latch
WR TRIS
Q
CK
TRIS Latch
Input
Buffer
RD TRIS
Q
D
ENEN
Reading the PORTA register reads the status of the
pins, whereas writing to it will write to the port latch.
The Data Latch register (LATA) is also memory mapped.
Read-modify-write operations on the LATA register read
and write the latched output value for PORTA.
The RA4 pin is multiplexed with the Timer0 module
clock input and the LCD segment drive to become the
RA4/T0CKI/SEG14 pin. Pins RA6 and RA7 are
multiplexed with the main oscillator pins; they are
enabled as oscillator or I/O pins by the selection of the
main oscillator in the Configuration register (see
Section 23.1 “Configuration Bits” for details). When
they are not used as port pins, RA6 and RA7 and their
associated TRIS and LAT bits are read as ‘0’.
The other PORTA pins are multiplexed with analog
inputs and the analog VREF+ and VREF- inputs. The
operation of pins RA3:RA0 and RA5 as A/D converter
inputs is selected by clearing or setting the control bits
in the ADCON1 register (A/D Control Register 1).
The TRISA register controls the direction of the PORTA
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.
RA5:RA2 are also multiplexed with LCD segment
drives controlled by bits in the LCDSE1 and
LCDSE2 registers. I/O port functions are only
available when the segments are disabled.
EXAMPLE 9-1:
CLRF
RD PORT
Note 1:
PORTA is an 8-bit wide, bidirectional 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
high-impedance mode). Clearing a TRISA bit (= 0) will
make the corresponding PORTA pin an output (i.e., put
the contents of the output latch on the selected pin).
The RA4/T0CKI/SEG14 pin is a Schmitt Trigger input
and an open-drain output. All other PORTA pins have
TTL input levels and full CMOS output drivers.
CK
D
PORTA, TRISA and
LATA Registers
I/O pins have diode protection to VDD and VSS.
CLRF
MOVLW
MOVWF
MOVWF
MOVWF
MOVLW
MOVWF
© 2007 Microchip Technology Inc.
PORTA
;
;
;
LATA
;
;
;
07h
;
ADCON1 ;
07h
;
CMCON
;
0CFh
;
;
;
TRISA
;
;
INITIALIZING PORTA
Initialize PORTA by
clearing output
data latches
Alternate method
to clear output
data latches
Configure A/D
for digital inputs
Configure comparators
for digital input
Value used to
initialize data
direction
Set RA<3:0> as inputs
RA<5:4> as outputs
DS39629C-page 109
PIC18F6390/6490/8390/8490
TABLE 9-1:
Pin Name
PORTA FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RA0
0
O
DIG
1
I
TTL
PORTA<0> data input. Reads ‘0’ on POR.
AN0
1
I
ANA
A/D input channel 0. Default configuration on POR.
RA1
0
O
DIG
LATA<1> data output. Not affected by analog pin setting.
RA0/AN0
RA1/AN1
RA2/AN2/VREF-/
SEG16
RA3/AN3/VREF+/
SEG17
RA4/T0CKI/
SEG14
LATA<0> data output. Not affected by analog pin setting.
1
I
TTL
PORTA<1> data input. Reads ‘0’ on POR.
AN1
1
I
ANA
A/D input channel 1. Default configuration on POR.
RA2
0
O
DIG
LATA<2> data output. Not affected by analog pin setting; disabled
when LCD segment enabled.
1
I
TTL
PORTA<2> data input. Reads ‘0’ on POR.
AN2
1
I
ANA
A/D input channel 2. Default configuration on POR.
VREF-
1
I
ANA
A/D low reference voltage input.
SEG16
x
O
ANA
Segment 16 analog output for LCD.
RA3
0
O
DIG
LATA<3> data output. Output is unaffected by analog pin setting;
disabled when LCD segment enabled.
1
I
TTL
PORTA<3> data input. Reads ‘0’ on POR.
AN3
1
I
ANA
A/D input channel 3. Default configuration on POR.
VREF+
1
I
ANA
A/D high reference voltage input.
SEG17
x
O
ANA
Segment 17 analog output for LCD. Disables all other digital outputs.
RA4
0
O
DIG
LATA<4> data output; disabled when LCD segment enabled.
1
I
ST
PORTA<4> data input.
I
ST
T0CKI
Timer0 clock input.
SEG14
x
O
ANA
Segment 14 analog output for LCD.
RA5
0
O
DIG
LATA<5> data output. Not affected by analog pin setting; disabled
when LCD segment enabled.
1
I
TTL
PORTA<5> data input. Reads ‘0’ on POR.
AN4
1
I
ANA
A/D input channel 5. Default configuration on POR.
HLVDIN
1
I
ANA
High/Low-Voltage Detect external trip point input.
RA5/AN4/
HLVDIN/SEG15
OSC2/CLKO/RA6
OSC1/CLKI/RA7
Legend:
Description
SEG15
x
O
ANA
Segment 15 analog output for LCD.
OSC2
x
O
ANA
Main oscillator feedback output connection (XT, HS and LP modes).
CLKO
x
O
DIG
System cycle clock output (FOSC/4) in all oscillator modes except
RCIO, INTIO2 and ECIO.
RA6
0
O
DIG
LATA<6> data output. Enabled in RCIO, INTIO2 and ECIO modes only.
1
I
TTL
PORTA<6> data input. Enabled in RCIO, INTIO2 and ECIO modes only.
x
I
ANA
Main oscillator input connection, all modes except INTIO.
OSC1
CLKI
x
I
ANA
Main clock input connection, all modes except INTIO.
RA7
0
O
DIG
LATA<7> data output. Available only in INTIO modes; otherwise reads
as ‘0’.
1
I
TTL
PORTA<7> data input. Available only in INTIO modes; otherwise reads
as ‘0’.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
DS39629C-page 110
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 9-2:
Name
PORTA
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RA7(1)
RA6(1)
RA5
RA4
RA3
RA2
RA1
RA0
(1)
LATA6(1) LATA Data Output Register
LATA
LATA7
TRISA
TRISA7(1) TRISA6(1) PORTA Data Direction Register
Reset
Values
on Page
62
62
62
ADCON1
—
—
VCFG1
VCFG0
PCFG3
PCFG2
PCFG1
PCFG0
61
LCDSE1
SE15
SE14
SE13
SE12
SE11
SE10
SE9
SE8
64
LCDSE2
SE23
SE22
SE21
SE20
SE19
SE18
SE17
SE16
64
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA.
Note 1: RA7:RA6 and their associated latch and data direction bits are enabled as I/O pins based on oscillator
configuration; otherwise, they are read as ‘0’.
© 2007 Microchip Technology Inc.
DS39629C-page 111
PIC18F6390/6490/8390/8490
9.2
PORTB, TRISB and
LATB Registers
PORTB is an 8-bit wide, bidirectional 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 high-impedance mode). Clearing a TRISB bit (= 0)
will make the corresponding PORTB pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATB) is also memory
mapped. Read-modify-write operations on the LATB
register read and write the latched output value for
PORTB.
EXAMPLE 9-2:
CLRF
PORTB
CLRF
LATB
MOVLW
0CFh
MOVWF
TRISB
Four of the PORTB pins (RB7:RB4) have an
interrupt-on-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 interrupt-on-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 ORed together to generate the RB Port
Change Interrupt with Flag bit, RBIF (INTCON<0>).
This interrupt can wake the device from
power-managed modes. The user, in the Interrupt
Service Routine, can clear the interrupt in the following
manner:
a)
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.
DS39629C-page 112
b)
Any read or write of PORTB (except with the
MOVFF (ANY), PORTB instruction). This will
end the mismatch condition.
Clear flag bit, RBIF.
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.
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.
RB4:RB1 are also multiplexed with LCD segment
drives controlled by bits in the LCDSE1 register. I/O
port functions are only available when the segments
are disabled.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 9-3:
Pin Name
RB0/INT0
RB1/INT1/SEG8
RB2/INT2/SEG9
PORTB FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RB0
0
O
DIG
LATB<0> data output.
1
I
TTL
PORTB<0> data input; programmable weak pull-up.
INT0
1
I
ST
External interrupt 0 input.
RB1
0
O
DIG
LATB<1> data output; disabled when LCD segment enabled.
PORTB<1> data input; weak pull-up when RBPU bit is cleared.
1
I
TTL
INT1
1
I
ST
SEG8
x
O
ANA
Segment 8 analog output for LCD. Disables digital output.
RB2
0
O
DIG
LATB<2> data output; disabled when LCD segment enabled.
1
I
TTL
PORTB<2> data input; weak pull-up when RBPU bit is cleared.
1
I
ST
External interrupt 2 input.
INT2
RB3/INT3/
SEG10
RB4/KBI0/
SEG11
RB5/KBI1
RB6/KBI2/PGC
RB7/KBI3/PGD
Legend:
Note 1:
Description
External interrupt 1 input.
SEG9
x
O
ANA
Segment 9 analog output for LCD
RB3
0
O
DIG
LATB<3> data output; disabled when LCD segment enabled.
1
I
TTL
PORTB<3> data input; weak pull-up when RBPU bit is cleared.
INT3
1
I
ST
SEG10
x
O
ANA
Segment 10 analog output for LCD.
External interrupt 3 input.
RB4
0
O
DIG
LATB<4> data output; disabled when LCD segment enabled.
PORTB<4> data input; weak pull-up when RBPU bit is cleared.
1
I
TTL
KBI0
1
I
TTL
Interrupt-on-pin change.
SEG11
x
O
ANA
Segment 11 analog output for LCD.
RB5
0
O
DIG
LATB<5> data output; disabled when LCD segment enabled.
PORTB<5> data input; weak pull-up when RBPU bit is cleared.
1
I
TTL
KBI1
1
I
TTL
Interrupt-on-pin change.
RB6
0
O
DIG
LATB<6> data output; unavailable when ICD or ICSP™ enabled.
1
I
TTL
PORTB<6> data input; unavailable when ICD or ICSP enabled.
KBI2
1
I
TTL
Interrupt-on-pin change; unavailable when ICD or ICSP enabled.
PGC
x
I
ST
Serial execution (ICSP) clock input for ICSP and ICD operation.(1)
RB7
0
O
DIG
LATB<7> data output; unavailable when ICD or ICSP enabled.
1
I
TTL
PORTB<7> data input; unavailable when ICD or ICSP enabled.
KBI3
1
I
TTL
Interrupt-on-pin change; unavailable when ICD or ICSP enabled.
PGD
x
O
DIG
Serial execution data output for ICSP and ICD operation.(1)
x
I
ST
Serial execution data input for ICSP and ICD operation.(1)
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
All other pin functions are disabled when ICSP or ICD are enabled.
© 2007 Microchip Technology Inc.
DS39629C-page 113
PIC18F6390/6490/8390/8490
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
Reset
Values
on Page
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
62
LATB
LATB Data Output Register
62
TRISB
PORTB Data Direction Register
62
INTCON
GIE/GIEH PEIE/GIEL
TMR0IF
INT0IF
RBIF
59
INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP
TMR0IE
INT0IE
RBIE
INT3IP
RBIP
59
INT3IF
INT2IF
INT1IF
59
SE10
SE9
SE8
64
INTCON2
RBPU
INTCON3
INT2IP
INT1IP
INT3IE
INT2IE
INT1IE
LCDSE1
SE15
SE14
SE13
SE12
SE11
Legend: Shaded cells are not used by PORTB.
DS39629C-page 114
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
9.3
PORTC, TRISC and
LATC Registers
PORTC is an 8-bit wide, bidirectional 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 high-impedance mode). Clearing a TRISC bit (= 0)
will make the corresponding PORTC pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATC) is also memory
mapped. Read-modify-write operations on the LATC
register read and write the latched output value for
PORTC.
PORTC is multiplexed with several peripheral functions
(Table 9-5). The 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).
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.
© 2007 Microchip Technology Inc.
Note:
On a Power-on Reset, these pins are
configured as digital inputs.
The contents of the TRISC register are affected by
peripheral overrides. Reading TRISC always returns
the current contents, even though a peripheral device
may be overriding one or more of the pins.
RC2 and RC5 are also multiplexed with LCD segment
drives controlled by bits in the LCDSE1 register. I/O
port functions are only available when the segments
are disabled.
EXAMPLE 9-3:
CLRF
PORTC
CLRF
LATC
MOVLW
0CFh
MOVWF
TRISC
INITIALIZING PORTC
;
;
;
;
;
;
;
;
;
;
;
;
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
DS39629C-page 115
PIC18F6390/6490/8390/8490
TABLE 9-5:
Pin Name
PORTC FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RC0
0
O
DIG
1
I
ST
T1OSO
x
O
ANA
T13CKI
x
I
ST
Timer1/Timer3 clock input.
RC1
0
O
DIG
LATC<1> data output; disabled when Timer1 oscillator is used.
1
I
ST
T1OSI
x
I
ANA
Timer1 oscillator input.
CCP2(1)
0
O
DIG
CCP2 compare output or PWM output; takes priority over digital I/O data.
RC0/T1OSO/
T13CKI/
RC1/T1OSI/
CCP2
RC2/CCP1/
SEG13
RC2
CCP1
PORTC<0> data input; disabled when Timer1 oscillator is used.
Timer1 oscillator output.
PORTC<1> data input; disabled when Timer1 oscillator is used.
1
I
ST
CCP2 capture input.
0
O
DIG
LATC<2> data output; disabled when LCD segment enabled.
1
I
ST
PORTC<2> data input.
0
O
DIG
CCP1 compare output or PWM output; takes priority over digital I/O data.
1
I
ST
x
O
ANA
Segment 13 analog output for LCD.
RC3
0
O
DIG
LATC<3> data output.
1
I
ST
PORTC<3> data input.
0
O
DIG
SPI clock output (MSSP module); takes priority over port data.
1
I
ST
SPI clock input (MSSP module).
0
O
DIG
I2C™ clock output (MSSP module); takes priority over port data.
1
I
ST
I2C clock input (MSSP module); input type depends on module setting.
0
O
DIG
LATC<4> data output.
1
I
ST
PORTC<4> data input.
SDI
1
I
ST
SPI data input (MSSP module).
SDA
1
O
DIG
I2C data output (MSSP module); takes priority over port data.
1
I
ST
I2C data input (MSSP module); input type depends on module setting.
0
O
DIG
LATC<5> data output; disabled when LCD segment enabled.
1
I
ST
PORTC<5> data input.
SDO
0
O
DIG
SPI data output (MSSP module); takes priority over port data.
SEG12
x
O
ANA
Segment 12 analog output for LCD.
RC6
0
O
DIG
LATC<6> data output.
1
I
ST
PORTC<6> data input.
TX1
1
O
DIG
Synchronous serial data output (EUSART module); takes priority over
port data.
CK1
1
O
DIG
Synchronous serial data input (EUSART module). User must configure
as an input.
SCK
SCL
RC4/SDI/SDA
RC4
RC5/SDO/
SEG12
RC5
RC6/TX1/CK1
RC7/RX1/DT1
Note 1:
LATC<0> data output; disabled when Timer1 oscillator is used.
SEG13
RC3/SCK/SCL
Legend:
Description
RC7
CCP1 capture input.
1
I
ST
Synchronous serial clock input (EUSART module).
0
O
DIG
LATC<7> data output.
1
I
ST
PORTC<7> data input.
RX1
1
I
ST
Asynchronous serial receive data input (EUSART module).
DT1
1
O
DIG
Synchronous serial data output (EUSART module); takes priority over
port data.
1
I
ST
Synchronous serial data input (EUSART module). User must configure
as an input.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Default assignment for CCP2 (CCP2MX Configuration bit = 1).
DS39629C-page 116
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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
Reset
Values
on Page
RC7
RC6
RC5
RC4
RC3
RC2
RC1
RC0
62
LATC
LATC Data Output Register
62
TRISC
PORTC Data Direction Register
62
LCDSE1
SE15
SE14
SE13
SE12
SE11
SE10
SE9
SE8
64
Legend: Shaded cells are not used by PORTC.
© 2007 Microchip Technology Inc.
DS39629C-page 117
PIC18F6390/6490/8390/8490
9.4
PORTD, TRISD and
LATD Registers
PORTD is also multiplexed with LCD segment drives
controlled by the LCDSE0 register. I/O port functions
are only available when the segments are disabled.
PORTD is an 8-bit wide, bidirectional 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 high-impedance mode). Clearing a TRISD bit (= 0)
will make the corresponding PORTD pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATD) is also memory
mapped. Read-modify-write operations on the LATD
register read and write the latched output value for
PORTD.
EXAMPLE 9-4:
CLRF
PORTD
CLRF
LATD
MOVLW
0CFh
MOVWF
TRISD
All pins on PORTD are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note:
;
;
;
;
;
;
;
;
;
;
;
;
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
On a Power-on Reset, these pins are
configured as digital inputs.
TABLE 9-7:
Pin Name
PORTD FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RD0
0
O
DIG
1
I
ST
SEG0
x
O
ANA
Segment 0 analog output for LCD.
RD1
0
O
DIG
LATD<1> data output; disabled when LCD segment enabled.
1
I
ST
PORTD<1> data input.
RD0/SEG0
RD1/SEG1
RD2/SEG2
RD3/SEG3
RD4/SEG4
RD5/SEG5
RD6/SEG6
RD7/SEG7
Description
LATD<0> data output; disabled when LCD segment enabled.
PORTD<0> data input.
SEG1
x
O
ANA
Segment 1 analog output for LCD.
RD2
0
O
DIG
LATD<2> data output; disabled when LCD segment enabled.
1
I
ST
SEG2
x
O
ANA
Segment 2 analog output for LCD.
RD3
0
O
DIG
LATD<3> data output; disabled when LCD segment enabled.
1
I
ST
SEG3
x
O
ANA
Segment 3 analog output for LCD.
RD4
0
O
DIG
LATD<4> data output; disabled when LCD segment enabled.
PORTD<2> data input.
PORTD<3> data input.
1
I
ST
SEG4
x
O
ANA
Segment 4 analog output for LCD module.
RD5
0
O
DIG
LATD<5> data output; disabled when LCD segment enabled.
1
I
ST
PORTD<5> data input.
PORTD<4> data input.
SEG5
x
O
ANA
Segment 5 analog output for LCD.
RD6
0
O
DIG
LATD<6> data output; disabled when LCD segment enabled.
1
I
ST
SEG6
x
O
ANA
Segment 6 analog output for LCD.
RD7
0
O
DIG
LATD<7> data output; disabled when LCD segment enabled.
1
I
ST
x
O
ANA
SEG7
Legend:
INITIALIZING PORTD
PORTD<6> data input.
PORTD<7> data input.
Segment 7 analog output for LCD.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
DS39629C-page 118
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 9-8:
Name
PORTD
SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
RD7
RD6
RD5
RD4
RD3
RD2
RD1
RD0
62
LATD
LATD Data Output Register
62
TRISD
PORTD Data Direction Register
62
LCDSE0
SE7
SE6
© 2007 Microchip Technology Inc.
SE5
SE4
SE3
SE2
SE1
SE0
64
DS39629C-page 119
PIC18F6390/6490/8390/8490
9.5
PORTE, TRISE and
LATE Registers
PORTE is a 4-bit wide, bidirectional 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 high-impedance mode). Clearing a TRISE bit (= 0)
will make the corresponding PORTE pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATE) is also memory
mapped. Read-modify-write operations on the LATE
register read and write the latched output value for
PORTE.
All pins on PORTE are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note:
On a Power-on Reset, these pins are
configured as digital inputs.
Pins RE6:RE4 are multiplexed with three of the LCD
common drives. I/O port functions are only available on
those PORTE pins, depending on which commons are
active. The configuration is determined by the
LMUX1:LMUX0 control bits (LCDCON<1:0>). The
availability is summarized in Table 9-9.
RE7 is also multiplexed with LCD segment drive
(SEG31) controlled by the LCDSE3<7> bit. I/O port
function is only available when the segment is disabled.
Note:
RE7 also can be configured as the alternate peripheral
pin for the CCP2 module. This is done by clearing the
CCP2MX Configuration bit.
TABLE 9-9:
PORTE PINS AVAILABLE IN
DIFFERENT LCD DRIVE
CONFIGURATIONS
LCDCON
<1:0>
Active LCD
Commons
PORTE Available
for I/O
00
COM0
RE6, RE5, RE4
01
COM0, COM1
RE6, RE5
10
COM0, COM1
and COM2
RE6
11
All (COM0
through COM3)
None
EXAMPLE 9-5:
CLRF
PORTE
CLRF
LATE
MOVLW
30h
MOVWF
TRISE
INITIALIZING PORTE
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTE by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RE<5:4> as inputs
RE<7:6> as outputs
The pins corresponding to RE2:RE0 of
other PIC18F parts have the function of
LCDBIAS3:LCDBIAS1 and the pin
corresponding to RE3 of other PIC18F
parts has the function of COM0. These four
pins cannot be used as digital I/O.
DS39629C-page 120
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 9-10:
Pad Name
PORTE FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RE4
0
O
DIG
1
I
ST
COM1
x
O
ANA
Common 1 analog output for LCD.
RE5
0
O
DIG
LATE<5> data output; disabled when LCD common enabled.
1
I
ST
COM2
x
O
ANA
Common 2 analog output for LCD.
RE6
0
O
DIG
LATE<6> data output; disabled when LCD segment enabled.
1
I
ST
PORTE<6> data input.
RE4/COM1
RE5/COM2
RE6/COM3
RE7/CCP2/
SEG31
PORTE
PORTE<5> data input.
x
O
ANA
Common 3 analog output for LCD.
0
O
DIG
LATE<7> data output; disabled when LCD segment enabled.
1
I
ST
PORTE<7> data input.
0
O
DIG
CCP2 compare output and CCP2 PWM output; takes priority over port data.
1
I
ST
x
O
ANA
CCP2 capture input.
Segment 31 analog output for LCD.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Alternate assignment for CCP2 when the CCP2MX Configuration bit = 0.
TABLE 9-11:
Name
PORTE<4> data input.
RE7
SEG31
Note 1:
LATE<4> data output; disabled when LCD common enabled.
COM3
CCP2(1)
Legend:
Description
SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
RE7
RE6
RE5
RE4
—
—
—
—
62
—
—
—
—
62
LATE
LATE Data Output Register
TRISE
PORTE Data Direction Register
—
—
—
—
62
LCDCON
LCDEN
SLPEN
WERR
—
CS1
CS0
LMUX1
LMUX0
64
LCDSE3
SE31
SE30
SE29
SE28
SE27
SE26
SE25
SE24
64
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTE.
© 2007 Microchip Technology Inc.
DS39629C-page 121
PIC18F6390/6490/8390/8490
9.6
PORTF, LATF and TRISF Registers
PORTF is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISF. Setting a
TRISF bit (= 1) will make the corresponding PORTF pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISF bit (= 0) will
make the corresponding PORTF pin an output (i.e., put
the contents of the output latch on the selected pin).
The Data Latch register (LATF) is also memory
mapped. Read-modify-write operations on the LATF
register read and write the latched output value for
PORTF.
All pins on PORTF are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
EXAMPLE 9-6:
CLRF
CLRF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
PORTF
;
;
;
LATF
;
;
;
0x07
;
CMCON
;
0x0F
;
ADCON1 ;
0xCF
;
;
;
TRISF
;
;
;
INITIALIZING PORTF
Initialize PORTF by
clearing output
data latches
Alternate method
to clear output
data latches
Turn off comparators
Set PORTF as digital I/O
Value used to
initialize data
direction
Set RF3:RF0 as inputs
RF5:RF4 as outputs
RF7:RF6 as inputs
PORTF is multiplexed with several analog peripheral
functions, including the A/D converter inputs and
comparator inputs, outputs and voltage reference.
Note 1: On a Power-on Reset, the RF6:RF0 pins
are configured as inputs and read as ‘0’.
2: To configure PORTF as digital I/O, turn off
comparators and set ADCON1 value.
PORTF is also multiplexed with LCD segment drives
controlled by bits in the LCDSE2 and LCDSE3
registers. I/O port functions are only available when the
segments are disabled.
DS39629C-page 122
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 9-12:
Pin Name
RF0/AN5/
SEG18
RF1/AN6/
C2OUT/SEG19
RF2/AN7/
C1OUT/SEG20
RF3/AN8/
SEG21
RF4/AN9/
SEG22
RF5/AN10/
CVREF/SEG23
RF6/AN11/
SEG24
RF7/SS/SEG25
Legend:
PORTF FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
Description
RF0
0
O
DIG
LATF<0> data output. Output is unaffected by analog input; disabled
when LCD segment is enabled.
1
I
ST
PORTF<0> data input. Reads ‘0’ on POR.
AN5
1
I
ANA
A/D input channel 5. Default configuration on POR.
SEG18
x
O
ANA
Segment 18 analog output for LCD.
RF1
0
O
DIG
LATF<1> data output. Output is unaffected by analog input; disabled
when LCD segment is enabled.
1
I
ST
AN6
1
I
ANA
A/D input channel 6. Default configuration on POR.
PORTF<1> data input. Reads ‘0’ on POR.
C2OUT
0
O
DIG
Comparator 2 output; takes priority over port data.
SEG19
x
O
ANA
Segment 19 analog output for LCD.
RF2
0
O
DIG
LATF<2> data output. Output is unaffected by analog input; disabled
when LCD segment is enabled.
1
I
ST
AN7
1
I
ANA
PORTF<2> data input. Reads ‘0’ on POR.
C1OUT
0
O
TTL
Comparator 1 output; takes priority over port data.
SEG20
x
O
ANA
Segment 20 analog output for LCD.
RF3
0
O
DIG
LATF<3> data output. Output is unaffected by analog input; disabled
when LCD segment is enabled.
1
I
ST
PORTF<3> data input. Reads ‘0’ on POR.
AN8
1
I
ANA
A/D input channel 8 and Comparator C2+ input. Default input
configuration on POR; not affected by analog output.
SEG21
x
O
ANA
Segment 21 analog output for LCD.
RF4
0
O
DIG
LATF<4> data output. Output is unaffected by analog input; disabled
when LCD segment is enabled.
1
I
ST
PORTF<4> data input. Reads ‘0’ on POR.
AN9
1
I
ANA
A/D input channel 9 and Comparator C2- input. Default input
configuration on POR; does not affect digital output.
SEG22
x
O
ANA
Segment 22 analog output for LCD.
RF5
0
O
DIG
LATF<5> data output. Output unaffected by analog input; disabled
when either LCD segment or CVREF is enabled.
1
I
ST
PORTF<5> data input. Reads ‘0’ on POR.
AN10
1
I
ANA
A/D input channel 10 and Comparator C1+ input. Default input
configuration on POR.
CVREF
0
O
ANA
Comparator voltage reference output. Enabling this feature disables
digital I/O.
A/D input channel 7. Default configuration on POR.
SEG23
x
O
ANA
Segment 23 analog output for LCD.
RF6
0
O
DIG
LATF<6> data output. Output is unaffected by analog input; disabled
when LCD segment is enabled.
1
I
ST
AN11
1
I
ANA
A/D input channel 11 and Comparator C1- input. Default input
configuration on POR; does not affect digital output.
PORTF<6> data input. Reads ‘0’ on POR.
SEG24
x
O
ANA
Segment 24 analog output for LCD.
RF7
0
O
DIG
LATF<7> data output; disabled when LCD segment is enabled.
1
I
ST
PORTF<7> data input.
SS
1
I
TTL
Slave select input for MSSP module.
SEG25
x
O
ANA
Segment 25 analog output for LCD.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
© 2007 Microchip Technology Inc.
DS39629C-page 123
PIC18F6390/6490/8390/8490
TABLE 9-13:
Name
TRISF
SUMMARY OF REGISTERS ASSOCIATED WITH PORTF
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset Values
on Page
PORTF Data Direction Register
62
PORTF
Read PORTF Data Latch/Write PORTF Data Latch
62
LATF
LATF Data Output Register
62
ADCON1
—
—
VCFG1
VCFG0
PCFG3
PCFG2
PCFG1
PCFG0
61
CMCON
C2OUT
C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
61
CVRCON
CVREN
CVROE
CVRR
CVRSS
CVR3
CVR2
CVR1
CVR0
61
LCDSE2
SE23
SE22
SE21
SE20
SE19
SE18
SE17
SE16
64
LCDSE3
SE31
SE30
SE29
SE28
SE27
SE26
SE25
SE24
64
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTF.
DS39629C-page 124
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
9.7
PORTG, TRISG and
LATG Registers
PORTG is a 6-bit wide, bidirectional port. The corresponding Data Direction register is TRISG. Setting a
TRISG bit (= 1) will make the corresponding PORTG
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISG bit (= 0)
will make the corresponding PORTG pin an output (i.e.,
put the contents of the output latch on the selected pin).
The Data Latch register (LATG) is also memory
mapped. Read-modify-write operations on the LATG
register read and write the latched output value for
PORTG.
PORTG<4:0> are also multiplexed with LCD segment
drives controlled by bits in the LCDSE3 register. I/O
port functions are only available when the segments
are disabled.
The sixth pin of PORTG (MCLR/VPP/RG5) is an input
only pin. Its operation is controlled by the MCLRE
Configuration bit. When selected as a port pin
(MCLRE = 0), it functions as a digital input only pin; as
such, it does not have TRIS or LAT bits associated with
its operation. Otherwise, it functions as the device’s
Master Clear input. In either configuration, RG5 also
functions as the programming voltage input during
programming.
Note:
PORTG is multiplexed with both USART and LCD
functions (Table 9-14). PORTG pins have Schmitt
Trigger input buffers.
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTG 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. 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.
© 2007 Microchip Technology Inc.
On a Power-on Reset, RG5 is enabled as
a digital input only if Master Clear
functionality is disabled. All other 5 pins
are configured as digital inputs.
EXAMPLE 9-7:
CLRF
PORTG
CLRF
LATG
MOVLW
0x04
MOVWF
TRISG
INITIALIZING PORTG
;
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTG by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RG1:RG0 as outputs
RG2 as input
RG4:RG3 as inputs
DS39629C-page 125
PIC18F6390/6490/8390/8490
TABLE 9-14:
Pin Name
PORTG FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RG0
0
O
DIG
LATG<0> data output; disabled when LCD segment enabled.
1
I
ST
PORTG<0> data input.
RG0/SEG30
SEG30
x
O
ANA
Segment 30 analog output for LCD.
RG1
0
O
DIG
LATG<1> data output; disabled when LCD segment enabled.
RG1/TX2/CK2/
SEG29
ST
PORTG<1> data input.
O
DIG
Synchronous serial data output (AUSART module); takes priority over
port data.
CK2
1
O
DIG
Synchronous serial data input (AUSART module). User must configure
as an input.
1
I
ST
Synchronous serial clock input (AUSART module).
x
O
ANA
0
O
DIG
LATG<2> data output; disabled when LCD segment enabled.
1
I
ST
PORTG<2> data input.
RX2
1
I
ST
Asynchronous serial receive data input (AUSART module).
DT2
1
O
DIG
Synchronous serial data output (AUSART module); takes priority over
port data.
1
I
ST
Synchronous serial data input (AUSART module). User must configure
as an input.
Segment 29 analog output for LCD.
SEG28
x
O
ANA
Segment 28 analog output for LCD.
RG3
0
O
DIG
LATG<3> data output; disabled when LCD segment enabled.
1
I
ST
SEG27
0
O
ANA
RG4
0
O
DIG
LATG<4> data output; disabled when LCD segment enabled.
1
I
ST
PORTG<4> data input.
SEG26
x
O
ANA
MCLR
—(1)
I
ST
VPP
—(1)
I
ANA
RG5
—(1)
I
ST
RG4/SEG26
MCLR/VPP/RG5
PORTG<3> data input.
Segment 27 analog output for LCD.
Segment 26 analog output for LCD.
External Master Clear input; enabled when MCLRE Configuration bit is set.
High-voltage detection; used for ICSP™ mode entry detection. Always
available, regardless of pin mode.
PORTG<5> data input; enabled when MCLRE Configuration bit is clear.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
RG5 does not have a corresponding TRISG bit.
TABLE 9-15:
Name
I
1
RG2
RG3/SEG27
Note 1:
1
TX2
SEG29
RG2/RX2/DT2/
SEG28
Legend:
Description
SUMMARY OF REGISTERS ASSOCIATED WITH PORTG
Bit 6
Bit 5
PORTG
—
—
RG5(1)
Read PORTG pin/Write PORTG Data Latch
62
LATG
—
—
—
LATG Data Output Register
62
TRISG
—
—
—
PORTG Data Direction Register
62
SE31
SE30
SE29
LCDSE3
Bit 4
SE28
Bit 3
SE27
Bit 2
SE26
Bit 1
SE25
Bit 0
Reset Values
on Page
Bit 7
SE24
64
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTG.
Note 1: RG5 is available as an input only when MCLR is disabled.
DS39629C-page 126
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
9.8
Note:
PORTH, LATH and
TRISH Registers
PORTH is available only on 80-pin
devices.
PORTH is an 8-bit wide, bidirectional I/O port. The corresponding Data Direction register is TRISH. Setting a
TRISH bit (= 1) will make the corresponding PORTH
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISH bit (= 0)
will make the corresponding PORTH pin an output (i.e.,
put the contents of the output latch on the selected pin).
EXAMPLE 9-8:
CLRF
PORTH
CLRF
LATH
MOVLW
0CFh
MOVWF
TRISH
INITIALIZING PORTH
;
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTH by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RH3:RH0 as inputs
RH5:RH4 as outputs
RH7:RH6 as inputs
The Data Latch register (LATH) is also memory
mapped. Read-modify-write operations on the LATH
register read and write the latched output value for
PORTH.
All pins on PORTH are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note:
On a Power-on Reset, these pins are
configured as digital inputs.
PORTH is also multiplexed with LCD segment drives
controlled by the LCDSE5 register. I/O port functions
are only available when the segments are disabled.
© 2007 Microchip Technology Inc.
DS39629C-page 127
PIC18F6390/6490/8390/8490
TABLE 9-16:
Pin Name
PORTH FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RH0
0
O
DIG-4
1
I
ST
SEG47
x
O
ANA
Segment 47 analog output for LCD.
RH1
0
O
DIG
LATH<1> data output; disabled when LCD segment enabled.
RH0/SEG47
RH1/SEG46
RH2/SEG45
RH3/SEG44
RH4/SEG40
RH5/SEG41
RH6/SEG42
RH7/SEG43
TRISH
PORTH<0> data input.
1
I
ST
x
O
ANA
Segment 46 analog output for LCD.
PORTH<1> data input.
RH2
0
O
DIG
LATH<2> data output; disabled when LCD segment enabled.
1
I
ST
PORTH<2> data input.
SEG45
x
O
ANA
Segment 45 analog output for LCD.
RH3
0
O
DIG
LATH<3> data output; disabled when LCD segment enabled.
1
I
ST
SEG44
x
O
ANA
Segment 44 analog output for LCD.
RH4
0
O
DIG
LATH<4> data output; disabled when LCD segment enabled.
1
I
ST
SEG40
x
O
ANA
Segment 40 analog output for LCD
RH5
0
O
DIG
LATH<5> data output; disabled when LCD segment enabled.
PORTH<3> data input.
PORTH<4> data input.
1
I
ST
SEG41
x
O
ANA
Segment 41 analog output for LCD.
PORTH<5> data input.
RH6
0
O
DIG
LATH<6> data output; disabled when LCD segment enabled.
1
I
ST
PORTH<6> data input.
SEG42
x
O
ANA
Segment 42 analog output for LCD.
RH7
0
O
DIG
LATH<7> data output; disabled when LCD segment enabled.
1
I
ST
x
O
ANA
PORTH<7> data input.
Segment 43 analog output for LCD.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 9-17:
Name
LATH<0> data output; disabled when LCD segment enabled.
SEG46
SEG43
Legend:
Description
SUMMARY OF REGISTERS ASSOCIATED WITH PORTH
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset Values
on Page
PORTH Data Direction Register
62
PORTH
Read PORTH pin/Write PORTH Data Latch
62
LATH
LATH Data Output Register
62
LCDSE5
SE47
DS39629C-page 128
SE46
SE45
SE44
SE43
SE42
SE41
SE40
64
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
9.9
Note:
PORTJ, TRISJ and
LATJ Registers
EXAMPLE 9-9:
CLRF
PORTJ
CLRF
LATJ
PORTJ is available only on 80-pin devices.
PORTJ is an 8-bit wide, bidirectional port. The corresponding Data Direction register is TRISJ. Setting a
TRISJ bit (= 1) will make the corresponding PORTJ pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISJ bit (= 0) will
make the corresponding PORTJ pin an output (i.e., put
the contents of the output latch on the selected pin).
The Data Latch register (LATJ) is also memory
mapped. Read-modify-write operations on the LATJ
register read and write the latched output value for
PORTJ.
MOVLW 0xCF
MOVWF TRISJ
INITIALIZING PORTJ
;
;
;
;
;
;
;
;
;
;
;
;
Initialize PORTG by
clearing output
data latches
Alternate method
to clear output
data latches
Value used to
initialize data
direction
Set RJ3:RJ0 as inputs
RJ5:RJ4 as output
RJ7:RJ6 as inputs
All pins on PORTJ are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note:
On a Power-on Reset, these pins are
configured as digital inputs.
PORTJ is also multiplexed with LCD segment drives
controlled by the LCDSE4 register. I/O port functions
are only available when the segments are disabled.
© 2007 Microchip Technology Inc.
DS39629C-page 129
PIC18F6390/6490/8390/8490
TABLE 9-18:
Pin Name
PORTJ FUNCTIONS
Function
TRIS
Setting
I/O
Buffer
RJ0
0
O
DIG
1
I
ST
SEG32
x
O
ANA
Segment 32 analog output for LCD.
RJ1
0
O
DIG
LATJ<1> data output; disabled when LCD segment enabled.
RJ0/SEG32
RJ1/SEG33
RJ2/SEG34
RJ3/SEG35
RJ4/SEG39
RJ5/SEG38
RJ6/SEG37
RJ7/SEG36
PORTJ
PORTJ<0> data input.
1
I
ST
x
O
ANA
Segment 33 analog output for LCD.
PORTJ<1> data input.
RJ2
0
O
DIG
LATJ<2> data output; disabled when LCD segment enabled.
1
I
ST
PORTJ<2> data input.
SEG34
x
O
ANA
Segment 34 analog output for LCD.
RJ3
0
O
DIG
LATJ<3> data output; disabled when LCD segment enabled.
1
I
ST
SEG35
x
O
ANA
Segment 35 analog output for LCD.
RJ4
0
O
DIG
LATJ<4> data output; disabled when LCD segment enabled.
1
I
ST
SEG39
x
O
ANA
Segment 39 analog output for LCD.
RJ5
0
O
DIG
LATJ<5> data output; disabled when LCD segment enabled.
PORTJ<3> data input.
PORTJ<4> data input.
1
I
ST
SEG38
x
O
ANA
Segment 38 analog output for LCD.
PORTJ<5> data input.
RJ6
0
O
DIG
LATJ<6> data output; disabled when LCD segment enabled.
1
I
ST
PORTJ<6> data input.
SEG37
x
O
ANA
Segment 37 analog output for LCD.
RJ7
0
O
DIG
LATJ<7> data output; disabled when LCD segment enabled.
1
I
ST
x
O
ANA
PORTJ<7> data input.
Segment 36 analog output for LCD.
O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input, TTL = TTL Buffer Input,
x = Don’t care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 9-19:
Name
LATJ<0> data output; disabled when LCD segment enabled.
SEG33
SEG36
Legend:
Description
SUMMARY OF REGISTERS ASSOCIATED WITH PORTJ
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset Values
on Page
Read PORTJ pin/Write PORTJ Data Latch
62
LATJ
LATJ Data Output Register
62
TRISJ
PORTJ Data Direction Register
62
LCDSE4
SE39
DS39629C-page 130
SE38
SE37
SE36
SE35
SE34
SE33
SE32
64
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
10.0
TIMER0 MODULE
The Timer0 module incorporates the following features:
• Software selectable operation as a timer or
counter in both 8-bit or 16-bit modes
• Readable and writable registers
• Dedicated 8-bit software programmable prescaler
• Selectable clock source (internal or external)
• Edge select for external clock
• Interrupt-on-overflow
REGISTER 10-1:
The T0CON register (Register 10-1) controls all
aspects of the module’s operation, including the
prescale selection. It is both readable and writable.
A simplified block diagram of the Timer0 module in
8-bit mode is shown in Figure 10-1. Figure 10-2
shows a simplified block diagram of the Timer0
module in 16-bit mode.
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
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
TMR0ON: Timer0 On/Off Control bit
1 = Enables Timer0
0 = Stops Timer0
bit 6
T08BIT: Timer0 8-Bit/16-Bit Control bit
1 = Timer0 is configured as an 8-bit timer/counter
0 = Timer0 is configured as a 16-bit timer/counter
bit 5
T0CS: Timer0 Clock Source Select bit
1 = Transition on T0CKI pin
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
© 2007 Microchip Technology Inc.
DS39629C-page 131
PIC18F6390/6490/8390/8490
10.1
Timer0 Operation
Timer0 can operate as either a timer or a counter; the
mode is selected by clearing the T0CS bit (T0CON<5>).
In Timer mode (T0CS = 0), the module increments on
every clock by default, unless a different prescaler value
is selected (see Section 10.3 “Prescaler”). If the TMR0
register is written to, the increment is inhibited for the
following two instruction cycles. The user can work
around this by writing an adjusted value to the TMR0
register.
The Counter mode is selected by setting the T0CS bit
(= 1). In Counter mode, Timer0 increments either on
every rising or falling edge of pin RA4/T0CKI. The
incrementing edge is determined by the Timer0 Source
Edge Select bit, T0SE (T0CON<4>); clearing this bit
selects the rising edge. Restrictions on the external
clock input are discussed below.
An external clock source can be used to drive Timer0;
however, it must meet certain requirements to ensure
that the external clock can be synchronized with the
FIGURE 10-1:
internal phase clock (TOSC). There is a delay between
synchronization and the onset of incrementing the
timer/counter.
10.2
Timer0 Reads and Writes in
16-Bit Mode
TMR0H is not the actual high byte of Timer0 in 16-bit
mode; it is actually a buffered version of the real high
byte of Timer0, which is not directly readable nor
writable (refer to Figure 10-2). TMR0H is updated with
the contents of the high byte of Timer0 during a read of
TMR0L. This provides the ability to read all 16 bits of
Timer0, without having to verify that the read of the high
and low byte were valid, due to a rollover between
successive reads of the high and low byte.
Similarly, a write to the high byte of Timer0 must also
take place through the TMR0H Buffer register. The high
byte is updated with the contents of TMR0H when a
write occurs to TMR0L. This allows all 16 bits of Timer0
to be updated at once.
TIMER0 BLOCK DIAGRAM (8-BIT MODE)
FOSC/4
0
1
1
T0CKI pin
T0SE
Programmable
Prescaler
0
Sync with
Internal
Clocks
(2 TCY Delay)
8
3
T0CS
Set
TMR0IF
on Overflow
TMR0L
8
T0PS2:T0PS0
Internal Data Bus
PSA
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.
FIGURE 10-2:
TIMER0 BLOCK DIAGRAM (16-BIT MODE)
FOSC/4
0
1
1
T0CKI pin
T0SE
T0CS
Programmable
Prescaler
0
Sync with
Internal
Clocks
TMR0
High Byte
TMR0L
8
(2 TCY Delay)
3
Read TMR0L
T0PS2:T0PS0
PSA
Set
TMR0IF
on Overflow
Write TMR0L
8
8
TMR0H
8
8
Internal Data Bus
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.
DS39629C-page 132
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
10.3
Prescaler
10.3.1
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not directly readable or writable;
its value is set by the PSA and T0PS2:T0PS0 bits
(T0CON<3:0>), which determine the prescaler
assignment and prescale ratio.
Clearing the PSA bit assigns the prescaler to the
Timer0 module. When it is assigned, prescale values
from 1:2 through 1:256 in power-of-2 increments are
selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0, MOVWF
TMR0, BSF TMR0, etc.) clear the prescaler count.
Note:
Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count, but will not change the prescaler
assignment.
TABLE 10-1:
Name
Bit 7
Bit 6
Bit 5
Timer0 Register Low Byte
TMR0H
Timer0 Register High Byte
INTCON
GIE/GIEH PEIE/GIEL TMR0IE
TRISA
The prescaler assignment is fully under software
control and can be changed “on-the-fly” during program
execution.
10.4
Timer0 Interrupt
The TMR0 interrupt is generated when the TMR0
register overflows from FFh to 00h in 8-bit mode, or
from FFFFh to 0000h in 16-bit mode. This overflow sets
the TMR0IF flag bit. The interrupt can be masked by
clearing the TMR0IE bit (INTCON<5>). Before
re-enabling the interrupt, the TMR0IF bit must be
cleared in software by the Interrupt Service Routine.
Since Timer0 is shut down in Sleep mode, the TMR0
interrupt cannot awaken the processor from Sleep.
REGISTERS ASSOCIATED WITH TIMER0
TMR0L
T0CON
SWITCHING PRESCALER
ASSIGNMENT
TMR0ON
T08BIT
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
60
60
T0CS
PORTA Data Direction Register
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
T0SE
PSA
T0PS2
T0PS1
T0PS0
59
60
62
Legend: Shaded cells are not used by Timer0.
© 2007 Microchip Technology Inc.
DS39629C-page 133
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 134
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
11.0
TIMER1 MODULE
The Timer1 timer/counter module incorporates these
features:
• Software selectable operation as a 16-bit timer or
counter
• Readable and writable 8-bit registers (TMR1H
and TMR1L)
• Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
• Interrupt-on-overflow
• Reset on CCP Special Event Trigger
• Device clock status flag (T1RUN)
REGISTER 11-1:
A simplified block diagram of the Timer1 module is
shown in Figure 11-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 11-2.
The module incorporates its own low-power oscillator
to provide an additional clocking option. The Timer1
oscillator can also be used as a low-power clock source
for the microcontroller in power-managed operation.
Timer1 can also be used to provide Real-Time Clock
(RTC) functionality to applications with only a minimal
addition of external components and code overhead.
Timer1 is controlled through the T1CON Control
register (Register 11-1). It also contains the Timer1
Oscillator Enable bit (T1OSCEN). Timer1 can be
enabled or disabled by setting or clearing control bit,
TMR1ON (T1CON<0>).
T1CON: TIMER1 CONTROL REGISTER
R/W-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
RD16
T1RUN
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
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
T1RUN: Timer1 System Clock Status bit
1 = Device clock is derived from Timer1 oscillator
0 = Device clock is derived from another source
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
© 2007 Microchip Technology Inc.
DS39629C-page 135
PIC18F6390/6490/8390/8490
11.1
Timer1 Operation
cycle (FOSC/4). When the bit is set, Timer1 increments
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
Timer1 can operate in one of these modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
When Timer1 is enabled, the RC1/T1OSI and
RC0/T1OSO/T13CKI pins become inputs. This means
the values of TRISC<1:0> are ignored and the pins are
read as ‘0’.
The operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>). When TMR1CS is cleared
(= 0), Timer1 increments on every internal instruction
FIGURE 11-1:
TIMER1 BLOCK DIAGRAM
Timer1 Oscillator
On/Off
T1OSO/T13CKI
1
FOSC/4
Internal
Clock
T1OSI
1
Synchronize
Prescaler
1, 2, 4, 8
0
Detect
0
2
T1OSCEN
(1)
Sleep Input
TMR1CS
Timer1
On/Off
T1CKPS1:T1CKPS0
T1SYNC
TMR1ON
Clear TMR1
(CCP Special Event Trigger)
Set
TMR1IF
on Overflow
TMR1
High Byte
TMR1L
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
FIGURE 11-2:
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Oscillator
1
T1OSO/T13CKI
1
FOSC/4
Internal
Clock
T1OSI
Synchronize
Prescaler
1, 2, 4, 8
0
Detect
0
2
T1OSCEN(1)
Sleep Input
TMR1CS
Timer1
On/Off
T1CKPS1:T1CKPS0
T1SYNC
TMR1ON
Clear TMR1
(CCP Special Event Trigger)
TMR1
High Byte
TMR1L
8
Set
TMR1IF
on Overflow
Read TMR1L
Write TMR1L
8
8
TMR1H
8
8
Internal Data Bus
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
DS39629C-page 136
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
11.2
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 register. This
provides the user with the ability to accurately read all
16 bits of Timer1 without having to determine whether
a read of the high byte, followed by a read of the low
byte, has become invalid due to a rollover between
reads.
TABLE 11-1: CAPACITOR SELECTION FOR
THE TIMER1 OSCILLATOR(2,3,4)
Osc Type
LP
11.3
Timer1 Oscillator
An on-chip crystal oscillator circuit is incorporated
between pins T1OSI (input) and T1OSO (amplifier
output). It is enabled by setting the Timer1 Oscillator
Enable bit, T1OSCEN (T1CON<3>). The oscillator is a
low-power circuit rated for 32 kHz crystals. It will
continue to run during all power-managed modes. The
circuit for a typical LP oscillator is shown in Figure 11-3.
Table 11-1 shows the capacitor selection for the Timer1
oscillator.
The user must provide a software time delay to ensure
proper start-up of the Timer1 oscillator.
FIGURE 11-3:
EXTERNAL
COMPONENTS FOR THE
TIMER1 LP OSCILLATOR
C1
33 pF
PIC18FXXXX
T1OSI
XTAL
32.768 kHz
T1OSO
C2
33 pF
Note:
See the Notes with Table 11-1 for additional
information about capacitor selection.
© 2007 Microchip Technology Inc.
32 kHz
C1
27
pF(1)
C2
27 pF(1)
Note 1: Microchip suggests these values 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.
A write to the high byte of Timer1 must also take place
through the TMR1H Buffer register. The Timer1 high
byte is updated with the contents of TMR1H when a
write occurs to TMR1L. This allows a user to write all
16 bits to both the high and low bytes of Timer1 at once.
The high byte of Timer1 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer1 High Byte Buffer register.
Writes to TMR1H do not clear the Timer1 prescaler.
The prescaler is only cleared on writes to TMR1L.
Freq
4: Capacitor values are for design guidance
only.
11.3.1
USING TIMER1 AS A CLOCK
SOURCE
The Timer1 oscillator is also available as a clock source
in power-managed modes. By setting the clock select
bits, SCS1:SCS0 (OSCCON<1:0>), to ‘01’, the device
switches to SEC_RUN mode; both the CPU and
peripherals are clocked from the Timer1 oscillator. If the
IDLEN bit (OSCCON<7>) is cleared and a SLEEP
instruction is executed, the device enters SEC_IDLE
mode. Additional details are available in Section 3.0
“Power-Managed Modes”.
Whenever the Timer1 oscillator is providing the clock
source, the Timer1 system clock status flag, T1RUN
(T1CON<6>), is set. This can be used to determine the
controller’s current clocking mode. It can also indicate
the clock source being currently used by the Fail-Safe
Clock Monitor. If the Clock Monitor is enabled and the
Timer1 oscillator fails while providing the clock, polling
the T1RUN bit will indicate whether the clock is being
provided by the Timer1 oscillator or another source.
11.3.2
LOW-POWER TIMER1 OPTION
The Timer1 oscillator can operate at two distinct levels
of power consumption based on device configuration.
When the LPT1OSC Configuration bit is set, the Timer1
oscillator operates in a low-power mode. When
LPT1OSC is not set, Timer1 operates at a higher power
level. Power consumption for a particular mode is
relatively constant, regardless of the device’s operating
mode. The default Timer1 configuration is the higher
power mode.
As the Low-Power Timer1 mode tends to be more
sensitive to interference, high noise environments may
cause some oscillator instability. The low-power option
is therefore best suited for low noise applications where
power conservation is an important design
consideration.
DS39629C-page 137
PIC18F6390/6490/8390/8490
11.3.3
TIMER1 OSCILLATOR LAYOUT
CONSIDERATIONS
The Timer1 oscillator circuit draws very little power
during operation. Due to the low-power nature of the
oscillator, it may also be sensitive to rapidly changing
signals in close proximity.
The oscillator circuit, shown in Figure 11-3, should be
located as close as possible to the microcontroller.
There should be no circuits passing within the oscillator
circuit boundaries other than VSS or VDD.
If a high-speed circuit must be located near the
oscillator (such as the CCP1 pin in Output Compare or
PWM mode, or the primary oscillator using the OSC2
pin), a grounded guard ring around the oscillator circuit,
as shown in Figure 11-4, may be helpful when used on
a single sided PCB or in addition to a ground plane.
FIGURE 11-4:
OSCILLATOR CIRCUIT
WITH GROUNDED
GUARD RING
11.5
If either of the CCP modules is configured in Compare
mode to generate a Special Event Trigger
(CCP1M3:CCP1M0 or CCP2M3:CCP2M0 = 1011),
this signal will reset Timer1. The trigger from CCP2 will
also start an A/D conversion if the A/D module is
enabled (see Section 14.3.4 “Special Event Trigger”
for more information.).
The module must be configured as either a timer or a
synchronous counter to take advantage of this feature.
When used this way, the CCPRH:CCPRL register pair
effectively becomes a period register for Timer1.
If Timer1 is running in Asynchronous Counter mode,
this Reset operation may not work.
In the event that a write to Timer1 coincides with a
Special Event Trigger, the write operation will take
precedence.
Note:
VDD
VSS
OSC1
OSC2
RC0
RC1
RC2
Note: Not drawn to scale.
11.4
Timer1 Interrupt
The TMR1 register pair (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
Timer1 interrupt, if enabled, is generated on overflow,
which is latched in interrupt flag bit, TMR1IF
(PIR1<0>). This interrupt can be enabled or disabled
by setting or clearing the Timer1 Interrupt Enable bit,
TMR1IE (PIE1<0>).
Resetting Timer1 Using the CCP
Special Event Trigger
11.6
The Special Event Triggers from the CCP2
module will not set the TMR1IF interrupt
flag bit (PIR1<0>).
Using Timer1 as a
Real-Time Clock
Adding an external LP oscillator to Timer1 (such as the
one described in Section 11.3 “Timer1 Oscillator”,
above) gives users the option to include RTC functionality to their applications. This is accomplished with an
inexpensive watch crystal to provide an accurate time
base and several lines of application code to calculate
the time. When operating in Sleep mode and using a
battery or supercapacitor as a power source, it can
completely eliminate the need for a separate RTC
device and battery backup.
The application code routine, RTCisr, shown in
Example 11-1, demonstrates a simple method to
increment a counter at one-second intervals using an
Interrupt Service Routine. Incrementing the TMR1
register pair to overflow, triggers the interrupt and calls
the routine, which increments the seconds counter by
one; additional counters for minutes and hours are
incremented as the previous counter overflows.
Since the register pair is 16 bits wide, counting up to
overflow the register directly from a 32.768 kHz clock
would take 2 seconds. To force the overflow at the
required one-second intervals, it is necessary to
preload it. The simplest method is to set the Most Significant bit of TMR1H with a BSF instruction. Note that
the TMR1L register is never preloaded or altered; doing
so may introduce cumulative error over many cycles.
For this method to be accurate, Timer1 must operate in
Asynchronous mode and the Timer1 overflow interrupt
must be enabled (PIE1<0> = 1), as shown in the
routine, RTCinit. The Timer1 oscillator must also be
enabled and running at all times.
DS39629C-page 138
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
EXAMPLE 11-1:
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
RTCinit
MOVLW
MOVWF
CLRF
MOVLW
MOVWF
CLRF
CLRF
MOVLW
MOVWF
BSF
RETURN
80h
TMR1H
TMR1L
b’00001111’
T1OSC
secs
mins
.12
hours
PIE1, TMR1IE
BSF
BCF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
CLRF
INCF
MOVLW
CPFSGT
RETURN
MOVLW
MOVWF
RETURN
TMR1H, 7
PIR1, TMR1IF
secs, F
.59
secs
; Preload TMR1 register pair
; for 1 second overflow
; Configure for external clock,
; Asynchronous operation, external oscillator
; Initialize timekeeping registers
;
; Enable Timer1 interrupt
RTCisr
TABLE 11-2:
Name
INTCON
secs
mins, F
.59
mins
mins
hours, F
.23
hours
;
;
;
;
Preload for 1 sec overflow
Clear interrupt flag
Increment seconds
60 seconds elapsed?
;
;
;
;
No, done
Clear seconds
Increment minutes
60 minutes elapsed?
;
;
;
;
No, done
clear minutes
Increment hours
24 hours elapsed?
; No, done
; Reset hours to 1
.01
hours
; Done
REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Bit 7
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
Bit 6
GIE/GIEH PEIE/GIEL
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
IPR1
TMR1L
Timer1 Register Low Byte
TMR1H
Timer1 Register High Byte
T1CON
RD16
T1RUN
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
60
60
TMR1CS
TMR1ON
60
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.
© 2007 Microchip Technology Inc.
DS39629C-page 139
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 140
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
12.0
TIMER2 MODULE
12.1
The Timer2 timer module incorporates the following
features:
• 8-bit Timer and Period registers (TMR2 and PR2,
respectively)
• Readable and writable (both registers)
• Software programmable prescaler (1:1, 1:4 and
1:16)
• Software programmable postscaler (1:1 through
1:16)
• Interrupt on TMR2 to PR2 match
• Optional use as the shift clock for the MSSP
module
The module is controlled through the T2CON register
(Register 12-1), which enables or disables the timer
and configures the prescaler and postscaler. Timer2
can be shut off by clearing control bit, TMR2ON
(T2CON<2>), to minimize power consumption.
A simplified block diagram of the module is shown in
Figure 12-1.
Timer2 Operation
In normal operation, TMR2 is incremented from 00h on
each clock (FOSC/4). A 2-bit counter/prescaler on the
clock input gives direct input, divide-by-4 and
divide-by-16 prescale options; these are selected by
the prescaler control bits, T2CKPS1:T2CKPS0
(T2CON<1:0>). The value of TMR2 is compared to that
of the Period register, PR2, on each clock cycle. When
the two values match, the comparator generates a
match signal as the timer output. This signal also resets
the value of TMR2 to 00h on the next cycle and drives
the output counter/postscaler (see Section 12.2
“Timer2 Interrupt”).
The TMR2 and PR2 registers are both directly readable
and writable. The TMR2 register is cleared on any
device Reset, while the PR2 register initializes at FFh.
Both the prescaler and postscaler counters are cleared
on the following events:
• a write to the TMR2 register
• a write to the T2CON register
• any device Reset (Power-on Reset, MCLR Reset,
Watchdog Timer Reset, or Brown-out Reset)
TMR2 is not cleared when T2CON is written.
REGISTER 12-1:
T2CON: TIMER2 CONTROL REGISTER
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
T2OUTPS3
T2OUTPS2
T2OUTPS1
T2OUTPS0
TMR2ON
T2CKPS1
T2CKPS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
Unimplemented: Read as ‘0’
bit 6-3
T2OUTPS3:T2OUTPS0: 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
© 2007 Microchip Technology Inc.
x = Bit is unknown
DS39629C-page 141
PIC18F6390/6490/8390/8490
12.2
Timer2 Interrupt
12.3
Timer2 also can generate an optional device interrupt.
The Timer2 output signal (TMR2 to PR2 match)
provides
the
input
for
the
4-bit
output
counter/postscaler. This counter generates the TMR2
match interrupt flag which is latched in TMR2IF
(PIR1<1>). The interrupt is enabled by setting the
TMR2 Match Interrupt Enable bit, TMR2IE (PIE1<1>).
TMR2 Output
The unscaled output of TMR2 is available primarily to
the CCP modules, where it is used as a time base for
operations in PWM mode.
Timer2 can be optionally used as the shift clock source
for the MSSP module operating in SPI mode.
Additional information is provided in Section 15.0
“Master Synchronous Serial Port (MSSP) Module”.
A range of 16 postscale options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS3:T2OUTPS0 (T2CON<6:3>).
FIGURE 12-1:
TIMER2 BLOCK DIAGRAM
4
T2OUTPS3:T2OUTPS0
Set TMR2IF
2
T2CKPS1:T2CKPS0
TMR2
TMR2 Output
(to PWM or MSSP)
TMR2/PR2
Match
Reset
1:1, 1:4, 1:16
Prescaler
FOSC/4
1:1 to 1:16
Postscaler
Comparator
8
PR2
8
8
Internal Data Bus
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
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
INTCON GIE/GIEH PEIE/GIEL
TMR2
T2CON
PR2
Timer2 Register
—
60
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
Timer2 Period Register
60
60
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
DS39629C-page 142
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
13.0
TIMER3 MODULE
The Timer3 timer/counter module incorporates these
features:
• Software selectable operation as a 16-bit timer or
counter
• Readable and writable 8-bit registers (TMR3H
and TMR3L)
• Selectable clock source (internal or external), with
device clock or Timer1 oscillator internal options
• Interrupt-on-overflow
• Module Reset on CCP Special Event Trigger
REGISTER 13-1:
A simplified block diagram of the Timer3 module is
shown in Figure 13-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 13-2.
The Timer3 module is controlled through the T3CON
register (Register 13-1). It also selects the clock source
options for the CCP modules (see Section 14.1.1
“CCP Modules and Timer Resources” for more
information).
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
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
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 capture/compare clock source for the CCPx modules
01 = Timer3 is the capture/compare clock source for the CCP2 module;
Timer1 is the capture/compare clock source for the CCP1 module
00 = Timer1 is the capture/compare clock source for the CCPx 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 device 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 T13CKI (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
© 2007 Microchip Technology Inc.
DS39629C-page 143
PIC18F6390/6490/8390/8490
13.1
Timer3 Operation
cycle (FOSC/4). When the bit is set, Timer3 increments
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
Timer3 can operate in one of three modes:
• Timer
• Synchronous counter
• Asynchronous counter
As
with
Timer1,
the
RC1/T1OSI
and
RC0/T1OSO/T13CKI pins become inputs when the
Timer1 oscillator is enabled. This means the values of
TRISC<1:0> are ignored and the pins are read as ‘0’.
The operating mode is determined by the clock select
bit, TMR3CS (T3CON<1>). When TMR3CS is cleared
(= 0), Timer3 increments on every internal instruction
FIGURE 13-1:
TIMER3 BLOCK DIAGRAM
Timer1 Oscillator
1
T1OSO/T13CKI
1
FOSC/4
Internal
Clock
T1OSI
Synchronize
Prescaler
1, 2, 4, 8
0
Detect
0
2
T1OSCEN
(1)
Sleep Input
TMR3CS
Timer3
On/Off
T3CKPS1:T3CKPS0
T3SYNC
TMR3ON
CCP Special Event Trigger
T3CCPx
Clear TMR3
Set
TMR3IF
on Overflow
TMR3
High Byte
TMR3L
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
FIGURE 13-2:
TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Oscillator
Timer1 Clock Input
1
T1OSO/T13CKI
1
FOSC/4
Internal
Clock
T1OSI
Synchronize
Prescaler
1, 2, 4, 8
0
Detect
0
2
(1)
T1OSCEN
T3CKPS1:T3CKPS0
T3SYNC
TMR3ON
Sleep Input
TMR3CS
CCP Special Event Trigger
T3CCPx
Clear TMR3
Timer3
On/Off
TMR3
High Byte
TMR3L
8
Set
TMR3IF
on Overflow
Read TMR3L
Write TMR3L
8
8
TMR3H
8
8
Internal Data Bus
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
DS39629C-page 144
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
13.2
Timer3 16-Bit Read/Write Mode
13.4
Timer3 Interrupt
Timer3 can be configured for 16-bit reads and writes
(see Figure 13-2). When the RD16 control bit
(T3CON<7>) is set, the address for TMR3H is mapped
to a buffer register for the high byte of Timer3. A read
from TMR3L will load the contents of the high byte of
Timer3 into the Timer3 High Byte Buffer register. This
provides the user with the ability to accurately read all
16 bits of Timer1 without having to determine whether
a read of the high byte, followed by a read of the low
byte, has become invalid due to a rollover between
reads.
The TMR3 register pair (TMR3H:TMR3L) increments
from 0000h to FFFFh and overflows to 0000h. The
Timer3 interrupt, if enabled, is generated on overflow
and is latched in interrupt flag bit, TMR3IF (PIR2<1>).
This interrupt can be enabled or disabled by setting or
clearing the Timer3 Interrupt Enable bit, TMR3IE
(PIE2<1>).
A write to the high byte of Timer3 must also take place
through the TMR3H Buffer register. The Timer3 high
byte is updated with the contents of TMR3H when a
write occurs to TMR3L. This allows a user to write all
16 bits to both the high and low bytes of Timer3 at once.
If either of the CCP modules is configured in Compare
mode to generate a Special Event Trigger
(CCP1M3:CCP1M0 or CCP2M3:CCP2M0 = 1011),
this signal will reset Timer1. The trigger from CCP2 will
also start an A/D conversion if the A/D module is
enabled (see Section 14.3.4 “Special Event Trigger”
for more information.).
The high byte of Timer3 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer3 High Byte Buffer register.
13.5
Resetting Timer3 Using the CCP
Special Event Trigger
Writes to TMR3H do not clear the Timer3 prescaler.
The prescaler is only cleared on writes to TMR3L.
The module must be configured as either a timer or
synchronous counter to take advantage of this feature.
When used this way, the CCPR2H:CCPR2L register
pair effectively becomes a Period register for Timer3.
13.3
If Timer3 is running in Asynchronous Counter mode,
the Reset operation may not work.
Using the Timer1 Oscillator as the
Timer3 Clock Source
The Timer1 internal oscillator may be used as the clock
source for Timer3. The Timer1 oscillator is enabled by
setting the T1OSCEN (T1CON<3>) bit. To use it as the
Timer3 clock source, the TMR3CS bit must also be set.
As previously noted, this also configures Timer3 to
increment on every rising edge of the oscillator source.
In the event that a write to Timer3 coincides with a
Special Event Trigger from a CCP module, the write will
take precedence.
Note:
The Special Event Triggers from the CCP2
module will not set the TMR3IF interrupt
flag bit (PIR2<1>).
The Timer1 oscillator is described in Section 11.0
“Timer1 Module”.
TABLE 13-1:
Name
INTCON
REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR2
OSCFIF
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
61
PIE2
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
61
IPR2
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
61
TMR3L
Timer3 Register Low Byte
61
TMR3H
Timer3 Register High Byte
61
T1CON
RD16
T1RUN
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
TMR1CS
TMR1ON
60
T3CON
RD16
T3CCP2
T3CKPS1 T3CKPS0
TMR3CS
TMR3ON
61
T3CCP1
T3SYNC
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.
© 2007 Microchip Technology Inc.
DS39629C-page 145
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 146
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
14.0
CAPTURE/COMPARE/PWM
(CCP) MODULES
PIC18F6390/6490/8390/8490 devices have two CCP
(Capture/Compare/PWM) modules, designated CCP1
and CCP2. Both modules implement standard capture,
compare and Pulse-Width Modulation (PWM) modes.
REGISTER 14-1:
Each CCP module contains a 16-bit register which can
operate as a 16-bit Capture register, a 16-bit Compare
register or a PWM Master/Slave Duty Cycle register.
For the sake of clarity, all CCP module operation in the
following sections is described with respect to CCP2,
but is equally applicable to CCP1.
CCPxCON: CCPx CONTROL REGISTER
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
DCxB1
DCxB0
CCPxM3
CCPxM2
CCPxM1
CCPxM0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
Unimplemented: Read as ‘0’
bit 5-4
DCxB1:DCxB0: PWM Duty Cycle bit 1 and bit 0 for CCPx Module
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two Least Significant bits (bit 1 and bit 0) of the 10-bit PWM duty cycle. The eight Most
Significant bits (DCxB9:DCxB2) of the duty cycle are found in CCPRxL.
bit 3-0
CCPxM3:CCPxM0: CCPx Module 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 CCPx pin low; on compare match, force CCPx pin high (CCPxIF bit is set)
1001 = Compare mode: initialize CCPx pin high; on compare match, force CCPx pin low (CCPxIF bit is set)
1010 = Compare mode: generate software interrupt on compare match (CCPxIF bit is set, CCPx pin
reflects I/O state)
1011 = Compare mode: trigger special event, reset timer, start A/D conversion on CCPx match (CCPxIF
bit is set)(1)
11xx = PWM mode
Note 1:
CCPxM3:CCPxM0 = 1011 will only reset the timer and not start the A/D conversion on the CCPx match.
© 2007 Microchip Technology Inc.
DS39629C-page 147
PIC18F6390/6490/8390/8490
14.1
CCP Module Configuration
The assignment of a particular timer to a module is
determined by the Timer to CCP enable bits in the
T3CON register (Register 13-1). Both modules may be
active at any given time and may share the same timer
resource if they are configured to operate in the same
mode (capture/compare or PWM) at the same time.
The interactions between the two modules are
summarized in Table 14-2.
Each Capture/Compare/PWM module is associated
with a control register (generically, CCPxCON) and a
data register (CCPRx). The data register in turn is comprised of two 8-bit registers: CCPRxL (low byte) and
CCPRxH (high byte). All registers are both readable
and writable.
14.1.1
Depending on the configuration selected, up to four
timers may be active at once, with modules in the same
configuration (capture/compare or PWM) sharing timer
resources. The possible configurations are shown in
Figure 14-1.
CCP MODULES AND TIMER
RESOURCES
The CCP modules utilize Timers 1, 2 or 3, depending
on the mode selected. Timer1 and Timer3 are available
to modules in Capture or Compare modes, while
Timer2 is available for modules in PWM mode.
TABLE 14-1:
14.1.2
The pin assignment for CCP2 (capture input, compare
and PWM output) can change based on device configuration. The CCP2MX Configuration bit determines
which pin CCP2 is multiplexed to. By default, it is
assigned to RC1 (CCP2MX = 1). If the Configuration bit
is cleared, CCP2 is multiplexed with RE7.
CCP MODE – TIMER
RESOURCE
CCP Mode
Timer Resource
Capture
Compare
PWM
Timer1 or Timer3
Timer1 or Timer3
Timer2
FIGURE 14-1:
CCP2 PIN ASSIGNMENT
Changing the pin assignment of CCP2 does not
automatically change any requirements for configuring
the port pin. Users must always verify that the appropriate TRIS register is configured correctly for CCP2
operation, regardless of where it is located.
CCP AND TIMER INTERCONNECT CONFIGURATIONS
T3CCP<2:1> = 00
T3CCP<2:1> = 01
TMR1
TMR1
TMR3
CCP1
TMR3
CCP1
Timer1 is used for all capture
and compare operations for
all CCP modules. Timer2 is
used for PWM operations for
all CCP modules. Modules
may share either timer
resource as a common time
base.
DS39629C-page 148
TMR1
TMR3
CCP1
CCP2
TMR2
T3CCP<2:1> = 1x
CCP2
TMR2
Timer1 is used for capture
and compare operations for
CCP1 and Timer 3 is used for
CCP2.
Both the modules use Timer2
as a common time base if they
are in PWM modes.
CCP2
TMR2
Timer3 is used for all capture
and compare operations for
all CCP modules. Timer2 is
used for PWM operations for
all CCP modules. Modules
may share either timer
resource as a common time
base.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 14-2:
INTERACTIONS BETWEEN CCP1 AND CCP2 FOR TIMER RESOURCES
CCP1 Mode CCP2 Mode
Interaction
Capture
Capture
Each module can use TMR1 or TMR3 as the time base. The time base can be different
for each CCP.
Capture
Compare
CCP2 can be configured for the Special Event Trigger to reset TMR1 or TMR3
(depending upon which time base is used). Automatic A/D conversions on trigger event
can also be done. Operation of CCP1 could be affected if it is using the same timer as a
time base.
Compare
Capture
CCP1 can be configured for the Special Event Trigger to reset TMR1 or TMR3
(depending upon which time base is used). Operation of CCP2 could be affected if it is
using the same timer as a time base.
Compare
Compare
Either module can be configured for the Special Event Trigger to reset the time base.
Automatic A/D conversions on CCP2 trigger event can be done. Conflicts may occur if
both modules are using the same time base.
Capture
PWM*
None
Compare
PWM*
None
PWM*
Capture
None
PWM*
Compare
None
PWM*
PWM
*
Both PWMs will have the same frequency and update rate (TMR2 interrupt).
Includes standard and Enhanced PWM operation.
© 2007 Microchip Technology Inc.
DS39629C-page 149
PIC18F6390/6490/8390/8490
14.2
Capture Mode
14.2.3
SOFTWARE INTERRUPT
In Capture mode, the CCPR2H:CCPR2L register pair
captures the 16-bit value of the TMR1 or TMR3
registers when an event occurs on the CCP2 pin (RC1
or RE7, depending on device configuration). An event
is defined as one of the following:
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep bit
CCP2IE (PIE2<0>) clear to avoid false interrupts and
should clear the flag bit, CCP2IF, following any such
change in operating mode.
•
•
•
•
14.2.4
every falling edge
every rising edge
every 4th rising edge
every 16th rising edge
There are four prescaler settings in Capture mode; they
are specified as part of the operating mode selected by
the mode select bits (CCP2M3:CCP2M0). 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.
The event is selected by the mode select bits,
CCP2M3:CCP2M0 (CCP2CON<3:0>). When a
capture is made, the interrupt request flag bit, CCP2IF
(PIR2<0>), is set; it must be cleared in software. If
another capture occurs before the value in register
CCPR2 is read, the old captured value is overwritten by
the new captured value.
14.2.1
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.
CCP PIN CONFIGURATION
In Capture mode, the appropriate CCPx pin should be
configured as an input by setting the corresponding
TRIS direction bit.
Note:
14.2.2
EXAMPLE 14-1:
If RC1/CCP2 or RE7/CCP2 is configured
as an output, a write to the port can cause
a capture condition.
CLRF
MOVLW
TIMER1/TIMER3 MODE SELECTION
MOVWF
The timers that are to be used with the capture feature
(Timer1 and/or Timer3) must be running in Timer mode or
Synchronized Counter mode. In Asynchronous Counter
mode, the capture operation may not work. The timer to
be used with each CCP module is selected in the T3CON
register (see Section 14.1.1 “CCP Modules and Timer
Resources”).
FIGURE 14-2:
CCP PRESCALER
CHANGING BETWEEN
CAPTURE PRESCALERS
CCP2CON
; Turn CCP module off
NEW_CAPT_PS ; Load WREG with the
; new prescaler mode
; value and CCP ON
CCP2CON
; Load CCP2CON with
; this value
CAPTURE MODE OPERATION BLOCK DIAGRAM
TMR3H
Set CCP1IF
T3CCP2
CCP1 pin
Prescaler
÷ 1, 4, 16
and
Edge Detect
CCP1CON<3:0>
Q1:Q4
CCP2CON<3:0>
4
4
CCPR1L
TMR1
Enable
TMR1H
TMR1L
TMR3H
TMR3L
Set CCP2IF
4
T3CCP1
T3CCP2
CCP2 pin
Prescaler
÷ 1, 4, 16
TMR3
Enable
CCPR1H
T3CCP2
TMR3L
and
Edge Detect
TMR3
Enable
CCPR2H
CCPR2L
TMR1
Enable
T3CCP2
T3CCP1
DS39629C-page 150
TMR1H
TMR1L
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
14.3
Compare Mode
14.3.3
SOFTWARE INTERRUPT MODE
In Compare mode, the 16-bit CCPR2 register value is
constantly compared against either the TMR1 or TMR3
register pair value. When a match occurs, the CCP2
pin can be:
When the Generate Software Interrupt mode is chosen
(CCP2M3:CCP2M0 = 1010), the CCP2 pin is not
affected. Only a CCP interrupt is generated if enabled
and the CCP2IE bit is set.
•
•
•
•
14.3.4
driven high
driven low
toggled (high-to-low or low-to-high)
remain unchanged (that is, reflects the state of the
I/O latch)
Both CCP modules are equipped with a Special Event
Trigger. This is an internal hardware signal generated
in Compare mode to trigger actions by other modules.
The Special Event Trigger is enabled by selecting
the Compare Special Event Trigger mode
(CCP2M3:CCP2M0 = 1011).
The action on the pin is based on the value of the mode
select bits (CCP2M3:CCP2M0). At the same time, the
interrupt flag bit, CCP2IF, is set.
14.3.1
For either CCP module, the Special Event Trigger resets
the Timer register pair for whichever timer resource is
currently assigned as the module’s time base. This
allows the CCPRx registers to serve as a programmable
Period register for either timer.
CCP PIN CONFIGURATION
The user must configure the CCPx pin as an output by
clearing the appropriate TRIS bit.
Note:
14.3.2
SPECIAL EVENT TRIGGER
The Special Event Trigger for CCP2 can also start an
A/D conversion. In order to do this, the A/D converter
must already be enabled.
Clearing the CCP2CON register will force
the RC1 or RE7 compare output latch
(depending on device configuration) to the
default low level. This is not the PORTC or
PORTE I/O data latch.
Note:
TIMER1/TIMER3 MODE SELECTION
The Special Event Trigger of CCP1 only
resets Timer1/Timer3 and cannot start an
A/D conversion even when the A/D
converter is enabled.
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.
FIGURE 14-3:
COMPARE MODE OPERATION BLOCK DIAGRAM
CCPR1H
Special Event Trigger
(Timer1 Reset)
Set CCP1IF
CCPR1L
CCP1 pin
Comparator
Output
Logic
Compare
Match
S
Q
R
TRIS
Output Enable
4
CCP1CON<3:0>
0
TMR1H
TMR1L
0
1
TMR3H
TMR3L
1
T3CCP1
Special Event Trigger
(Timer1/Timer3 Reset, A/D Trigger)
T3CCP2
Set CCP2IF
Comparator
CCPR2H
CCPR2L
Compare
Match
CCP2 pin
Output
Logic
4
S
Q
R
TRIS
Output Enable
CCP2CON<3:0>
© 2007 Microchip Technology Inc.
DS39629C-page 151
PIC18F6390/6490/8390/8490
TABLE 14-3:
Name
INTCON
REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
IPEN
SBOREN
—
RI
TO
PD
POR
BOR
60
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
RCON
PIR2
OSCFIF
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
61
PIE2
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
61
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
IPR2
TRISC
PORTC Data Direction Register
TRISE
PORTE Data Direction Register
TMR1L
Timer1 Register Low Byte
TMR1H
Timer1 Register High Byte
T1CON
RD16
T1RUN
Timer3 Register High Byte
TMR3L
Timer3 Register Low Byte
T3CON
RD16
T3CCP2
—
—
—
—
62
60
60
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC
TMR3H
61
62
TMR1CS TMR1ON
60
61
61
T3CKPS1 T3CKPS0
T3CCP1
T3SYNC
TMR3CS TMR3ON
61
CCPR1L
Capture/Compare/PWM Register 1 Low Byte
61
CCPR1H
Capture/Compare/PWM Register 1 High Byte
61
—
CCP1CON
—
DC1B1
DC1B0
CCPR2L
Capture/Compare/PWM Register 2 Low Byte
CCPR2H
Capture/Compare/PWM Register 2 High Byte
CCP2CON
—
—
DC2B1
DC2B0
CCP1M3
CCP1M2
CCP1M1
CCP1M0
61
61
61
CCP2M3
CCP2M2
CCP2M1
CCP2M0
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by capture/compare, Timer1 or Timer3.
DS39629C-page 152
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
14.4
PWM Mode
In Pulse-Width Modulation (PWM) mode, the CCP2 pin
produces up to a 10-bit resolution PWM output. Since
the CCP2 pin is multiplexed with a PORTC or PORTE
data latch, the appropriate TRIS bit must be cleared to
make the CCP2 pin an output.
Note:
A PWM output (Figure 14-5) 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 14-5:
PWM OUTPUT
Period
Clearing the CCP2CON register will force
the RC1 or RE7 output latch (depending
on device configuration) to the default low
level. This is not the PORTC or PORTE
I/O data latch.
Duty Cycle
TMR2 = PR2
Figure 14-4 shows a simplified block diagram of the
CCP2 module in PWM mode.
For a step-by-step procedure on how to set up the CCP
module for PWM operation, see Section 14.4.3
“Setup for PWM Operation”.
FIGURE 14-4:
SIMPLIFIED PWM BLOCK
DIAGRAM
Duty Cycle Registers
TMR2 = Duty Cycle
TMR2 = PR2
14.4.1
PWM PERIOD
The PWM period is specified by writing to the PR2
register. The PWM period can be calculated using the
following formula:
CCP2CON<5:4>
EQUATION 14-1:
CCPR2L
PWM Period = (PR2) + 1] • 4 • TOSC •
(TMR2 Prescale Value)
PWM frequency is defined as 1/[PWM period].
CCPR2H (Slave)
R
Comparator
When TMR2 is equal to PR2, the following three events
occur on the next increment cycle:
Q
CCP2
TMR2
(Note 1)
S
TRISC<2>
Comparator
PR2
Clear Timer,
CCP2 pin and
latch D.C.
Note 1: The 8-bit TMR2 value is concatenated with the 2-bit
internal Q clock, or 2 bits of the prescaler, to create the
10-bit time base.
© 2007 Microchip Technology Inc.
• TMR2 is cleared
• The CCP2 pin is set (exception: if PWM duty
cycle = 0%, the CCP2 pin will not be set)
• The PWM duty cycle is latched from CCPR2L into
CCPR2H
Note:
The Timer2 postscalers (see Section 12.0
“Timer2 Module”) are not used in the
determination of the PWM frequency. The
postscaler could be used to have a servo
update rate at a different frequency than
the PWM output.
DS39629C-page 153
PIC18F6390/6490/8390/8490
14.4.2
PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the
CCPR2L register and to the CCP2CON<5:4> bits. Up
to 10-bit resolution is available. The CCPR2L contains
the eight MSbs and the CCP2CON<5:4> bits contain
the two LSbs. This 10-bit value is represented by
CCPR2L:CCP2CON<5:4>. The following equation is
used to calculate the PWM duty cycle in time:
EQUATION 14-2:
When the CCPR2H and 2-bit latch match TMR2,
concatenated with an internal 2-bit Q clock or 2 bits of
the TMR2 prescaler, the CCP2 pin is cleared.
The maximum PWM resolution (bits) for a given PWM
frequency is given by the equation:
EQUATION 14-3:
PWM Duty Cycle = (CCPR2L:CCP2CON<5:4>) •
TOSC • (TMR2 Prescale Value)
CCPR2L and CCP2CON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPR2H until after a match between PR2 and TMR2
occurs (i.e., the period is complete). In PWM mode,
CCPR2H is a read-only register.
TABLE 14-4:
The CCPR2H 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.
F OSC
log ⎛ ---------------⎞
⎝ F PWM⎠
PWM Resolution (max) = -----------------------------bits
log ( 2 )
Note:
If the PWM duty cycle value is longer than
the PWM period, the CCP2 pin will not be
cleared.
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
PWM Frequency
Timer Prescaler (1, 4, 16)
PR2 Value
Maximum Resolution (bits)
DS39629C-page 154
2.44 kHz
9.77 kHz
39.06 kHz
156.25 kHz
312.50 kHz
416.67 kHz
16
4
1
1
1
1
FFh
FFh
FFh
3Fh
1Fh
17h
14
12
10
8
7
6.58
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
14.4.3
SETUP FOR PWM OPERATION
3.
The following steps should be taken when configuring
the CCP2 module for PWM operation:
1.
2.
Set the PWM period by writing to the PR2
register.
Set the PWM duty cycle by writing to the
CCPR2L register and CCP2CON<5:4> bits.
TABLE 14-5:
Name
INTCON
4.
5.
Make the CCP2 pin an output by clearing the
appropriate TRIS bit.
Set the TMR2 prescale value, then enable
Timer2 by writing to T2CON.
Configure the CCP2 module for PWM operation.
REGISTERS ASSOCIATED WITH PWM AND TIMER2
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
—
RI
TO
PD
POR
BOR
60
IPEN
SBOREN
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
—
—
—
—
RCON
TRISC
PORTC Data Direction Register
TRISE
PORTE Data Direction Register
TMR2
Timer2 Register
60
PR2
Timer2 Period Register
60
T2CON
—
62
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
CCPR1L
Capture/Compare/PWM Register 1 Low Byte
CCPR1H
Capture/Compare/PWM Register 1 High Byte
CCP1CON
—
—
DC1B1
DC1B0
62
60
61
61
CCP1M3
CCP1M2
CCP1M1 CCP1M0
61
CCPR2L
Capture/Compare/PWM Register 2 Low Byte
61
CCPR2H
Capture/Compare/PWM Register 2 High Byte
61
CCP2CON
—
—
DC2B1
DC2B0
CCP2M3
CCP2M2
CCP2M1 CCP2M0
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PWM or Timer2.
© 2007 Microchip Technology Inc.
DS39629C-page 155
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 156
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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/SEG12
• Serial Data In (SDI) – RC4/SDI/SDA
• Serial Clock (SCK) – RC3/SCK/SCL
Additionally, a fourth pin may be used when in a Slave
mode of operation:
• Slave Select (SS) – RF7/SS/SEG25
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
Read
• Master mode
• Multi-Master mode
• Slave mode
15.2
Control Registers
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.
Write
SSPBUF reg
RC4/SDI/SDA
SSPSR reg
RC5/SDO/SEG12
RF7/SS/
SEG25
Shift
Clock
bit 0
SS Control
Enable
Edge
Select
2
Clock Select
RC3/SCK/
SCL
SSPM3:SSPM0
SMP:CKE 4
TMR2 Output
2
2
(
Edge
Select
)
Prescaler TOSC
4, 16, 64
Data to TXx/RXx in SSPSR
TRIS bit
© 2007 Microchip Technology Inc.
DS39629C-page 157
PIC18F6390/6490/8390/8490
15.3.1
REGISTERS
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.
The MSSP module has four registers for SPI mode
operation. These are:
•
•
•
•
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.
MSSP Control Register 1 (SSPCON1)
MSSP Status Register (SSPSTAT)
Serial Receive/Transmit Buffer Register (SSPBUF)
MSSP Shift Register (SSPSR) – Not directly
accessible
During transmission, the SSPBUF is not doublebuffered. A write to SSPBUF will write to both SSPBUF
and SSPSR.
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 2 bits of the
SSPSTAT are read/write.
REGISTER 15-1:
SSPSTAT: MSSP STATUS REGISTER (SPI 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
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SMP: Sample bit
SPI Master mode:
1 = Input data 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 bit
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 Information bit
Used in I2C mode only.
bit 1
UA: Update Address bit
Used in I2C mode only.
bit 0
BF: Buffer Full Status bit (Receive mode only)
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty
DS39629C-page 158
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 15-2:
SSPCON1: MSSP CONTROL REGISTER 1 (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(1)
SSPEN(2)
CKP
SSPM3(3)
SSPM2(3)
SSPM1(3)
SSPM0(3)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
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(1)
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
bit 5
SSPEN: Synchronous Serial Port Enable bit(2)
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
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: Master Synchronous Serial Port Mode Select bits(3)
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 1:
2:
3:
In Master mode, the overflow bit is not set, since each new reception (and transmission) is initiated by
writing to the SSPBUF register.
When enabled, these pins must be properly configured as inputs or outputs.
Bit combinations not specifically listed here are either reserved or implemented in I2C™ mode only.
© 2007 Microchip Technology Inc.
DS39629C-page 159
PIC18F6390/6490/8390/8490
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
EXAMPLE 15-1:
LOOP
reading the data that was just received. Any write to the
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. The
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
BTFSS
BRA
MOVF
SSPSTAT, BF
LOOP
SSPBUF, W
MOVWF
RXDATA
;Save in user RAM, if data is meaningful
MOVF
MOVWF
TXDATA, W
SSPBUF
;W reg = contents of TXDATA
;New data to xmit
DS39629C-page 160
;Has data been received (transmit complete)?
;No
;WREG reg = contents of SSPBUF
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.3.3
ENABLING SPI I/O
15.3.4
To enable the serial port, MSSP Enable bit, SSPEN
(SSPCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, reinitialize the
SSPCONx 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 as follows:
• 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 TRISF<7> 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 = 00xx)
SPI Slave (SSPM3:SSPM0 = 010x)
SDO
SDI
Serial Input Buffer
(SSPBUF)
SDI
Shift Register
(SSPSR)
MSb
Serial Input Buffer
(SSPBUF)
LSb
© 2007 Microchip Technology Inc.
Shift Register
(SSPSR)
MSb
SCK
PROCESSOR 1
SDO
Serial Clock
LSb
SCK
PROCESSOR 2
DS39629C-page 161
PIC18F6390/6490/8390/8490
15.3.5
MASTER MODE
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, 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.
FIGURE 15-3:
•
•
•
•
FOSC/4 (or TCY)
FOSC/16 (or 4 • TCY)
FOSC/64 (or 16 • TCY)
Timer2 output/2
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.
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)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
SDO
(CKE = 1)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
SDI
(SMP = 0)
bit 0
bit 7
Input
Sample
(SMP = 0)
SDI
(SMP = 1)
bit 7
bit 0
Input
Sample
(SMP = 1)
SSPIF
SSPSR to
SSPBUF
DS39629C-page 162
Next Q4 Cycle
after Q2↓
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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.
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
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 longer driven,
FIGURE 15-4:
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.
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.
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)
bit 7
bit 6
bit 7
bit 0
bit 0
bit 7
bit 7
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
© 2007 Microchip Technology Inc.
Next Q4 Cycle
after Q2↓
DS39629C-page 163
PIC18F6390/6490/8390/8490
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)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
bit 0
bit 7
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
bit 7
SDI
(SMP = 0)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
bit 0
Input
Sample
(SMP = 0)
SSPIF
Interrupt
Flag
SSPSR to
SSPBUF
DS39629C-page 164
Next Q4 Cycle
after Q2↓
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.3.8
SLEEP OPERATION
15.3.9
In SPI Master mode, module clocks may be operating
at a different speed than when in Full-Power mode; in
the case of Sleep mode, all clocks are halted.
In most power-managed modes, a clock is provided to
the peripherals. That clock should be from the primary
clock source, the secondary clock (Timer1 oscillator at
32.768 kHz) or the INTOSC source. See Section 2.7
“Clock Sources and Oscillator Switching” for
additional information.
In most cases, the speed that the master clocks SPI
data is not important; however, this should be
evaluated for each system.
A Reset disables the MSSP module and terminates the
current transfer.
15.3.10
BUS MODE COMPATIBILITY
Table 15-1 shows the compatibility between the
standard SPI modes and the states of the CKP and
CKE control bits.
TABLE 15-1:
SPI BUS MODES
Control Bits State
Standard SPI Mode
Terminology
CKP
CKE
0, 0
0
1
0, 1
0
0
1, 0
1
1
1, 1
1
0
If MSSP interrupts are enabled, they can wake the controller from Sleep mode, or one of the Idle modes, when
the master completes sending data. If an exit from
Sleep or Idle mode is not desired, MSSP interrupts
should be disabled.
If the Sleep mode is selected, all module clocks are
halted and the transmission/reception will remain in
that state until the devices wakes. After the device
returns to Run mode, the module will resume
transmitting and receiving data.
EFFECTS OF A RESET
There is also an SMP bit which controls when the data
is sampled.
In SPI Slave mode, the SPI Transmit/Receive Shift
register operates asynchronously to the device. This
allows the device to be placed in any power-managed
mode and data to be shifted into the SPI Transmit/
Receive Shift register. When all 8 bits have been
received, the MSSP interrupt flag bit will be set and if
enabled, will wake the device.
TABLE 15-2:
Name
INTCON
REGISTERS ASSOCIATED WITH SPI OPERATION
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
IPR1
TRISC
PORTC Data Direction Register
62
TRISF
PORTF Data Direction Register
62
SSPBUF
MSSP Receive Buffer/Transmit Register
60
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
60
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
60
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP in SPI mode.
© 2007 Microchip Technology Inc.
DS39629C-page 165
PIC18F6390/6490/8390/8490
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 by setting
the TRISC<4:3> bits.
FIGURE 15-7:
MSSP BLOCK DIAGRAM
(I2C™ MODE)
Internal
Data Bus
Read
Write
SSPBUF reg
RC3/SCK/SCL
Shift
Clock
MSb
Match Detect
LSb
Addr Match
SSPADD reg
Start and
Stop bit Detect
DS39629C-page 166
The MSSP module has six registers for I2C operation.
These are:
•
•
•
•
MSSP Control Register 1 (SSPCON1)
MSSP Control Register 2 (SSPCON2)
MSSP Status Register (SSPSTAT)
Serial Receive/Transmit Buffer Register
(SSPBUF)
• MSSP Shift Register (SSPSR) – Not directly
accessible
• MSSP Address Register (SSPADD)
SSPCON1, SSPCON2 and SSPSTAT are the control
and status registers in I2C mode operation. The
SSPCON1 and SSPCON2 registers are readable and
writable. The lower 6 bits of the SSPSTAT are read-only.
The upper 2 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.
SSPADD register holds the slave device address
when the MSSP is configured in I2C Slave mode.
When the MSSP is configured in Master mode, the
lower 7 bits of SSPADD act as the Baud Rate
Generator reload value.
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
REGISTERS
During transmission, the SSPBUF is not doublebuffered. A write to SSPBUF will write to both SSPBUF
and SSPSR.
Set, Reset
S, P bits
(SSPSTAT reg)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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(1)
S(1)
R/W(2,3)
UA
BF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SMP: Slew Rate Control bit
In Master or Slave mode:
1 = Slew rate control 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)
1 = Indicates that a Stop bit has been detected last
0 = Stop bit was not detected last
bit 3
S: Start bit(1)
1 = Indicates that a Start bit has been detected last
0 = Start bit was not detected last
bit 2
R/W: Read/Write Information bit(2,3)
In Slave mode:
1 = Read
0 = Write
In Master mode:
1 = Transmit is in progress
0 = Transmit is not in progress
bit 1
UA: Update Address bit (10-Bit Slave mode only)
1 = Indicates that the user needs to update the address in the 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
Note 1:
2:
3:
This bit is cleared on Reset and when SSPEN is cleared.
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.
ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is in Idle mode.
© 2007 Microchip Technology Inc.
DS39629C-page 167
PIC18F6390/6490/8390/8490
REGISTER 15-4:
R/W-0
SSPCON1: MSSP CONTROL REGISTER 1 (I2C™ MODE)
R/W-0
WCOL
SSPOV
R/W-0
SSPEN
(1)
R/W-0
CKP
R/W-0
SSPM3
(2)
R/W-0
SSPM2
(2)
R/W-0
SSPM1
(2)
R/W-0
SSPM0(2)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
WCOL: Write Collision Detect bit
In Master Transmit mode:
1 = A write to the SSPxBUF register was attempted while the I2C conditions were not valid for a
transmission to be started (must be cleared in software)
0 = No collision
In Slave Transmit mode:
1 = The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in
software)
0 = No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit.
bit 6
SSPOV: Receive Overflow Indicator bit
In Receive mode:
1 = A byte is received while the SSPxBUF register is still holding the previous byte (must be cleared in
software)
0 = No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode.
bit 5
SSPEN: Synchronous Serial Port Enable bit(1)
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
bit 4
CKP: SCK Release Control bit
In Slave mode:
1 = Releases clock
0 = Holds clock low (clock stretch), used to ensure data setup time
In Master mode:
Unused in this mode.
bit 3-0
SSPM3:SSPM0: Synchronous Serial Port Mode Select bits(2)
1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1011 = I2C Firmware Controlled Master mode (Slave Idle)
1000 = I2C Master mode, clock = FOSC/(4 * (SSPADD + 1))
0111 = I2C Slave mode, 10-bit address
0110 = I2C Slave mode, 7-bit address
Note 1:
2:
When enabled, the SDA and SCL pins must be configured as inputs.
Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
DS39629C-page 168
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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(1)
ACKEN(2)
RCEN(2)
PEN(2)
RSEN(2)
SEN(2)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
GCEN: General Call Enable bit (Slave mode only)
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)
1 = Not Acknowledge
0 = Acknowledge
bit 4
ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)(2)
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)(2)
1 = Enables Receive mode for I2C
0 = Receive Idle
bit 2
PEN: Stop Condition Enable bit (Master mode only)(2)
1 = Initiate Stop condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Stop condition Idle
bit 1
RSEN: Repeated Start Condition Enable bit (Master mode only)(2)
1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware.
0 = Repeated Start condition Idle
bit 0
SEN: Start Condition Enable/Stretch Enable bit(2)
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 disabled
Note 1:
2:
Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive.
If the I2C module is not in the Idle mode, these bits may not be set (no spooling) and the SSPBUF may not
be written (or writes to the SSPBUF are disabled).
© 2007 Microchip Technology Inc.
DS39629C-page 169
PIC18F6390/6490/8390/8490
15.4.2
OPERATION
The MSSP module functions are enabled by setting
MSSP Enable bit, SSPEN (SSPCON1<5>).
The SSPCON1 register allows control of the I 2C
operation. Four mode selection bits (SSPCON1<3:0>)
allow one of the following I 2C modes to be selected:
I2C Master mode, clock = (FOSC/4) x (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 mode, 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 ensure 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).
The I 2C Slave mode hardware will always generate an
interrupt on an address match. Through the mode
select bits, the user can also choose to interrupt on
Start and Stop bits
When an address is matched, or the data transfer after
an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse
and load the SSPBUF register with the received value
currently in the SSPSR register.
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.
In this case, the SSPSR register value is not loaded
into the SSPBUF, but the SSPIF bit (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 Addressing mode, two address bytes need to
be received by the slave. The five Most Significant bits
(MSbs) of the first address byte specify if this is a 10-bit
address. Bit R/W (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 Addressing mode is as follows, with steps 7
through 9 for the slave-transmitter:
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 (SSPCON1<6>), was
set before the transfer was received.
Addressing
6.
7.
8.
9.
Receive first (high) byte of address (bits SSPIF,
BF and 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 (SSPIF and
BF bits 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 time 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.
DS39629C-page 170
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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.
If SEN is enabled (SSPCON2<0> = 1), RC3/SCK/SCL
will be held low (clock stretch) following each data
transfer. The clock must be released by setting bit
CKP (SSPCON1<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 Section 15.4.4 “Clock
Stretching” 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 8 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).
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 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.
© 2007 Microchip Technology Inc.
DS39629C-page 171
DS39629C-page 172
CKP (SSPCON1<4>)
SSPOV (SSPCON1<6>)
BF (SSPSTAT<0>)
SSPIF (PIR1<3>)
1
SCL
S
A7
3
4
A4
5
A3
Receiving Address
A5
6
A2
7
A1
8
9
ACK
R/W = 0
(CKP does not reset to ‘0’ when SEN = 0)
2
A6
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
PIC18F6390/6490/8390/8490
I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
© 2007 Microchip Technology Inc.
© 2007 Microchip Technology Inc.
1
2
A6
Data in
sampled
CKP (SSPCON1<4>)
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
4
D4
5
D3
Cleared in software
3
D5
6
D2
SSPBUF is written in software
2
D6
CKP is set in software
Clear by reading
SCL held low
while CPU
responds to SSPIF
1
D7
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
PIC18F6390/6490/8390/8490
I2C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
DS39629C-page 173
DS39629C-page 174
2
1
3
1
4
1
5
0
7
A8
UA is set indicating that
the SSPADD needs to be
updated
8
9
(CKP does not reset to ‘0’ when SEN = 0)
CKP (SSPCON1<4>)
UA (SSPSTAT<1>)
SSPOV (SSPCON1<6>)
6
A9
SSPBUF is written with
contents of SSPSR
Cleared in software
BF (SSPSTAT<0>)
SSPIF (PIR1<3>)
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
PIC18F6390/6490/8390/8490
I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
© 2007 Microchip Technology Inc.
© 2007 Microchip Technology Inc.
2
CKP (SSPCON1<4>)
UA (SSPSTAT<1>)
BF (SSPSTAT<0>)
SSPIF (PIR1<3>)
1
S
SCL
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
3
1
Receive First Byte of Address
1
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
8
A6 A5 A4 A3 A2 A1 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
Cleared in software
3
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
D7 D6 D5 D4 D3 D2 D1 D0
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
PIC18F6390/6490/8390/8490
I2C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
DS39629C-page 175
PIC18F6390/6490/8390/8490
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 highorder 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.
DS39629C-page 176
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.4.4.5
Clock Synchronization and
the CKP bit
When the CKP bit is cleared, the SCL output is forced
to ‘0’. However, setting the CKP bit will not assert the
SCL output low until the SCL output is already sampled low. Therefore, the CKP bit will not assert the
SCL line until an external I2C master device has
FIGURE 15-12:
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 deasserted SCL. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCL (see
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
deasserts clock
WR
SSPCON
© 2007 Microchip Technology Inc.
DS39629C-page 177
DS39629C-page 178
CKP (SSPON1<4>)
SSPOV (SSPCON1<6>)
BF (SSPSTAT<0>)
SSPIF (PIR1<3>)
1
SCL
S
A7
2
A6
3
4
A4
5
A3
6
A2
Receiving Address
A5
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
PIC18F6390/6490/8390/8490
I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
© 2007 Microchip Technology Inc.
© 2007 Microchip Technology Inc.
2
1
3
1
4
1
5
0
CKP (SSPCON1<4>)
UA (SSPSTAT<1>)
SSPOV (SSPCON1<6>)
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>)
SSPIF (PIR1<3>)
1
SCL
S
1
9
ACK
R/W = 0
A7
2
4
A4
5
A3
6
A2
Cleared in software
3
A5
7
A1
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
Dummy read of SSPBUF
to clear BF flag
1
A6
Receive Second Byte of Address
9
ACK
2
4
5
6
D3 D2
Cleared in software
3
D5 D4
7
D1
8
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.
9
ACK
1
4
5
6
Cleared in software
3
CKP written to ‘1’
in software
2
D3 D2
Receive Data Byte
D7 D6 D5 D4
Clock is held low until
CKP is set to ‘1’
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
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
PIC18F6390/6490/8390/8490
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PIC18F6390/6490/8390/8490
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 Addressing mode, then the second
half of the address is not necessary, the UA bit will not
be set and the slave will begin receiving data after the
Acknowledge (Figure 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 ADDRESSING MODE)
Address is compared to General Call Address
after ACK, set interrupt
R/W = 0
ACK D7
General Call Address
SDA
SCL
S
1
2
3
4
5
6
7
8
9
1
Receiving Data
ACK
D6
D5
D4
D3
D2
D1
D0
2
3
4
5
6
7
8
9
SSPIF
BF (SSPSTAT<0>)
Cleared in software
SSPBUF is read
SSPOV (SSPCON1<6>)
‘0’
GCEN (SSPCON2<7>)
‘1’
DS39629C-page 180
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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 the MSSP Interrupt
Flag bit, SSPIF, to be set (MSSP 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.
1.
2.
3.
4.
5.
6.
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:
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.
Start condition
Stop condition
Data transfer byte transmitted/received
Acknowledge transmit
Repeated Start
MSSP BLOCK DIAGRAM (I2C™ MASTER MODE)
Internal
Data Bus
Read
SSPM3:SSPM0
SSPADD<6:0>
Write
SSPBUF
SDA
Baud
Rate
Generator
Shift
Clock
SDA In
SCL In
Bus Collision
© 2007 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)
15.4.6
Set/Reset, S, P, WCOL (SSPSTAT),
Set SSPIF, BCLIF,
Reset ACKSTAT, PEN (SSPCON2)
DS39629C-page 181
PIC18F6390/6490/8390/8490
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 the 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” for more detail.
DS39629C-page 182
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 8 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.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.4.7
BAUD RATE
2
In I C 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:
Note 1:
SSPADD<6:0>
Reload
BRG Down Counter
FOSC/4
I2C™ CLOCK RATE w/BRG
FCY
FCY * 2
BRG Value
FSCL
(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
100 kHz
1 MHz
2 MHz
00h
1 MHz(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.
© 2007 Microchip Technology Inc.
DS39629C-page 183
PIC18F6390/6490/8390/8490
15.4.7.1
Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
deasserts 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
FIGURE 15-18:
SCL pin is 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 deasserted 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
DS39629C-page 184
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.4.8
I2C MASTER MODE START
CONDITION TIMING
Note:
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.
FIGURE 15-19:
15.4.8.1
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.
WCOL Status Flag
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).
Note:
Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPCON2 is disabled until the Start
condition is complete.
FIRST START BIT TIMING
Write to SEN bit occurs here
Set S bit (SSPSTAT<3>)
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
© 2007 Microchip Technology Inc.
DS39629C-page 185
PIC18F6390/6490/8390/8490
15.4.9
I2C MASTER MODE REPEATED
START CONDITION TIMING
Note 1: If RSEN is programmed while any other
event is in progress, it will not take effect.
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 deasserted (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.
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’.
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 8 bits are transmitted and an ACK is received,
the user may then transmit an additional eight bits of
address (10-bit mode) or 8 bits of data (7-bit mode).
15.4.9.1
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:
FIGURE 15-20:
WCOL Status Flag
Because queueing of events is not
allowed, writing of the lower 5 bits of
SSPCON2 is disabled until the Repeated
Start condition is complete.
REPEAT START CONDITION WAVEFORM
Write to SSPCON2
occurs here.
SDA = 1,
SCL (no change).
Set S (SSPSTAT<3>)
SDA = 1,
SCL = 1
TBRG
TBRG
At completion of Start bit,
hardware clears RSEN bit
and sets SSPIF
TBRG
1st bit
SDA
Falling edge of ninth clock,
end of Xmit
Write to SSPBUF occurs here
TBRG
SCL
TBRG
Sr = Repeated Start
DS39629C-page 186
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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
7 address bits and the R/W bit are completed. On the
falling edge of the eighth clock, the master will deassert
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:
The MSSP module must be in an Idle state
before the RCEN bit is set 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.
© 2007 Microchip Technology Inc.
DS39629C-page 187
DS39629C-page 188
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
After Start condition, SEN cleared by hardware
SSPBUF written
1
D7
1
SCL held low
while CPU
responds to SSPIF
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 MSSP 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
PIC18F6390/6490/8390/8490
I 2C™ MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
© 2007 Microchip Technology Inc.
© 2007 Microchip Technology Inc.
ACKEN
SSPOV
BF
(SSPSTAT<0>)
SDA = 0, SCL = 1
while CPU
responds to SSPIF
SSPIF
4
5
Cleared in software
3
6
2
1
SCL
S
A6 A5 A4 A3 A2
Transmit Address to Slave
A7
SDA
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
PIC18F6390/6490/8390/8490
I 2C™ MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
DS39629C-page 189
PIC18F6390/6490/8390/8490
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 deasserted. 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 deasserted (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
SDA
ACKEN automatically cleared
TBRG
ACK
D0
SCL
TBRG
8
9
SSPIF
Set SSPIF at the end
of receive
Cleared in
software
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.
DS39629C-page 190
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
15.4.14
SLEEP OPERATION
15.4.17
2
While in Sleep mode, the I C 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 I 2C 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 MSSP 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 deasserted 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 deasserted 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
© 2007 Microchip Technology Inc.
DS39629C-page 191
PIC18F6390/6490/8390/8490
15.4.17.1
Bus Collision During a Start
Condition
During a Start condition, a bus collision occurs if:
a)
b)
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).
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
deasserted. 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.
MSSP 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
DS39629C-page 192
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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
© 2007 Microchip Technology Inc.
Interrupts cleared
in software
DS39629C-page 193
PIC18F6390/6490/8390/8490
15.4.17.2
Bus Collision During a Repeated
Start Condition
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 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)
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 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
(see Figure 15-30).
When the user deasserts 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 deasserted and
when sampled high, the SDA pin is sampled.
FIGURE 15-29:
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.
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
DS39629C-page 194
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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 deasserted and
allowed to float high, SDA is sampled low after
the BRG has timed out.
After the SCL pin is deasserted, SCL is sampled
low before SDA goes high.
FIGURE 15-31:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
TBRG
TBRG
TBRG
SDA
SDA sampled
low after TBRG,
set BCLIF
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’
© 2007 Microchip Technology Inc.
DS39629C-page 195
PIC18F6390/6490/8390/8490
TABLE 15-4:
Name
INTCON
REGISTERS ASSOCIATED WITH I2C™ OPERATION
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values on
Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
IPR1
TRISC
PORTC Data Direction Register
SSPBUF
MSSP Receive Buffer/Transmit Register
SSPADD
61
62
60
2
2
MSSP Address Register in I C Slave Mode. MSSP Baud Rate Reload Register in I C Slave Mode.
60
SSPCON1
WCOL
SSPOV
SSPEN
CKP
SSPM3
SSPM2
SSPM1
SSPM0
60
SSPCON2
GCEN
ACKSTAT
ACKDT
ACKEN
RCEN
PEN
RSEN
SEN
60
SSPSTAT
SMP
CKE
D/A
P
S
R/W
UA
BF
60
Legend:
— = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP in SPI mode.
DS39629C-page 196
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
16.0
ENHANCED UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (EUSART)
PIC18F6390/6490/8390/8490 devices have three
serial I/O modules: the MSSP module, discussed in the
previous chapter and two Universal Synchronous
Asynchronous Receiver Transmitter (USART) modules. (Generically, the 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. It can also be
configured as a half-duplex synchronous system that
can communicate with peripheral devices, such as A/D
or D/A integrated circuits, serial EEPROMs, etc.
There are two distinct implementations of the USART
module in these devices: the Enhanced USART
(EUSART) discussed here and the Addressable
USART discussed in the next chapter. For this device
family, USART1 always refers to the EUSART, while
USART2 is always the AUSART.
The pins of the EUSART are multiplexed with the
functions
of
PORTC
(RC6/TX1/CK1
and
RC7/RX1/DT1). In order to configure these pins as an
EUSART:
• bit SPEN (RCSTA1<7>) must be set (= 1)
• bit TRISC<7> must be set (= 1)
• bit TRISC<6> must be set (= 1)
Note:
The USART control will automatically
reconfigure the pin from input to output as
needed.
The operation of the Enhanced USART module is
controlled through three registers:
• Transmit Status and Control Register 1 (TXSTA1)
• Receive Status and Control Register 1 (RCSTA1)
• Baud Rate Control Register 1 (BAUDCON1)
The registers are described
Register 16-2 and Register 16-3.
in
Register 16-1,
The EUSART and AUSART modules implement the
same core features for serial communications; their
basic operation is essentially the same. The EUSART
module provides additional features, including
Automatic Baud Rate Detection (ABD) and calibration,
automatic wake-up on Sync Break reception and 12-bit
Break character transmit. These features make it
ideally suited for use in Local Interconnect Network bus
(LIN bus) systems.
The EUSART can be configured in the following
modes:
• Asynchronous (full-duplex) with:
- Auto-wake-up on character reception
- Auto-baud calibration
- 12-bit Break character transmission
• Synchronous – Master (half-duplex) with
selectable clock polarity
• Synchronous – Slave (half-duplex) with selectable
clock polarity
© 2007 Microchip Technology Inc.
DS39629C-page 197
PIC18F6390/6490/8390/8490
REGISTER 16-1:
TXSTA1: EUSART TRANSMIT STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-1
R/W-0
CSRC
TX9
TXEN(1)
SYNC
SENDB
BRGH
TRMT
TX9D
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care.
Synchronous mode:
1 = Master mode (clock generated internally from BRG)
0 = Slave mode (clock from external source)
bit 6
TX9: 9-Bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5
TXEN: Transmit Enable bit(1)
1 = Transmit enabled
0 = Transmit disabled
bit 4
SYNC: EUSART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
bit 3
SENDB: Send Break Character bit
Asynchronous mode:
1 = Send Sync Break on next transmission (cleared by hardware upon completion)
0 = Sync Break transmission completed
Synchronous mode:
Don’t care.
bit 2
BRGH: High Baud Rate Select bit
Asynchronous mode:
1 = High speed
0 = Low speed
Synchronous mode:
Unused in this mode.
bit 1
TRMT: Transmit Shift Register Status bit
1 = TSR empty
0 = TSR full
bit 0
TX9D: 9th bit of Transmit Data
Can be address/data bit or a parity bit.
Note 1:
SREN/CREN overrides TXEN in Sync mode.
DS39629C-page 198
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 16-2:
RCSTA1: EUSART RECEIVE STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
R-0
R-x
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SPEN: Serial Port Enable bit
1 = Serial port enabled (configures RX1/DT1 and TX1/CK1 pins as serial port pins)
0 = Serial port disabled (held in Reset)
bit 6
RX9: 9-Bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5
SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care.
Synchronous mode – Master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave:
Don’t care.
bit 4
CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables receiver
0 = Disables receiver
Synchronous mode:
1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3
ADDEN: Address Detect Enable bit
Asynchronous mode 9-Bit (RX9 = 1):
1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set
0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit
Asynchronous mode 9-Bit (RX9 = 0):
Don’t care.
bit 2
FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREG1 register and receiving next valid byte)
0 = No framing error
bit 1
OERR: Overrun Error bit
1 = Overrun error (can be cleared by clearing bit, CREN)
0 = No overrun error
bit 0
RX9D: 9th bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
© 2007 Microchip Technology Inc.
DS39629C-page 199
PIC18F6390/6490/8390/8490
REGISTER 16-3:
BAUDCON1: BAUD RATE CONTROL REGISTER 1
R/W-0
R-1
U-0
R/W-0
R/W-0
U-0
R/W-0
R/W-0
ABDOVF
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
ABDOVF: Auto-Baud Acquisition Rollover Status bit
1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software)
0 = No BRG rollover has occurred
bit 6
RCIDL: Receive Operation Idle Status bit
1 = Receive operation is Idle
0 = Receive operation is active
bit 5
Unimplemented: Read as ‘0’
bit 4
SCKP: Synchronous Clock Polarity Select bit
Asynchronous mode:
Unused in this mode.
Synchronous mode:
1 = Idle state for clock (CK1) is a high level
0 = Idle state for clock (CK1) is a low level
bit 3
BRG16: 16-Bit Baud Rate Register Enable bit
1 = 16-bit Baud Rate Generator – SPBRGH1 and SPBRG1
0 = 8-bit Baud Rate Generator – SPBRG1 only (Compatible mode), SPBRGH1 value ignored
bit 2
Unimplemented: Read as ‘0’
bit 1
WUE: Wake-up Enable bit
Asynchronous mode:
1 = EUSART will continue to sample the RX1 pin – interrupt generated on falling edge; bit cleared in
hardware on following rising edge
0 = RX1 pin not monitored or rising edge detected
Synchronous mode:
Unused in this mode.
bit 0
ABDEN: Auto-Baud Detect Enable bit
Asynchronous mode:
1 = Enable baud rate measurement on the next character. Requires reception of a Sync field (55h);
cleared in hardware upon completion.
0 = Baud rate measurement disabled or completed
Synchronous mode:
Unused in this mode.
DS39629C-page 200
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
16.1
EUSART Baud Rate Generator
(BRG)
The BRG is a dedicated, 8-bit or 16-bit generator that
supports both the Asynchronous and Synchronous
modes of the EUSART. By default, the BRG operates
in 8-bit mode; setting the BRG16 bit (BAUDCON1<3>)
selects 16-bit mode.
The SPBRGH1:SPBRG1 register pair controls the period
of a free-running timer. In Asynchronous mode, the
BRGH (TXSTA1<2>) and BRG16 (BAUDCON1<3>) bits
also control the baud rate. In Synchronous mode, BRGH
is ignored. Table 16-1 shows the formula for computation
of the baud rate for different EUSART modes that only
apply in Master mode (internally generated clock).
Given the desired baud rate and FOSC, the nearest
integer value for the SPBRGH1:SPBRG1 registers can
be calculated using the formulas in Table 16-1. From
this, the error in baud rate can be determined. An example calculation is shown in Example 16-1. Typical baud
rates and error values for the various Asynchronous
modes are shown in Table 16-3. It may be advanta-
TABLE 16-1:
geous to use the high baud rate (BRGH = 1) or the 16-bit
BRG to reduce the baud rate error, or achieve a slow
baud rate for a fast oscillator frequency.
Writing a new value to the SPBRGH1:SPBRG1 registers causes the BRG timer to be reset (or cleared). This
ensures the BRG does not wait for a timer overflow
before outputting the new baud rate.
16.1.1
OPERATION IN POWER-MANAGED
MODES
The device clock is used to generate the desired baud
rate. When one of the power-managed modes is
entered, the new clock source may be operating at a
different frequency. This may require an adjustment to
the value in the SPBRG1 register pair.
16.1.2
SAMPLING
The data on the RX1 pin is sampled three times by a
majority detect circuit to determine if a high or a low
level is present at the RX1 pin.
BAUD RATE FORMULAS
Configuration Bits
SYNC
BRG16
BRGH
BRG/EUSART Mode
Baud Rate Formula
0
0
0
8-Bit/Asynchronous
0
0
1
8-Bit/Asynchronous
0
1
0
16-Bit/Asynchronous
0
1
1
16-Bit/Asynchronous
1
0
x
8-Bit/Synchronous
1
1
x
16-Bit/Synchronous
Legend: x = Don’t care, n = Value of SPBRGH1:SPBRG1 register pair
EXAMPLE 16-1:
FOSC/[64 (n + 1)]
FOSC/[16 (n + 1)]
FOSC/[4 (n + 1)]
CALCULATING BAUD RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG:
Desired Baud Rate
= FOSC/(64 ([SPBRGH1:SPBRG1] + 1))
Solving for SPBRGH1:SPBRG1:
X = ((FOSC/Desired Baud Rate)/64) – 1
= ((16000000/9600)/64) – 1
= [25.042] = 25
Calculated Baud Rate = 16000000/(64 (25 + 1))
= 9615
Error
= (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate
= (9615 – 9600)/9600 = 0.16%
TABLE 16-2:
Name
TXSTA1
RCSTA1
REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset Values
on Page
CSRC
SPEN
TX9
RX9
TXEN
SREN
SYNC
CREN
SENDB
ADDEN
BRGH
FERR
TRMT
OERR
TX9D
RX9D
61
61
—
WUE
ABDEN
62
62
—
SCKP
BRG16
BAUDCON1 ABDOVF RCIDL
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.
© 2007 Microchip Technology Inc.
61
DS39629C-page 201
PIC18F6390/6490/8390/8490
TABLE 16-3:
BAUD RATES FOR ASYNCHRONOUS MODES
SYNC = 0, BRGH = 0, BRG16 = 0
BAUD
RATE
(K)
FOSC = 40.000 MHz
Actual
Rate (K)
%
Error
FOSC = 20.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 10.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 8.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
—
—
—
—
—
—
—
—
—
—
—
—
1.2
—
—
—
1.221
1.73
255
1.202
0.16
129
1.201
-0.16
103
2.4
2.441
1.73
255
2.404
0.16
129
2.404
0.16
64
2.403
-0.16
51
9.6
9.615
0.16
64
9.766
1.73
31
9.766
1.73
15
9.615
-0.16
12
19.2
19.531
1.73
31
19.531
1.73
15
19.531
1.73
7
—
—
—
57.6
56.818
-1.36
10
62.500
8.51
4
52.083
-9.58
2
—
—
—
115.2
125.000
8.51
4
104.167
-9.58
2
78.125
-32.18
1
—
—
—
SYNC = 0, BRGH = 0, BRG16 = 0
BAUD
RATE
(K)
FOSC = 4.000 MHz
Actual
Rate (K)
%
Error
FOSC = 2.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 1.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
0.300
0.16
207
0.300
-0.16
103
0.300
-0.16
51
1.2
1.202
0.16
51
1.201
-0.16
25
1.201
-0.16
12
2.4
2.404
0.16
25
2.403
-0.16
12
—
—
—
9.6
8.929
-6.99
6
—
—
—
—
—
—
19.2
20.833
8.51
2
—
—
—
—
—
—
57.6
62.500
8.51
0
—
—
—
—
—
—
115.2
62.500
-45.75
0
—
—
—
—
—
—
SYNC = 0, BRGH = 1, BRG16 = 0
BAUD
RATE
(K)
FOSC = 40.000 MHz
Actual
Rate (K)
%
Error
FOSC = 20.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 10.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 8.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
—
0.3
—
—
—
—
—
—
—
—
—
—
—
1.2
—
—
—
—
—
—
—
—
—
—
—
—
2.4
—
—
—
—
—
—
2.441
1.73
255
2.403
-0.16
207
9.6
9.766
1.73
255
9.615
0.16
129
9.615
0.16
64
9.615
-0.16
51
19.2
19.231
0.16
129
19.231
0.16
64
19.531
1.73
31
19.230
-0.16
25
57.6
58.140
0.94
42
56.818
-1.36
21
56.818
-1.36
10
55.555
3.55
8
115.2
113.636
-1.36
21
113.636
-1.36
10
125.000
8.51
4
—
—
—
SYNC = 0, BRGH = 1, BRG16 = 0
BAUD
RATE
(K)
FOSC = 4.000 MHz
Actual
Rate (K)
%
Error
FOSC = 2.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 1.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
—
—
—
—
—
—
0.300
-0.16
207
1.2
1.202
0.16
207
1.201
-0.16
103
1.201
-0.16
51
2.4
2.404
0.16
103
2.403
-0.16
51
2.403
-0.16
25
9.6
9.615
0.16
25
9615
-0.16
12
—
—
—
19.2
19.231
0.16
12
—
—
—
—
—
—
57.6
62.500
8.51
3
—
—
—
—
—
—
115.2
125.000
8.51
1
—
—
—
—
—
—
DS39629C-page 202
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 16-3:
BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
SYNC = 0, BRGH = 0, BRG16 = 1
BAUD
RATE
(K)
FOSC = 40.000 MHz
Actual
Rate (K)
%
Error
FOSC = 20.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 10.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 8.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
1.2
0.300
1.200
0.00
0.02
8332
2082
0.300
1.200
0.02
-0.03
4165
1041
0.300
1.200
0.02
-0.03
2082
520
0.300
1.201
-0.04
-0.16
1665
415
2.4
2.402
0.06
1040
2.399
-0.03
520
2.404
0.16
259
2.403
-0.16
207
9.6
9.615
0.16
259
9.615
0.16
129
9.615
0.16
64
9.615
-0.16
51
19.2
19.231
0.16
129
19.231
0.16
64
19.531
1.73
31
19.230
-0.16
25
57.6
58.140
0.94
42
56.818
-1.36
21
56.818
-1.36
10
55.555
3.55
8
115.2
113.636
-1.36
21
113.636
-1.36
10
125.000
8.51
4
—
—
—
SYNC = 0, BRGH = 0, BRG16 = 1
BAUD
RATE
(K)
FOSC = 4.000 MHz
Actual
Rate (K)
%
Error
FOSC = 2.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 1.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
0.300
0.04
832
0.300
-0.16
415
0.300
-0.16
207
1.2
1.202
0.16
207
1.201
-0.16
103
1.201
-0.16
51
2.4
2.404
0.16
103
2.403
-0.16
51
2.403
-0.16
25
9.6
9.615
0.16
25
9.615
-0.16
12
—
—
—
19.2
19.231
0.16
12
—
—
—
—
—
—
57.6
62.500
8.51
3
—
—
—
—
—
—
115.2
125.000
8.51
1
—
—
—
—
—
—
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
BAUD
RATE
(K)
FOSC = 40.000 MHz
Actual
Rate (K)
%
Error
FOSC = 20.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 10.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 8.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
0.300
0.00
33332
0.300
0.00
16665
0.300
0.00
8332
0.300
-0.01
6665
1.2
1.200
0.00
8332
1.200
0.02
4165
1.200
0.02
2082
1.200
-0.04
1665
2.4
2.400
0.02
4165
2.400
0.02
2082
2.402
0.06
1040
2.400
-0.04
832
9.6
9.606
0.06
1040
9.596
-0.03
520
9.615
0.16
259
9.615
-0.16
207
19.2
19.193
-0.03
520
19.231
0.16
259
19.231
0.16
129
19.230
-0.16
103
57.6
57.803
0.35
172
57.471
-0.22
86
58.140
0.94
42
57.142
0.79
34
115.2
114.943
-0.22
86
116.279
0.94
42
113.636
-1.36
21
117.647
-2.12
16
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
BAUD
RATE
(K)
FOSC = 4.000 MHz
Actual
Rate (K)
%
Error
FOSC = 2.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 1.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
0.300
0.01
3332
0.300
-0.04
1665
0.300
-0.04
832
1.2
1.200
0.04
832
1.201
-0.16
415
1.201
-0.16
207
103
2.4
2.404
0.16
415
2.403
-0.16
207
2403
-0.16
9.6
9.615
0.16
103
9.615
-0.16
51
9.615
-0.16
25
19.2
19.231
0.16
51
19.230
-0.16
25
19.230
-0.16
12
57.6
58.824
2.12
16
55.555
3.55
8
—
—
—
115.2
111.111
-3.55
8
—
—
—
—
—
—
© 2007 Microchip Technology Inc.
DS39629C-page 203
PIC18F6390/6490/8390/8490
16.1.3
AUTO-BAUD RATE DETECT
The Enhanced USART module supports the automatic
detection and calibration of baud rate. This feature is
active only in Asynchronous mode and while the WUE
bit is clear.
Note 1: If the WUE bit is set with the ABDEN bit,
Auto-Baud Rate Detection will occur on
the byte following the Break character.
2: It is up to the user to determine that the
incoming character baud rate is within the
range of the selected BRG clock source.
Some combinations of oscillator frequency
and EUSART baud rates are not possible
due to bit error rates. Overall system
timing and communication baud rates
must be taken into consideration when
using the Auto-Baud Rate Detection
feature.
The automatic baud rate measurement sequence
(Figure 16-1) begins whenever a Start bit is received
and the ABDEN bit is set. The calculation is
self-averaging.
In the Auto-Baud Rate Detect (ABD) mode, the clock to
the BRG is reversed. Rather than the BRG clocking the
incoming RX1 signal, the RX1 signal is timing the BRG.
In ABD mode, the internal Baud Rate Generator is
used as a counter to time the bit period of the incoming
serial byte stream.
Once the ABDEN bit is set, the state machine will clear
the BRG and look for a Start bit. The Auto-Baud Rate
Detect must receive a byte with the value, 55h (ASCII
“U”, which is also the LIN bus Sync character), in order
to calculate the proper bit rate. The measurement is
taken over both a low and a high bit time in order to
minimize any effects caused by asymmetry of the
incoming signal. After a Start bit, the SPBRG1 begins
counting up, using the preselected clock source on the
first rising edge of RX1. After eight bits on the RX1 pin
or the fifth rising edge, an accumulated value totalling
the
proper
BRG
period
is
left
in
the
SPBRGH1:SPBRG1 register pair. Once the 5th edge is
seen (this should correspond to the Stop bit), the
ABDEN bit is automatically cleared.
If a rollover of the BRG occurs (an overflow from FFFFh
to 0000h), the event is trapped by the ABDOVF status bit
(BAUDCON1<7>). It is set in hardware by BRG rollovers
and can be set or cleared by the user in software. ABD
mode remains active after rollover events and the
ABDEN bit remains set (Figure 16-2).
3: When the auto-baud feature is enabled,
the BRG16 bit (BAUDCON<3>) must be
set.
TABLE 16-4:
BRG COUNTER CLOCK
RATES
BRG16
BRGH
BRG Counter Clock
0
0
FOSC/512
0
1
FOSC/128
1
0
FOSC/128
1
1
FOSC/32
16.1.3.1
ABD and EUSART Transmission
Since the BRG clock is reversed during ABD acquisition, the EUSART transmitter cannot be used during
ABD. This means that whenever the ABDEN bit is set,
TXREG1 cannot be written to. Users should also
ensure that ABDEN does not become set during a
transmit sequence. Failing to do this may result in
unpredictable EUSART operation.
While calibrating the baud rate period, the BRG registers are clocked at 1/8th the preconfigured clock rate.
Note that the BRG clock will be configured by the
BRG16 and BRGH bits. This allows the user to verify
that no carry occurred for 8-bit modes by checking for
00h in the SPBRGH1 register. Refer to Table 16-4 for
counter clock rates to the BRG.
While the ABD sequence takes place, the EUSART
state machine is held in Idle. The RC1IF interrupt is set
once the fifth rising edge on RX1 is detected. The value
in the RCREG1 needs to be read to clear the RC1IF
interrupt. The contents of RCREG1 should be
discarded.
DS39629C-page 204
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 16-1:
BRG Value
AUTOMATIC BAUD RATE CALCULATION
XXXXh
0000h
001Ch
Start
RX1 pin
Edge #1
Bit 1
Bit 0
Edge #2
Bit 3
Bit 2
Edge #3
Bit 5
Bit 4
Edge #4
Bit 7
Bit 6
Edge #5
Stop Bit
BRG Clock
Auto-Cleared
Set by User
ABDEN bit
RC1IF bit
(Interrupt)
Read
RCREG1
SPBRG1
XXXXh
1Ch
SPBRGH1
XXXXh
00h
Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.
FIGURE 16-2:
BRG OVERFLOW SEQUENCE
BRG Clock
ABDEN bit
RX1 pin
Start
Bit 0
ABDOVF bit
FFFFh
BRG Value
XXXXh
© 2007 Microchip Technology Inc.
0000h
0000h
DS39629C-page 205
PIC18F6390/6490/8390/8490
16.2
EUSART Asynchronous Mode
Once the TXREG1 register transfers the data to the
TSR register (occurs in one TCY), the TXREG1 register
is empty and the TX1IF flag bit (PIR1<4>) is set. This
interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF
will be set regardless of the state of TX1IE; it cannot be
cleared in software. TX1IF is also not cleared immediately upon loading TXREG1, but becomes valid in the
second instruction cycle following the load instruction.
Polling TX1IF immediately following a load of TXREG1
will return invalid results.
The Asynchronous mode of operation is selected by
clearing the SYNC bit (TXSTA1<4>). In this mode, the
EUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop
bit). The most common data format is 8 bits. An
on-chip, dedicated 8-bit/16-bit Baud Rate Generator
can be used to derive standard baud rate frequencies
from the oscillator.
The EUSART transmits and receives the LSb first. The
EUSART’s transmitter and receiver are functionally
independent, but use the same data format and baud
rate. The Baud Rate Generator produces a clock, either
x16 or x64 of the bit shift rate, depending on the BRGH
and BRG16 bits (TXSTA1<2> and BAUDCON1<3>).
Parity is not supported by the hardware but can be
implemented in software and stored as the 9th data bit.
While TX1IF indicates the status of the TXREG1 register, another bit, TRMT (TXSTA1<1>), shows the status
of the TSR register. 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.
Note 1: The TSR register is not mapped in data
memory so it is not available to the user.
When operating in Asynchronous mode, the EUSART
module consists of the following important elements:
•
•
•
•
•
•
•
2: Flag bit, TX1IF, is set when enable bit
TXEN is set.
Baud Rate Generator
Sampling Circuit
Asynchronous Transmitter
Asynchronous Receiver
Auto-Wake-up on Sync Break Character
12-Bit Break Character Transmit
Auto-Baud Rate Detection
16.2.1
To set up an Asynchronous Transmission:
1.
2.
EUSART ASYNCHRONOUS
TRANSMITTER
3.
4.
The EUSART transmitter block diagram is shown in
Figure 16-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSR). The Shift register obtains
its data from the Read/Write Transmit Buffer register,
TXREG1. The TXREG1 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 TXREG1 register (if available).
FIGURE 16-3:
5.
6.
7.
8.
Initialize the SPBRGH1:SPBRG1 registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
If interrupts are desired, set enable bit, TX1IE.
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, TX1IF.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
Load data to the TXREG1 register (starts
transmission).
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
EUSART TRANSMIT BLOCK DIAGRAM
Data Bus
TX1IF
TXREG1 Register
TX1IE
8
MSb
(8)
LSb
• • •
Pin Buffer
and Control
0
TSR Register
TX1 pin
Interrupt
TXEN
Baud Rate CLK
TRMT
BRG16
SPBRGH1
SPBRG1
Baud Rate Generator
DS39629C-page 206
SPEN
TX9
TX9D
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 16-4:
ASYNCHRONOUS TRANSMISSION
Write to TXREG1
Word 1
BRG Output
(Shift Clock)
TX1 (pin)
Start bit
bit 0
bit 1
bit 7/8
Stop bit
Word 1
TX1IF bit
(Transmit Buffer
Reg. Empty Flag)
1 TCY
Word 1
Transmit Shift Reg
TRMT bit
(Transmit Shift
Reg. Empty Flag)
FIGURE 16-5:
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
Write to TXREG1
Word 2
Word 1
BRG Output
(Shift Clock)
TX1 (pin)
Start bit
bit 1
1 TCY
TX1IF bit
(Interrupt Reg. Flag)
bit 7/8
Stop bit
Start bit
bit 0
Word 2
Word 1
1 TCY
Word 1
Transmit Shift Reg.
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Note:
bit 0
Word 2
Transmit Shift Reg.
This timing diagram shows two consecutive transmissions.
TABLE 16-5:
Name
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
61
INTCON
RCSTA1
TXREG1
GIE/GIEH PEIE/GIEL
EUSART1 Transmit Register
61
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
61
BAUDCON1
ABDOVF
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
62
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
62
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
61
TXSTA1
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
© 2007 Microchip Technology Inc.
DS39629C-page 207
PIC18F6390/6490/8390/8490
16.2.2
EUSART ASYNCHRONOUS
RECEIVER
16.2.3
The receiver block diagram is shown in Figure 16-6.
The data is received on the RX1 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.
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1.
Initialize the SPBRGH1:SPBRG1 registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
3. If interrupts are required, set the RCEN bit and
select the desired priority level with the RC1IP
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 RC1IF bit will be set when reception is
complete. The interrupt will be Acknowledged if
the RC1IE and GIE bits are set.
8. Read the RCSTA1 register to determine if any
error occurred during reception, as well as read
bit 9 of data (if applicable).
9. Read RCREG1 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.
To set up an Asynchronous Reception:
1.
Initialize the SPBRGH1:SPBRG1 registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
3. If interrupts are desired, set enable bit, RC1IE.
4. If 9-bit reception is desired, set bit, RX9.
5. Enable the reception by setting bit, CREN.
6. Flag bit, RC1IF, will be set when reception is
complete and an interrupt will be generated if
enable bit, RC1IE, was set.
7. Read the RCSTA1 register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
8. Read the 8-bit received data by reading the
RCREG1 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 16-6:
SETTING UP 9-BIT MODE WITH
ADDRESS DETECT
EUSART RECEIVE BLOCK DIAGRAM
CREN
OERR
FERR
x64 Baud Rate CLK
BRG16
SPBRGH1
SPBRG1
Baud Rate Generator
÷ 64
or
÷ 16
or
÷4
RSR Register
MSb
Stop
(8)
7
• • •
LSb
1
0
Start
RX9
Pin Buffer
and Control
Data
Recovery
RX1
RX9D
RCREG1 Register
FIFO
SPEN
8
Interrupt
RC1IF
Data Bus
RC1IE
DS39629C-page 208
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 16-7:
ASYNCHRONOUS RECEPTION
Start
bit
RX1 (pin)
bit 0
bit 1
bit 7/8 Stop
bit
Rcv Shift Reg
Rcv Buffer Reg
Start
bit
bit 0
Stop
bit
Start
bit
bit 7/8
Stop
bit
Word 2
RCREG1
Word 1
RCREG1
RCREG1
Read Rcv
Buffer Reg
bit 7/8
RC1IF
(Interrupt Flag)
OERR bit
CREN bit
Note:
This timing diagram shows three words appearing on the RX1 input. The RCREG1 (Receive Buffer register) is read after the third word
causing the OERR (Overrun) bit to be set.
TABLE 16-6:
Name
INTCON
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
61
IPR1
RCSTA1
RCREG1
TXSTA1
EUSART1 Receive Register
61
CSRC
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
61
BAUDCON1
ABDOVF
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
62
62
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
61
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
© 2007 Microchip Technology Inc.
DS39629C-page 209
PIC18F6390/6490/8390/8490
16.2.4
AUTO-WAKE-UP ON SYNC BREAK
CHARACTER
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the Baud Rate Generator
is inactive and a proper byte reception cannot be performed. The auto-wake-up feature allows the controller
to wake-up, due to activity on the RX1/DT1 line, while
the EUSART is operating in Asynchronous mode.
The auto-wake-up feature is enabled by setting the
WUE bit (BAUDCON<1>). Once set, the typical receive
sequence on RX1/DT1 is disabled and the EUSART
remains in an Idle state, monitoring for a wake-up event
independent of the CPU mode. A wake-up event
consists of a high-to-low transition on the RX1/DT1
line. (This coincides with the start of a Sync Break or a
Wake-up Signal character for the LIN protocol.)
Following a wake-up event, the module generates an
RC1IF interrupt. The interrupt is generated synchronously to the Q clocks in normal operating modes
(Figure 16-8) and asynchronously, if the device is in
Sleep mode (Figure 16-9). The interrupt condition is
cleared by reading the RCREG1 register.
The WUE bit is automatically cleared once a low-to-high
transition is observed on the RX1 line following the
wake-up event. At this point, the EUSART module is in
Idle mode and returns to normal operation. This signals
to the user that the Sync Break event is over.
16.2.4.1
Special Considerations Using
Auto-Wake-up
Since auto-wake-up functions by sensing rising edge
transitions on RX1/DT1, information with any state
changes before the Stop bit may signal a false
FIGURE 16-8:
End-Of-Character (EOC) and cause data or framing
errors. Therefore, to work properly, the initial character
in the transmission must be all ‘0’s. This can be 00h
(8 bytes) for standard RS-232 devices, or 000h
(12 bits) for LIN bus.
Oscillator start-up time must also be considered,
especially in applications using oscillators with longer
start-up intervals (i.e., XT or HS mode). The Sync
Break (or Wake-up Signal) character must be of
sufficient length and be followed by a sufficient interval
to allow enough time for the selected oscillator to start
and provide proper initialization of the EUSART.
16.2.4.2
Special Considerations Using
the WUE Bit
The timing of WUE and RC1IF events may cause some
confusion when it comes to determining the validity of
received data. As noted, setting the WUE bit places the
EUSART in an Idle mode. The wake-up event causes
a receive interrupt by setting the RC1IF bit. The WUE
bit is cleared after this when a rising edge is seen on
RX1/DT1. The interrupt condition is then cleared by
reading the RCREG1 register. Ordinarily, the data in
RCREG1 will be dummy data and should be discarded.
The fact that the WUE bit has been cleared (or is still
set), and the RC1IF flag is set, should not be used as
an indicator of the integrity of the data in RCREG1.
Users should consider implementing a parallel method
in firmware to verify received data integrity.
To assure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process. If
a receive operation is not occurring, the WUE bit may
then be set just prior to entering the Sleep mode.
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
Bit set by user
Auto-Cleared
WUE bit
RX1/DT1 Line
RC1IF
Note:
Cleared due to user read of RCREG1
The EUSART remains in Idle while the WUE bit is set.
FIGURE 16-9:
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
Q1
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Bit set by user
Auto-Cleared
WUE bit
RX1/DT1 Line
Note 1
RC1IF
SLEEP Command Executed
Note 1:
2:
Sleep Ends
Cleared due to user read of RCREG1
If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur while the stposc signal is still active.
This sequence should not depend on the presence of Q clocks.
The EUSART remains in Idle while the WUE bit is set.
DS39629C-page 210
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
16.2.5
BREAK CHARACTER SEQUENCE
The Enhanced USART module has the capability of
sending the special Break character sequences that are
required by the LIN bus standard. The Break character
transmit consists of a Start bit, followed by twelve ‘0’ bits
and a Stop bit. The Frame Break character is sent
whenever the SENDB and TXEN bits (TXSTA<3> and
TXSTA<5>) are set while the Transmit Shift Register is
loaded with data. Note that the value of data written to
TXREG1 will be ignored and all ‘0’s will be transmitted.
The SENDB bit is automatically reset by hardware after
the corresponding Stop bit is sent. This allows the user
to preload the transmit FIFO with the next transmit byte
following the Break character (typically, the Sync
character in the LIN specification).
Note that the data value written to the TXREG1 for the
Break character is ignored. The write simply serves the
purpose of initiating the proper sequence.
The TRMT bit indicates when the transmit operation is
active or Idle, just as it does during normal transmission. See Figure 16-10 for the timing of the Break
character sequence.
16.2.5.1
Break and Sync Transmit Sequence
The following sequence will send a message frame
header made up of a Break, followed by an Auto-Baud
Sync byte. This sequence is typical of a LIN bus master.
1.
2.
Configure the EUSART for the desired mode.
Set the TXEN and SENDB bits to set up the
Break character.
FIGURE 16-10:
Write to TXREG1
3.
4.
5.
Load the TXREG1 with a dummy character to
initiate transmission (the value is ignored).
Write ‘55h’ to TXREG1 to load the Sync
character into the transmit FIFO buffer.
After the Break has been sent, the SENDB bit is
reset by hardware. The Sync character now
transmits in the preconfigured mode.
When the TXREG1 becomes empty, as indicated by the
TX1IF, the next data byte can be written to TXREG1.
16.2.6
RECEIVING A BREAK CHARACTER
The Enhanced USART module can receive a Break
character in two ways.
The first method forces configuration of the baud rate
at a frequency of 9/13 the typical speed. This allows for
the Stop bit transition to be at the correct sampling
location (13 bits for Break versus Start bit and 8 data
bits for typical data).
The second method uses the auto-wake-up feature
described in Section 16.2.4 “Auto-Wake-up on Sync
Break Character”. By enabling this feature, the
EUSART will sample the next two transitions on
RX1/DT1, cause an RC1IF interrupt and receive the
next data byte followed by another interrupt.
Note that following a Break character, the user will
typically want to enable the Auto-Baud Rate Detect
feature. For both methods, the user can set the ABD bit
once the TX1IF interrupt is observed.
SEND BREAK CHARACTER SEQUENCE
Dummy Write
BRG Output
(Shift Clock)
TX1 (pin)
Start bit
bit 0
bit 1
bit 11
Stop bit
Break
TX1IF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
SENDB sampled here
Auto-Cleared
SENDB
(Transmit Shift
Reg. Empty Flag)
© 2007 Microchip Technology Inc.
DS39629C-page 211
PIC18F6390/6490/8390/8490
16.3
EUSART Synchronous
Master Mode
Once the TXREG1 register transfers the data to the
TSR register (occurs in one TCYCLE), the TXREG1 is
empty and the TX1IF flag bit (PIR1<4>) is set. The
interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF is
set regardless of the state of enable bit, TX1IE; it
cannot be cleared in software. It will reset only when
new data is loaded into the TXREG1 register.
The Synchronous Master mode is entered by setting
the CSRC bit (TXSTA<7>). In this mode, the data is
transmitted in a half-duplex manner (i.e., transmission
and reception do not occur at the same time). When
transmitting data, the reception is inhibited and vice
versa. Synchronous mode is entered by setting bit,
SYNC (TXSTA<4>). In addition, enable bit, SPEN
(RCSTA1<7>), is set in order to configure the TX1 and
RX1 pins to CK1 (clock) and DT1 (data) lines,
respectively.
While flag bit, TX1IF, indicates the status of the TXREG1
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.
The Master mode indicates that the processor transmits the master clock on the CK1 line. Clock polarity is
selected with the SCKP bit (BAUDCON<4>); setting
SCKP sets the Idle state on CK1 as high, while clearing
the bit sets the Idle state as low. This option is provided
to support Microwire devices with this module.
16.3.1
To set up a Synchronous Master Transmission:
1.
EUSART SYNCHRONOUS MASTER
TRANSMISSION
2.
The EUSART transmitter block diagram is shown in
Figure 16-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSR). The Shift register obtains
its data from the Read/Write Transmit Buffer register,
TXREG1. The TXREG1 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 TXREG1 (if available).
FIGURE 16-11:
7.
8.
SYNCHRONOUS TRANSMISSION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX1/DT1
pin
bit 0
bit 1
bit 2
Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4
bit 7
Word 1
RC6/TX1/CK1 pin
(SCKP = 0)
RC6/TX1/CK1 pin
(SCKP = 1)
Write to
TXREG1 Reg
3.
4.
5.
6.
Initialize the SPBRGH1:SPBRG1 registers for
the appropriate baud rate. Set or clear the
BRG16 bit, as required, to achieve the desired
baud rate.
Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
If interrupts are desired, set enable bit, TX1IE.
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
TXREG1 register.
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
Write Word 1
bit 0
bit 1
bit 7
Word 2
Write Word 2
TX1IF bit
(Interrupt Flag)
TRMT bit
TXEN bit
Note:
‘1’
‘1’
Sync Master mode, SPBRG1 = 0, continuous transmission of two 8-bit words.
DS39629C-page 212
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 16-12:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RC7/RX1/DT1 pin
bit 0
bit 1
bit 2
bit 6
bit 7
RC6/TX1/CK1 pin
Write to
TXREG1 Reg
TX1IF bit
TRMT bit
TXEN bit
TABLE 16-7:
Name
INTCON
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
61
IPR1
RCSTA1
TXREG1
TXSTA1
EUSART1 Transmit Register
CSRC
BAUDCON1 ABDOVF
61
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
61
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
62
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
62
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
© 2007 Microchip Technology Inc.
DS39629C-page 213
PIC18F6390/6490/8390/8490
16.3.2
EUSART SYNCHRONOUS
MASTER RECEPTION
Once Synchronous mode is selected, reception is
enabled by setting either the Single Receive Enable bit,
SREN (RCSTA1<5>), or the Continuous Receive
Enable bit, CREN (RCSTA1<4>). Data is sampled on
the RX1 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.
Initialize the SPBRGH1:SPBRG1 registers for the
appropriate baud rate. Set or clear the BRG16 bit,
as required, to achieve the desired baud rate.
Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
FIGURE 16-13:
3.
4.
5.
6.
Ensure bits, CREN and SREN, are clear.
If interrupts are desired, set enable bit, RC1IE.
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, RC1IF, will be set when reception is complete and an interrupt will be generated
if the enable bit, RC1IE, was set.
8. Read the RCSTA1 register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREG1 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.
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 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
RC7/RX1/DT1
pin
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
RC6/TX1/CK1 pin
(SCKP = 0)
RC6/TX1/CK1 pin
(SCKP = 1)
Write to
SREN bit
SREN bit
CREN bit ‘0’
‘0’
RC1IF bit
(Interrupt)
Read
RCREG1
Note:
Timing diagram demonstrates Sync Master mode with SREN bit = 1 and BRGH bit = 0.
TABLE 16-8:
Name
INTCON
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
61
IPR1
RCSTA1
RCREG1
TXSTA1
EUSART1 Receive Register
CSRC
BAUDCON1 ABDOVF
61
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
61
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
62
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
62
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
DS39629C-page 214
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
16.4
EUSART Synchronous Slave Mode
Synchronous Slave mode is entered by clearing bit,
CSRC (TXSTA1<7>). This mode differs from the
Synchronous Master mode in that the shift clock is
supplied externally at the CK1 pin (instead of being
supplied internally in Master mode). This allows the
device to transfer or receive data while in any
low-power mode.
16.4.1
EUSART SYNCHRONOUS SLAVE
TRANSMIT
If two words are written to the TXREG1, 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.
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, TX1IE.
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
TXREG1 register.
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
The first word will immediately transfer to the
TSR register and transmit.
The second word will remain in the TXREG1
register.
Flag bit, TX1IF, will not be set.
When the first word has been shifted out of TSR,
the TXREG1 register will transfer the second
word to the TSR and flag bit, TX1IF, will now be
set.
If enable bit, TX1IE, is set, the interrupt will wake
the chip from Sleep. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
TABLE 16-9:
Name
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
61
INTCON
RCSTA1
TXREG1
TXSTA1
GIE/GIEH PEIE/GIEL
EUSART1 Transmit Register
CSRC
BAUDCON1 ABDOVF
61
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
61
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
62
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
62
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
© 2007 Microchip Technology Inc.
DS39629C-page 215
PIC18F6390/6490/8390/8490
16.4.2
EUSART 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 Sleep or any
Idle mode and bit, SREN, which is a “don’t care” in
Slave mode.
If receive is enabled by setting the CREN bit prior to
entering Sleep or any Idle mode, then a word may be
received while in this low-power mode. Once the word
is received, the RSR register will transfer the data to the
RCREG1 register. If the RC1IE enable bit is set, the
interrupt generated will wake the chip from the
low-power mode. If the global interrupt is enabled, the
program will branch to the interrupt vector.
2.
3.
4.
5.
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, RC1IE.
If 9-bit reception is desired, set bit, RX9.
To enable reception, set enable bit, CREN.
Flag bit, RC1IF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RC1IE, was set.
Read the RCSTA1 register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
Read the 8-bit received data by reading the
RCREG1 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 16-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name
INTCON
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
RCSTA1
RCREG1
TXSTA1
EUSART1 Receive Register
CSRC
BAUDCON1 ABDOVF
61
61
TX9
TXEN
SYNC
SENDB
BRGH
TRMT
TX9D
61
RCIDL
—
SCKP
BRG16
—
WUE
ABDEN
62
SPBRGH1
EUSART1 Baud Rate Generator Register High Byte
62
SPBRG1
EUSART1 Baud Rate Generator Register Low Byte
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
DS39629C-page 216
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
17.0
ADDRESSABLE UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (AUSART)
The Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) module is very
similar in function to the Enhanced USART module,
discussed in the previous chapter. It is provided as an
additional channel for serial communication, with
external devices, for those situations that do not require
Auto-Baud Detection or LIN bus support.
The AUSART can be configured in the following modes:
• Asynchronous (full-duplex)
• Synchronous – Master (half-duplex)
• Synchronous – Slave (half-duplex)
© 2007 Microchip Technology Inc.
The pins of the AUSART module are multiplexed with
the functions of PORTG (RG1/TX2/CK2/SEG29 and
RG2/RX2/DT2/SEG28, respectively). In order to
configure these pins as an AUSART:
• SPEN bit (RCSTA2<7>) must be set (= 1)
• TRISG<2> bit must be set (= 1)
• TRISG<1> bit must be cleared (= 0) for
Asynchronous and Synchronous Master modes
• TRISG<1> bit must be set (= 1) for Synchronous
Slave mode
Note:
The AUSART control will automatically
reconfigure the pin from input to output as
needed.
The operation of the Addressable USART module is
controlled through two registers, TXSTA2 and
RXSTA2. These are detailed in Register 17-1 and
Register 17-2 respectively.
DS39629C-page 217
PIC18F6390/6490/8390/8490
REGISTER 17-1:
TXSTA2: AUSART TRANSMIT STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
U-0
R/W-0
R-1
R/W-0
CSRC
TX9
TXEN(1)
SYNC
—
BRGH
TRMT
TX9D
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care.
Synchronous mode:
1 = Master mode (clock generated internally from BRG)
0 = Slave mode (clock from external source)
bit 6
TX9: 9-Bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
bit 5
TXEN: Transmit Enable bit(1)
1 = Transmit enabled
0 = Transmit disabled
bit 4
SYNC: AUSART 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.
Note 1:
x = Bit is unknown
SREN/CREN overrides TXEN in Sync mode.
DS39629C-page 218
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 17-2:
RCSTA2: AUSART RECEIVE STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R-0
R-0
R-x
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
SPEN: Serial Port Enable bit
1 = Serial port enabled (configures RX2/DT2 and TX2/CK2 pins as serial port pins)
0 = Serial port disabled (held in Reset)
bit 6
RX9: 9-Bit Receive Enable bit
1 = Selects 9-bit reception
0 = Selects 8-bit reception
bit 5
SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care.
Synchronous mode – Master:
1 = Enables single receive
0 = Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave:
Don’t care.
bit 4
CREN: Continuous Receive Enable bit
Asynchronous mode:
1 = Enables receiver
0 = Disables receiver
Synchronous mode:
1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN)
0 = Disables continuous receive
bit 3
ADDEN: Address Detect Enable bit
Asynchronous mode 9-Bit (RX9 = 1):
1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set
0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit
Asynchronous mode 9-Bit (RX9 = 0):
Don’t care.
bit 2
FERR: Framing Error bit
1 = Framing error (can be updated by reading RCREG2 register and receiving next valid byte)
0 = No framing error
bit 1
OERR: Overrun Error bit
1 = Overrun error (can be cleared by clearing bit, CREN)
0 = No overrun error
bit 0
RX9D: 9th bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
© 2007 Microchip Technology Inc.
DS39629C-page 219
PIC18F6390/6490/8390/8490
17.1
AUSART Baud Rate Generator
(BRG)
geous to use the high baud rate (BRGH = 1) to reduce
the baud rate error, or achieve a slow baud rate for a
fast oscillator frequency.
The BRG is a dedicated 8-bit generator that supports
both the Asynchronous and Synchronous modes of the
AUSART.
The SPBRG2 register controls the period of a
free-running timer. In Asynchronous mode, bit BRGH
(TXSTA<2>) also controls the baud rate. In Synchronous mode, BRGH is ignored. Table 17-1 shows the
formula for computation of the baud rate for different
AUSART modes, which only apply in Master mode
(internally generated clock).
Given the desired baud rate and FOSC, the nearest
integer value for the SPBRG2 register can be calculated using the formulas in Table 17-1. From this, the
error in baud rate can be determined. An example
calculation is shown in Example 17-1. Typical baud
rates and error values for the various Asynchronous
modes are shown in Table 17-3. It may be advanta-
TABLE 17-1:
Writing a new value to the SPBRG2 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.
17.1.1
OPERATION IN POWER-MANAGED
MODES
The device clock is used to generate the desired baud
rate. When one of the power-managed modes is
entered, the new clock source may be operating at a
different frequency. This may require an adjustment to
the value in the SPBRG2 register.
17.1.2
SAMPLING
The data on the RX2 pin is sampled three times by a
majority detect circuit to determine if a high or a low
level is present at the RX2 pin.
BAUD RATE FORMULAS
Configuration Bits
BRG/AUSART Mode
Baud Rate Formula
0
Asynchronous
FOSC/[64 (n + 1)]
1
Asynchronous
FOSC/[16 (n + 1)]
x
Synchronous
FOSC/[4 (n + 1)]
SYNC
BRGH
0
0
1
Legend: x = Don’t care, n = Value of SPBRG2 register
EXAMPLE 17-1:
CALCULATING BAUD RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, BRGH = 0:
Desired Baud Rate
= FOSC/(64 ([SPBRG2] + 1))
Solving for SPBRG2:
X = ((FOSC/Desired Baud Rate)/64) – 1
= ((16000000/9600)/64) – 1
= [25.042] = 25
Calculated Baud Rate = 16000000/(64 (25 + 1))
= 9615
Error
= (Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate
= (9615 – 9600)/9600 = 0.16%
TABLE 17-2:
Name
TXSTA2
RCSTA2
SPBRG2
REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values on
Page
CSRC
TX9
TXEN
SYNC
—
BRGH
TRMT
TX9D
63
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
63
AUSART2 Baud Rate Generator Register
63
Legend: Shaded cells are not used by the BRG.
DS39629C-page 220
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 17-3:
BAUD RATES FOR ASYNCHRONOUS MODES
BRGH = 0
FOSC = 40.000 MHz
BAUD
RATE
(K)
Actual
Rate (K)
%
Error
FOSC = 20.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 10.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 8.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
—
—
—
—
—
—
—
—
—
—
—
—
1.2
—
—
—
1.221
1.73
255
1.202
0.16
129
1.201
-0.16
103
2.4
2.441
1.73
255
2.404
0.16
129
2.404
0.16
64
2.403
-0.16
51
9.6
9.615
0.16
64
9.766
1.73
31
9.766
1.73
15
9.615
-0.16
12
19.2
19.531
1.73
31
19.531
1.73
15
19.531
1.73
7
—
—
—
57.6
56.818
-1.36
10
62.500
8.51
4
52.083
-9.58
2
—
—
—
115.2
125.000
8.51
4
104.167
-9.58
2
78.125
-32.18
1
—
—
—
BRGH = 0
FOSC = 4.000 MHz
FOSC = 2.000 MHz
FOSC = 1.000 MHz
BAUD
RATE
(K)
Actual
Rate (K)
0.3
0.300
0.16
207
0.300
-0.16
103
1.2
1.202
0.16
51
1.201
-0.16
25
2.4
2.404
0.16
25
2.403
-0.16
9.6
8.929
-6.99
6
—
19.2
20.833
8.51
2
57.6
62.500
8.51
0
115.2
62.500
-45.75
0
%
Error
SPBRG Actual
value
Rate (K)
(decimal)
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.300
-0.16
51
1.201
-0.16
12
12
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
%
Error
BRGH = 1
BAUD
RATE
(K)
FOSC = 40.000 MHz
Actual
Rate (K)
%
Error
FOSC = 20.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 10.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 8.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
—
—
—
—
—
—
—
—
—
—
—
—
1.2
—
—
—
—
—
—
—
—
—
—
—
—
2.4
—
—
—
—
—
—
2.441
1.73
255
2.403
-0.16
207
9.6
9.766
1.73
255
9.615
0.16
129
9.615
0.16
64
9.615
-0.16
51
19.2
19.231
0.16
129
19.231
0.16
64
19.531
1.73
31
19.230
-0.16
25
57.6
58.140
0.94
42
56.818
-1.36
21
56.818
-1.36
10
55.555
3.55
8
115.2
113.636
-1.36
21
113.636
-1.36
10
125.000
8.51
4
—
—
—
BRGH = 1
BAUD
RATE
(K)
FOSC = 4.000 MHz
Actual
Rate (K)
%
Error
FOSC = 2.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
FOSC = 1.000 MHz
SPBRG Actual
value
Rate (K)
(decimal)
%
Error
SPBRG
value
(decimal)
0.3
—
—
—
—
—
—
0.300
-0.16
207
1.2
1.202
0.16
207
1.201
-0.16
103
1.201
-0.16
51
2.4
2.404
0.16
103
2.403
-0.16
51
2.403
-0.16
25
9.6
9.615
0.16
25
9.615
-0.16
12
—
—
—
19.2
19.231
0.16
12
—
—
—
—
—
—
57.6
62.500
8.51
3
—
—
—
—
—
—
115.2
125.000
8.51
1
—
—
—
—
—
—
© 2007 Microchip Technology Inc.
DS39629C-page 221
PIC18F6390/6490/8390/8490
17.2
AUSART Asynchronous Mode
Once the TXREG2 register transfers the data to the
TSR register (occurs in one TCY), the TXREG2 register
is empty and the TX2IF flag bit (PIR3<4>) is set. This
interrupt can be enabled or disabled by setting or
clearing the interrupt enable bit, TX2IE (PIE3<4>).
TX2IF will be set regardless of the state of TX2IE; it
cannot be cleared in software. TX2IF is also not
cleared immediately upon loading TXREG2, but
becomes valid in the second instruction cycle following
the load instruction. Polling TX2IF immediately
following a load of TXREG2 will return invalid results.
The Asynchronous mode of operation is selected by
clearing the SYNC bit (TXSTA2<4>). In this mode, the
AUSART uses standard Non-Return-to-Zero (NRZ)
format (one Start bit, eight or nine data bits and one
Stop bit). The most common data format is 8 bits. An
on-chip, dedicated 8-bit Baud Rate Generator can be
used to derive standard baud rate frequencies from the
oscillator.
The AUSART transmits and receives the LSb first. The
AUSART’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 the
BRGH bit (TXSTA2<2>). Parity is not supported by the
hardware but can be implemented in software and
stored as the 9th data bit.
While TX2IF indicates the status of the TXREG2
register, another bit, TRMT (TXSTA2<1>), shows the
status of the TSR register. 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.
Note 1: The TSR register is not mapped in data
memory, so it is not available to the user.
When operating in Asynchronous mode, the AUSART
module consists of the following important elements:
•
•
•
•
2: Flag bit, TX2IF, is set when enable bit,
TXEN is set.
Baud Rate Generator
Sampling Circuit
Asynchronous Transmitter
Asynchronous Receiver
17.2.1
To set up an Asynchronous Transmission:
1.
AUSART ASYNCHRONOUS
TRANSMITTER
2.
The AUSART transmitter block diagram is shown in
Figure 17-1. 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,
TXREG2. The TXREG2 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 TXREG2 register (if available).
3.
4.
5.
6.
7.
8.
FIGURE 17-1:
Initialize the SPBRG2 register for the appropriate
baud rate. Set or clear the BRGH bit, as required,
to achieve the desired baud rate.
Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
If interrupts are desired, set enable bit, TX2IE.
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, TX2IF.
If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
Load data to the TXREG2 register (starts
transmission).
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
AUSART TRANSMIT BLOCK DIAGRAM
Data Bus
TX2IF
TXREG2 Register
TX2IE
8
MSb
(8)
LSb
• • •
Pin Buffer
and Control
0
TSR Register
TX2 pin
Interrupt
TXEN
Baud Rate CLK
TRMT
SPBRG2
Baud Rate Generator
SPEN
TX9
TX9D
DS39629C-page 222
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 17-2:
ASYNCHRONOUS TRANSMISSION
Write to TXREG2
Word 1
BRG Output
(Shift Clock)
TX2 (pin)
Start bit
bit 0
bit 1
bit 7/8
Stop bit
Word 1
TX2IF bit
(Transmit Buffer
Reg. Empty Flag)
1 TCY
Word 1
Transmit Shift Reg
TRMT bit
(Transmit Shift
Reg. Empty Flag)
FIGURE 17-3:
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)
Write to TXREG2
Word 2
Word 1
BRG Output
(Shift Clock)
TX2 (pin)
Start bit
bit 1
1 TCY
TX2IF bit
(Interrupt Reg. Flag)
bit 7/8
Stop bit
Start bit
bit 0
Word 2
Word 1
1 TCY
Word 1
Transmit Shift Reg.
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Note:
bit 0
Word 2
Transmit Shift Reg.
This timing diagram shows two consecutive transmissions.
TABLE 17-4:
Name
INTCON
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
IPR3
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
63
RCSTA2
TXREG2
TXSTA2
SPBRG2
AUSART2 Transmit Register
CSRC
TX9
TXEN
63
SYNC
AUSART2 Baud Rate Generator Register
—
BRGH
TRMT
TX9D
63
63
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
© 2007 Microchip Technology Inc.
DS39629C-page 223
PIC18F6390/6490/8390/8490
17.2.2
AUSART ASYNCHRONOUS
RECEIVER
17.2.3
The receiver block diagram is shown in Figure 17-4.
The data is received on the RX2 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.
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1.
Initialize the SPBRG2 register for the appropriate
baud rate. Set or clear the BRGH and BRG16
bits, as required, to achieve the desired baud
rate.
2. Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
3. If interrupts are required, set the RCEN bit and
select the desired priority level with the RC2IP
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 RC2IF bit will be set when reception is
complete. The interrupt will be Acknowledged if
the RC2IE and GIE bits are set.
8. Read the RCSTA2 register to determine if any
error occurred during reception, as well as read
bit 9 of data (if applicable).
9. Read RCREG2 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.
To set up an Asynchronous Reception:
1.
Initialize the SPBRG2 register for the appropriate
baud rate. Set or clear the BRGH bit, as required,
to achieve the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
3. If interrupts are desired, set enable bit, RC2IE.
4. If 9-bit reception is desired, set bit, RX9.
5. Enable the reception by setting bit, CREN.
6. Flag bit, RC2IF, will be set when reception is
complete and an interrupt will be generated if
enable bit, RC2IE, was set.
7. Read the RCSTA2 register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
8. Read the 8-bit received data by reading the
RCREG2 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 17-4:
SETTING UP 9-BIT MODE WITH
ADDRESS DETECT
AUSART RECEIVE BLOCK DIAGRAM
CREN
OERR
FERR
x64 Baud Rate CLK
SPBRG2
Baud Rate Generator
÷ 64
or
÷ 16
or
÷4
MSb
Stop
RSR Register
(8)
7
• • •
1
LSb
0
Start
RX9
Pin Buffer
and Control
Data
Recovery
RX2
RX9D
RCREG2 Register
FIFO
SPEN
8
Interrupt
RC2IF
Data Bus
RC2IE
DS39629C-page 224
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 17-5:
ASYNCHRONOUS RECEPTION
Start
bit
bit 0
RX2 (pin)
bit 1
Start
bit
bit 7/8 Stop
bit
Rcv Shift Reg
Rcv Buffer Reg
bit 0
Stop
bit
Start
bit
bit 7/8
Stop
bit
Word 2
RCREG2
Word 1
RCREG2
Read Rcv
Buffer Reg
RCREG2
bit 7/8
RC2IF
(Interrupt Flag)
OERR bit
CREN
Note:
This timing diagram shows three words appearing on the RX2 input. The RCREG2 (Receive Buffer register) is read after the third
word causing the OERR (Overrun) bit to be set.
TABLE 17-5:
Name
INTCON
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
63
SYNC
—
BRGH
TRMT
TX9D
IPR3
RCSTA2
RCREG2
TXSTA2
SPBRG2
AUSART2 Receive Register
CSRC
TX9
TXEN
63
AUSART2 Baud Rate Generator Register
63
63
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
© 2007 Microchip Technology Inc.
DS39629C-page 225
PIC18F6390/6490/8390/8490
17.3
AUSART Synchronous
Master Mode
Once the TXREG2 register transfers the data to the
TSR register (occurs in one TCYCLE), the TXREG2 is
empty and the TX2IF flag bit (PIR3<4>) is set. The
interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX2IE (PIE3<4>). TX2IF is
set regardless of the state of enable bit, TX2IE; it
cannot be cleared in software. It will reset only when
new data is loaded into the TXREG2 register.
The Synchronous Master mode is entered by setting
the CSRC bit (TXSTA2<7>). In this mode, the data is
transmitted in a half-duplex manner (i.e., transmission
and reception do not occur at the same time). When
transmitting data, the reception is inhibited and vice
versa. Synchronous mode is entered by setting bit,
SYNC (TXSTA2<4>). In addition, enable bit, SPEN
(RCSTA2<7>), is set in order to configure the TX2 and
RX2 pins to CK2 (clock) and DT2 (data) lines,
respectively.
While flag bit, TX2IF, indicates the status of the TXREG2
register, another bit, TRMT (TXSTA2<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.
The Master mode indicates that the processor transmits
the master clock on the CK2 line.
17.3.1
To set up a Synchronous Master Transmission:
AUSART SYNCHRONOUS MASTER
TRANSMISSION
1.
The AUSART transmitter block diagram is shown in
Figure 17-1. 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,
TXREG2. The TXREG2 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 TXREG2 (if available).
2.
3.
4.
5.
6.
7.
8.
FIGURE 17-6:
Initialize the SPBRG2 register for the appropriate
baud rate.
Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
If interrupts are desired, set enable bit, TX2IE.
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
TXREG2 register.
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
SYNCHRONOUS TRANSMISSION
Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4
RX2/DT2 pin
bit 0
bit 1
bit 2
Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
bit 7
Word 1
bit 0
bit 1
bit 7
Word 2
TX2/CK2 pin
Write to
TXREG2 Reg
Write Word 1
Write Word 2
TX2IF bit
(Interrupt Flag)
TRMT bit
TXEN bit
Note:
‘1’
‘1’
Sync Master mode, SPBRG2 = 0, continuous transmission of two 8-bit words.
DS39629C-page 226
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 17-7:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
RX2/DT2 pin
bit 0
bit 1
bit 2
bit 6
bit 7
TX2/CK2 pin
Write to
TXREG2 Reg
TX2IF bit
TRMT bit
TXEN bit
TABLE 17-6:
Name
INTCON
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Bit 7
Bit 6
Bit 5
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
IPR3
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
63
RCSTA2
TXREG2
TXSTA2
SPBRG2
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
AUSART2 Transmit Register
CSRC
TX9
TXEN
63
SYNC
—
BRGH
TRMT
TX9D
AUSART2 Baud Rate Generator Register
63
63
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
© 2007 Microchip Technology Inc.
DS39629C-page 227
PIC18F6390/6490/8390/8490
17.3.2
AUSART SYNCHRONOUS
MASTER RECEPTION
4.
5.
6.
If interrupts are desired, set enable bit, RC2IE.
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, RC2IF, will be set when reception is complete and an interrupt will be generated
if the enable bit, RC2IE, was set.
8. Read the RCSTA2 register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREG2 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.
Once Synchronous mode is selected, reception is
enabled by setting either the Single Receive Enable bit,
SREN (RCSTA2<5>), or the Continuous Receive
Enable bit, CREN (RCSTA2<4>). Data is sampled on
the RX2 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 SPBRG2 register for the appropriate
baud rate.
Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
Ensure bits, CREN and SREN, are clear.
FIGURE 17-8:
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
RX2/DT2 pin
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
TX2/CK2 pin
Write to
SREN bit
SREN bit
CREN bit ‘0’
‘0’
RC2IF bit
(Interrupt)
Read
RCREG2
Note:
Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0.
TABLE 17-7:
Name
INTCON
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Bit 7
Bit 6
GIE/GIEH PEIE/GIEL
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
63
SYNC
—
BRGH
TRMT
TX9D
IPR3
RCSTA2
RCREG2
TXSTA2
SPBRG2
AUSART2 Receive Register
CSRC
TX9
TXEN
63
AUSART2 Baud Rate Generator Register
63
63
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
DS39629C-page 228
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
17.4
AUSART Synchronous Slave Mode
Synchronous Slave mode is entered by clearing bit,
CSRC (TXSTA2<7>). This mode differs from the
Synchronous Master mode in that the shift clock is
supplied externally at the CK2 pin (instead of being
supplied internally in Master mode). This allows the
device to transfer or receive data while in any
low-power mode.
17.4.1
AUSART SYNCHRONOUS
SLAVE TRANSMIT
If two words are written to the TXREG2 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.
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, TX2IE.
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
TXREG2 register.
If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
The first word will immediately transfer to the
TSR register and transmit.
The second word will remain in the TXREG2
register.
Flag bit, TX2IF, will not be set.
When the first word has been shifted out of TSR,
the TXREG2 register will transfer the second
word to the TSR and flag bit, TX2IF, will now be
set.
If enable bit, TX2IE, is set, the interrupt will wake
the chip from Sleep. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
TABLE 17-8:
Name
INTCON
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Bit 7
Bit 6
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
IPR3
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
63
RCSTA2
TXREG2
TXSTA2
SPBRG2
GIE/GIEH PEIE/GIEL
Bit 5
AUSART2 Transmit Register
CSRC
TX9
TXEN
63
SYNC
—
BRGH
TRMT
TX9D
AUSART2 Baud Rate Generator Register
63
63
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
© 2007 Microchip Technology Inc.
DS39629C-page 229
PIC18F6390/6490/8390/8490
17.4.2
AUSART 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 Sleep, or any
Idle mode and bit SREN, which is a “don’t care” in
Slave mode.
If receive is enabled by setting the CREN bit prior to
entering Sleep, or any Idle mode, then a word may be
received while in this low-power mode. Once the word
is received, the RSR register will transfer the data to the
RCREG2 register; if the RC2IE enable bit is set, the
interrupt generated will wake the chip from low-power
mode. If the global interrupt is enabled, the program will
branch to the interrupt vector.
Enable the synchronous master serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
If interrupts are desired, set enable bit, RC2IE.
If 9-bit reception is desired, set bit, RX9.
To enable reception, set enable bit, CREN.
Flag bit, RC2IF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RC2IE, was set.
Read the RCSTA2 register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
Read the 8-bit received data by reading the
RCREG2 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.
2.
3.
4.
5.
6.
7.
8.
9.
TABLE 17-9:
Name
INTCON
REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Bit 7
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
IPR3
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
RCSTA2
RCREG2
TXSTA2
SPBRG2
AUSART2 Receive Register
CSRC
TX9
TXEN
63
63
SYNC
—
BRGH
TRMT
TX9D
AUSART2 Baud Rate Generator Register
63
63
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
DS39629C-page 230
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
18.0
10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) converter module has
12 inputs for the PIC18F6X90/8X90 devices. This
module allows conversion of an analog input signal to
a corresponding 10-bit digital number.
The module has five registers:
•
•
•
•
•
A/D Result High Register (ADRESH)
A/D Result Low Register (ADRESL)
A/D Control Register 0 (ADCON0)
A/D Control Register 1 (ADCON1)
A/D Control Register 2 (ADCON2)
The ADCON0 register, shown in Register 18-1,
controls the operation of the A/D module. The
ADCON1 register, shown in Register 18-2, configures
the functions of the port pins. The ADCON2 register,
shown in Register 18-3, configures the A/D clock
source, programmed acquisition time and justification.
REGISTER 18-1:
ADCON0: A/D CONTROL REGISTER 0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-6
Unimplemented: Read as ‘0’
bit 5-2
CHS3:CHS0: Analog Channel Select bits
0000 = Channel 0 (AN0)
0001 = Channel 1 (AN1)
0010 = Channel 2 (AN2)
0011 = Channel 3 (AN3)
0100 = Channel 4 (AN4)
0101 = Channel 5 (AN5)
0110 = Channel 6 (AN6)
0111 = Channel 7 (AN7)
1000 = Channel 8 (AN8)
1001 = Channel 9 (AN9)
1010 = Channel 10 (AN10)
1011 = Channel 11 (AN11)
1100 = Unimplemented(1)
1101 = Unimplemented(1)
1110 = Unimplemented(1)
1111 = Unimplemented(1)
bit 1
GO/DONE: A/D Conversion Status bit
When ADON = 1:
1 = A/D conversion in progress
0 = A/D Idle
bit 0
ADON: A/D On bit
1 = A/D converter module is enabled
0 = A/D converter module is disabled
Note 1:
x = Bit is unknown
Performing a conversion on unimplemented channels will return a floating input measurement.
© 2007 Microchip Technology Inc.
DS39629C-page 231
PIC18F6390/6490/8390/8490
REGISTER 18-2:
ADCON1: A/D CONTROL REGISTER 1
U-0
U-0
R/W-0
R/W-0
R/W-q
R/W-q
R/W-q
R/W-q
—
—
VCFG1
VCFG0
PCFG3
PCFG2
PCFG1
PCFG0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
PCFG3:
PCFG0
AN5
AN4
AN3
AN2
AN1
AN0
PCFG3:PCFG0: A/D Port Configuration Control bits:
AN6
bit 3-0
AN7
VCFG0: Voltage Reference Configuration bit (VREF+ source)
1 = VREF+ (AN3)
0 = AVDD
AN8
bit 4
AN9
VCFG1: Voltage Reference Configuration bit (VREF- source)
1 = VREF- (AN2)
0 = AVSS
AN10
Unimplemented: Read as ‘0’
bit 5
AN11
bit 7-6
x = Bit is unknown
0000
A
A
A
A
D
D
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
D
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
D
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
A = Analog input
DS39629C-page 232
D = Digital I/O
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 18-3:
ADCON2: A/D CONTROL REGISTER 2
R/W-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
ADFM
—
ACQT2
ACQT1
ACQT0
ADCS2
ADCS1
ADCS0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
ADFM: A/D Result Format Select bit
1 = Right justified
0 = Left justified
bit 6
Unimplemented: Read as ‘0’
bit 5-3
ACQT2:ACQT0: A/D Acquisition Time Select bits
111 = 20 TAD
110 = 16 TAD
101 = 12 TAD
100 = 8 TAD
011 = 6 TAD
010 = 4 TAD
001 = 2 TAD
000 = 0 TAD(1)
bit 2-0
ADCS2:ADCS0: A/D Conversion Clock Select bits
111 = FRC (clock derived from A/D RC oscillator)(1)
110 = FOSC/64
101 = FOSC/16
100 = FOSC/4
011 = FRC (clock derived from A/D RC oscillator)(1)
010 = FOSC/32
001 = FOSC/8
000 = FOSC/2
Note 1:
x = Bit is unknown
If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D
clock starts. This allows the SLEEP instruction to be executed before starting a conversion.
© 2007 Microchip Technology Inc.
DS39629C-page 233
PIC18F6390/6490/8390/8490
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(AVDD and AVSS), or the voltage level on the
RA3/AN3/VREF+/SEG17 and RA2/AN2/VREF-/SEG16
pins.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted.
Each port pin associated with the A/D converter can be
configured as an analog input or as a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH/ADRESL
registers, the GO/DONE bit (ADCON0<1>) is cleared
and the A/D Interrupt Flag bit, ADIF, is set. The block
diagram of the A/D module is shown in Figure 18-1.
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.
FIGURE 18-1:
A/D BLOCK DIAGRAM
CHS3:CHS0
1011
1010
1001
1000
0111
0110
0101
0100
VAIN
0011
(Input Voltage)
10-Bit
A/D
Converter
0010
0001
VCFG1:VCFG0
AVDD(1)
Reference
Voltage
VREF+
VREF-
0000
AN11
AN10
AN9
AN8
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
X0
X1
1X
0X
AVSS(1)
Note 1:
I/O pins have diode protection to VDD and VSS.
DS39629C-page 234
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
Wait for A/D conversion to complete, by either:
• Polling for the GO/DONE bit to be cleared
OR
6.
7.
• Waiting for the A/D interrupt
Read A/D Result registers (ADRESH:ADRESL);
clear ADIF bit, 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 3 TAD is
required before the next acquisition starts.
FIGURE 18-2:
The following steps should be followed to perform an
A/D conversion:
3FFh
1.
3FEh
FIGURE 18-3:
Digital Code Output
002h
001h
1023 LSB
1023.5 LSB
1022 LSB
1022.5 LSB
3 LSB
Analog Input Voltage
ANALOG INPUT MODEL
VDD
Rs
VAIN
2 LSB
000h
2.5 LSB
3.
4.
003h
0.5 LSB
2.
Configure the A/D module:
• Configure analog pins, voltage reference and
digital I/O (ADCON1)
• Select A/D input channel (ADCON0)
• Select A/D acquisition time (ADCON2)
• Select A/D conversion clock (ADCON2)
• Turn on A/D module (ADCON0)
Configure A/D interrupt (if desired):
• Clear ADIF bit
• Set ADIE bit
• Set GIE bit
Wait the required acquisition time (if required).
Start conversion:
• Set GO/DONE bit (ADCON0<1>)
A/D TRANSFER FUNCTION
1 LSB
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 18.1
“A/D Acquisition Requirements”. After this acquisition time has elapsed, the A/D conversion can be
started. An acquisition time can be programmed to
occur between setting the GO/DONE bit and the actual
start of the conversion.
5.
1.5 LSB
The value 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.
Sampling
Switch
VT = 0.6V
ANx
RIC ≤ 1k
CPIN
5 pF
VT = 0.6V
SS
RSS
ILEAKAGE
±100 nA
CHOLD = 25 pF
VSS
Legend: CPIN
VT
ILEAKAGE
RIC
SS
CHOLD
RSS
= Input Capacitance
= Threshold Voltage
= Leakage Current at the pin due to
various junctions
= Interconnect Resistance
= Sampling Switch
= Sample/Hold Capacitance (from DAC)
= Sampling Switch Resistance
© 2007 Microchip Technology Inc.
VDD
6V
5V
4V
3V
2V
1
2
3
4
Sampling Switch (kΩ)
DS39629C-page 235
PIC18F6390/6490/8390/8490
18.1
A/D Acquisition Requirements
For the A/D converter to meet its specified accuracy,
the charge holding capacitor (CHOLD) must be allowed
to fully charge to the input channel voltage level. The
analog input model is shown in Figure 18-3. 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), the channel must be sampled for
at least the minimum acquisition time before starting a
conversion.
Note:
CHOLD
Rs
Conversion Error
VDD
Temperature
=
=
≤
=
=
25 pF
2.5 kΩ
1/2 LSb
5V → Rss = 2 kΩ
85°C (system max.)
ACQUISITION TIME
=
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
=
TAMP + TC + TCOFF
EQUATION 18-2:
VHOLD
or
TC
Example 18-3 shows the calculation of the minimum
required acquisition time, TACQ. This calculation is
based on the following application system
assumptions:
When the conversion is started, the
holding capacitor is disconnected from the
input pin.
EQUATION 18-1:
TACQ
To calculate the minimum acquisition time,
Equation 18-1 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.
A/D MINIMUM CHARGING TIME
=
(VREF – (VREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS)))
=
-(CHOLD)(RIC + RSS + RS) ln(1/2048)
EQUATION 18-3:
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
TACQ
=
TAMP + TC + TCOFF
TAMP
=
0.2 μs
TCOFF
=
(Temp – 25°C)(0.02 μs/°C)
(50°C – 25°C)(0.02 μs/°C)
1.2 μs
Temperature coefficient is only required for temperatures > 25°C. Below 25°C, TCOFF = 0 ms.
TC
=
-(CHOLD)(RIC + RSS + RS) ln(1/2047) μs
-(25 pF) (1 kΩ + 2 kΩ + 2.5 kΩ) ln(0.0004883) μs
5.03 μs
TACQ
=
0.2 μs + 5 μs + 1.2 μs
6.4 μs
DS39629C-page 236
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
18.2
Selecting and Configuring
Automatic Acquisition Time
The ADCON2 register allows the user to select an
acquisition time that occurs each time the GO/DONE
bit is set.
When the GO/DONE bit is set, sampling is stopped and
a conversion begins. The user is responsible for ensuring the required acquisition time has passed between
selecting the desired input channel and setting the
GO/DONE bit. This occurs when the ACQT2:ACQT0
bits (ADCON2<5:3>) remain in their Reset state (‘000’)
and is compatible with devices that do not offer
programmable acquisition times.
If desired, the ACQT bits can be set to select a
programmable acquisition time for the A/D module.
When the GO/DONE bit is set, the A/D module continues to sample the input for the selected acquisition
time, then automatically begins a conversion. Since the
acquisition time is programmed, there may be no need
to wait for an acquisition time between selecting a
channel and setting the GO/DONE bit.
In either case, when the conversion is completed, the
GO/DONE bit is cleared, the ADIF flag is set and the
A/D begins sampling the currently selected channel
again. If an acquisition time is programmed, there is
nothing to indicate if the acquisition time has ended or
if the conversion has begun.
TABLE 18-1:
The A/D conversion time per bit is defined as TAD. The
A/D conversion requires 11 TAD per 10-bit conversion.
The source of the A/D conversion clock is software
selectable. There are seven possible options for TAD:
•
•
•
•
•
•
•
2 TOSC
4 TOSC
8 TOSC
16 TOSC
32 TOSC
64 TOSC
Internal RC Oscillator
For correct A/D conversions, the A/D conversion clock
(TAD) must be as short as possible, but greater than the
minimum TAD (approximately 2 μs, see parameter 130
for more information).
Table 18-1 shows the resultant TAD times derived from
the device operating frequencies and the A/D clock
source selected.
Maximum Device Frequency
PIC18LF6X90/8X90(4)
Operation
ADCS2:ADCS0
PIC18F6X90/8X90
2 TOSC
000
1.25 MHz
666 kHz
TOSC
100
2.50 MHz
1.33 MHz
8 TOSC
001
5.00 MHz
2.66 MHz
16 TOSC
101
10.0 MHz
5.33 MHz
32 TOSC
010
20.0 MHz
10.65 MHz
64 TOSC
110
40.0 MHz
21.33 MHz
RC(3)
x11
1.00 MHz(1)
1.00 MHz(2)
4
4:
Selecting the A/D Conversion
Clock
TAD vs. DEVICE OPERATING FREQUENCIES
AD Clock Source (TAD)
Note 1:
2:
3:
18.3
The RC source has a typical TAD time of 4 μs.
The RC source has a typical TAD time of 6 μs.
For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or the A/D
accuracy may be out of specification.
Low-power (PIC18LFXXXX) devices only.
© 2007 Microchip Technology Inc.
DS39629C-page 237
PIC18F6390/6490/8390/8490
18.4
Operation in Power-Managed
Modes
The selection of the automatic acquisition time and A/D
conversion clock is determined in part by the clock
source and frequency while in a power-managed
mode.
If the A/D is expected to operate while the device is in
a power-managed mode, the ACQT2:ACQT0 and
ADCS2:ADCS0 bits in ADCON2 should be updated in
accordance with the power-managed mode clock that
will be used. After the power-managed mode is
entered, an A/D acquisition or conversion may be
started. Once an acquisition or conversion is started,
the device should continue to be clocked by the same
power-managed mode clock source until the conversion has been completed. If desired, the device may be
placed into the corresponding power-managed Idle
mode during the conversion.
If the power-managed mode clock frequency is less
than 1 MHz, the A/D RC clock source should be
selected.
18.5
Configuring Analog Port Pins
The ADCON1, TRISA and TRISF registers all
configure the A/D port pins. The port pins needed as
analog inputs must have their corresponding TRIS bits
set (input). If the TRIS bit is cleared (output), the digital
output level (VOH or VOL) will be converted.
The A/D operation is independent of the state of the
CHS3: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 be accurately
converted.
2: Analog levels on any pin defined as a
digital input may cause the digital input
buffer to consume current out of the
device’s specification limits.
Operation in the Sleep mode requires the A/D FRC
clock to be selected. If bits, ACQT2:ACQT0, are set to
‘000’ and a conversion is started, the conversion will be
delayed one instruction cycle to allow execution of the
SLEEP instruction and entry to Sleep mode. The IDLEN
and SCS bits in the OSCCON register must have
already been cleared prior to starting the conversion.
DS39629C-page 238
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
18.6
A/D Conversions
After the A/D conversion is completed or aborted, a
2 TAD wait is required before the next acquisition can be
started. After this wait, acquisition on the selected
channel is automatically started.
Figure 18-4 shows the operation of the A/D converter
after the GO/DONE bit has been set and the
ACQT2:ACQT0 bits are cleared. A conversion is
started after the following instruction to allow entry into
Sleep mode before the conversion begins.
Note:
Figure 18-5 shows the operation of the A/D converter
after the GO/DONE bit has been set, the
ACQT2:ACQT0 bits are set to ‘010’ and a 4 TAD acquisition time has been selected before the conversion
starts.
18.7
Discharge
The discharge phase is used to initialize the value of
the capacitor array. The array is discharged before
every sample. This feature helps to optimize the
unity-gain amplifier as the circuit always needs to
charge
the
capacitor
array,
rather
than
charge/discharge based on previous measure values.
Clearing the GO/DONE bit during a conversion will
abort the current conversion. The A/D Result register
pair will NOT be updated with the partially completed
A/D
conversion
sample.
This
means
the
ADRESH:ADRESL registers will continue to contain
the value of the last completed conversion (or the last
value written to the ADRESH:ADRESL registers).
FIGURE 18-4:
The GO/DONE bit should NOT be set in
the same instruction that turns on the A/D.
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)
TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 TAD1
b4
b1
b0
b6
b7
b2
b9
b8
b3
b5
Conversion starts
Discharge
Holding capacitor is disconnected from analog input (typically 100 ns)
Set GO/DONE bit
On the following cycle:
ADRESH:ADRESL is loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)
FIGURE 18-5:
TAD Cycles
TACQT Cycles
1
2
3
Automatic
Acquisition
Time
4
1
2
3
4
5
6
7
8
9
10
11
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
Conversion starts
(Holding capacitor is disconnected)
Set GO/DONE bit
(Holding capacitor continues
acquiring input)
© 2007 Microchip Technology Inc.
TAD1
Discharge
On the following cycle:
ADRESH:ADRESL is loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
DS39629C-page 239
PIC18F6390/6490/8390/8490
18.8
Use of the CCP2 Trigger
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 acquisition
and conversion and the Timer1 (or Timer3) counter will
be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal
TABLE 18-2:
Name
INTCON
software overhead (moving ADRESH/ADRESL to the
desired location). The appropriate analog input channel must be selected and the minimum acquisition
period is either timed by the user, or an appropriate
TACQ time selected before the “Special Event Trigger”
sets the GO/DONE bit (starts a conversion).
If the A/D module is not enabled (ADON is cleared), the
“Special Event Trigger” will be ignored by the A/D
module, but will still reset the Timer1 (or Timer3)
counter.
REGISTERS ASSOCIATED WITH A/D OPERATION
Bit 7
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
Bit 6
GIE/GIEH PEIE/GIEL
PIR1
—
ADIF
RC1IF
TX1IF
SSPIF
CCP1IF
TMR2IF
TMR1IF
61
PIE1
—
ADIE
RC1IE
TX1IE
SSPIE
CCP1IE
TMR2IE
TMR1IE
61
IPR1
—
ADIP
RC1IP
TX1IP
SSPIP
CCP1IP
TMR2IP
TMR1IP
61
PIR2
OSCFIF
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
61
PIE2
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
61
IPR2
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
61
ADRESH
A/D Result Register High Byte
61
ADRESL
A/D Result Register Low Byte
61
ADCON0
—
—
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
61
ADCON1
—
—
VCFG1
VCFG0
PCFG3
PCFG2
PCFG1
PCFG0
61
ADCON2
ADFM
—
ACQT2
ACQT1
ACQT0
ADCS2
ADCS1
ADCS0
61
PORTA
RA7(1)
RA6(1)
RA5
RA4
RA3
RA2
RA1
RA0
62
TRISA
TRISA7(1) TRISA6(1) PORTA Data Direction Register
62
PORTF
Read PORTF pins, Write LATF Latch
62
TRISF
PORTF Data Direction Register
62
LATF
LATF Data Output Register
62
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: These pins may be configured as port pins depending on the oscillator mode selected.
DS39629C-page 240
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
19.0
COMPARATOR MODULE
The analog comparator module contains two
comparators that can be configured in a variety of
ways. The inputs can be selected from the analog
inputs multiplexed with pins RF3 through RF6, as well
as the on-chip voltage reference (see Section 20.0
“Comparator Voltage Reference Module”). The digital outputs (normal or inverted) are available at the pin
level and can also be read through the control register.
REGISTER 19-1:
R-0
C2OUT
The CMCON register (Register 19-1) selects the
comparator input and output configuration. Block
diagrams of the various comparator configurations are
shown in Figure 19-1.
CMCON: COMPARATOR CONTROL REGISTER
R-0
C1OUT
R/W-0
C2INV
R/W-0
C1INV
R/W-0
CIS
R/W-1
CM2
R/W-1
CM1
R/W-1
CM0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
C2OUT: Comparator 2 Output bit
When C2INV = 0:
1 = C2 VIN+ > C2 VIN0 = C2 VIN+ < C2 VINWhen C2INV = 1:
1 = C2 VIN+ < C2 VIN0 = C2 VIN+ > C2 VINC1OUT: Comparator 1 Output bit
When C1INV = 0:
1 = C1 VIN+ > C1 VIN0 = C1 VIN+ < C1 VINWhen C1INV = 1:
1 = C1 VIN+ < C1 VIN0 = C1 VIN+ > C1 VINC2INV: Comparator 2 Output Inversion bit
1 = C2 output inverted
0 = C2 output not inverted
C1INV: Comparator 1 Output Inversion bit
1 = C1 Output inverted
0 = C1 Output not inverted
CIS: Comparator Input Switch bit
When CM2:CM0 = 110:
1 = C1 VIN- connects to RF5/AN10
C2 VIN- connects to RF3/AN8
0 = C1 VIN- connects to RF6/AN11
C2 VIN- connects to RF4/AN9
CM2:CM0: Comparator Mode bits
Figure 19-1 shows the Comparator modes and the CM2:CM0 bit settings.
© 2007 Microchip Technology Inc.
DS39629C-page 241
PIC18F6390/6490/8390/8490
19.1
Comparator Configuration
There are eight modes of operation for the comparators, shown in Figure 19-1. Bits, CM2:CM0 of the
CMCON register, are used to select these modes. The
TRISF register controls the data direction of the
comparator pins for each mode. If the Comparator
FIGURE 19-1:
RF4/AN9/
SEG22
RF3/AN8/
SEG21
A
A
Note:
Comparator interrupts should be disabled
during a Comparator mode change;
otherwise, a false interrupt may occur.
COMPARATOR I/O OPERATING MODES
Comparators Reset (POR Default Value)
CM2:CM0 = 000
RF6/AN11/ A
SEG24
RF5/AN10/ A
CVREF/SEG23
mode is changed, the comparator output level may not
be valid for the specified mode change delay shown in
Section 26.0 “Electrical Characteristics”.
C1
Off (Read as ‘0’)
RF6/AN11/ D
SEG24
RF5/AN10/ D
CVREF/SEG23
C2
Off (Read as ‘0’)
RF4/AN9/
SEG22
RF3/AN8/
SEG21
VINVIN+
VINVIN+
Comparators Off
CM2:CM0 = 111
Two Independent Comparators
CM2:CM0 = 010
RF6/AN11/ A
VINSEG24
C1
VIN+
RF5/AN10/ A
CVREF/SEG23
C1OUT
VINVIN+
D
VIN-
D
VIN+
C1
Off (Read as ‘0’)
C2
Off (Read as ‘0’)
Two Independent Comparators with Outputs
CM2:CM0 = 011
RF6/AN11/ A
VINSEG24
C1OUT
C1
V
IN+
RF5/AN10/ A
CVREF/SEG23
RF2/AN7/C1OUT*/SEG20
RF4/AN9/
SEG22
RF3/AN8/
SEG21
A
VIN-
A
VIN+
C2
C2OUT
RF4/AN9/
SEG22
RF3/AN8/
SEG21
A
VIN-
A
VIN+
C2OUT
C2
RF1/AN6/C2OUT*/SEG19
Two Common Reference Comparators
CM2:CM0 = 100
RF6/AN11/ A
VINSEG24
C1OUT
C1
IN+
V
RF5/AN10/ A
CVREF/SEG23
Two Common Reference Comparators with Outputs
CM2:CM0 = 101
RF6/AN11/
SEG24
RF5/AN10/
CVREF/SEG23
A
VIN-
A
VIN+
C1
C1OUT
C2
C2OUT
RF2/AN7/C1OUT*/SEG20
RF4/AN9/
SEG22
RF3/AN8/
SEG21
A
VIN-
D
VIN+
C2
C2OUT
RF4/AN9/
SEG22
RF3/AN8/
SEG21
A
VIN-
D
VIN+
RF1/AN6/C2OUT*/SEG19
One Independent Comparator with Output
CM2:CM0 = 001
RF6/AN11/ A
SEG24
RF5/AN10/ A
CVREF/SEG23
VINVIN+
C1
C1OUT
RF2/AN7/C1OUT*/SEG20
RF4/AN9/
SEG22
RF3/AN8/
SEG21
D
VIN-
D
VIN+
C2
Off (Read as ‘0’)
Four Inputs Multiplexed to Two Comparators
CM2:CM0 = 110
RF6/AN11/ A
SEG24
RF5/AN10/ A
CVREF/SEG23
CIS = 0
CIS = 1
VIN-
RF4/AN9/
SEG22
RF3/AN8/
SEG21
CIS = 0
CIS = 1
VIN-
VIN+
C1
C1OUT
C2
C2OUT
A
A
VIN+
CVREF
From VREF Module
A = Analog Input, port reads zeros always
D = Digital Input
CIS (CMCON<3>) is the Comparator Input Switch
* Setting the TRISF<2:1> bits will disable the comparator outputs by configuring the pins as inputs.
DS39629C-page 242
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
19.2
Comparator Operation
19.3.2
INTERNAL REFERENCE SIGNAL
A single comparator is shown in Figure 19-2, along with
the relationship between the analog input levels and
the digital output. When the analog input at VIN+ is less
than the analog input VIN-, the output of the comparator
is a digital low level. When the analog input at VIN+ is
greater than the analog input VIN-, the output of the
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 19-2 represent
the uncertainty, due to input offsets and response time.
The comparator module also allows the selection of an
internally generated voltage reference from the comparator voltage reference module. This module is
described in more detail in Section 20.0 “Comparator
Voltage Reference Module”.
19.3
19.4
Comparator Reference
Depending on the comparator operating mode, either
an external or internal voltage reference may be used.
The analog signal present at VIN- is compared to the
signal at VIN+ and the digital output of the comparator
is adjusted accordingly (Figure 19-2).
FIGURE 19-2:
VIN+
VIN-
SINGLE COMPARATOR
+
–
The internal reference is only available in the mode
where four inputs are multiplexed to two comparators
(CM2:CM0 = 110). In this mode, the internal voltage
reference is applied to the VIN+ pin of both comparators.
Response time is the minimum time, after selecting a
new reference voltage or input source, before the
comparator output has a valid level. If the internal reference is changed, the maximum delay of the internal
voltage reference must be considered when using the
comparator outputs. Otherwise, the maximum delay of
the comparators should be used (see Section 26.0
“Electrical Characteristics”).
19.5
Output
VINVIN+
Comparator Response Time
Comparator Outputs
The comparator outputs are read through the CMCON
register. These bits are read-only. The comparator
outputs may also be directly output to the RF2 and RF1
I/O pins. When enabled, multiplexers in the output path
of the RF2 and RF1 pins will switch and the output of
each pin will be the unsynchronized output of the
comparator. The uncertainty of each of the
comparators is related to the input offset voltage and
the response time given in the specifications.
Figure 19-3 shows the comparator output block
diagram.
The TRISF bits will still function as an output enable/
disable for the RF2 and RF1 pins while in this mode.
Output
The polarity of the comparator outputs can be changed
using the C2INV and C1INV bits (CMCON<5:4>).
19.3.1
EXTERNAL REFERENCE SIGNAL
When external voltage references are used, the
comparator module can be configured to have the comparators operate from the same, or different reference
sources. However, threshold detector applications may
require the same reference. The reference signal must
be between VSS and VDD and can be applied to either
pin of the comparator(s).
© 2007 Microchip Technology Inc.
Note 1: When reading the PORT register, all pins
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert an analog input according to the
Schmitt Trigger input specification.
2: Analog levels on any pin defined as a
digital input may cause the input buffer to
consume more current than is specified.
DS39629C-page 243
PIC18F6390/6490/8390/8490
+
To RF2 or
RF1 pin
-
Port pins
COMPARATOR OUTPUT BLOCK DIAGRAM
MULTIPLEX
FIGURE 19-3:
D
Q
Bus
Data
CxINV
Read CMCON
EN
D
Q
EN
CL
From
Other
Comparator
Reset
19.6
Comparator Interrupts
The comparator interrupt flag is set whenever there is
a change in the output value of either comparator.
Software will need to maintain information about the
status of the output bits, as read from CMCON<7:6>, to
determine the actual change that occurred. The CMIF
bit (PIR2<6>) is the Comparator Interrupt Flag. The
CMIF bit must be reset by clearing it. Since it is also
possible to write a ‘1’ to this register, a simulated
interrupt may be initiated.
Both the CMIE bit (PIE2<6>) and the PEIE bit
(INTCON<6>) must be set to enable the interrupt. In
addition, the GIE bit (INTCON<7>) must also be set. If
any of these bits are clear, the interrupt is not enabled,
though the CMIF bit will still be set if an interrupt
condition occurs.
Note:
If a change in the CMCON register
(C1OUT or C2OUT) should occur when a
read operation is being executed (start of
the Q2 cycle), then the CMIF (PIR2<6>)
interrupt flag may not get set.
The user, in the Interrupt Service Routine, can clear the
interrupt in the following manner:
a)
b)
Any read or write of CMCON will end the
mismatch condition.
Clear flag bit, CMIF.
Set
CMIF
bit
19.7
Comparator Operation During
Sleep
When a comparator is active and the device is placed
in Sleep mode, the comparator remains active and the
interrupt is functional, if enabled. This interrupt will
wake-up the device from Sleep mode, when enabled.
While the comparator is powered up, higher Sleep
currents than shown in the power-down current
specification will occur. Each operational comparator
will consume additional current, as shown in the
comparator specifications. To minimize power
consumption while in Sleep mode, turn off the
comparators (CM2:CM0 = 111) before entering Sleep.
If the device wakes up from Sleep, the contents of the
CMCON register are not affected.
19.8
Effects of a Reset
A device Reset forces the CMCON register to its Reset
state, causing the comparator module to be in the
Comparator Reset mode (CM2:CM0 = 000). This
ensures that all potential inputs are analog inputs.
Device current is minimized when analog inputs are
present at Reset time. The comparators are powered
down during the Reset interval.
A mismatch condition will continue to set flag bit, CMIF.
Reading CMCON will end the mismatch condition and
allow flag bit, CMIF, to be cleared.
DS39629C-page 244
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
19.9
Analog Input Connection
Considerations
range by more than 0.6V in either direction, one of the
diodes is forward biased and a latch-up condition may
occur. A maximum source impedance of 10 kΩ is
recommended for the analog sources. Any external
component connected to an analog input pin, such as
a capacitor or a Zener diode, should have very little
leakage current.
A simplified circuit for an analog input is shown in
Figure 19-4. Since the analog pins are connected to a
digital output, they have reverse biased diodes to VDD
and VSS. The analog input, therefore, must be between
VSS and VDD. If the input voltage deviates from this
FIGURE 19-4:
COMPARATOR ANALOG INPUT MODEL
VDD
VT = 0.6V
RS < 10k
Comparator
Input
AIN
CPIN
5 pF
VA
RIC
VT = 0.6V
ILEAKAGE
±500 nA
VSS
Legend: CPIN
VT
ILEAKAGE
RIC
RS
VA
TABLE 19-1:
=
=
=
=
=
=
Input Capacitance
Threshold Voltage
Leakage Current at the pin due to various junctions
Interconnect Resistance
Source Impedance
Analog Voltage
REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
CMCON
C2OUT
C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
61
CVRCON
CVREN
CVROE
CVRR
CVRSS
CVR3
CVR2
CVR1
CVR0
61
Name
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR2
INTCON
GIE/GIEH PEIE/GIEL
OSCFIF
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
61
PIE2
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
61
IPR2
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
61
PORTF
Read PORTF pins, Write LATF Latch
62
LATF
LATF Data Output Register
62
TRISF
PORTF Data Direction Register
62
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module.
© 2007 Microchip Technology Inc.
DS39629C-page 245
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 246
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
20.0
COMPARATOR VOLTAGE
REFERENCE MODULE
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
A block diagram of the module is shown in Figure 20-1.
The resistor ladder is segmented to provide two ranges
of CVREF values and has a power-down function to
conserve power when the reference is not being used.
The module’s supply reference can be provided from
either device VDD/VSS, or an external voltage
reference.
20.1
Configuring the Comparator
Voltage Reference
The voltage reference module is controlled through the
CVRCON register (Register 20-1). The comparator
voltage reference provides two ranges of output
voltage, each with 16 distinct levels. The range to be
REGISTER 20-1:
used is selected by the CVRR bit (CVRCON<5>). The
primary difference between the ranges is the size of the
steps selected by the CVREF selection bits
(CVR3:CVR0), with one range offering finer resolution.
The equations used to calculate the output of the
comparator voltage reference are as follows:
If CVRR = 1:
CVREF = ((CVR3:CVR0)/24) x CVRSRC
If CVRR = 0:
CVREF = (CVDD x 1/4) + (((CVR3:CVR0)/32) x
CVRSRC)
The comparator reference supply voltage can come
from either VDD and VSS, or the external VREF+ and
VREF- that are multiplexed with RA2 and RA3. The
voltage source is selected by the CVRSS bit
(CVRCON<4>).
The settling time of the comparator voltage reference
must be considered when changing the CVREF
output (see Table 26-3 in Section 26.0 “Electrical
Characteristics”).
CVRCON: COMPARATOR VOLTAGE REFERENCE 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
CVREN
CVROE(1)
CVRR
CVRSS
CVR3
CVR2
CVR1
CVR0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
CVREN: Comparator Voltage Reference Enable bit
1 = CVREF circuit powered on
0 = CVREF circuit powered down
bit 6
CVROE: Comparator VREF Output Enable bit(1)
1 = CVREF voltage level is also output on the RF5/AN10/CVREF/SEG23 pin
0 = CVREF voltage is disconnected from the RF5/AN10/CVREF/SEG23 pin
bit 5
CVRR: Comparator VREF Range Selection bit
1 = 0.00 CVRSRC to 0.75 CVRSRC, with CVRSRC/24 step size
0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size
bit 4
CVRSS: Comparator VREF Source Selection bit
1 = Comparator reference source, CVRSRC = (VREF+) – (VREF-)
0 = Comparator reference source, CVRSRC = VDD – VSS
bit 3-0
CVR3:CVR0: Comparator VREF Value Selection bits (0 ≤ (CVR3:CVR0) ≤ 15)
When CVRR = 1:
CVREF = ((CVR3:CVR0)/24) • (CVRSRC)
When CVRR = 0:
CVREF = (CVRSRC/4) + ((CVR3:CVR0)/32) • (CVRSRC)
Note 1:
CVROE overrides the TRISF<5> bit setting if enabled for output; RF5 must also be configured as an input
by setting TRISF<5> to ‘1’.
© 2007 Microchip Technology Inc.
DS39629C-page 247
PIC18F6390/6490/8390/8490
FIGURE 20-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
VREF+
VDD
CVRSS = 1
8R
CVRSS = 0
CVR3:CVR0
R
CVREN
R
R
16-to-1 MUX
R
16 Steps
R
CVREF
R
R
CVRR
VREF-
8R
CVRSS = 1
CVRSS = 0
20.2
Voltage Reference Accuracy/Error
The full range of voltage reference cannot be realized
due to the construction of the module. The transistors
on the top and bottom of the resistor ladder network
(Figure 20-1) keep CVREF from approaching the reference source rails. The voltage reference is derived
from the reference source; therefore, the CVREF output
changes with fluctuations in that source. The tested
absolute accuracy of the voltage reference can be
found in Section 26.0 “Electrical Characteristics”.
20.3
Operation During Sleep
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the CVRCON register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
20.4
Effects of a Reset
A device Reset disables the voltage reference by
clearing bit, CVREN (CVRCON<7>). This Reset also disconnects the reference from the RA2 pin by clearing bit,
CVROE (CVRCON<6>), and selects the high-voltage
range by clearing bit, CVRR (CVRCON<5>). The CVR
value select bits are also cleared.
20.5
Connection Considerations
The voltage reference module operates independently
of the comparator module. The output of the reference
generator may be connected to the RF5 pin if the
TRISF<5> bit and the CVROE bit are both set.
Enabling the voltage reference output onto the RF5 pin,
with an input signal present, will increase current
consumption. Connecting RF5 as a digital output with
CVRSS enabled will also increase current
consumption.
The RF5 pin can be used as a simple D/A output with
limited drive capability. Due to the limited current drive
capability, a buffer must be used on the voltage
reference output for external connections to VREF.
Figure 20-2 shows an example buffering technique.
DS39629C-page 248
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 20-2:
VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
PIC18FXXXX
CVREF
Module
R(1)
Voltage
Reference
Output
Impedance
Note 1:
TABLE 20-1:
Name
CVREF Output
R is dependent upon the voltage reference configuration bits, CVRCON<3:0> and CVRCON<5>.
REGISTERS ASSOCIATED WITH THE COMPARATOR VOLTAGE REFERENCE
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
CVROE
CVRR
CVRSS
CVR3
CVR2
CVR1
CVR0
61
C1OUT
C2INV
C1INV
CIS
CM2
CM1
CM0
61
Bit 7
Bit 6
CVRCON
CVREN
CMCON
C2OUT
TRISF
+
–
RF5
PORTF Data Direction Register
62
Legend: Shaded cells are not used with the comparator voltage reference.
© 2007 Microchip Technology Inc.
DS39629C-page 249
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 250
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
21.0
HIGH/LOW-VOLTAGE
DETECT (HLVD)
PIC18F6390/6490/8390/8490
devices
have
a
High/Low-Voltage Detect module (HLVD). This is a programmable circuit that allows the user to specify both a
device voltage trip point and the direction of change
from that point. If the device experiences an excursion
past the trip point in that direction, an interrupt flag is
set. If the interrupt is enabled, the program execution
will branch to the interrupt vector address and the
software can then respond to the interrupt.
REGISTER 21-1:
The High/Low-Voltage Detect Control register
(Register 21-1) completely controls the operation of the
HLVD module. This allows the circuitry to be “turned
off” by the user under software control, which
minimizes the current consumption for the device.
The block diagram for the HLVD module is shown in
Figure 21-1.
HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER
R/W-0
U-0
R-0
R/W-0
R/W-0
R/W-1
R/W-0
R/W-1
VDIRMAG
—
IRVST
HLVDEN
HLVDL3(1)
HLVDL2(1)
HLVDL1(1)
HLVDL0(1)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
VDIRMAG: Voltage Direction Magnitude Select bit
1 = Event occurs when voltage equals or exceeds trip point (HLVDL3:HLVDL0)
0 = Event occurs when voltage equals or falls below trip point (HLVDL3:HLVDL0)
bit 6
Unimplemented: Read as ‘0’
bit 5
IRVST: Internal Reference Voltage Stable Flag bit
1 = Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range
0 = Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage
range and the HLVD interrupt should not be enabled
bit 4
HLVDEN: High/Low-Voltage Detect Power Enable bit
1 = HLVD enabled
0 = HLVD disabled
bit 3-0
HLVDL3:HLVDL0: Voltage Detection Limit bits(1)
1111 = External analog input is used (input comes from the HLVDIN pin)
1110 = 4.41V-4.87V
1101 = 4.11V-4.55V
1100 = 3.92V-4.34V
1011 = 3.72V-4.12V
1010 = 3.53V-3.91V
1001 = 3.43V-3.79V
1000 = 3.24V-3.58V
0111 = 2.95V-3.26V
0110 = 2.75V-3.03V
0101 = 2.64V-2.92V
0100 = 2.43V-2.69V
0011 = 2.35V-2.59V
0010 = 2.16V-2.38V
0001 = 1.96V-2.16V
0000 = Reserved
Note 1:
HLVDL3:HLVDL0 modes that result in a trip point below the valid operating voltage of the device are not
tested.
© 2007 Microchip Technology Inc.
DS39629C-page 251
PIC18F6390/6490/8390/8490
The module is enabled by setting the HLVDEN bit.
Each time that the HLVD module is enabled, the circuitry requires some time to stabilize. The IRVST bit is
a read-only bit and is used to indicate when the circuit
is stable. The module can only generate an interrupt
after the circuit is stable and IRVST is set.
event, depending on the configuration of the module.
When the supply voltage is equal to the trip point, the
voltage tapped off of the resistor array is equal to the
internal reference voltage generated by the voltage
reference module. The comparator then generates an
interrupt signal by setting the HLVDIF bit.
The VDIRMAG bit determines the overall operation of
the module. When VDIRMAG is cleared, the module
monitors for drops in VDD below a predetermined set
point. When the bit is set, the module monitors for rises
in VDD above the set point.
The trip point voltage is software programmable to any
one of 16 values. The trip point is selected by
programming
the
HLVDL3:HLVDL0
bits
(HLVDCON<3:0>).
21.1
The HLVD 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,
HLVDL3:HLVDL0, are set to ‘1111’. In this state, the
comparator input is multiplexed from the external input
pin, HLVDIN. This gives users flexibility because it
allows them to configure the High/Low-Voltage Detect
interrupt to occur at any voltage in the valid operating
range.
Operation
When the HLVD module is enabled, a comparator uses
an internally generated reference voltage as the set
point. The set point is compared with the trip point
where each node in the resistor divider represents a
trip point voltage. The “trip point” voltage is the voltage
level at which the device detects a high or low-voltage
FIGURE 21-1:
HLVD MODULE BLOCK DIAGRAM (WITH EXTERNAL INPUT)
Externally Generated
Trip Point
VDD
VDD
HLVDCON
Register
HLVDEN
HLVDIN
16-to-1 MUX
HLVDIN
HLVDL3:HLVDL0
VDIRMAG
Set
HLVDIF
HLVDEN
BOREN
DS39629C-page 252
Internal Voltage
Reference
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
21.2
HLVD Setup
Depending on the application, the HLVD module does
not need to be operating constantly. To decrease the
current requirements, the HLVD circuitry may only
need to be enabled for short periods where the voltage
is checked. After doing the check, the HLVD module
may be disabled.
The following steps are needed to set up the HLVD
module:
1.
2.
3.
4.
5.
6.
Disable the module by clearing the HLVDEN bit
(HLVDCON<4>).
Write the value to the HLVDL3:HLVDL0 bits that
selects the desired HLVD trip point.
Set the VDIRMAG bit to detect high voltage
(VDIRMAG = 1) or low voltage (VDIRMAG = 0).
Enable the HLVD module by setting the
HLVDEN bit.
Clear the HLVD interrupt flag (PIR2<2>), which
may have been set from a previous interrupt.
Enable the HLVD interrupt, if interrupts are
desired, by setting the HLVDIE and GIE bits
(PIE<2> and INTCON<7>). An interrupt will not
be generated until the IRVST bit is set.
21.3
21.4
The internal reference voltage of the HLVD module,
specified in electrical specification parameter #D423,
may be used by other internal circuitry, such as the
programmable Brown-out Reset. If the HLVD or other
circuits using the voltage reference are disabled to
lower the device’s current consumption, the reference
voltage circuit will require time to become stable before
a low or high-voltage condition can be reliably
detected. This start-up time, TIRVST, is an interval that
is independent of device clock speed. It is specified in
electrical specification parameter 36 (Table 26-10).
Current Consumption
The HLVD interrupt flag is not enabled until TIRVST has
expired and a stable reference voltage is reached. For
this reason, brief excursions beyond the set point may
not be detected during this interval. Refer to
Figure 21-2 or Figure 21-3.
When the module is enabled, the HLVD comparator
and voltage divider are enabled and will consume static
current. The total current consumption, when enabled,
is specified in electrical specification parameter
#D022B.
FIGURE 21-2:
HLVD Start-up Time
LOW-VOLTAGE DETECT OPERATION (VDIRMAG = 0)
CASE 1:
HLVDIF may not be set
VDD
VLVD
HLVDIF
Enable HLVD
TIRVST
IRVST
Internal Reference is stable
HLVDIF cleared in software
CASE 2:
VDD
VLVD
HLVDIF
Enable HLVD
TIRVST
IRVST
Internal Reference is stable
HLVDIF cleared in software
HLVDIF cleared in software,
HLVDIF remains set since HLVD condition still exists
© 2007 Microchip Technology Inc.
DS39629C-page 253
PIC18F6390/6490/8390/8490
FIGURE 21-3:
HIGH-VOLTAGE DETECT OPERATION (VDIRMAG = 1)
CASE 1:
HLVDIF may not be set
VLVD
VDD
HLVDIF
Enable HLVD
TIRVST
IRVST
HLVDIF cleared in software
Internal Reference is stable
CASE 2:
VLVD
VDD
HLVDIF
Enable HLVD
TIRVST
IRVST
Internal Reference is stable
HLVDIF cleared in software
HLVDIF cleared in software,
HLVDIF remains set since HLVD condition still exists
Applications
In many applications, the ability to detect a drop below,
or rise above a particular threshold, is desirable. For
example, the HLVD module could be periodically
enabled to detect USB attach or detach. This assumes
the device is powered by a lower voltage source than
the Universal Serial Bus when detached. An attach
would indicate a high-voltage detect from, for example,
3.3V to 5V (the voltage on USB) and vice versa for a
detach. This feature could save a design a few extra
components and an attach signal (input pin).
For general battery applications, Figure 21-4 shows a
possible voltage curve. Over time, the device voltage
decreases. When the device voltage reaches voltage,
VA, the HLVD logic generates an interrupt at time, TA.
The interrupt could cause the execution of an ISR,
which would allow the application to perform “housekeeping tasks” and perform a controlled shutdown
before the device voltage exits the valid operating
range at TB. The HLVD, thus, would give the
application a time window, represented by the
difference between TA and TB, to safely exit.
DS39629C-page 254
FIGURE 21-4:
TYPICAL LOW-VOLTAGE
DETECT APPLICATION
VA
VB
Voltage
21.5
Time
TA
TB
Legend: VA = HLVD trip point
VB = Minimum valid device
operating voltage
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
21.6
Operation During Sleep
21.7
When enabled, the HLVD circuitry continues to operate
during Sleep. If the device voltage crosses the trip
point, the HLVDIF bit will be set and the device will
wake-up from Sleep. Device execution will continue
from the interrupt vector address if interrupts have
been globally enabled.
TABLE 21-1:
Effects of a Reset
A device Reset forces all registers to their Reset state.
This forces the HLVD module to be turned off.
REGISTERS ASSOCIATED WITH HIGH/LOW-VOLTAGE DETECT MODULE
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
HLVDCON
VDIRMAG
—
IRVST
HLVDEN
HLVDL3
HLVDL2
HLVDL1
HLVDL0
60
INTCON
GIE/GIEH PEIE/GIEL
TMR0IE
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR2
OSCFIF
CMIF
—
—
BCLIF
HLVDIF
TMR3IF
CCP2IF
61
PIE2
OSCFIE
CMIE
—
—
BCLIE
HLVDIE
TMR3IE
CCP2IE
61
IPR2
OSCFIP
CMIP
—
—
BCLIP
HLVDIP
TMR3IP
CCP2IP
61
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the HLVD module.
© 2007 Microchip Technology Inc.
DS39629C-page 255
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 256
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
22.0
LIQUID CRYSTAL DISPLAY
(LCD) DRIVER MODULE
The Liquid Crystal Display (LCD) driver module
generates the timing control to drive a static or
multiplexed LCD panel. In the 80-pin devices
(PIC18F8390/8490), the module drives the panels of
up to four commons and up to 48 segments and in the
64-pin devices (PIC18F6390/6490), the module drives
the panels of up to four commons and up to
32 segments. It also provides control of the LCD pixel
data.
The LCD driver module supports:
• Direct driving of LCD panel
• Three LCD clock sources with selectable prescaler
• Up to four commons:
- Static
- 1/2 multiplex
- 1/3 multiplex
- 1/4 multiplex
• Up to 48 (in 80-pin devices)/32 (in 64-pin devices)
segments
• Static, 1/2 or 1/3 LCD bias
A simplified block diagram of the module is shown in
Figure 22-1.
FIGURE 22-1:
LCD DRIVER MODULE BLOCK DIAGRAM
Data Bus
LCDDATAx
Registers
24 x 8
(= 4 x 48)
192-to-48
MUX
SE<47:0>
To I/O Pads
Timing Control
LCDCON
LCDPS
COM3:COM0
To I/O Pads
LCDSEx
FOSC/4
T13CKI
INTRC Oscillator
© 2007 Microchip Technology Inc.
Clock Source
Select and
Prescaler
DS39629C-page 257
PIC18F6390/6490/8390/8490
22.1
LCD Registers
The LCD driver module has 32 registers:
used to enable or disable the LCD module. The LCD
panel can also operate during Sleep by clearing the
SLPEN (LCDCON<6>) bit.
• LCD Control Register (LCDCON)
• LCD Phase Register (LCDPS)
• Six LCD Segment Enable Registers
(LCDSE5:LCDSE0)
• 24 LCD Data Registers
(LCDDATA23:LCDDATA0)
The LCDPS register, shown in Register 22-2,
configures the LCD clock source prescaler and the type
of waveform, Type-A or Type-B. Details on these
features are provided in Section 22.2 “LCD Clock
Source Selection”, Section 22.3 “LCD Bias Types”
and Section 22.8 “LCD Waveform Generation”.
The LCDCON register, shown in Register 22-1,
controls the overall operation of the module. Once the
module is configured, the LCDEN (LCDCON<7>) bit is
REGISTER 22-1:
LCDCON: LCD CONTROL REGISTER
R/W-0
R/W-0
R/C-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
LCDEN
SLPEN
WERR
—
CS1
CS0
LMUX1
LMUX0
bit 7
bit 0
Legend:
C = Clearable Only bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
LCDEN: LCD Driver Enable bit
1 = LCD driver module is enabled
0 = LCD driver module is disabled
bit 6
SLPEN: LCD Driver Enable in Sleep mode bit
1 = LCD driver module is disabled in Sleep mode
0 = LCD driver module is enabled in Sleep mode
bit 5
WERR: LCD Write Failed Error bit
1 = LCDDATAx register written while LCDPS<WA> = 0 (must be cleared in software)
0 = No LCD write error
bit 4
Unimplemented: Read as ‘0’
bit 3-2
CS1:CS0: Clock Source Select bits
00 = (FOSC/4)/8192
01 = T13CKI (Timer1)/32
1x = INTRC (31.25 kHz)/32
bit 1-0
LMUX1:LMUX0: Commons Select bits
Maximum
Maximum
Number of
Number of
Pixels
Pixels
(PIC18F6X90) (PIC18F8X90)
LMUX1:LMUX0
Multiplex
00
Static (COM0)
01
1/2 (COM1:COM0)
64
96
1/2 or 1/3
10
1/3 (COM2:COM0)
96
144
1/2 or 1/3
11
1/4 (COM3:COM0)
128
192
1/3
DS39629C-page 258
32
48
Bias
Static
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 22-2:
LCDPS: LCD PHASE REGISTER
R/W-0
R/W-0
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
WFT
BIASMD
LCDA
WA
LP3
LP2
LP1
LP0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7
WFT: Waveform Type Select bit
1 = Type-B waveform (phase changes on each frame boundary)
0 = Type-A waveform (phase changes within each common type)
bit 6
BIASMD: Bias Mode Select bit
When LMUX1:LMUX0 = 00:
0 = Static Bias mode (do not set this bit to ‘1’)
When LMUX1:LMUX0 = 01:
1 = 1/2 Bias mode
0 = 1/3 Bias mode
When LMUX1:LMUX0 = 10:
1 = 1/2 Bias mode
0 = 1/3 Bias mode
When LMUX1:LMUX0 = 11:
0 = 1/3 Bias mode (do not set this bit to ‘1’)
bit 5
LCDA: LCD Active Status bit
1 = LCD driver module is active
0 = LCD driver module is inactive
bit 4
WA: LCD Write Allow Status bit
1 = Write into the LCDDATAx registers is allowed
0 = Write into the LCDDATAx registers is not allowed
bit 3-0
LP3:LP0: LCD Prescaler Select bits
1111 = 1:16
1110 = 1:15
1101 = 1:14
1100 = 1:13
1011 = 1:12
1010 = 1:11
1001 = 1:10
1000 = 1:9
0111 = 1:8
0110 = 1:7
0101 = 1:6
0100 = 1:5
0011 = 1:4
0010 = 1:3
0001 = 1:2
0000 = 1:1
© 2007 Microchip Technology Inc.
x = Bit is unknown
DS39629C-page 259
PIC18F6390/6490/8390/8490
The LCDSE5:LCDSE0 registers configure the
functions of the port pins. Setting the segment enable
bit for a particular segment configures that pin as an
LCD driver. There are six LCD Segment Enable
registers listed in Table 22-1. The prototype LCDSEx
register is shown in Register 22-3.
TABLE 22-1:
LCDSE REGISTERS AND
ASSOCIATED SEGMENTS
Register
Segments
LCDSE0
7:0
LCDSE1
15:8
LCDSE2
23:16
LCDSE3
31:24
LCDSE4
39:32
LCDSE5
47:40
Once the module is initialized for the LCD panel, the
individual bits of the LCDDATA23:LCDDATA0 registers
are cleared or set to represent a clear or dark pixel,
respectively. Specific sets of LCDDATA registers are
used with specific segments and common signals.
Each bit represents a unique combination of a specific
segment connected to a specific common. Individual
LCDDATA bits are named by the convention “SxxCy”,
with “xx” as the segment number and “y” as the
common number. The relationship is summarized in
Table 22-2. The prototype LCDDATAx register is
shown in Register 22-4.
Note:
.
Note:
Writing into the registers, LCDDATA4,
LCDDATA5, LCDDATA10, LCDDATA11,
LCDDATA16, LCDDATA17, LCDDATA22
and LCDDATA23, in PIC18F6X90 devices
will not affect the status of any pixel and
these registers can be used as General
Purpose Registers.
The LCDSE5:LCDSE4 registers are not
implemented in PIC18F6X90 devices.
REGISTER 22-3:
LCDSEx: LCD SEGMENTx ENABLE 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
SE(n + 7)
SE(n + 6)
SE(n + 5)
SE(n + 4)
SE(n + 3)
SE(n + 2)
SE(n + 1)
SE(n)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-0
x = Bit is unknown
SE(n + 7):SE(n): Segment Enable bits
For LCDSE0: n = 0
For LCDSE1: n = 8
For LCDSE2: n = 16
For LCDSE3: n = 24
For LCDSE4: n = 32
For LCDSE5: n = 40
1 = Segment function of the pin is enabled, digital I/O is disabled
0 = I/O function of the pin is enabled
DS39629C-page 260
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 22-2:
LCDDATA REGISTERS AND BITS FOR SEGMENT AND COM COMBINATIONS
COM Lines
Segments
0 through 7
8 through 15
16 through 23
24 through 31
32 through 39
40 through 47
Note 1:
0
1
2
3
LCDDATA0
LCDDATA6
LCDDATA12
LCDDATA18
S00C0:S07C0
S00C1:S07C1
S00C2:S07C2
S00C3:S07C3
LCDDATA1
LCDDATA7
LCDDATA13
LCDDATA19
S08C0:S15C0
S08C1:S15C1
S08C2:S15C2
S08C0:S15C3
LCDDATA2
LCDDATA8
LCDDATA14
LCDDATA20
S16C0:S23C0
S16C1:S23C1
S16C2:S23C2
S16C3:S23C3
LCDDATA3
LCDDATA9
LCDDATA15
LCDDATA21
S24C0:S31C0
S24C1:S31C1
S24C2:S31C2
S24C3:S31C3
LCDDATA4(1)
LCDDATA10(1)
LCDDATA16(1)
LCDDATA22(1)
S32C0:S39C0
S32C1:S39C1
S32C2:S39C2
S32C3:S39C3
LCDDATA5(1)
LCDDATA11(1)
LCDDATA17(1)
LCDDATA23(1)
S40C0:S47C0
S40C1:S47C1
S40C2:S47C2
S40C3:S47C3
These registers are implemented but not used as LCD data registers in 64-pin devices. They may be used
as general purpose data memory.
REGISTER 22-4:
LCDDATAx: LCD DATAx 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
S(n + 7)Cy
S(n + 6)Cy
S(n + 5)Cy
S(n + 4)Cy
S(n + 3)Cy
S(n + 2)Cy
S(n + 1)Cy
S(n)Cy
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-0
x = Bit is unknown
S(n + 7)Cy:S(n)Cy: Pixel On bits
For LCDDATA0 through LCDDATA5: n = (8x), y = 0
For LCDDATA6 through LCDDATA11: n = (8(x – 6)), y = 1
For LCDDATA12 through LCDDATA17: n = (8(x – 12)), y = 2
For LCDDATA18 through LCDDATA23: n = (8(x – 18)), y = 3
1 = Pixel on (dark)
0 = Pixel off (clear)
© 2007 Microchip Technology Inc.
DS39629C-page 261
PIC18F6390/6490/8390/8490
22.2
LCD Clock Source Selection
The LCD driver module has 3 possible clock sources:
The third clock source is a 31.25 kHz internal RC
oscillator/32, which provides approximately 1 kHz
output.
• (FOSC/4)/8192
• T13CKI Clock/32
• INTRC/32
The second and third clock sources may be used to
continue running the LCD while the processor is in
Sleep.
The first clock source is the system clock divided by
8192 ((FOSC/4)/8192). This divider ratio is chosen to
provide about 1 kHz output when the system clock is
8 MHz. The divider is not programmable. Instead, the
LCD prescaler bits, LCDPS<3:0>, are used to set the
LCD frame clock rate.
Using the bits, CS1:CS0 (LCDCON<3:2>), any of these
clock sources can be selected.
The second clock source is the Timer1 oscillator/32.
This also gives about 1 kHz when a 32.768 kHz crystal
is used with the Timer1 oscillator. To use the Timer1
oscillator as a clock source, the T1OSCEN
(T1CON<3>) bit should be set.
A 16-bit counter is available as a prescaler for the LCD
clock. The prescaler is not directly readable or writable;
its value is set by the LP3:LP0 bits (LCDPS<3:0>), which
determine the prescaler assignment and prescale ratio.
The prescale values from 1:1 through 1:32768 in
power-of-2 increments are selectable.
TMR1 32 kHz
Crystal Oscillator
Internal RC Oscillator
Nom FRC = 31.25 kHz
COM3
COM1
COM2
LCD CLOCK GENERATION
System Clock
(FOSC/4)
÷8192
÷32
÷32
CS1:CS0
(LCDCON<3:2>)
DS39629C-page 262
LCD PRESCALER
COM0
FIGURE 22-2:
22.2.1
÷4
STAT
÷2
DUP
4-Bit Prog Prescaler
÷1, 2, 3, 4
Ring Counter
TRIP
QUAD
LP3:LP0
(LCDPS<3:0>)
LMUX1:LMUX0
(LCDCON<1:0>)
LMUX1:LMUX0
(LCDCON<1:0>)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
22.3
LCD Bias Types
The LCD driver module can be configured into three
bias types:
• Static Bias (2 voltage levels: AVSS and AVDD)
• 1/2 Bias (3 voltage levels: AVSS, 1/2 AVDD and
AVDD)
• 1/3 Bias (4 voltage levels: AVSS, 1/3 AVDD, 2/3 AVDD
and AVDD)
This module uses an external resistor ladder to
generate the LCD bias voltages.
The external resistor ladder should be connected to the
Bias 1 pin, Bias 2 pin, Bias 3 pin and VSS. The Bias 3
pin should also be connected to AVDD.
Figure 22-3 shows the proper way to connect the
resistor ladder to the Bias pins.
22.4
LCD Multiplex Types
The LCD driver module can be configured into four
multiplex types:
•
•
•
•
Static (only COM0 used)
1/2 multiplex (COM0 and COM1 are used)
1/3 multiplex (COM0, COM1 and COM2 are used)
1/4 multiplex (all COM0, COM1, COM2 and COM3
are used)
The LMUX1:LMUX0 setting decides the function of the
PORTE<6:4> bits (see Table 22-3 for details).
FIGURE 22-3:
If the pin is a digital I/O, the corresponding TRIS bit
controls the data direction. If the pin is a COM drive,
then the TRIS setting of that pin is overridden.
Note:
On a Power-on Reset, the LMUX1:LMUX0
bits are ‘00’.
TABLE 22-3:
PORTE<6:4> FUNCTION
LMUX1:
LMUX0
PORTE<6>
00
Digital I/O
Digital I/O
Digital I/O
01
Digital I/O
Digital I/O
COM1 Driver
Digital I/O
10
PORTE<5>
COM2 Driver COM1 Driver
COM3 Driver COM2 Driver COM1 Driver
11
22.5
Segment Enables
The LCDSEx registers are used to select the pin
function for each segment pin. The selection allows
each pin to operate as either an LCD segment driver or
a digital only pin. To configure the pin as a segment pin,
the corresponding bits in the LCDSEx registers must
be set to ‘1’.
If the pin is a digital I/O, the corresponding TRIS bit
controls the data direction. Any bit set in the LCDSEx
registers overrides any bit settings in the corresponding
TRIS register.
Note:
On a Power-on Reset, these pins are
configured as digital I/O.
LCD BIAS RESISTOR LADDER CONNECTION DIAGRAM
Static
Bias
VLCD 3 To
VLCD 2 LCD
VLCD 1 Driver
VLCD 0
LCD Bias 3
LCD Bias 2
LCD Bias 1
1/2 Bias 1/3 Bias
VLCD 0
AVSS
AVSS
VLCD 1
—
1/2 AVDD 1/3 AVDD
VLCD 2
—
1/2 AVDD 2/3 AVDD
VLCD 3
AVDD
AVDD
AVSS
AVDD
Connections for External R-ladder
Static Bias
AVDD*
AVDD*
PORTE<4>
10 kΩ*
1/2 Bias
10 kΩ*
AVSS
AVDD*
10 kΩ*
10 kΩ*
1/3 Bias
10 kΩ*
AVSS
* These values are provided for design guidance only and should be optimized for the application by the designer.
© 2007 Microchip Technology Inc.
DS39629C-page 263
PIC18F6390/6490/8390/8490
22.6
Pixel Control
22.8
The LCDDATAx registers contain bits which define the
state of each pixel. Each bit defines one unique pixel.
LCD Waveform Generation
Table 22-2 shows the correlation of each bit in the
LCDDATAx registers to the respective common and
segment signals.
LCD waveform generation is based on the philosophy
that the net AC voltage across the dark pixel should be
maximized and the net AC voltage across the clear
pixel should be minimized. The net DC voltage across
any pixel should be zero.
Any LCD pixel location not being used for display can
be used as general purpose RAM.
The COM signal represents the time slice for each
common, while the SEG contains the pixel data.
22.7
The pixel signal (COM-SEG) will have no DC component and it can take only one of the two rms values.
The higher rms value will create a dark pixel and a
lower rms value will create a clear pixel.
LCD Frame Frequency
The rate at which the COM and SEG outputs changes
is called the LCD frame frequency
TABLE 22-4:
FRAME FREQUENCY
FORMULAS
Multiplex
Frame Frequency =
Static
Clock Source/(4 x 1 x (LP3:LP0 + 1))
1/2
Clock Source/(2 x 2 x (LP3:LP0 + 1))
1/3
Clock Source/(1 x 3 x (LP3:LP0 + 1))
1/4
Clock Source/(1 x 4 x (LP3:LP0 + 1))
Note:
Clock source is (FOSC/4)/8192,
Timer1 Osc/32 or INTRC/32.
TABLE 22-5:
APPROXIMATE FRAME
FREQUENCY (IN Hz) USING
FOSC @ 32 MHz,
TIMER1 @ 32.768 kHz OR
INTRC OSCILLATOR
LP3:LP0
Static
1/2
1/3
1/4
1
125
125
167
125
2
83
83
111
83
3
62
62
83
62
4
50
50
67
50
5
42
42
56
42
6
36
36
48
36
7
31
31
42
31
DS39629C-page 264
As the number of commons increases, the delta
between the two rms values decreases. The delta
represents the maximum contrast that the display can
have.
The LCDs can be driven by two types of waveform:
Type-A and Type-B. In Type-A waveform, the phase
changes within each common type, whereas in Type-B
waveform, the phase changes on each frame
boundary. Thus, Type-A waveform maintains 0 VDC
over a single frame, whereas Type-B waveform takes
two frames.
Note 1: If Sleep has to be executed with LCD
Sleep enabled (LCDCON<SLPEN> is
‘1’), then care must be taken to execute
Sleep only when VDC on all the pixels is
‘0’.
2: When the LCD clock source is
(FOSC/4)/8192, if Sleep is executed
irrespective of the LCDCON<SLPEN>
setting, the LCD goes into Sleep. Thus,
take care to see that VDC on all pixels is ‘0’
when Sleep is executed.
Figure 22-4 through Figure 22-14 provide waveforms
for static, half-multiplex, one-third-multiplex and
quarter-multiplex drives for Type-A and Type-B
waveforms.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 22-4:
TYPE-A/TYPE-B WAVEFORMS IN STATIC DRIVE
V1
COM0
V0
COM0
V1
SEG0
V0
V1
SEG1
SEG0
SEG2
SEG7
SEG6
SEG5
SEG4
SEG3
SEG1
V0
V1
V0
COM0-SEG0
-V1
COM0-SEG1
V0
1 Frame
© 2007 Microchip Technology Inc.
DS39629C-page 265
PIC18F6390/6490/8390/8490
FIGURE 22-5:
TYPE-A WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE
V2
COM0
V1
V0
COM1
V2
COM0
COM1
V1
V0
V2
V1
SEG0
V0
SEG0
SEG1
SEG2
SEG3
V2
V1
SEG1
V0
V2
V1
V0
COM0-SEG0
-V1
-V2
V2
V1
V0
COM0-SEG1
-V1
-V2
1 Frame
DS39629C-page 266
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 22-6:
TYPE-B WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE
V2
V1
COM0
COM1
V0
COM0
V2
COM1
V1
V0
V2
SEG0
V1
SEG0
SEG1
SEG2
SEG3
V0
V2
SEG1
V1
V0
V2
V1
V0
COM0-SEG0
-V1
-V2
V2
V1
V0
COM0-SEG1
-V1
-V2
2 Frames
© 2007 Microchip Technology Inc.
DS39629C-page 267
PIC18F6390/6490/8390/8490
FIGURE 22-7:
TYPE-A WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE
V3
V2
COM0
V1
COM1
V0
V3
COM0
V2
COM1
V1
V0
V3
V2
SEG0
V1
V0
SEG0
SEG1
SEG2
SEG3
V3
V2
SEG1
V1
V0
V3
V2
V1
V0
COM0-SEG0
-V1
-V2
-V3
V3
V2
V1
V0
COM0-SEG1
-V1
-V2
1 Frame
DS39629C-page 268
-V3
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 22-8:
TYPE-B WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE
V3
V2
COM0
V1
COM1
V0
V3
COM0
V2
COM1
V1
V0
V3
V2
SEG0
V1
V0
SEG0
SEG1
SEG2
SEG3
V3
V2
SEG1
V1
V0
V3
V2
V1
V0
COM0-SEG0
-V1
-V2
-V3
V3
V2
V1
V0
COM0-SEG1
-V1
-V2
2 Frames
© 2007 Microchip Technology Inc.
-V3
DS39629C-page 269
PIC18F6390/6490/8390/8490
FIGURE 22-9:
TYPE-A WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE
V2
COM0
V1
V0
COM2
V2
COM1
V1
V0
COM1
COM0
V2
COM2
V1
V0
V2
SEG0
SEG2
V1
SEG0
SEG1
SEG2
V0
V2
SEG1
V1
V0
V2
V1
V0
COM0-SEG0
-V1
-V2
V2
V1
V0
COM0-SEG1
-V1
-V2
1 Frame
DS39629C-page 270
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 22-10:
TYPE-B WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE
V2
COM0
V1
V0
COM2
V2
COM1
V1
COM1
V0
COM0
V2
COM2
V1
V0
V2
V1
V0
SEG0
SEG1
SEG2
SEG0
V2
SEG1
V1
V0
V2
V1
V0
COM0-SEG0
-V1
-V2
V2
V1
V0
COM0-SEG1
-V1
-V2
2 Frames
© 2007 Microchip Technology Inc.
DS39629C-page 271
PIC18F6390/6490/8390/8490
FIGURE 22-11:
TYPE-A WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE
V3
V2
COM0
V1
V0
V3
COM2
V2
COM1
V1
COM1
V0
COM0
V3
V2
COM2
V1
V0
V3
V2
V1
V0
SEG0
SEG1
SEG2
SEG0
SEG2
V3
V2
SEG1
V1
V0
V3
V2
V1
V0
COM0-SEG0
-V1
-V2
-V3
V3
V2
V1
V0
COM0-SEG1
-V1
-V2
-V3
1 Frame
DS39629C-page 272
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 22-12:
TYPE-B WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE
V3
V2
COM0
V1
V0
V3
COM2
V2
COM1
V1
COM1
V0
COM0
V3
V2
COM2
V1
V0
V3
V2
V1
V0
SEG0
SEG1
SEG2
SEG0
V3
V2
SEG1
V1
V0
V3
V2
V1
V0
COM0-SEG0
-V1
-V2
-V3
V3
V2
V1
V0
COM0-SEG1
-V1
-V2
-V3
2 Frames
© 2007 Microchip Technology Inc.
DS39629C-page 273
PIC18F6390/6490/8390/8490
FIGURE 22-13:
TYPE-A WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE
COM3
COM2
COM1
COM0
V3
V2
V1
V0
COM1
V3
V2
V1
V0
COM2
V3
V2
V1
V0
COM3
V3
V2
V1
V0
SEG0
V3
V2
V1
V0
SEG1
V3
V2
V1
V0
COM0-SEG0
V3
V2
V1
V0
-V1
-V2
-V3
COM0-SEG1
V3
V2
V1
V0
-V1
-V2
-V3
SEG0
SEG1
COM0
1 Frame
DS39629C-page 274
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 22-14:
TYPE-B WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE
COM3
COM2
COM1
COM0
V3
V2
V1
V0
COM1
V3
V2
V1
V0
COM2
V3
V2
V1
V0
COM3
V3
V2
V1
V0
SEG0
V3
V2
V1
V0
SEG1
V3
V2
V1
V0
COM0-SEG0
V3
V2
V1
V0
-V1
-V2
-V3
COM0-SEG1
V3
V2
V1
V0
-V1
-V2
-V3
SEG0
SEG1
COM0
2 Frames
© 2007 Microchip Technology Inc.
DS39629C-page 275
PIC18F6390/6490/8390/8490
22.9
LCD Interrupts
When the LCD driver is running with Type-B waveforms
and the LMUX1:LMUX0 bits are not equal to ‘00’, there
are some additional issues that must be addressed.
Since the DC voltage on the pixel takes two frames to
maintain zero volts, the pixel data must not change
between subsequent frames. If the pixel data were
allowed to change, the waveform for the odd frames
would not necessarily be the complement of the
waveform generated in the even frames and a DC
component would be introduced into the panel. Therefore, when using Type-B waveforms, the user must
synchronize the LCD pixel updates to occur within a
subframe after the frame interrupt.
The LCD timing generation provides an interrupt that
defines the LCD frame timing. This interrupt can be
used to coordinate the writing of the pixel data with the
start of a new frame. Writing pixel data at the frame
boundary allows a visually crisp transition of the image.
This interrupt can also be used to synchronize external
events to the LCD. For example, the interface to an
external segment driver can be synchronized for
segment data update to the LCD frame.
A new frame is defined to begin at the leading edge of
the COM0 common signal. The interrupt will be set
immediately after the LCD controller completes
accessing all pixel data required for a frame. This will
occur at a fixed interval before the frame boundary
(TFINT), as shown in Figure 22-15. The LCD controller
will begin to access data for the next frame within the
interval from the interrupt to when the controller begins
to access data after the interrupt (TFWR). New data
must be written within TFWR, as this is when the LCD
controller will begin to access the data for the next
frame.
FIGURE 22-15:
To correctly sequence writing while in Type-B, the
interrupt will only occur on complete phase intervals. If
the user attempts to write when the write is disabled,
the WERR (LCDCON<5>) bit is set.
Note:
The interrupt is not generated when the
Type-A waveform is selected and when the
Type-B with no multiplex (static) is
selected.
EXAMPLE WAVEFORMS AND INTERRUPT TIMING IN QUARTER-DUTY
CYCLE DRIVE
LCD
Interrupt
Occurs
Controller Accesses
Next Frame Data
COM0
V3
V2
V1
V0
COM1
V3
V2
V1
V0
COM2
V3
V2
V1
V0
V3
V2
V1
V0
COM3
2 Frames
TFINT
Frame
Boundary
Frame
Boundary
TFWR
Frame
Boundary
TFWR = TFRAME/2*(LMUX1:LMUX0 + 1) + TCY/2
TFINT = (TFWR/2 – (2 TCY + 40 ns)) → minimum = 1.5(TFRAME/4) – (2 TCY + 40 ns)
(TFWR/2 – (1 TCY + 40 ns)) → maximum = 1.5(TFRAME/4) – (1 TCY + 40 ns)
DS39629C-page 276
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
22.10 Operation During Sleep
The LCD module can operate during Sleep. The selection is controlled by bit, SLPEN (LCDCON<6>). Setting
the SLPEN bit allows the LCD module to go to Sleep.
Clearing the SLPEN bit allows the module to continue
to operate during Sleep.
If a SLEEP instruction is executed and SLPEN = 1, the
LCD module will cease all functions and go into a very
low-current consumption mode. The module will stop
operation immediately and drive the minimum LCD
voltage on both segment and common lines.
Figure 22-16 shows this operation.
To ensure that no DC component is introduced on the
panel, the SLEEP instruction should be executed
immediately after a LCD frame boundary. The LCD
interrupt can be used to determine the frame boundary.
See Section 22.9 “LCD Interrupts” for the formulas to
calculate the delay.
FIGURE 22-16:
If a SLEEP instruction is executed and SLPEN = 0, the
module will continue to display the current contents of
the LCDDATA registers. To allow the module to
continue operation while in Sleep, the clock source
must be either the internal RC oscillator or Timer1
external oscillator. While in Sleep, the LCD data cannot
be changed. The LCD module current consumption will
not decrease in this mode, however, the overall
consumption of the device will be lower due to shut
down of the core and other peripheral functions.
If the system clock is selected and the module is
programmed to not Sleep, the module will ignore the
SLPEN bit and stop operation immediately. The
minimum LCD voltage will then be driven onto the
segments and commons.
Note:
The internal RC oscillator or external
Timer1 oscillator must be used to operate
the LCD module during Sleep.
SLEEP ENTRY/EXIT WHEN SLPEN = 1 OR CS1:CS0 = 00
V3
V2
V1
COM0
V0
V3
V2
V1
V0
COM1
V3
V2
V1
V0
COM2
V3
V2
V1
V0
SEG0
2 Frames
SLEEP Instruction Execution
© 2007 Microchip Technology Inc.
Wake-up
DS39629C-page 277
PIC18F6390/6490/8390/8490
22.11 Configuring the LCD Module
4.
The following is the sequence of steps to configure the
LCD module.
5.
1.
2.
3.
Select the frame clock prescale using bits,
LP3:LP0 (LCDPS<3:0>).
Configure the appropriate pins to function as
segment drivers using the LCDSEx registers.
Configure the LCD module for the following
using the LCDCON register:
- Multiplex and Bias mode, LMUX1:LMUX0
bits
- Timing source, CS1:CS0 bits
- Sleep mode, SLPEN bit
DS39629C-page 278
6.
Write initial values to Pixel Data registers,
LCDDATA0 through LCDDATA23.
Clear LCD Interrupt Flag, LCDIF (PIR3<6>),
and if desired, enable the interrupt by setting bit,
LCDIE (PIE3<6>).
Enable the LCD module by setting bit, LCDEN
(LCDCON<7>).
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 22-6:
Name
REGISTERS ASSOCIATED WITH LCD OPERATION
Bit 7
INTCON
Bit 6
Bit 5
GIE/GIEH PEIE/GIEL TMR0IE
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reset
Values
on Page
INT0IE
RBIE
TMR0IF
INT0IF
RBIF
59
PIR3
—
LCDIF
RC2IF
TX2IF
—
—
—
—
61
PIE3
—
LCDIE
RC2IE
TX2IE
—
—
—
—
61
IPR3
—
LCDIP
RC2IP
TX2IP
—
—
—
—
61
IPEN
SBOREN
—
RI
TO
PD
POR
BOR
60
LCDDATA23(1)
S47C3
S46C3
S45C3
S44C3
S43C3
S42C3
S41C3
S40C3
63
LCDDATA22(1)
S39C3
S38C3
S37C3
S36C3
S35C3
S34C3
S33C3
S32C3
63
LCDDATA21
S31C3
S30C3
S29C3
S28C3
S27C3
S26C3
S25C3
S24C3
63
LCDDATA20
S23C3
S22C3
S21C3
S20C3
S19C3
S18C3
S17C3
S16C3
63
LCDDATA19
S15C3
S14C3
S13C3
S12C3
S11C3
S10C3
S09C3
S08C3
63
LCDDATA18
S07C3
S06C3
S05C3
S04C3
S03C3
S02C3
S01C3
S00C3
63
(1)
LCDDATA17
S47C2
S46C2
S45C2
S44C2
S43C2
S42C2
S41C2
S40C2
63
LCDDATA16(1)
S39C2
S38C2
S37C2
S36C2
S35C2
S34C2
S33C2
S32C2
63
LCDDATA15
S31C2
S30C2
S29C2
S28C2
S27C2
S26C2
S25C2
S24C2
63
LCDDATA14
S23C2
S22C2
S21C2
S20C2
S19C2
S18C2
S17C2
S16C2
63
LCDDATA13
S15C2
S14C2
S13C2
S12C2
S11C2
S10C2
S09C2
S08C2
63
LCDDATA12
S07C2
S06C2
S05C2
S04C2
S03C2
S02C2
S01C2
S00C2
63
(1)
LCDDATA11
S47C1
S46C1
S45C1
S44C1
S43C1
S42C1
S41C1
S40C1
63
LCDDATA10(1)
S39C1
S38C1
S37C1
S36C1
S35C1
S34C1
S33C1
S32C1
63
LCDDATA9
S31C1
S30C1
S29C1
S28C1
S27C1
S26C1
S25C1
S24C1
63
LCDDATA8
S23C1
S22C1
S21C1
S20C1
S19C1
S18C1
S17C1
S16C1
63
LCDDATA7
S15C1
S14C1
S13C1
S12C1
S11C1
S10C1
S09C1
S08C1
63
LCDDATA6
S07C1
S06C1
S05C1
S04C1
S03C1
S02C1
S01C1
S00C1
63
(1)
LCDDATA5
S47C0
S46C0
S45C0
S44C0
S43C0
S42C0
S41C0
S40C0
63
LCDDATA4(1)
S39C0
S38C0
S37C0
S36C0
S35C0
S34C0
S33C0
S32C0
63
LCDDATA3
S31C0
S30C0
S29C0
S28C0
S27C0
S26C0
S25C0
S24C0
63
LCDDATA2
S23C0
S22C0
S21C0
S20C0
S19C0
S18C0
S17C0
S16C0
63
LCDDATA1
S15C0
S14C0
S13C0
S12C0
S11C0
S10C0
S09C0
S08C0
63
LCDDATA0
S07C0
S06C0
S05C0
S04C0
S03C0
S02C0
S01C0
S00C0
63
(2)
LCDSE5
SE47
SE46
SE45
SE44
SE43
SE42
SE41
SE40
64
LCDSE4(2)
SE39
SE38
SE37
SE36
SE35
SE34
SE33
SE32
64
LCDSE3
SE31
SE30
SE29
SE28
SE27
SE26
SE25
SE24
64
LCDSE2
SE23
SE22
SE21
SE20
SE19
SE18
SE17
SE16
64
LCDSE1
SE15
SE14
SE13
SE12
SE11
SE10
SE9
SE8
64
LCDSE0
SE7
SE6
SE5
SE4
SE3
SE2
SE1
SE0
64
LCDCON
LCDEN
SLPEN
WERR
—
CS1
CS0
LMUX1
LMUX0
64
WFT
BIASMD
LCDA
WA
LP3
LP2
LP1
LP0
64
RCON
LCDPS
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: These registers are implemented but unused on 64-pin devices and may be used as general purpose data
RAM.
2: These registers are unimplemented on 64-pin devices.
© 2007 Microchip Technology Inc.
DS39629C-page 279
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 280
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
23.0
SPECIAL FEATURES
OF THE CPU
A complete discussion of device Resets and interrupts
is available in previous sections of this data sheet.
In addition to their Power-up and Oscillator Start-up
Timers provided for Resets, PIC18F6390/6490/8390/
8490 devices have a Watchdog Timer, which is either
permanently enabled via the Configuration bits, or
software controlled (if configured as disabled).
PIC18F6390/6490/8390/8490 devices include several
features intended to maximize reliability and minimize
cost through elimination of external components.
These are:
• Oscillator Selection
• Resets:
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
• Interrupts
• Watchdog Timer (WDT)
• Fail-Safe Clock Monitor
• Two-Speed Start-up
• Code Protection
• ID Locations
• In-Circuit Serial Programming™ (ICSP™)
The inclusion of an internal RC oscillator also provides
the additional benefits of a Fail-Safe Clock Monitor
(FSCM) and Two-Speed Start-up. FSCM provides for
background monitoring of the peripheral clock and
automatic switchover in the event of its failure. TwoSpeed Start-up enables code to be executed almost
immediately on start-up, while the primary clock source
completes its start-up delays.
All of these features are enabled and configured by
setting the appropriate Configuration register bits.
23.1
The oscillator can be configured for the application
depending on frequency, power, accuracy and cost. All
of the options are discussed in detail in Section 2.0
“Oscillator Configurations”.
TABLE 23-1:
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.
CONFIGURATION BITS AND DEVICE IDs
File Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
FOSC1
FOSC0
Default/
Unprogrammed
Value
300001h
CONFIG1H
IESO
FCMEN
—
—
FOSC3
FOSC2
300002h
CONFIG2L
—
—
—
BORV1
BORV0
BOREN1
300003h
CONFIG2H
—
—
—
300005h
CONFIG3H
MCLRE
—
—
—
—
LPT1OSC
300006h
CONFIG4L
DEBUG
XINST
—
—
—
—
300008h
CONFIG5L
—
—
—
—
—
3FFFFEh DEVID1
DEV2
DEV1
DEV0
REV4
3FFFFFh
DEVID2
DEV10
DEV9
DEV8
DEV7
Legend:
x = unknown, u = unchanged, - = unimplemented, q = value depends on condition.
Shaded cells are unimplemented, read as ‘0’.
See Register 23-7 for DEVID values. DEVID registers are read-only and cannot be programmed by the user.
Note 1:
© 2007 Microchip Technology Inc.
BOREN0 PWRTEN
WDTPS3 WDTPS2 WDTPS1 WDTPS0
00-- 0111
---1 1111
WDTEN
---1 1111
—
CCP2MX
1--- -0-1
—
STVREN
10-- ---1
—
—
CP
---- ---1
REV3
REV2
REV1
REV0
xxxx xxxx(1)
DEV6
DEV5
DEV4
DEV3
0000 xxxx(1)
DS39629C-page 281
PIC18F6390/6490/8390/8490
REGISTER 23-1:
CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
R/P-0
R/P-0
U-0
U-0
R/P-0
R/P-1
R/P-1
R/P-1
IESO
FCMEN
—
—
FOSC3
FOSC2
FOSC1
FOSC0
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
bit 7
IESO: Internal/External Oscillator Switchover bit
1 = Oscillator Switchover mode enabled
0 = Oscillator Switchover mode disabled
bit 6
FCMEN: Fail-Safe Clock Monitor Enable bit
1 = Fail-Safe Clock Monitor enabled
0 = Fail-Safe Clock Monitor disabled
bit 5-4
Unimplemented: Read as ‘0’
bit 3-0
FOSC3:FOSC0: Oscillator Selection bits
11xx = External RC oscillator, CLKO function on RA6
101x = External RC oscillator, CLKO function on RA6
1001 = Internal oscillator block, CLKO function on RA6, port function on RA7
1000 = Internal oscillator block, port function on RA6 and RA7
0111 = External RC oscillator, port function on RA6
0110 = HS oscillator, PLL enabled (clock frequency = 4 x FOSC1)
0101 = EC oscillator, port function on RA6
0100 = EC oscillator, CLKO function on RA6
0011 = External RC oscillator, CLKO function on RA6
0010 = HS oscillator
0001 = XT oscillator
0000 = LP oscillator
DS39629C-page 282
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 23-2:
CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h)
U-0
U-0
U-0
R/P-1
R/P-1
R/P-1
R/P-1
R/P-1
—
—
—
BORV1
BORV0
BOREN1(1)
BOREN0(1)
PWRTEN(1)
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
bit 7-5
Unimplemented: Read as ‘0’
bit 4-3
BORV1:BORV0: Brown-out Reset Voltage bits
11 = VBOR set to 2.1V
10 = VBOR set to 2.8V
01 = VBOR set to 4.3V
00 = VBOR set to 4.6V
bit 2-1
BOREN1:BOREN0 Brown-out Reset Enable bits(1)
11 = Brown-out Reset enabled in hardware only (SBOREN is disabled)
10 = Brown-out Reset enabled in hardware only and disabled in Sleep mode (SBOREN is disabled)
10 = Brown-out Reset enabled and controlled by software (SBOREN is enabled)
10 = Brown-out Reset disabled in hardware and software
bit 0
PWRTEN: Power-up Timer Enable bit(1)
1 = PWRT disabled
0 = PWRT enabled
Note 1:
The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently
controlled.
© 2007 Microchip Technology Inc.
DS39629C-page 283
PIC18F6390/6490/8390/8490
REGISTER 23-3:
CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h)
U-0
U-0
U-0
R/P-1
R/P-1
R/P-1
R/P-1
R/P-1
—
—
—
WDTPS3
WDTPS2
WDTPS1
WDTPS0
WDTEN
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
bit 7-5
Unimplemented: Read as ‘0’
bit 4-1
WDTPS3:WDTPS0: Watchdog Timer Postscale Select bits
1111 = 1:32,768
1110 = 1:16,384
1101 = 1:8,192
1100 = 1:4,096
1011 = 1:2,048
1010 = 1:1,024
1001 = 1:512
1000 = 1:256
0111 = 1:128
0110 = 1:64
0101 = 1:32
0100 = 1:16
0011 = 1:8
0010 = 1:4
0001 = 1:2
0000 = 1:1
bit 0
WDTEN: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled (control is placed on the SWDTEN bit)
REGISTER 23-4:
CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h)
R/P-1
U-0
U-0
U-0
U-0
R/P-0
U-0
R/P-1
MCLRE
—
—
—
—
LPT1OSC
—
CCP2MX
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
bit 7
MCLRE: MCLR Pin Enable bit
1 = MCLR pin enabled; RG5 input pin disabled
0 = RG5 input pin enabled; MCLR disabled
bit 6-3
Unimplemented: Read as ‘0’
bit 2
LPT1OSC: Low-Power Timer 1 Oscillator Enable bit
1 = Timer1 configured for low-power operation
0 = Timer1 configured for higher power operation
bit 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 RE7
DS39629C-page 284
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
REGISTER 23-5:
CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h)
R/P-1
R/P-0
U-0
U-0
U-0
U-0
U-0
R/P-1
DEBUG
XINST
—
—
—
—
—
STVREN
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
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
XINST: Extended Instruction Set Enable bit
1 = Instruction set extension and Indexed Addressing mode enabled
0 = Instruction set extension and Indexed Addressing mode disabled (Legacy mode)
bit 5-1
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
REGISTER 23-6:
CONFIG5L: CONFIGURATION REGISTER 5 LOW (BYTE ADDRESS 300008h)
U-0
U-0
U-0
U-0
U-0
U-0
U-0
R/C-1
—
—
—
—
—
—
—
CP
bit 7
bit 0
Legend:
R = Readable bit
C = Clearable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
bit 7-1
Unimplemented: Read as ‘0’
bit 0
CP: Code Protection bit
1 = Program memory block (000000-003FFFh) not code-protected
0 = Program memory block (000000-003FFFh) code-protected
© 2007 Microchip Technology Inc.
DS39629C-page 285
PIC18F6390/6490/8390/8490
REGISTER 23-7:
DEVID1: DEVICE ID REGISTER 1 FOR PIC18F6390/6490/8390/8490 DEVICES
R
R
R
R
R
R
R
R
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
bit 7-5
DEV2:DEV0: Device ID bits
100 = PIC18F8390/8490
101 = PIC18F6390/6490
bit 4-0
REV4:REV0: Revision ID bits
These bits are used to indicate the device revision.
REGISTER 23-8:
DEVID2: DEVICE ID REGISTER 2 FOR PIC18F6390/6490/8390/8490 DEVICES
R
R
R
R
R
R
R
R
DEV10(1)
DEV9(1)
DEV8(1)
DEV7(1)
DEV6(1)
DEV5(1)
DEV4(1)
DEV3(1)
bit 7
bit 0
Legend:
R = Readable bit
P = Programmable bit
-n = Value when device is unprogrammed
bit 7-0
Note 1:
U = Unimplemented bit, read as ‘0’
u = Unchanged from programmed state
DEV10:DEV3: Device ID bits(1)
These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the part number.
0000 0110 = PIC18F6490/8490 devices
0000 1011 = PIC18F6390/8390 devices
These values for DEV10:DEV3 may be shared with other devices. The specific device is always identified
by using the entire DEV10:DEV0 bit sequence.
DS39629C-page 286
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
23.2
Watchdog Timer (WDT)
For PIC18F6390/6490/8390/8490 devices, the WDT is
driven by the INTRC source. When the WDT is
enabled, the clock source is also enabled. The nominal
WDT period is 4 ms and has the same stability as the
INTRC oscillator.
The 4 ms period of the WDT is multiplied by a 16-bit
postscaler. Any output of the WDT postscaler is
selected by a multiplexer, controlled by bits in Configuration Register 2H. Available periods range from 4 ms
to 134.2 seconds (2.24 minutes). The WDT and
postscaler are cleared when any of the following events
occur: a SLEEP or CLRWDT instruction is executed, the
IRCF bits (OSCCON<6:4>) are changed, or a clock
failure has occurred.
FIGURE 23-1:
SWDTEN
WDTEN
Note 1: The CLRWDT and SLEEP instructions
clear the WDT and postscaler counts
when executed.
2: Changing the setting of the IRCF bits
(OSCCON<6:4>) clears the WDT and
postscaler counts.
3: When a CLRWDT instruction is executed,
the postscaler count will be cleared.
23.2.1
CONTROL REGISTER
Register 23-9 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, but only if the Configuration bit has
disabled the WDT.
WDT BLOCK DIAGRAM
Enable WDT
INTRC Control
WDT Counter
INTRC Source
Wake-up from
Power-Managed
Modes
÷128
Change on IRCF bits
Programmable Postscaler
1:1 to 1:32,768
CLRWDT
All Device Resets
WDTPS<3:0>
Reset
WDT
Reset
WDT
4
Sleep
© 2007 Microchip Technology Inc.
DS39629C-page 287
PIC18F6390/6490/8390/8490
REGISTER 23-9:
WDTCON: WATCHDOG TIMER CONTROL REGISTER
U-0
U-0
U-0
U-0
U-0
U-0
U-0
R/W-0
—
—
—
—
—
—
—
SWDTEN(1)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-1
Unimplemented: Read as ‘0’
bit 0
SWDTEN: Software Controlled Watchdog Timer Enable bit(1)
1 = Watchdog Timer is on
0 = Watchdog Timer is off
Note 1:
This bit has no effect if the Configuration bit, WDTEN, is enabled.
TABLE 23-2:
Name
RCON
WDTCON
x = Bit is unknown
SUMMARY OF WATCHDOG TIMER REGISTERS
Bit 0
Reset
Values
on Page
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
IPEN
SBOREN
—
RI
TO
PD
POR
BOR
60
—
—
—
—
—
—
—
SWDTEN
60
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.
DS39629C-page 288
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
23.3
Two-Speed Start-up
Reset. For wake-ups from Sleep, the INTOSC or
postscaler clock sources can be selected by setting the
IRCF2:IRCF0 bits prior to entering Sleep mode.
The Two-Speed Start-up feature helps to minimize the
latency period from oscillator start-up to code execution
by allowing the microcontroller to use the INTRC
oscillator as a clock source until the primary clock
source is available. It is enabled by setting the IESO
Configuration bit.
In all other power-managed modes, Two-Speed Start-up
is not used. The device will be clocked by the currently
selected clock source until the primary clock source
becomes available. The setting of the IESO bit is
ignored.
Two-Speed Start-up should be enabled only if the
primary oscillator mode is LP, XT, HS or HSPLL
(Crystal-Based modes). Other sources do not require a
OST start-up delay; for these, Two-Speed Start-up
should be disabled.
23.3.1
While using the INTRC oscillator in Two-Speed
Start-up, the device still obeys the normal command
sequences for entering power-managed modes,
including serial SLEEP instructions (refer to
Section 3.1.2 “Entering Power-Managed Modes”).
In practice, this means that user code can change
the SCS1:SCS0 bit settings or issue SLEEP
instructions before the OST times out. This would
allow an application to briefly wake-up, perform
routine “housekeeping” tasks and return to Sleep
before the device starts to operate from the primary
oscillator.
When enabled, Resets and wake-ups from Sleep mode
cause the device to configure itself to run from the
internal oscillator block as the clock source, following
the time-out of the Power-up Timer after a Power-on
Reset is enabled. This allows almost immediate code
execution while the primary oscillator starts and the
OST is running. Once the OST times out, the device
automatically switches to PRI_RUN mode.
Because the OSCCON register is cleared on Reset
events, the INTOSC (or postscaler) clock source is not
initially available after a Reset event; the INTRC clock
is used directly at its base frequency. To use a higher
clock speed on wake-up, the INTOSC or postscaler
clock sources can be selected to provide a higher clock
speed by setting bits, IRCF2:IRCF0, immediately after
FIGURE 23-2:
SPECIAL CONSIDERATIONS FOR
USING TWO-SPEED START-UP
User code can also check if the primary clock source is
currently providing the device clocking by checking the
status of the OSTS bit (OSCCON<3>). If the bit is set,
the primary oscillator is providing the clock. Otherwise,
the internal oscillator block is providing the clock during
wake-up from Reset or Sleep mode.
TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL)
Q1
Q2
Q3
Q4
Q2 Q3 Q4 Q1 Q2 Q3
Q1
INTOSC
Multiplexer
OSC1
TOST(1)
TPLL(1)
1
PLL Clock
Output
2
n-1 n
Clock
Transition
CPU Clock
Peripheral
Clock
Program
Counter
PC
Wake from Interrupt Event
PC + 2
PC + 4
PC + 6
OSTS bit Set
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
© 2007 Microchip Technology Inc.
DS39629C-page 289
PIC18F6390/6490/8390/8490
23.4
Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the
microcontroller to continue operation in the event of an
external oscillator failure by automatically switching the
device clock to the internal oscillator block. The FSCM
function is enabled by setting the FCMEN Configuration
bit.
When FSCM is enabled, the INTRC oscillator runs at
all times to monitor clocks to peripherals and provide a
backup clock in the event of a clock failure. Clock
monitoring (shown in Figure 23-3) is accomplished by
creating a sample clock signal, which is the INTRC output divided by 64. This allows ample time between
FSCM sample clocks for a peripheral clock edge to
occur. The peripheral device clock and the sample
clock are presented as inputs to the Clock Monitor latch
(CM). The CM is set on the falling edge of the device
clock source, but cleared on the rising edge of the
sample clock.
FIGURE 23-3:
FSCM BLOCK DIAGRAM
Clock Monitor
Latch (CM)
(edge-triggered)
Peripheral
Clock
INTRC
Source
(32 μs)
÷ 64
S
Q
C
Q
488 Hz
(2.048 ms)
The FSCM will detect failures of the primary or secondary clock sources only. If the internal oscillator block
fails, no failure would be detected, nor would any action
be possible.
23.4.1
Clock failure is tested for on the falling edge of the
sample clock. If a sample clock falling edge occurs
while CM is still set, a clock failure has been detected
(Figure 23-4). This causes the following:
• the FSCM generates an oscillator fail interrupt by
setting bit OSCFIF (PIR2<7>);
• the device clock source is switched to the internal
oscillator block (OSCCON is not updated to show
the current clock source – this is the Fail-Safe
condition); and
• the WDT is reset.
During switchover, the postscaler frequency from the
internal oscillator block may not be sufficiently stable for
timing sensitive applications. In these cases, it may be
desirable to select another clock configuration and enter
an alternate power-managed mode. This can be done to
attempt a partial recovery or execute a controlled shutdown. See Section 3.1.2 “Entering Power-Managed
Modes” and Section 23.3.1 “Special Considerations
for Using Two-Speed Start-up” for more details.
FSCM AND THE WATCHDOG TIMER
Both the FSCM and the WDT are clocked by the
INTRC oscillator. Since the WDT operates with a
separate divider and counter, disabling the WDT has
no effect on the operation of the INTRC oscillator when
the FSCM is enabled.
As already noted, the clock source is switched to the
INTOSC clock when a clock failure is detected.
Depending on the frequency selected by the
IRCF2:IRCF0 bits, this may mean a substantial change
in the speed of code execution. If the WDT is enabled
with a small prescale value, a decrease in clock speed
allows a WDT time-out to occur and a subsequent
device Reset. For this reason, Fail-Safe Clock Monitor
events also reset the WDT and postscaler, allowing
them to start timing from when execution speed was
changed and decreasing the likelihood of an erroneous
time-out.
23.4.2
Clock
Failure
Detected
DS39629C-page 290
To use a higher clock speed on wake-up, the INTOSC
or postscaler clock sources can be selected to provide
a higher clock speed by setting bits, IRCF2:IRCF0,
immediately after Reset. For wake-ups from Sleep, the
INTOSC or postscaler clock sources can be selected
by setting the IRCF2:IRCF0 bits prior to entering Sleep
mode.
EXITING FAIL-SAFE OPERATION
The Fail-Safe condition is terminated by either a device
Reset or by entering a power-managed mode. On
Reset, the controller starts the primary clock source
specified in Configuration Register 1H (with any
required start-up delays that are required for the oscillator mode, such as the OST or PLL timer). The
INTOSC multiplexer provides the device clock until the
primary clock source becomes ready (similar to a TwoSpeed Start-up). The clock source is then switched to
the primary clock (indicated by the OSTS bit in the
OSCCON register becoming set). The Fail-Safe Clock
Monitor then resumes monitoring the peripheral clock.
The primary clock source may never become ready
during start-up. In this case, operation is clocked by the
INTOSC multiplexer. The OSCCON register will remain
in its Reset state until a power-managed mode is
entered.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 23-4:
FSCM TIMING DIAGRAM
Sample Clock
Oscillator
Failure
Device
Clock
Output
CM Output
(Q)
Failure
Detected
OSCFIF
CM Test
Note:
23.4.3
CM Test
CM Test
The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in this
example have been chosen for clarity.
FSCM INTERRUPTS IN
POWER-MANAGED MODES
By entering a power-managed mode, the clock
multiplexer selects the clock source selected by the
OSCCON register. Fail-Safe Clock Monitoring of
the power-managed clock source resumes in the
power-managed mode.
If an oscillator failure occurs during power-managed
operation, the subsequent events depend on whether
or not the Oscillator Failure Interrupt Flag is enabled. If
enabled (OSCFIF = 1), code execution will be clocked
by the INTOSC multiplexer. An automatic transition
back to the failed clock source will not occur.
If the interrupt is disabled, the device will not exit the
power-managed mode on oscillator failure. Instead, the
device will continue to operate as before, but clocked
by the INTOSC multiplexer. While in Idle mode, subsequent interrupts will cause the CPU to begin
executing instructions while being clocked by the
INTOSC multiplexer.
23.4.4
POR OR WAKE FROM SLEEP
The FSCM is designed to detect oscillator failure at any
point after the device has exited Power-on Reset
(POR) or low-power Sleep mode. When the primary
device clock is EC, RC or INTRC modes, monitoring
can begin immediately following these events.
For oscillator modes involving a crystal or resonator
(HS, HSPLL, LP or XT), the situation is somewhat
different. Since the oscillator may require a start-up
time considerably longer than the FCSM sample clock
time, a false clock failure may be detected. To prevent
this, the internal oscillator block is automatically configured as the device clock and functions until the
primary clock is stable (the OST and PLL timers have
timed out). This is identical to Two-Speed Start-up
mode. Once the primary clock is stable, the INTRC
returns to its role as the FSCM source.
Note:
The same logic that prevents false
oscillator failure interrupts on POR, or
wake from Sleep, will also prevent the
detection of the oscillator’s failure to start
at all following these events. This can be
avoided by monitoring the OSTS bit and
using a timing routine to determine if the
oscillator is taking too long to start. Even
so, no oscillator failure interrupt will be
flagged.
As noted in Section 23.3.1 “Special Considerations
for Using Two-Speed Start-up”, it is also possible to
select another clock configuration and enter an
alternate power-managed mode while waiting for the
primary clock to become stable. When the new powermanaged mode is selected, the primary clock is
disabled.
© 2007 Microchip Technology Inc.
DS39629C-page 291
PIC18F6390/6490/8390/8490
23.5
Program Verification and
Code Protection
23.5.1
The overall structure of the code protection on the
PIC18F6390/6490/8390/8490 Flash devices differs
from previous PIC18 devices.
For all devices in the PIC18F6X90/8X90 family, the
user program memory is made of a single block.
Figure 23-5 shows the program memory organization
for individual devices. Code protection for this block is
controlled by a single bit, CP (CONFIG5L<0>). The CP
bit inhibits external reads from and writes to the entire
program memory space. It has no direct effect in
normal execution mode.
FIGURE 23-5:
READING PROGRAM MEMORY
AND OTHER LOCATIONS
The program memory may be read to any location
using the table read instructions. The Device ID and the
Configuration registers may be read with the table read
instructions.
23.5.2
CONFIGURATION REGISTER
PROTECTION
The Configuration registers can only be written via
ICSP using an external programmer. No separate
protection bit is associated with them.
CODE-PROTECTED PROGRAM MEMORY FOR PIC18F6390/6490/8390/8490
MEMORY SIZE/DEVICE
8 Kbytes
Address
(PIC18F6390/8390) Range
Program Memory
Block
000000h
001FFFh
16 Kbytes
(PIC18F6490/8490)
Address
Range
Program Memory
Block
000000h
003FFFh
002000h
Unimplemented
Read ‘0’s
Unimplemented
Read ‘0’s
300008h
(Unimplemented Memory Space)
1FFFFFh
SUMMARY OF CODE PROTECTION REGISTERS
File Name
Legend:
CP, EBTR
004000h
1FFFFFh
TABLE 23-3:
Block Code Protection
Controlled By:
CONFIG5L
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
—
—
—
—
—
—
—
CP
Shaded cells are unimplemented.
DS39629C-page 292
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
23.6
ID Locations
23.8
In-Circuit Debugger
Eight memory locations (200000h-200007h) are
designated as ID locations, where the user can store
checksum or other code identification numbers. These
locations are readable during normal execution through
the TBLRD instruction. During program/verify, these
locations are readable and writable. The ID locations
can be read when the device is code-protected.
When the DEBUG Configuration bit is programmed to
a ‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB® IDE. When the microcontroller has
this feature enabled, some resources are not available
for general use. Table 23-4 shows which resources are
required by the background debugger.
23.7
TABLE 23-4:
In-Circuit Serial Programming
PIC18F6390/6490/8390/8490 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.
© 2007 Microchip Technology Inc.
DEBUGGER RESOURCES
I/O pins:
RB6, RB7
Stack:
2 levels
Program Memory:
512 bytes
Data Memory:
10 bytes
To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial
Programming connections to MCLR/VPP, VDD, VSS,
RB7 and RB6. This will interface to the In-Circuit
Debugger module available from Microchip or one of
the third party development tool companies.
DS39629C-page 293
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 294
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
24.0
INSTRUCTION SET SUMMARY
PIC18FXX90 devices incorporate the standard set of
seventy-five PIC18 core instructions, as well as an
extended set of 8 new instructions for the optimization
of code that is recursive or that utilizes a software
stack. The extended set is discussed later in this
section.
24.1
Standard Instruction Set
The standard PIC18 instruction set adds many
enhancements to the previous PIC® MCU instruction
sets, while maintaining an easy migration from these
PIC MCU instruction sets. Most instructions are a
single program memory word (16 bits), but there are
four instructions that require two program memory
locations.
Each single-word instruction is a 16-bit word divided
into an opcode, which specifies the instruction type and
one or more operands, which further specify the
operation of the instruction.
The instruction set is highly orthogonal and is grouped
into four basic categories:
•
•
•
•
Byte-oriented operations
Bit-oriented operations
Literal operations
Control operations
The PIC18 instruction set summary in Table 24-2 lists
byte-oriented, bit-oriented, literal and control
operations. Table 24-1 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.
All bit-oriented instructions have three operands:
1.
2.
3.
The file register (specified by ‘f’)
The bit in the file register (specified by ‘b’)
The accessed memory (specified by ‘a’)
The literal instructions may use some of the following
operands:
• A literal value to be loaded into a file register
(specified by ‘k’)
• The desired FSR register to load the literal value
into (specified by ‘f’)
• No operand required
(specified by ‘—’)
The control instructions may use some of the following
operands:
• A program memory address (specified by ‘n’)
• The mode of the CALL or RETURN instructions
(specified by ‘s’)
• The mode of the table read and table write
instructions (specified by ‘m’)
• No operand required
(specified by ‘—’)
All instructions are a single word, except for four
double-word instructions. These instructions were
made double-word to contain the required information
in 32 bits. In the second word, the 4 MSbs are ‘1’s. If
this second word is executed as an instruction (by
itself), it will execute as a NOP.
All single-word instructions are executed in a single
instruction cycle, unless a conditional test is true or the
program counter is changed as a result of the instruction. In these cases, the execution takes two instruction
cycles with the additional instruction cycle(s) executed
as a NOP.
The double-word instructions execute in two instruction
cycles.
One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 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.
Figure 24-1 shows the general formats that the instructions can have. All examples use the convention ‘nnh’
to represent a hexadecimal number.
The Instruction Set Summary, shown in Table 24-2,
lists the standard instructions recognized by the
Microchip MPASMTM Assembler.
Section 24.1.1 “Standard Instruction Set” provides
a description of each instruction.
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.
© 2007 Microchip Technology Inc.
DS39629C-page 295
PIC18F6390/6490/8390/8490
TABLE 24-1:
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.
C, DC, Z, OV, N
ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative.
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 (00h to FFh), or 2-bit FSR designator (0h to 3h).
fs
12-bit register file address (000h to FFFh). This is the source address.
fd
12-bit register file address (000h to FFFh). This is the destination address.
GIE
Global Interrupt Enable bit.
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.
PC
Program Counter.
PCL
Program Counter Low Byte.
PCH
Program Counter High Byte.
PCLATH
Program Counter High Byte Latch.
PCLATU
Program Counter Upper Byte Latch.
PD
Power-Down bit.
PRODH
Product of Multiply High Byte.
PRODL
Product of Multiply Low Byte.
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)
TBLPTR
21-bit Table Pointer (points to a Program Memory location).
TABLAT
8-bit Table Latch.
TO
Time-out bit.
TOS
Top-of-Stack.
u
Unused or unchanged.
WDT
Watchdog Timer.
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.
zs
7-bit offset value for Indirect Addressing of register files (source).
7-bit offset value for Indirect Addressing of register files (destination).
zd
{
}
Optional argument.
[text]
Indicates an indexed address.
(text)
The contents of text.
[expr]<n>
Specifies bit n of the register indicated by the pointer expr.
→
Assigned to.
< >
Register bit field.
∈
In the set of.
italics
User-defined term (font is Courier New).
DS39629C-page 296
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 24-1:
GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations
15
10
9
OPCODE
Example Instruction
8 7
d
0
a
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
0
OPCODE
15
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
0
OPCODE b (BIT #) a
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
0
OPCODE
MOVLW 7Fh
k (literal)
k = 8-bit immediate value
Control operations
CALL, GOTO and Branch operations
15
8 7
0
OPCODE
15
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)
1111
S = Fast bit
15
11 10
OPCODE
15
0
8 7
OPCODE
© 2007 Microchip Technology Inc.
BRA MYFUNC
n<10:0> (literal)
0
n<7:0> (literal)
BC MYFUNC
DS39629C-page 297
PIC18F6390/6490/8390/8490
TABLE 24-2:
PIC18FXXXX INSTRUCTION SET
Mnemonic,
Operands
Description
Cycles
16-Bit Instruction Word
MSb
LSb
Status
Affected
Notes
BYTE-ORIENTED 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
Note 1:
2:
3:
4:
5:
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
0010
0001
0110
0001
0110
0110
0110
0000
0010
0100
0010
0011
0100
0001
0101
1100
1111
0110
0000
0110
0011
0100
0011
0100
0110
0101
01da
00da
01da
101a
11da
001a
010a
000a
01da
11da
11da
10da
11da
10da
00da
00da
ffff
ffff
111a
001a
110a
01da
01da
00da
00da
100a
01da
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 11da
0101 10da
ffff
ffff
ffff C, DC, Z, OV, N 1, 2
ffff C, DC, Z, OV, N
1
0011 10da
1 (2 or 3) 0110 011a
1
0001 10da
ffff
ffff
ffff
ffff None
ffff None
ffff Z, N
None
None
1, 2
C, DC, Z, OV, N
C, Z, N
1, 2
Z, N
C, Z, N
Z, N
None
1, 2
C, DC, Z, OV, N
4
1, 2
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 an input and is
driven low by an external device, the data will be written back with a ‘0’.
If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared
if assigned.
If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
If the table write starts the write cycle to internal memory, the write will continue until terminated.
DS39629C-page 298
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 24-2:
PIC18FXXXX INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands
Description
Cycles
16-Bit Instruction Word
MSb
LSb
Status
Affected
Notes
BIT-ORIENTED 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
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)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
2
1 (2)
2
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
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
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
2
2
1
0000 1100
0000 0000
0000 0000
kkkk
0001
0000
1, 2
1, 2
3, 4
3, 4
1, 2
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
s
Branch if Carry
Branch if Negative
Branch if Not Carry
Branch if Not Negative
Branch if Not Overflow
Branch if Not Zero
Branch if Overflow
Branch Unconditionally
Branch if Zero
Call Subroutine 1st word
2nd word
Clear Watchdog Timer
Decimal Adjust WREG
Go to Address 1st word
2nd word
No Operation
No Operation
Pop Top of Return Stack (TOS)
Push Top of Return Stack (TOS)
Relative Call
Software Device Reset
Return from Interrupt Enable
RETLW
RETURN
SLEEP
k
s
—
Return with Literal in WREG
Return from Subroutine
Go into Standby mode
Note 1:
2:
3:
4:
5:
1
1
2
TO, PD
C
None
None
None
None
None
None
All
GIE/GIEH,
PEIE/GIEL
kkkk None
001s None
0011 TO, PD
4
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 an input and is
driven low by an external device, the data will be written back with a ‘0’.
If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared
if assigned.
If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
If the table write starts the write cycle to internal memory, the write will continue until terminated.
© 2007 Microchip Technology Inc.
DS39629C-page 299
PIC18F6390/6490/8390/8490
TABLE 24-2:
PIC18FXXXX INSTRUCTION SET (CONTINUED)
Mnemonic,
Operands
Description
Cycles
16-Bit Instruction Word
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 FSR(f)
1st word
Move Literal to BSR<3:0>
Move Literal to WREG
Multiply Literal with WREG
Return with Literal in WREG
Subtract WREG from Literal
Exclusive OR Literal with WREG
1
1
1
2
1
1
1
2
1
1
0000
0000
0000
1110
1111
0000
0000
0000
0000
0000
0000
1111
1011
1001
1110
0000
0001
1110
1101
1100
1000
1010
kkkk
kkkk
kkkk
00ff
kkkk
0000
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
kkkk
C, DC, Z, OV, N
Z, N
Z, N
None
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+*
Note 1:
2:
3:
4:
5:
Table Read
2
Table Read with Post-Increment
Table Read with Post-Decrement
Table Read with Pre-Increment
Table Write
2
Table Write with Post-Increment
Table Write with Post-Decrement
Table Write with Pre-Increment
5
5
5
5
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 an input and is
driven low by an external device, the data will be written back with a ‘0’.
If this instruction is executed on the TMR0 register (and where applicable, ‘d’ = 1), the prescaler will be cleared
if assigned.
If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The
second cycle is executed as a NOP.
Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
If the table write starts the write cycle to internal memory, the write will continue until terminated.
DS39629C-page 300
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
24.1.1
STANDARD INSTRUCTION SET
ADDLW
ADD Literal to W
ADDWF
ADD W to f
Syntax:
ADDLW
Syntax:
ADDWF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) + (f) → dest
Status Affected:
N, OV, C, DC, Z
k
Operands:
0 ≤ k ≤ 255
Operation:
(W) + k → W
Status Affected:
N, OV, C, DC, Z
Encoding:
0000
1111
kkkk
kkkk
Description:
The contents of W are added to the
8-bit literal ‘k’ and the result is placed
in W.
Words:
1
Cycles:
1
Encoding:
0010
Description:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to W
Example:
ADDLW
01da
ffff
ffff
Add W to register ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’
(default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
15h
Before Instruction
W
= 10h
After Instruction
W =
25h
f {,d {,a}}
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ADDWF
Before Instruction
W
=
REG
=
After Instruction
W
=
REG
=
Note:
REG, 0, 0
17h
0C2h
0D9h
0C2h
All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
© 2007 Microchip Technology Inc.
DS39629C-page 301
PIC18F6390/6490/8390/8490
ADDWFC
ADD W and Carry bit to f
ANDLW
AND Literal with W
Syntax:
ADDWFC
Syntax:
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:
00da
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 is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Operands:
0 ≤ k ≤ 255
Operation:
(W) .AND. k → W
Status Affected:
N, Z
Encoding:
ffff
k
0000
1011
kkkk
kkkk
Description:
The contents of W are ANDed with the
8-bit literal ‘k’. The result is placed in W.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read literal
‘k’
Process
Data
Write to W
Example:
ANDLW
Before Instruction
W
=
After Instruction
W
=
05Fh
A3h
03h
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ADDWFC
Before Instruction
Carry bit =
REG
=
W
=
After Instruction
Carry bit =
REG
=
W
=
DS39629C-page 302
REG, 0, 1
1
02h
4Dh
0
02h
50h
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
ANDWF
AND W with f
BC
Branch if Carry
Syntax:
ANDWF
Syntax:
BC
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
-128 ≤ n ≤ 127
Operation:
if Carry bit is ‘1’,
(PC) + 2 + 2n → PC
Status Affected:
None
f {,d {,a}}
Operation:
(W) .AND. (f) → dest
Status Affected:
N, Z
Encoding:
0001
Description:
Encoding:
01da
ffff
ffff
1110
Description:
The contents of W are ANDed with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ANDWF
Before Instruction
W
=
REG
=
After Instruction
W
=
REG
=
REG, 0, 0
17h
C2h
02h
C2h
© 2007 Microchip Technology Inc.
0010
nnnn
nnnn
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.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
n
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
Before Instruction
PC
After Instruction
If Carry
PC
If Carry
PC
BC
5
=
address (HERE)
=
=
=
=
1;
address (HERE + 12)
0;
address (HERE + 2)
DS39629C-page 303
PIC18F6390/6490/8390/8490
BCF
Bit Clear f
BN
Branch if Negative
Syntax:
BCF
Syntax:
BN
Operands:
0 ≤ f ≤ 255
0≤b≤7
a ∈ [0,1]
Operands:
-128 ≤ n ≤ 127
Operation:
if Negative bit is ‘1’,
(PC) + 2 + 2n → PC
Status Affected:
None
f, b {,a}
Operation:
0 → f<b>
Status Affected:
None
Encoding:
1001
Description:
Encoding:
bbba
ffff
ffff
1110
Description:
Bit ‘b’ in register ‘f’ is cleared.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
BCF
Before Instruction
FLAG_REG = C7h
After Instruction
FLAG_REG = 47h
DS39629C-page 304
0110
nnnn
nnnn
If the Negative bit is ‘1’, then the
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Q Cycle Activity:
Example:
n
FLAG_REG,
7, 0
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
Before Instruction
PC
After Instruction
If Negative
PC
If Negative
PC
BN
Jump
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE + 2)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
BNC
Branch if Not Carry
BNN
Branch if Not Negative
Syntax:
BNC
Syntax:
BNN
n
n
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
Description:
0011
nnnn
nnnn
If the Carry bit is ‘0’, then the program
will branch.
Encoding:
1110
Description:
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.
nnnn
nnnn
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:
0111
If the Negative bit is ‘0’, then the
program will branch.
Q Cycle Activity:
If Jump:
If Jump:
Q1
Q2
Q3
Q4
Q1
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
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
If No Jump:
Example:
If No Jump:
HERE
Before Instruction
PC
After Instruction
If Carry
PC
If Carry
PC
BNC
Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
© 2007 Microchip Technology Inc.
Example:
HERE
Before Instruction
PC
After Instruction
If Negative
PC
If Negative
PC
BNN
Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
DS39629C-page 305
PIC18F6390/6490/8390/8490
BNOV
Branch if Not Overflow
BNZ
Branch if Not Zero
Syntax:
BNOV
Syntax:
BNZ
n
n
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
Description:
0101
nnnn
nnnn
If the Overflow bit is ‘0’, then the
program will branch.
Encoding:
1110
Description:
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.
nnnn
nnnn
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:
0001
If the Zero bit is ‘0’, then the program
will branch.
Q Cycle Activity:
If Jump:
If Jump:
Q1
Q2
Q3
Q4
Q1
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
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
If No Jump:
If No Jump:
Example:
HERE
Before Instruction
PC
After Instruction
If Overflow
PC
If Overflow
PC
DS39629C-page 306
BNOV Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
Example:
HERE
Before Instruction
PC
After Instruction
If Zero
PC
If Zero
PC
BNZ
Jump
=
address (HERE)
=
=
=
=
0;
address (Jump)
1;
address (HERE + 2)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
BRA
Unconditional Branch
BSF
Bit Set f
Syntax:
BRA
Syntax:
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:
n
1101
Description:
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:
1
Cycles:
2
Encoding:
1000
Description:
Q1
Q2
Q3
Q4
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
bbba
ffff
ffff
Bit ‘b’ in register ‘f’ is set.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Decode
f, b {,a}
Words:
1
Cycles:
1
Q Cycle Activity:
Example:
HERE
Before Instruction
PC
After Instruction
PC
BRA
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Jump
=
address (HERE)
=
address (Jump)
Example:
BSF
Before Instruction
FLAG_REG
After Instruction
FLAG_REG
© 2007 Microchip Technology Inc.
FLAG_REG, 7, 1
=
0Ah
=
8Ah
DS39629C-page 307
PIC18F6390/6490/8390/8490
BTFSC
Bit Test File, Skip if Clear
BTFSS
Bit Test File, Skip if Set
Syntax:
BTFSC f, b {,a}
Syntax:
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
Description:
bbba
ffff
ffff
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 two-cycle instruction.
Encoding:
1010
Description:
bbba
ffff
ffff
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 is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh).
See Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh).
See Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Words:
1
Cycles:
1(2)
Cycles:
1(2)
Note:
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
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:
If skip:
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
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
Before Instruction
PC
After Instruction
If FLAG<1>
PC
If FLAG<1>
PC
DS39629C-page 308
BTFSC
:
:
FLAG, 1, 0
=
address (HERE)
=
=
=
=
0;
address (TRUE)
1;
address (FALSE)
Example:
HERE
FALSE
TRUE
Before Instruction
PC
After Instruction
If FLAG<1>
PC
If FLAG<1>
PC
BTFSS
:
:
FLAG, 1, 0
=
address (HERE)
=
=
=
=
0;
address (FALSE)
1;
address (TRUE)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
BTG
Bit Toggle f
BOV
Branch if Overflow
Syntax:
BTG f, b {,a}
Syntax:
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:
0111
Description:
Encoding:
bbba
ffff
ffff
1110
Description:
Bit ‘b’ in data memory location ‘f’ is
inverted.
0100
nnnn
nnnn
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.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
n
Words:
1
Cycles:
1(2)
Q Cycle Activity:
If Jump:
Words:
1
Q1
Q2
Q3
Q4
Cycles:
1
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
BTG
PORTC,
4, 0
Before Instruction:
PORTC =
0111 0101 [75h]
After Instruction:
PORTC =
0110 0101 [65h]
© 2007 Microchip Technology Inc.
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
Before Instruction
PC
After Instruction
If Overflow
PC
If Overflow
PC
BOV
Jump
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE + 2)
DS39629C-page 309
PIC18F6390/6490/8390/8490
BZ
Branch if Zero
CALL
Subroutine Call
Syntax:
BZ
Syntax:
CALL k {,s}
n
Operands:
-128 ≤ n ≤ 127
Operands:
Operation:
if Zero bit is ‘1’,
(PC) + 2 + 2n → PC
0 ≤ k ≤ 1048575
s ∈ [0,1]
Operation:
Status Affected:
None
(PC) + 4 → TOS,
k → PC<20:1>;
if s = 1,
(W) → WS,
(STATUS) → STATUSS,
(BSR) → BSRS
Status Affected:
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)
Encoding:
1st word (k<7:0>)
Q2
Q3
Q4
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
Before Instruction
PC
After Instruction
If Zero
PC
If Zero
PC
DS39629C-page 310
BZ
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
=
address (HERE)
=
=
=
=
1;
address (Jump)
0;
address (HERE + 2)
kkkk0
kkkk8
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.
If Jump:
Q1
k7kkk
kkkk
110s
k19kkk
Description:
Q Cycle Activity:
Decode
1110
1111
2nd word(k<19:8>)
Example:
HERE
Before Instruction
PC
=
After Instruction
PC
=
TOS
=
WS
=
BSRS
=
STATUSS=
CALL
THERE,1
address (HERE)
address (THERE)
address (HERE + 4)
W
BSR
STATUS
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
CLRF
Clear f
Syntax:
CLRF
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
f {,a}
Operation:
000h → f,
1→Z
Status Affected:
Z
Encoding:
0110
Description:
101a
ffff
ffff
Clears the contents of the specified
register.
CLRWDT
Clear Watchdog Timer
Syntax:
CLRWDT
Operands:
None
Operation:
000h → WDT,
000h → WDT postscaler,
1 → TO,
1 → PD
Status Affected:
TO, PD
Encoding:
0000
Description:
Words:
1
Cycles:
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
CLRF
Before Instruction
FLAG_REG
After Instruction
FLAG_REG
Words:
1
Cycles:
FLAG_REG,1
=
5Ah
=
00h
© 2007 Microchip Technology Inc.
0100
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
Process
Data
No
operation
Example:
Q Cycle Activity:
0000
Watchdog Timer. It also resets the
postscaler of the WDT. Status bits, TO
and PD, are set.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
0000
CLRWDT instruction resets the
CLRWDT
Before Instruction
WDT Counter
After Instruction
WDT Counter
WDT Postscaler
TO
PD
=
?
=
=
=
=
00h
0
1
1
DS39629C-page 311
PIC18F6390/6490/8390/8490
COMF
Complement f
CPFSEQ
Compare f with W, Skip if f = W
Syntax:
COMF
Syntax:
CPFSEQ
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(f) – (W),
skip if (f) = (W)
(unsigned comparison)
Status Affected:
None
f {,d {,a}}
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
Operation:
(f) → dest
Status Affected:
N, Z
Encoding:
0001
Description:
11da
ffff
ffff
The contents of register ‘f’ are
complemented. If ‘d’ is ‘1’, the result is
stored in W. If ‘d’ is ‘0’, the result is
stored back in register ‘f’ (default).
Encoding:
Description:
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
COMF
Before Instruction
REG
=
After Instruction
REG
=
W
=
REG, 0, 0
ffff
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Decode
Q2
Read
register ‘f’
Q3
Process
Data
Q4
No
operation
If skip:
Q1
Q2
Q3
No
No
No
operation
operation
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
No
No
No
operation
operation
operation
No
No
No
operation
operation
operation
Example:
HERE
NEQUAL
EQUAL
Before Instruction
PC Address
W
REG
After Instruction
If REG
PC
If REG
PC
DS39629C-page 312
ffff
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘0’, the BSR is used to select the
GPR bank.
13h
13h
ECh
001a
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 two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
Words:
0110
f {,a}
Q4
No
operation
Q4
No
operation
No
operation
CPFSEQ REG, 0
:
:
=
=
=
HERE
?
?
=
=
≠
=
W;
Address (EQUAL)
W;
Address (NEQUAL)
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
CPFSGT
Compare f with W, Skip if f > W
CPFSLT
Compare f with W, Skip if f < W
Syntax:
CPFSGT
Syntax:
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
f {,a}
010a
ffff
ffff
Compares the contents of data memory
location ‘f’ to the contents of the W by
performing an unsigned subtraction.
Encoding:
0110
Description:
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.
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Q2
Read
register ‘f’
Q3
Process
Data
Q4
No
operation
Q1
Q2
Q3
No
No
No
operation
operation
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
No
No
No
operation
operation
operation
No
No
No
operation
operation
operation
Q4
No
operation
1
Cycles:
1(2)
Note:
Example:
HERE
NGREATER
GREATER
Before Instruction
PC
W
After Instruction
If REG
PC
If REG
PC
CPFSGT REG, 0
:
:
=
=
Address (HERE)
?
>
=
≤
=
W;
Address (GREATER)
W;
Address (NGREATER)
© 2007 Microchip Technology Inc.
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
If skip:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
If skip:
Q4
No
operation
No
operation
ffff
Compares the contents of data memory
location ‘f’ to the contents of W by
performing an unsigned subtraction.
Words:
1(2)
3 cycles if skip and followed
by a 2-word instruction.
ffff
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
1
Note:
000a
If the contents of ‘f’ are less than the
contents of W, then the fetched
instruction is discarded and a NOP is
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
f {,a}
Example:
HERE
NLESS
LESS
Before Instruction
PC
W
After Instruction
If REG
PC
If REG
PC
CPFSLT REG, 1
:
:
=
=
Address (HERE)
?
<
=
≥
=
W;
Address (LESS)
W;
Address (NLESS)
DS39629C-page 313
PIC18F6390/6490/8390/8490
DAW
Decimal Adjust W Register
DECF
Decrement f
Syntax:
DAW
Syntax:
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
Encoding:
If [W<7:4> >9] or [C = 1] then,
(W<7:4>) + 6 → W<7:4>,
C = 1;
else,
(W<7:4>) → W<7:4>
Status Affected:
0000
Description:
C
Encoding:
0000
0000
0000
DAW adjusts the eight-bit value in W,
resulting from the earlier addition of two
variables (each in packed BCD format)
and produces a correct packed BCD
result.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register W
Process
Data
Write
W
Example 1:
Before Instruction
W
=
C
=
DC
=
After Instruction
W
=
C
=
DC
=
DS39629C-page 314
A5h
0
0
05h
1
0
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’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
DAW
Before Instruction
W
=
C
=
DC
=
After Instruction
W
=
C
=
DC
=
Example 2:
ffff
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
0111
Description:
01da
Example:
DECF
Before Instruction
CNT
=
Z
=
After Instruction
CNT
=
Z
=
CNT,
1, 0
01h
0
00h
1
CEh
0
0
34h
1
0
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
DECFSZ
Decrement f, Skip if 0
DCFSNZ
Decrement f, Skip if not 0
Syntax:
DECFSZ f {,d {,a}}
Syntax:
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
Description:
11da
ffff
ffff
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).
Encoding:
0100
Description:
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.
1
1(2)
Note:
3 cycles if skip and followed
by a 2-word instruction.
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Words:
1
Cycles:
1(2)
Note:
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
No
operation
No
operation
No
operation
DECFSZ
GOTO
CNT, 1, 1
LOOP
Example:
HERE
CONTINUE
Before Instruction
PC
=
After Instruction
CNT
=
If CNT
=
PC =
If CNT
≠
PC =
Address (HERE)
CNT – 1
0;
Address (CONTINUE)
0;
Address (HERE + 2)
© 2007 Microchip Technology Inc.
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
If skip:
No
operation
ffff
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Q1
ffff
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Cycles:
11da
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 two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
Words:
f {,d {,a}}
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
ZERO
NZERO
Before Instruction
TEMP
After Instruction
TEMP
If TEMP
PC
If TEMP
PC
DCFSNZ
:
:
TEMP, 1, 0
=
?
=
=
=
≠
=
TEMP – 1,
0;
Address (ZERO)
0;
Address (NZERO)
DS39629C-page 315
PIC18F6390/6490/8390/8490
GOTO
Unconditional Branch
INCF
Increment f
Syntax:
GOTO k
Syntax:
INCF
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>)
1110
1111
2nd word(k<19:8>)
1111
k19kkk
k7kkk
kkkk
kkkk0
kkkk8
GOTO allows an unconditional branch
Description:
Encoding:
0010
Description:
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
Q1
Q2
Q3
Q4
Read literal
‘k’<7:0>,
No
operation
Read literal
‘k’<19:8>,
Write to PC
No
operation
No
operation
No
operation
No
operation
10da
ffff
ffff
The contents of register ‘f’ are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Decode
f {,d {,a}}
Words:
1
Cycles:
1
Q Cycle Activity:
Example:
GOTO THERE
After Instruction
PC =
Address (THERE)
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
INCF
Before Instruction
CNT
=
Z
=
C
=
DC
=
After Instruction
CNT
=
Z
=
C
=
DC
=
DS39629C-page 316
CNT, 1, 0
FFh
0
?
?
00h
1
1
1
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
INCFSZ
Increment f, Skip if 0
INFSNZ
Syntax:
INCFSZ
Syntax:
INFSNZ
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
f {,d {,a}}
Increment f, Skip if not 0
f {,d {,a}}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
Operation:
(f) + 1 → dest,
skip if result = 0
Operation:
(f) + 1 → dest,
skip if result ≠ 0
Status Affected:
None
Status Affected:
None
Encoding:
0011
Description:
11da
ffff
ffff
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).
Encoding:
0100
Description:
10da
ffff
ffff
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 the result is not ‘0’, the next
instruction which is already fetched is
discarded and a NOP is executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1(2)
Note:
Words:
1
Cycles:
1(2)
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Note:
3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Decode
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
If skip:
If skip:
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
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
Before Instruction
PC
=
After Instruction
CNT
=
If CNT
=
PC
=
If CNT
≠
PC
=
INCFSZ
:
:
Address (HERE)
CNT + 1
0;
Address (ZERO)
0;
Address (NZERO)
© 2007 Microchip Technology Inc.
CNT, 1, 0
Example:
HERE
ZERO
NZERO
Before Instruction
PC
=
After Instruction
REG
=
If REG
≠
PC
=
If REG
=
PC
=
INFSNZ
REG, 1, 0
Address (HERE)
REG + 1
0;
Address (NZERO)
0;
Address (ZERO)
DS39629C-page 317
PIC18F6390/6490/8390/8490
IORLW
Inclusive OR Literal with W
IORWF
Inclusive OR W with f
Syntax:
IORLW k
Syntax:
IORWF
Operands:
0 ≤ k ≤ 255
Operands:
Operation:
(W) .OR. k → W
Status Affected:
N, Z
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) .OR. (f) → dest
Status Affected:
N, Z
Encoding:
0000
1001
kkkk
kkkk
Description:
The contents of W are ORed with the
eight-bit literal ‘k’. The result is placed
in W.
Words:
1
Cycles:
1
Encoding:
0001
Description:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to W
Example:
IORLW
Before Instruction
W
=
After Instruction
W
=
00da
ffff
ffff
Inclusive OR W with register ‘f’. If ‘d’ is
‘0’, the result is placed in W. If ‘d’ is ‘1’,
the result is placed back in register ‘f’
(default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
35h
9Ah
BFh
f {,d {,a}}
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
IORWF
Before Instruction
RESULT =
W
=
After Instruction
RESULT =
W
=
DS39629C-page 318
RESULT, 0, 1
13h
91h
13h
93h
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
LFSR
Load FSR
MOVF
Move f
Syntax:
LFSR f, k
Syntax:
MOVF
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:
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
Encoding:
0101
Description:
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
Example:
After Instruction
FSR2H
FSR2L
Process
Data
03h
ABh
00da
ffff
ffff
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 is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Write literal
‘k’ to FSRfL
LFSR 2, 3ABh
=
=
f {,d {,a}}
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write W
Example:
MOVF
Before Instruction
REG
W
After Instruction
REG
W
© 2007 Microchip Technology Inc.
REG, 0, 0
=
=
22h
FFh
=
=
22h
22h
DS39629C-page 319
PIC18F6390/6490/8390/8490
MOVFF
Move f to f
MOVLB
Move Literal to Low Nibble in BSR
Syntax:
MOVFF fs,fd
Syntax:
MOVLW k
Operands:
0 ≤ fs ≤ 4095
0 ≤ fd ≤ 4095
Operands:
0 ≤ k ≤ 255
Operation:
k → BSR
None
Operation:
(fs) → fd
Status Affected:
Status Affected:
None
Encoding:
Encoding:
1st word (source)
1100
1111
2nd word (destin.)
Description:
ffff
ffff
ffffs
ffffd
ffff
ffff
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.
transferring a data memory location to a
peripheral register (such as the transmit
buffer or an I/O port).
The MOVFF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register
Words:
2
Cycles:
2 (3)
0001
kkkk
kkkk
Description:
The eight-bit literal ‘k’ is loaded into the
Bank Select Register (BSR). The value
of BSR<7:4> always remains ‘0’,
regardless of the value of k7:k4.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write literal
‘k’ to BSR
MOVLB
5
Either source or destination can be W
(a useful special situation).
MOVFF is particularly useful for
0000
Example:
Before Instruction
BSR Register =
After Instruction
BSR Register =
02h
05h
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
(src)
Process
Data
No
operation
Decode
No
operation
No
operation
Write
register ‘f’
(dest)
No dummy
read
Example:
MOVFF
Before Instruction
REG1
REG2
After Instruction
REG1
REG2
DS39629C-page 320
REG1, REG2
=
=
33h
11h
=
=
33h
33h
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
MOVLW
Move Literal to W
MOVWF
Move W to f
Syntax:
MOVLW k
Syntax:
MOVWF
Operands:
0 ≤ k ≤ 255
Operands:
Operation:
k→W
0 ≤ f ≤ 255
a ∈ [0,1]
Status Affected:
None
Encoding:
0000
Description:
1110
kkkk
kkkk
The eight-bit literal ‘k’ is loaded into W.
Words:
1
Cycles:
1
Operation:
(W) → f
Status Affected:
None
Encoding:
0110
Description:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to W
Example:
After Instruction
W
=
MOVLW
f {,a}
111a
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 is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
5Ah
5Ah
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
MOVWF
Before Instruction
W
=
REG
=
After Instruction
W
=
REG
=
© 2007 Microchip Technology Inc.
REG, 0
4Fh
FFh
4Fh
4Fh
DS39629C-page 321
PIC18F6390/6490/8390/8490
MULLW
Multiply Literal with W
MULWF
Multiply W with f
Syntax:
MULLW
Syntax:
MULWF
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(W) x (f) → PRODH:PRODL
Status Affected:
None
k
Operands:
0 ≤ k ≤ 255
Operation:
(W) x k → PRODH:PRODL
Status Affected:
None
Encoding:
0000
Description:
1101
kkkk
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 the PRODH:PRODL register
pair. PRODH contains the high byte.
Encoding:
0000
Description:
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.
1
Cycles:
1
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write
registers
PRODH:
PRODL
Example:
Before Instruction
W
PRODH
PRODL
After Instruction
W
PRODH
PRODL
MULLW
=
=
=
=
=
=
E2h
ADh
08h
If ‘a’ is ‘0’, the Access Bank is
selected. If ‘a’ is ‘1’, the BSR is used
to select the GPR bank.
If ‘a’ is ‘0’ and the extended
instruction set is enabled, this
instruction operates in Indexed Literal
Offset Addressing mode whenever
f ≤ 95 (5Fh). See Section 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
registers
PRODH:
PRODL
Example:
Before Instruction
W
REG
PRODH
PRODL
After Instruction
W
REG
PRODH
PRODL
DS39629C-page 322
ffff
Note that neither Overflow nor Carry is
possible in this operation. A Zero
result is possible but not detected.
0C4h
E2h
?
?
ffff
None of the Status flags are affected.
Q Cycle Activity:
Decode
001a
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.
W is unchanged.
Words:
f {,a}
MULWF
REG, 1
=
=
=
=
C4h
B5h
?
?
=
=
=
=
C4h
B5h
8Ah
94h
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
NEGF
Negate f
NOP
No Operation
Syntax:
NEGF
Syntax:
NOP
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
f {,a}
Operands:
None
Operation:
No operation
None
Operation:
(f) + 1 → f
Status Affected:
Status Affected:
N, OV, C, DC, Z
Encoding:
Encoding:
0110
Description:
110a
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 is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
0000
1111
ffff
0000
xxxx
Description:
No operation.
Words:
1
Cycles:
1
0000
xxxx
0000
xxxx
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
No
operation
No
operation
Example:
None.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
NEGF
Before Instruction
REG
=
After Instruction
REG
=
REG, 1
0011 1010 [3Ah]
1100 0110 [C6h]
© 2007 Microchip Technology Inc.
DS39629C-page 323
PIC18F6390/6490/8390/8490
POP
Pop Top of Return Stack
PUSH
Push Top of Return Stack
Syntax:
POP
Syntax:
PUSH
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
Encoding:
Description:
0000
0101
The PC + 2 is pushed onto the top of
the return stack. The previous TOS
value is pushed down on the stack.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
POP TOS
value
No
operation
POP
GOTO
NEW
Q1
Q2
Q3
Q4
Decode
PUSH
PC + 2 onto
return stack
No
operation
No
operation
Example:
Before Instruction
TOS
Stack (1 level down)
=
=
0031A2h
014332h
After Instruction
TOS
PC
=
=
014332h
NEW
DS39629C-page 324
0000
This instruction allows implementing a
software stack by modifying TOS and
then pushing it onto the return stack.
Q Cycle Activity:
Example:
0000
PUSH
Before Instruction
TOS
PC
=
=
345Ah
0124h
After Instruction
PC
TOS
Stack (1 level down)
=
=
=
0126h
0126h
345Ah
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
RCALL
Relative Call
RESET
Reset
Syntax:
RCALL
Syntax:
RESET
n
Operands:
-1024 ≤ n ≤ 1023
Operands:
None
Operation:
(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:
1101
Description:
1nnn
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
Encoding:
0000
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
1111
1111
This instruction provides a way to
execute a MCLR Reset in software.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Start
Reset
No
operation
No
operation
Example:
Q Cycle Activity:
0000
Description:
After Instruction
Registers =
Flags*
=
RESET
Reset Value
Reset Value
PUSH PC to
stack
No
operation
Example:
No
operation
HERE
RCALL Jump
Before Instruction
PC =
Address (HERE)
After Instruction
PC =
Address (Jump)
TOS =
Address (HERE + 2)
© 2007 Microchip Technology Inc.
DS39629C-page 325
PIC18F6390/6490/8390/8490
RETFIE
Return from Interrupt
RETLW
Return Literal to W
Syntax:
RETFIE {s}
Syntax:
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
0000
Description:
0000
0001
Words:
1
Cycles:
2
Q Cycle Activity:
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
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).
1100
Description:
GIE/GIEH, PEIE/GIEL.
Encoding:
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:
Q1
Q2
Q3
Q4
Decode
No
operation
No
operation
POP PC
from stack
Set GIEH or
GIEL
No
operation
Encoding:
No
operation
Example:
RETFIE
After Interrupt
PC
W
BSR
STATUS
GIE/GIEH, PEIE/GIEL
DS39629C-page 326
No
operation
No
operation
1
=
=
=
=
=
TOS
WS
BSRS
STATUSS
1
CALL
:
TABLE
ADDWF
RETLW
RETLW
:
:
RETLW
TABLE ;
;
;
;
W contains table
offset value
W now has
table value
PCL
k0
k1
; W = offset
; Begin table
;
kn
; End of table
Before Instruction
W
=
After Instruction
W
=
07h
value of kn
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
RETURN
Return from Subroutine
RLCF
Rotate Left f through Carry
Syntax:
RETURN {s}
Syntax:
RLCF
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
Status Affected:
None
Encoding:
0000
Description:
Encoding:
0000
0001
001s
0011
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
Q1
Q2
Q3
Q4
No
operation
Process
Data
POP PC
from stack
No
operation
No
operation
No
operation
No
operation
Example:
RETURN
After Interrupt
PC = TOS
ffff
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’ and the extended instruction
set is enabled, this instruction
operates in Indexed Literal Offset
Addressing mode whenever
f ≤ 95 (5Fh). See Section 24.2.3
“Byte-Oriented and Bit-Oriented
Instructions in Indexed Literal Offset
Mode” for details.
register f
C
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
Before Instruction
REG
=
C
=
After Instruction
REG
=
W
=
C
=
© 2007 Microchip Technology Inc.
01da
If ‘a’ is ‘0’, the Access Bank is
selected. If ‘a’ is ‘1’, the BSR is used to
select the GPR bank.
Q Cycle Activity:
Decode
f {,d {,a}}
RLCF
REG, 0, 0
1110 0110
0
1110 0110
1100 1100
1
DS39629C-page 327
PIC18F6390/6490/8390/8490
RLNCF
Rotate Left f (No Carry)
RRCF
Rotate Right f through Carry
Syntax:
RLNCF
Syntax:
RRCF
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:
f {,d {,a}}
01da
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).
Encoding:
0011
Description:
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
Cycles:
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
Before Instruction
REG
=
After Instruction
REG
=
DS39629C-page 328
RLNCF
Words:
1
Cycles:
1
register f
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
REG, 1, 0
1010 1011
0101 0111
ffff
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).
C
Q Cycle Activity:
ffff
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
register f
1
00da
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
f {,d {,a}}
Example:
RRCF
Before Instruction
REG
=
C
=
After Instruction
REG
=
W
=
C
=
REG, 0, 0
1110 0110
0
1110 0110
0111 0011
0
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
RRNCF
Rotate Right f (No Carry)
SETF
Syntax:
RRNCF
Syntax:
SETF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
FFh → f
Operation:
(f<n>) → dest<n – 1>,
(f<0>) → dest<7>
Status Affected:
None
Status Affected:
Encoding:
N, Z
Encoding:
0100
Description:
f {,d {,a}}
00da
Set f
ffff
ffff
0110
Description:
The contents of register ‘f’ are rotated
one bit to the right. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
register f
Words:
1
Cycles:
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example 1:
RRNCF
Before Instruction
REG
=
After Instruction
REG
=
Example 2:
ffff
The contents of the specified register
are set to FFh.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
SETF
Before Instruction
REG
After Instruction
REG
REG,1
=
5Ah
=
FFh
REG, 1, 0
1101 0111
1110 1011
RRNCF
Before Instruction
W
=
REG
=
After Instruction
W
=
REG
=
ffff
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
Q Cycle Activity:
100a
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
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.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
f {,a}
REG, 0, 0
?
1101 0111
1110 1011
1101 0111
© 2007 Microchip Technology Inc.
DS39629C-page 329
PIC18F6390/6490/8390/8490
SLEEP
Enter Sleep mode
SUBFWB
Subtract f from W with Borrow
Syntax:
SLEEP
Syntax:
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
Status Affected:
TO, PD
Encoding:
0000
Encoding:
0000
0000
0011
0101
Description:
The Power-Down status bit (PD) is
cleared. The Time-out status bit (TO)
is set. Watchdog Timer and its
postscaler are cleared.
Description:
1
Cycles:
1
Q1
Q2
Q3
Q4
No
operation
Process
Data
Go to
Sleep
Example:
SLEEP
Before Instruction
TO =
?
?
PD =
After Instruction
1†
TO =
PD =
0
† If WDT causes wake-up, this bit is cleared.
DS39629C-page 330
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’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Decode
01da
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
The processor is put into Sleep mode
with the oscillator stopped.
Words:
f {,d {,a}}
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
SUBFWB
REG, 1, 0
Example 1:
Before Instruction
REG
=
3
W
=
2
C
=
1
After Instruction
REG
=
FF
W
=
2
C
=
0
Z
=
0
N
=
1 ; result is negative
Example 2:
SUBFWB
REG, 0, 0
Before Instruction
REG
=
2
W
=
5
C
=
1
After Instruction
REG
=
2
W
=
3
C
=
1
Z
=
0
N
=
0 ; result is positive
SUBFWB
REG, 1, 0
Example 3:
Before Instruction
REG
=
1
W
=
2
C
=
0
After Instruction
REG
=
0
W
=
2
C
=
1
Z
=
1 ; result is zero
N
=
0
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
SUBLW
Subtract W from Literal
SUBWF
Subtract W from f
Syntax:
SUBLW k
Syntax:
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
Encoding:
0101
Description:
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write to W
Example 1:
Before Instruction
W
=
C
=
After Instruction
W
=
C
=
Z
=
N
=
Example 2:
Before Instruction
W
=
C
=
After Instruction
W
=
C
=
Z
=
N
=
Example 3:
Before Instruction
W
=
C
=
After Instruction
W
=
C
=
Z
=
N
=
SUBLW
02h
ffff
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
01h
?
SUBLW
ffff
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
02h
01h
1
; result is positive
0
0
11da
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).
Q Cycle Activity:
Decode
f {,d {,a}}
Words:
1
Cycles:
1
Q Cycle Activity:
02h
?
00h
1
; result is zero
1
0
SUBLW
02h
03h
?
FFh; (2’s complement)
0 ; result is negative
0
1
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
SUBWF
REG, 1, 0
Example 1:
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 2:
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 3:
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
© 2007 Microchip Technology Inc.
3
2
?
1
2
1
0
0
SUBWF
; result is positive
REG, 0, 0
2
2
?
2
0
1
1
0
SUBWF
; result is zero
REG, 1, 0
1
2
?
FFh ;(2’s complement)
2
0
; result is negative
0
1
DS39629C-page 331
PIC18F6390/6490/8390/8490
SUBWFB
Subtract W from f with Borrow
SWAPF
Swap f
Syntax:
SUBWFB
Syntax:
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:
(f<3:0>) → dest<7:4>,
Status Affected:
N, OV, C, DC, Z
Encoding:
0101
Description:
f {,d {,a}}
10da
(f<7:4>) → dest<3:0>
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).
Status Affected:
0011
Description:
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
1
Cycles:
1
Q Cycle Activity:
Q1
Decode
Q2
Read
register ‘f’
Example 1:
SUBWFB
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 2:
Q4
Write to
destination
(0001 1001)
(0000 1101)
0Ch
0Dh
1
0
0
(0000 1011)
(0000 1101)
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’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
REG, 1, 0
19h
0Dh
1
ffff
Example:
SWAPF
Before Instruction
REG
=
After Instruction
REG
=
REG, 1, 0
53h
35h
; result is positive
SUBWFB REG, 0, 0
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
=
C
=
Z
=
N
=
Example 3:
1Bh
1Ah
0
(0001 1011)
(0001 1010)
1Bh
00h
1
1
0
(0001 1011)
SUBWFB
Before Instruction
REG
=
W
=
C
=
After Instruction
REG
=
W
C
Z
N
Q3
Process
Data
10da
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
None
Encoding:
=
=
=
=
DS39629C-page 332
; result is zero
REG, 1, 0
03h
0Eh
1
(0000 0011)
(0000 1101)
F5h
(1111 0100)
; [2’s comp]
(0000 1101)
0Eh
0
0
1
; result is negative
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TBLRD
Table Read
TBLRD
Table Read (Continued)
Syntax:
TBLRD ( *; *+; *-; +*)
Example 1:
TBLRD
Operands:
None
Operation:
if TBLRD *,
(Prog Mem (TBLPTR)) → TABLAT,
TBLPTR – No Change;
if TBLRD *+,
(Prog Mem (TBLPTR)) → TABLAT,
(TBLPTR) + 1 → TBLPTR;
if TBLRD *-,
(Prog Mem (TBLPTR)) → TABLAT,
(TBLPTR) – 1 → TBLPTR;
if TBLRD +*,
(TBLPTR) + 1 → TBLPTR,
(Prog Mem (TBLPTR)) → TABLAT
Status Affected: None
Encoding:
Description:
0000
0000
0000
10nn
nn=0 *
=1 *+
=2 *=3 +*
Before Instruction
TABLAT
TBLPTR
MEMORY(00A356h)
After Instruction
TABLAT
TBLPTR
Example 2:
TBLRD
Before Instruction
TABLAT
TBLPTR
MEMORY(01A357h)
MEMORY(01A358h)
After Instruction
TABLAT
TBLPTR
*+ ;
=
=
=
55h
00A356h
34h
=
=
34h
00A357h
+* ;
=
=
=
=
0AAh
01A357h
12h
34h
=
=
34h
01A358h
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:
•
•
•
•
Words:
1
Cycles:
2
no change
post-increment
post-decrement
pre-increment
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
No
operation
No
operation
No
operation
No operation
(Write
TABLAT)
No
No operation
operation (Read Program
Memory)
© 2007 Microchip Technology Inc.
DS39629C-page 333
PIC18F6390/6490/8390/8490
TBLWT
Table Write
TBLWT
Table Write (Continued)
Syntax:
TBLWT ( *; *+; *-; +*)
Example 1:
TBLWT *+;
Operands:
None
Operation:
if TBLWT*,
(TABLAT) → Holding Register,
TBLPTR – No Change;
if TBLWT*+,
(TABLAT) → Holding Register,
(TBLPTR) + 1 → TBLPTR;
if TBLWT*-,
(TABLAT) → Holding Register,
(TBLPTR) – 1 → TBLPTR;
if TBLWT+*,
(TBLPTR) + 1 → TBLPTR,
Before Instruction
TABLAT
=
55h
TBLPTR
=
00A356h
HOLDING REGISTER
(00A356h)
=
FFh
After Instructions (table write completion)
TABLAT
=
55h
TBLPTR
=
00A357h
HOLDING REGISTER
(00A356h)
=
55h
Example 2:
(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 is written to.
The holding registers are used to program
the contents of Program Memory (P.M.).
(Refer to Section 6.0 “Flash Program
Memory” for additional details on
programming Flash memory.)
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory. TBLPTR
has a 2-MBtye address range. The LSb of
the TBLPTR selects which byte of the
program memory location to access.
TBLWT +*;
Before Instruction
TABLAT
=
34h
TBLPTR
=
01389Ah
HOLDING REGISTER
(01389Ah)
=
FFh
HOLDING REGISTER
(01389Bh)
=
FFh
After Instruction (table write completion)
TABLAT
=
34h
TBLPTR
=
01389Bh
HOLDING REGISTER
(01389Ah)
=
FFh
HOLDING REGISTER
(01389Bh)
=
34h
Note:
The table write (TBLWT) instructions are
not available in user mode in
PIC18F6X90/8X90 devices, as these
devices are standard Flash parts without
an external bus interface.
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:
•
•
•
•
Words:
1
Cycles:
2
no change
post-increment
post-decrement
pre-increment
Q Cycle Activity:
Q1
Decode
Q2
Q3
Q4
No
No
No
operation operation operation
No
No
No
No
operation operation operation operation
(Read
(Write to
TABLAT)
Holding
Register )
DS39629C-page 334
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TSTFSZ
Test f, Skip if 0
XORLW
Exclusive OR Literal with W
Syntax:
TSTFSZ f {,a}
Syntax:
XORLW k
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
0 ≤ k ≤ 255
Operation:
(W) .XOR. k → W
N, Z
Operation:
skip if f = 0
Status Affected:
Status Affected:
None
Encoding:
Encoding:
0110
Description:
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 two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1(2)
0000
1010
kkkk
kkkk
Description:
The contents of W are XORed with
the 8-bit literal ‘k’. The result is placed
in W.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to W
Example:
Before Instruction
W
=
After Instruction
W
=
XORLW
0AFh
B5h
1Ah
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
If skip:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
No
operation
Example:
HERE
NZERO
ZERO
Before Instruction
PC
After Instruction
If CNT
PC
If CNT
PC
TSTFSZ
:
:
CNT, 1
=
Address (HERE)
=
=
≠
=
00h,
Address (ZERO)
00h,
Address (NZERO)
© 2007 Microchip Technology Inc.
DS39629C-page 335
PIC18F6390/6490/8390/8490
XORWF
Exclusive OR W with f
Syntax:
XORWF
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) .XOR. (f) → dest
Status Affected:
N, Z
Encoding:
0001
Description:
f {,d {,a}}
10da
ffff
ffff
Exclusive OR the contents of W with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in the register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 24.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
XORWF
Before Instruction
REG
=
W
=
After Instruction
REG
=
W
=
DS39629C-page 336
REG, 1, 0
AFh
B5h
1Ah
B5h
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
24.2
Extended Instruction Set
A summary of the instructions in the extended instruction set is provided in Table 24-3. Detailed descriptions
are provided in Section 24.2.2 “Extended Instruction
Set”. The opcode field descriptions in Table 24-1 apply
to both the standard and extended PIC18 instruction
sets.
In addition to the standard 75 instructions of the PIC18
instruction set, PIC18FXX90 devices also provide an
optional extension to the core CPU functionality. The
added features include eight additional instructions that
augment Indirect and Indexed Addressing operations
and the implementation of Indexed Literal Offset
Addressing mode for many of the standard PIC18
instructions.
Note:
The additional features are disabled by default. To
enable them, users must set the XINST Configuration
bit.
The instructions in the extended set can all be
classified as literal operations, which either manipulate
the File Select Registers or use them for Indexed
Addressing. Two of the instructions, ADDFSR and
SUBFSR, each have an additional special instantiation
for using FSR2. These versions (ADDULNK and
SUBULNK) allow for automatic return after execution.
24.2.1
EXTENDED INSTRUCTION SYNTAX
Most of the extended instructions use indexed arguments, using one of the File Select Registers and some
offset to specify a source or destination register. When
an argument for an instruction serves as part of
Indexed Addressing, it is enclosed in square brackets
(“[ ]”). This is done to indicate that the argument is used
as an index or offset. MPASM™ Assembler will flag an
error if it determines that an index or offset value is not
bracketed.
The extended instructions are specifically implemented
to optimize re-entrant program code (that is, code that
is recursive or that uses a software stack) written in
high-level languages, particularly C. Among other
things, they allow users working in high-level
languages to perform certain operations on data
structures more efficiently. These include:
When the extended instruction set is enabled, brackets
are also used to indicate index arguments in byteoriented and bit-oriented instructions. This is in addition
to other changes in their syntax. For more details, see
Section 24.2.3.1 “Extended Instruction Syntax with
Standard PIC18 Commands”.
• dynamic allocation and deallocation of software
stack space when entering and leaving
subroutines
• Function Pointer invocation
• Software Stack Pointer manipulation
• manipulation of variables located in a software
stack
TABLE 24-3:
The instruction set extension and the
Indexed Literal Offset Addressing mode
were designed for optimizing applications
written in C; the user may likely never use
these instructions directly in assembler.
The syntax for these commands is provided as a reference for users who may be
reviewing code that has been generated
by a compiler.
Note:
In the past, square brackets have been
used to denote optional arguments in the
PIC18 and earlier instruction sets. In this
text and going forward, optional arguments
are denoted by braces (“{ }”).
EXTENSIONS TO THE PIC18 INSTRUCTION SET
Mnemonic,
Operands
ADDFSR
ADDULNK
CALLW
MOVSF
f, k
k
MOVSS
zs, zd
PUSHL
k
SUBFSR
SUBULNK
f, k
k
zs, fd
Description
Add Literal to FSR
Add Literal to FSR2 and Return
Call Subroutine using WREG
Move zs (source) to 1st word
fd (destination) 2nd word
Move zs (source) to 1st word
zd (destination) 2nd word
Store Literal at FSR2,
Decrement FSR2
Subtract Literal from FSR
Subtract Literal from FSR2 and
Return
© 2007 Microchip Technology Inc.
Cycles
1
2
2
2
16-Bit Instruction Word
MSb
LSb
Status
Affected
1000
1000
0000
1011
ffff
1011
xxxx
1010
ffkk
11kk
0001
0zzz
ffff
1zzz
xzzz
kkkk
kkkk
kkkk
0100
zzzz
ffff
zzzz
zzzz
kkkk
None
None
None
None
1
1110
1110
0000
1110
1111
1110
1111
1110
1
2
1110
1110
1001
1001
ffkk
11kk
kkkk
kkkk
None
None
2
None
None
DS39629C-page 337
PIC18F6390/6490/8390/8490
24.2.2
EXTENDED INSTRUCTION SET
ADDFSR
Add Literal to FSR
ADDULNK
Syntax:
ADDFSR f, k
Syntax:
ADDULNK k
Operands:
0 ≤ k ≤ 63
f ∈ [ 0, 1, 2 ]
Operands:
0 ≤ k ≤ 63
FSR(f) + k → FSR(f)
Operation:
Operation:
FSR2 + k → FSR2,
PC = (TOS)
Status Affected:
None
Status Affected:
None
Encoding:
1110
1000
ffkk
kkkk
Description:
The 6-bit literal ‘k’ is added to the
contents of the FSR specified by ‘f’.
Words:
1
Cycles:
1
Encoding:
1110
Description:
Q1
Q2
Q3
Q4
Read
literal ‘k’
Process
Data
Write to
FSR
Example:
ADDFSR 2, 23h
Before Instruction
FSR2
=
03FFh
After Instruction
FSR2
=
0422h
11kk
kkkk
The 6-bit literal ‘k’ is added to the
contents of FSR2. A RETURN is then
executed by loading the PC with the
TOS.
This may be thought of as a special case
of the ADDFSR instruction, where f = 3
(binary ‘11’); it operates only on FSR2.
Words:
1
Cycles:
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
FSR
No
Operation
No
Operation
No
Operation
No
Operation
Example:
Note:
1000
The instruction takes two cycles to
execute; a NOP is performed during the
second cycle.
Q Cycle Activity:
Decode
Add Literal to FSR2 and Return
ADDULNK 23h
Before Instruction
FSR2
=
PC
=
03FFh
0100h
After Instruction
FSR2
=
PC
=
0422h
(TOS)
All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction syntax then becomes: {label} instruction argument(s).
DS39629C-page 338
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
CALLW
Subroutine Call Using WREG
MOVSF
Syntax:
CALLW
Syntax:
MOVSF [zs], fd
Operands:
None
Operands:
Operation:
(PC + 2) → TOS,
(W) → PCL,
(PCLATH) → PCH,
(PCLATU) → PCU
0 ≤ zs ≤ 127
0 ≤ fd ≤ 4095
Operation:
((FSR2) + zs) → fd
Status Affected:
None
Status Affected:
0000
Description
Encoding:
None
Encoding:
0000
Move Indexed to f
0001
0100
First, the return address (PC + 2) is
pushed onto the return stack. Next, the
contents of W are written to PCL; the
existing value is discarded. Then, the
contents of PCLATH and PCLATU are
latched into PCH and PCU,
respectively. The second cycle is
executed as a NOP instruction while the
new next instruction is fetched.
1st word (source)
Description:
Unlike CALL, there is no option to
update W, STATUS or BSR.
Words:
1
Cycles:
2
Q1
Q2
Q3
Q4
Read
WREG
Push PC to
stack
No
operation
No
operation
No
operation
No
operation
No
operation
HERE
Before Instruction
PC
=
PCLATH =
PCLATU =
W
=
After Instruction
PC
=
TOS
=
PCLATH =
PCLATU =
W
=
CALLW
address (HERE)
10h
00h
06h
001006h
address (HERE + 2)
10h
00h
06h
© 2007 Microchip Technology Inc.
0zzz
ffff
zzzzs
ffffd
The contents of the source register are
moved to destination register ‘fd’. The
actual address of the source register is
determined by adding the 7-bit literal
offset ‘zs’ in the first word to the value of
FSR2. The address of the destination
register is specified by the 12-bit literal
‘fd’ in the second word. Both addresses
can be anywhere in the 4096-byte data
space (000h to FFFh).
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h.
Words:
2
Cycles:
2
Q Cycle Activity:
Q1
Example:
1011
ffff
The MOVSF instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
Q Cycle Activity:
Decode
1110
1111
2nd word (destin.)
Decode
Decode
Q2
Q3
Determine
Determine
source addr source addr
No
operation
No
operation
No dummy
read
Example:
MOVSF
Before Instruction
FSR2
Contents
of 85h
REG2
After Instruction
FSR2
Contents
of 85h
REG2
Q4
Read
source reg
Write
register ‘f’
(dest)
[05h], REG2
=
80h
=
=
33h
11h
=
80h
=
=
33h
33h
DS39629C-page 339
PIC18F6390/6490/8390/8490
MOVSS
Move Indexed to Indexed
PUSHL
Syntax:
Syntax:
PUSHL k
Operands:
MOVSS [zs], [zd]
0 ≤ zs ≤ 127
0 ≤ zd ≤ 127
Operands:
0 ≤ k ≤ 255
Operation:
((FSR2) + zs) → ((FSR2) + zd)
Operation:
k → (FSR2),
FSR2 – 1→ FSR2
Status Affected:
None
Status Affected: None
Encoding:
1st word (source)
1110
1111
2nd word (dest.)
Description
1011
xxxx
1zzz
xzzz
zzzzs
zzzzd
The contents of the source register are
moved to the destination register. The
addresses of the source and destination
registers are determined by adding the
7-bit literal offsets ‘zs’ or ‘zd’,
respectively, to the value of FSR2. Both
registers can be located anywhere in
the 4096-byte data memory space
(000h to FFFh).
The MOVSS instruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h. If the
resultant destination address points to
an Indirect Addressing register, the
instruction will execute as a NOP.
Words:
2
Cycles:
2
Store Literal at FSR2, Decrement FSR2
Encoding:
1111
Description:
1010
kkkk
kkkk
The 8-bit literal ‘k’ is written to the data
memory address specified by FSR2. FSR2 is
decremented by 1 after the operation.
This instruction allows users to push values
onto a software stack.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read ‘k’
Process
data
Write to
destination
Example:
PUSHL 08h
Before Instruction
FSR2H:FSR2L
Memory (01ECh)
=
=
01ECh
00h
After Instruction
FSR2H:FSR2L
Memory (01ECh)
=
=
01EBh
08h
Q Cycle Activity:
Q1
Decode
Decode
Q2
Q3
Determine
Determine
source addr source addr
Determine
dest addr
Example:
Write
to dest reg
MOVSS [05h], [06h]
Before Instruction
FSR2
Contents
of 85h
Contents
of 86h
After Instruction
FSR2
Contents
of 85h
Contents
of 86h
DS39629C-page 340
Determine
dest addr
Q4
Read
source reg
=
80h
=
33h
=
11h
=
80h
=
33h
=
33h
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
SUBFSR
Subtract Literal from FSR
SUBULNK
Syntax:
SUBFSR f, k
Syntax:
SUBULNK k
Operands:
0 ≤ k ≤ 63
f ∈ [ 0, 1, 2 ]
Operands:
0 ≤ k ≤ 63
Operation:
Operation:
FSRf – k → FSRf
FSR2 – k → FSR2,
(TOS) → PC
Status Affected:
None
Encoding:
1110
Subtract Literal from FSR2 and Return
Status Affected: None
1001
ffkk
kkkk
Description:
The 6-bit literal ‘k’ is subtracted from
the contents of the FSR specified
by ‘f’.
Words:
1
Cycles:
1
Encoding:
1110
Description:
1001
11kk
kkkk
The 6-bit literal ‘k’ is subtracted from the
contents of the FSR2. A RETURN is then
executed by loading the PC with the TOS.
The instruction takes two cycles to execute;
a NOP is performed during the second cycle.
This may be thought of as a special case of
the SUBFSR instruction, where f = 3 (binary
‘11’); it operates only on FSR2.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Words:
1
Cycles:
2
Q Cycle Activity:
Example:
SUBFSR 2, 23h
Before Instruction
FSR2
=
03FFh
After Instruction
FSR2
=
03DCh
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
No
Operation
No
Operation
No
Operation
No
Operation
Example:
© 2007 Microchip Technology Inc.
SUBULNK 23h
Before Instruction
FSR2
=
PC
=
03FFh
0100h
After Instruction
FSR2
=
PC
=
03DCh
(TOS)
DS39629C-page 341
PIC18F6390/6490/8390/8490
24.2.3
Note:
BYTE-ORIENTED AND
BIT-ORIENTED INSTRUCTIONS IN
INDEXED LITERAL OFFSET MODE
Enabling the PIC18 instruction set
extension may cause legacy applications
to behave erratically or fail entirely.
In addition to eight new commands in the extended set,
enabling the extended instruction set also enables
Indexed Literal Offset Addressing mode (Section 5.6.1
“Indexed Addressing With Literal Offset”). This has
a significant impact on the way that many commands of
the standard PIC18 instruction set are interpreted.
When the extended set is disabled, addresses embedded in opcodes are treated as literal memory locations:
either as a location in the Access Bank (a = 0), or in a
GPR bank designated by the BSR (a = 1). When the
extended instruction set is enabled and a = 0, however,
a file register argument of 5Fh or less is interpreted as
an offset from the pointer value in FSR2 and not as a
literal address. For practical purposes, this means that
all instructions that use the Access RAM bit as an
argument – that is, all byte-oriented and bit-oriented
instructions, or almost half of the core PIC18 instructions
– may behave differently when the extended instruction
set is enabled.
When the content of FSR2 is 00h, the boundaries of the
Access RAM are essentially remapped to their original
values. This may be useful in creating backward
compatible code. If this technique is used, it may be
necessary to save the value of FSR2 and restore it
when moving back and forth between ‘C’ and assembly
routines in order to preserve the Stack Pointer. Users
must also keep in mind the syntax requirements of the
extended instruction set (see Section 24.2.3.1
“Extended Instruction Syntax with Standard PIC18
Commands”).
24.2.3.1
Extended Instruction Syntax with
Standard PIC18 Commands
When the extended instruction set is enabled, the file
register argument, ‘f’, in the standard byte-oriented and
bit-oriented commands is replaced with the literal offset
value, ‘k’. As already noted, this occurs only when ‘f’ is
less than or equal to 5Fh. When an offset value is used,
it must be indicated by square brackets (“[ ]”). As with
the extended instructions, the use of brackets indicates
to the compiler that the value is to be interpreted as an
index or an offset. Omitting the brackets, or using a
value greater than 5Fh within brackets, will generate an
error in the MPASM™ Assembler.
If the index argument is properly bracketed for Indexed
Literal Offset Addressing, the Access RAM argument is
never specified; it will automatically be assumed to be
‘0’. This is in contrast to standard operation (extended
instruction set disabled) when ‘a’ is set on the basis of
the target address. Declaring the Access RAM bit in
this mode will also generate an error in the MPASM
Assembler.
The destination argument, ‘d’, functions as before.
In the latest versions of the MPASM Assembler,
language support for the extended instruction set must
be explicitly invoked. This is done with either the
command line option, /y, or the PE directive in the
source listing.
24.2.4
CONSIDERATIONS WHEN
ENABLING THE EXTENDED
INSTRUCTION SET
It is important to note that the extensions to the instruction set may not be beneficial to all users. In particular,
users who are not writing code that uses a software
stack may not benefit from using the extensions to the
instruction set.
Although the Indexed Literal Offset Addressing mode
can be very useful for dynamic stack and pointer
manipulation, it can also be very annoying if a simple
arithmetic operation is carried out on the wrong
register. Users who are accustomed to the PIC18
programming must keep in mind that, when the
extended instruction set is enabled, register addresses
of 5Fh or less are used for Indexed Literal Offset
Addressing.
Additionally, the Indexed Literal Offset Addressing
mode may create issues with legacy applications
written to the PIC18 assembler. This is because
instructions in the legacy code may attempt to address
registers in the Access Bank below 5Fh. Since these
addresses are interpreted as literal offsets to FSR2
when the instruction set extension is enabled, the
application may read or write to the wrong data
addresses.
Representative examples of typical byte-oriented and
bit-oriented instructions in the Indexed Literal Offset
Addressing mode are provided on the following page to
show how execution is affected. The operand
conditions shown in the examples are applicable to all
instructions of these types.
When porting an application to the PIC18FXX90, it is
very important to consider the type of code. A large, reentrant application that is written in ‘C’ and would benefit
from efficient compilation will do well when using the
instruction set extensions. Legacy applications that
heavily use the Access Bank will most likely not benefit
from using the extended instruction set.
DS39629C-page 342
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
ADDWF
ADD W to Indexed
(Indexed Literal Offset mode)
BSF
Bit Set Indexed
(Indexed Literal Offset mode)
Syntax:
ADDWF
Syntax:
BSF [k], b
Operands:
0 ≤ k ≤ 95
d ∈ [0,1]
a=0
Operands:
0 ≤ f ≤ 95
0≤b≤7
a=0
Operation:
(W) + ((FSR2) + k) → dest
Operation:
1 → ((FSR2 + k))<b>
Status Affected:
None
[k] {,d}
Status Affected: N, OV, C, DC, Z
Encoding:
0010
Description:
01d0
kkkk
kkkk
The contents of W are added to the contents
of the register indicated by FSR2, offset by the
value ‘k’.
If ‘d’ is ‘0’, the result is stored in W. If ‘d’ is ‘1’,
the result is stored back in register ‘f’ (default).
Words:
1
Cycles:
1
Encoding:
bbb0
kkkk
kkkk
Description:
Bit ‘b’ of the register indicated by FSR2,
offset by the value ‘k’, is set.
Words:
1
Cycles:
1
Q Cycle Activity:
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read ‘k’
Process
Data
Write to
destination
Example:
1000
ADDWF
Before Instruction
W
OFST
FSR2
Contents
of 0A2Ch
After Instruction
W
Contents
of 0A2Ch
[OFST] ,0
=
=
=
17h
2Ch
0A00h
=
20h
=
37h
=
20h
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
BSF
Before Instruction
FLAG_OFST
FSR2
Contents
of 0A0Ah
After Instruction
Contents
of 0A0Ah
[FLAG_OFST], 7
=
=
0Ah
0A00h
=
55h
=
D5h
SETF
Set Indexed
(Indexed Literal Offset mode)
Syntax:
SETF [k]
Operands:
0 ≤ k ≤ 95
Operation:
FFh → ((FSR2) + k)
Status Affected:
None
Encoding:
0110
1000
kkkk
kkkk
Description:
The contents of the register indicated by
FSR2, offset by ‘k’, are set to FFh.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read ‘k’
Process
Data
Write
register
Example:
SETF
Before Instruction
OFST
FSR2
Contents
of 0A2Ch
After Instruction
Contents
of 0A2Ch
© 2007 Microchip Technology Inc.
[OFST]
=
=
2Ch
0A00h
=
00h
=
FFh
DS39629C-page 343
PIC18F6390/6490/8390/8490
24.2.5
SPECIAL CONSIDERATIONS WITH
MICROCHIP MPLAB® IDE TOOLS
The latest versions of Microchip’s software tools have
been designed to fully support the extended instruction
set of the PIC18FXX90 family of devices. This includes
the MPLAB C18 C compiler, MPASM assembly
language and MPLAB Integrated Development
Environment (IDE).
When selecting a target device for software development, MPLAB IDE will automatically set default Configuration bits for that device. The default setting for the
XINST Configuration bit is ‘0’, disabling the extended
instruction set and Indexed Literal Offset Addressing
mode. For proper execution of applications developed
to take advantage of the extended instruction set,
XINST must be set during programming.
DS39629C-page 344
To develop software for the extended instruction set,
the user must enable support for the instructions and
the Indexed Addressing mode in their language tool(s).
Depending on the environment being used, this may be
done in several ways:
• A menu option, or dialog box within the
environment, that allows the user to configure the
language tool and its settings for the project
• A command line option
• A directive in the source code
These options vary between different compilers,
assemblers and development environments. Users are
encouraged to review the documentation accompanying their development systems for the appropriate
information.
© 2007 Microchip Technology Inc.
PIC18FXX90
25.0
DEVELOPMENT SUPPORT
The PIC® 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 C18 and MPLAB C30 C Compilers
- MPLINKTM Object Linker/
MPLIBTM Object Librarian
- MPLAB ASM30 Assembler/Linker/Library
• Simulators
- MPLAB SIM Software Simulator
• Emulators
- MPLAB ICE 2000 In-Circuit Emulator
- MPLAB REAL ICE™ In-Circuit Emulator
• In-Circuit Debugger
- MPLAB ICD 2
• Device Programmers
- PICSTART® Plus Development Programmer
- MPLAB PM3 Device Programmer
- PICkit™ 2 Development Programmer
• Low-Cost Demonstration and Development
Boards and Evaluation Kits
25.1
MPLAB Integrated Development
Environment Software
The MPLAB IDE software brings an ease of software
development previously unseen in the 8/16-bit microcontroller market. The MPLAB IDE is a Windows®
operating system-based application that contains:
• A single graphical interface to all debugging tools
- Simulator
- Programmer (sold separately)
- Emulator (sold separately)
- In-Circuit Debugger (sold separately)
• A full-featured editor with color-coded context
• A multiple project manager
• Customizable data windows with direct edit of
contents
• High-level source code debugging
• Visual device initializer for easy register
initialization
• Mouse over variable inspection
• Drag and drop variables from source to watch
windows
• Extensive on-line help
• Integration of select third party tools, such as
HI-TECH Software C Compilers and IAR
C Compilers
The MPLAB IDE allows you to:
• Edit your source files (either assembly or C)
• One touch assemble (or compile) and download
to PIC MCU emulator and simulator tools
(automatically updates all project information)
• Debug using:
- Source files (assembly or C)
- Mixed assembly and C
- Machine code
MPLAB IDE supports multiple debugging tools in a
single development paradigm, from the cost-effective
simulators, through low-cost in-circuit debuggers, to
full-featured emulators. This eliminates the learning
curve when upgrading to tools with increased flexibility
and power.
© 2007 Microchip Technology Inc.
DS39629C-page 345
PIC18FXX90
25.2
MPASM Assembler
The MPASM Assembler is a full-featured, universal
macro assembler for all PIC MCUs.
The MPASM Assembler generates relocatable object
files for the MPLINK Object Linker, Intel® standard HEX
files, MAP files to detail memory usage and symbol
reference, absolute LST files that contain source lines
and generated machine code and COFF files for
debugging.
The MPASM Assembler features include:
• Integration into MPLAB IDE projects
• User-defined macros to streamline
assembly code
• Conditional assembly for multi-purpose
source files
• Directives that allow complete control over the
assembly process
25.3
MPLAB C18 and MPLAB C30
C Compilers
The MPLAB C18 and MPLAB C30 Code Development
Systems are complete ANSI C compilers for
Microchip’s PIC18 and PIC24 families of microcontrollers and the dsPIC30 and dsPIC33 family of digital signal controllers. These compilers provide powerful
integration capabilities, superior code optimization and
ease of use not found with other compilers.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
25.4
MPLINK Object Linker/
MPLIB Object Librarian
The MPLINK Object Linker combines relocatable
objects created by the MPASM Assembler and the
MPLAB C18 C Compiler. It can link relocatable objects
from precompiled libraries, using directives from a
linker script.
25.5
MPLAB ASM30 Assembler, Linker
and Librarian
MPLAB ASM30 Assembler produces relocatable
machine code from symbolic assembly language for
dsPIC30F devices. MPLAB C30 C Compiler uses the
assembler to produce its object file. The assembler
generates relocatable object files that can then be
archived or linked with other relocatable object files and
archives to create an executable file. Notable features
of the assembler include:
•
•
•
•
•
•
Support for the entire dsPIC30F instruction set
Support for fixed-point and floating-point data
Command line interface
Rich directive set
Flexible macro language
MPLAB IDE compatibility
25.6
MPLAB SIM Software Simulator
The MPLAB SIM Software Simulator allows code
development in a PC-hosted environment by simulating the PIC MCUs and dsPIC® DSCs on an instruction
level. On any given instruction, the data areas can be
examined or modified and stimuli can be applied from
a comprehensive stimulus controller. Registers can be
logged to files for further run-time analysis. The trace
buffer and logic analyzer display extend the power of
the simulator to record and track program execution,
actions on I/O, most peripherals and internal registers.
The MPLAB SIM Software Simulator fully supports
symbolic debugging using the MPLAB C18 and
MPLAB C30 C Compilers, and the MPASM and
MPLAB ASM30 Assemblers. The software simulator
offers the flexibility to develop and debug code outside
of the hardware laboratory environment, making it an
excellent, economical software development tool.
The MPLIB Object Librarian manages the creation and
modification of library files of precompiled code. When
a routine from a library is called from a source file, only
the modules that contain that routine will be linked in
with the application. This allows large libraries to be
used efficiently in many different applications.
The object linker/library features include:
• Efficient linking of single libraries instead of many
smaller files
• Enhanced code maintainability by grouping
related modules together
• Flexible creation of libraries with easy module
listing, replacement, deletion and extraction
DS39629C-page 346
© 2007 Microchip Technology Inc.
PIC18FXX90
25.7
MPLAB ICE 2000
High-Performance
In-Circuit Emulator
The MPLAB ICE 2000 In-Circuit Emulator is intended
to provide the product development engineer with a
complete microcontroller design tool set for PIC
microcontrollers. Software control of the MPLAB ICE
2000 In-Circuit Emulator is advanced by the MPLAB
Integrated Development Environment, 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 architecture of the MPLAB
ICE 2000 In-Circuit Emulator allows expansion to
support new PIC microcontrollers.
The MPLAB ICE 2000 In-Circuit Emulator system has
been designed as a real-time emulation system with
advanced features that are typically found on more
expensive development tools. The PC platform and
Microsoft® Windows® 32-bit operating system were
chosen to best make these features available in a
simple, unified application.
25.8
MPLAB REAL ICE In-Circuit
Emulator System
MPLAB REAL ICE In-Circuit Emulator System is
Microchip’s next generation high-speed emulator for
Microchip Flash DSC and MCU devices. It debugs and
programs PIC® Flash MCUs and dsPIC® Flash DSCs
with the easy-to-use, powerful graphical user interface of
the MPLAB Integrated Development Environment (IDE),
included with each kit.
The MPLAB REAL ICE probe is connected to the design
engineer’s PC using a high-speed USB 2.0 interface and
is connected to the target with either a connector
compatible with the popular MPLAB ICD 2 system
(RJ11) or with the new high-speed, noise tolerant, LowVoltage Differential Signal (LVDS) interconnection
(CAT5).
25.9
MPLAB ICD 2 In-Circuit Debugger
Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a
powerful, low-cost, run-time development tool,
connecting to the host PC via an RS-232 or high-speed
USB interface. This tool is based on the Flash PIC
MCUs and can be used to develop for these and other
PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes
the in-circuit debugging capability built into the Flash
devices. This feature, along with Microchip’s In-Circuit
Serial ProgrammingTM (ICSPTM) protocol, offers costeffective, 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 setting breakpoints, single stepping and watching variables, and CPU status and
peripheral registers. Running at full speed enables
testing hardware and applications in real time. MPLAB
ICD 2 also serves as a development programmer for
selected PIC devices.
25.10 MPLAB PM3 Device Programmer
The MPLAB PM3 Device Programmer is a universal,
CE compliant device programmer with programmable
voltage verification at VDDMIN and VDDMAX for
maximum reliability. It features a large LCD display
(128 x 64) for menus and error messages and a modular, detachable socket assembly to support various
package types. The ICSP™ cable assembly is included
as a standard item. In Stand-Alone mode, the MPLAB
PM3 Device Programmer can read, verify and program
PIC devices without a PC connection. It can also set
code protection in this mode. The MPLAB PM3
connects to the host PC via an RS-232 or USB cable.
The MPLAB PM3 has high-speed communications and
optimized algorithms for quick programming of large
memory devices and incorporates an SD/MMC card for
file storage and secure data applications.
MPLAB REAL ICE is field upgradeable through future
firmware downloads in MPLAB IDE. In upcoming
releases of MPLAB IDE, new devices will be supported,
and new features will be added, such as software breakpoints and assembly code trace. MPLAB REAL ICE
offers significant advantages over competitive emulators
including low-cost, full-speed emulation, real-time
variable watches, trace analysis, complex breakpoints, a
ruggedized probe interface and long (up to three meters)
interconnection cables.
© 2007 Microchip Technology Inc.
DS39629C-page 347
PIC18FXX90
25.11 PICSTART Plus Development
Programmer
25.13 Demonstration, Development and
Evaluation Boards
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
most PIC devices in DIP packages 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.
A wide variety of demonstration, development and
evaluation boards for various PIC MCUs and dsPIC
DSCs allows quick application development on fully functional systems. Most boards include prototyping areas for
adding custom circuitry and provide application firmware
and source code for examination and modification.
25.12 PICkit 2 Development Programmer
The PICkit™ 2 Development Programmer is a low-cost
programmer and selected Flash device debugger with
an easy-to-use interface for programming many of
Microchip’s baseline, mid-range and PIC18F families of
Flash memory microcontrollers. The PICkit 2 Starter Kit
includes a prototyping development board, twelve
sequential lessons, software and HI-TECH’s PICC™
Lite C compiler, and is designed to help get up to speed
quickly using PIC® microcontrollers. The kit provides
everything needed to program, evaluate and develop
applications using Microchip’s powerful, mid-range
Flash memory family of microcontrollers.
DS39629C-page 348
The boards support a variety of features, including LEDs,
temperature sensors, switches, speakers, RS-232
interfaces, LCD displays, potentiometers and additional
EEPROM memory.
The demonstration and development boards can be
used in teaching environments, for prototyping custom
circuits and for learning about various microcontroller
applications.
In addition to the PICDEM™ and dsPICDEM™ demonstration/development board series of circuits, Microchip
has a line of evaluation kits and demonstration software
for analog filter design, KEELOQ® security ICs, CAN,
IrDA®, PowerSmart battery management, SEEVAL®
evaluation system, Sigma-Delta ADC, flow rate
sensing, plus many more.
Check the Microchip web page (www.microchip.com)
for the complete list of demonstration, development
and evaluation kits.
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings(†)
Ambient temperature under bias.............................................................................................................-40°C to +125°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on any pin with respect to VSS (except VDD and MCLR) ................................................... -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
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 all ports .......................................................................................................................200 mA
Maximum current sourced by all ports ..................................................................................................................200 mA
Note 1: Power dissipation is calculated as follows:
Pdis = VDD x {IDD – ∑ IOH} + ∑ {(VDD – VOH) x IOH} + ∑(VOL x IOL)
2: Voltage spikes below VSS at the MCLR/VPP/RG5 pin, inducing currents greater than 80 mA, may cause
latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR/VPP/
RG5 pin, rather than pulling this pin directly to VSS.
† 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.
© 2007 Microchip Technology Inc.
DS39629C-page 349
PIC18F6390/6490/8390/8490
FIGURE 26-1:
PIC18F6390/6490/8390/8490 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V
5.5V
5.0V
PIC18FX390/X490
Voltage
4.5V
4.2V
4.0V
3.5V
3.0V
2.5V
2.0V
40 MHz
Frequency
FIGURE 26-2:
PIC18LF6390/6490/8390/8490 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V
5.5V
Voltage
5.0V
PIC18LFX390/X490
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 PIC® device in the application.
DS39629C-page 350
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.1
DC Characteristics:
Supply Voltage
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
D001
Symbol
VDD
Characteristic
Min
Typ
Max Units
PIC18LF6390/6490/8390/8490
2.0
—
5.5
V
PIC18F6390/6490/8390/8490
4.2
—
5.5
V
Supply Voltage
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
HS, XT, RC and LP Oscillator modes
See section on Power-on Reset for
details
V/ms See section on Power-on Reset for
details
PIC18LF6390/6490/8390/8490
BORV1:BORV0 = 11
2.00
2.05
2.16
V
BORV1:BORV0 = 10
2.65
2.79
2.93
V
D005
Legend:
Note 1:
Conditions
All devices
BORV1:BORV0 = 01
4.11
4.33
4.55
V
BORV1:BORV0 = 00
4.36
4.59
4.82
V
Shading of rows is to assist in readability of the table.
This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data.
© 2007 Microchip Technology Inc.
DS39629C-page 351
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
0.1
1
μA
-40°C
0.1
1
μA
+25°C
+85°C
Power-Down Current (IPD)(1)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
Legend:
Note 1:
2:
3:
4:
0.2
5
μA
0.1
2
μA
-40°C
0.1
2
μA
+25°C
+85°C
0.3
8
μA
0.1
2.0
μA
-40°C
0.1
2.0
μA
+25°C
0.4
15
μA
+85°C
VDD = 2.0V
(Sleep mode)
VDD = 3.0V
(Sleep mode)
VDD = 5.0V
(Sleep mode)
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
DS39629C-page 352
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
12
26
μA
-40°C
12
24
μA
+25°C
+85°C
Supply Current (IDD)(2)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
Legend:
Note 1:
2:
3:
4:
12
23
μA
32
50
μA
-40°C
27
48
μA
+25°C
+85°C
22
46
μA
84
134
μA
-40°C
82
128
μA
+25°C
72
128
μA
+85°C
.26
.8
mA
-40°C
.26
.8
mA
+25°C
.26
.8
mA
+85°C
.48
1.04
mA
-40°C
.44
.96
mA
+25°C
.48
.88
mA
+85°C
.88
1.84
mA
-40°C
.88
1.76
mA
+25°C
.8
1.68
mA
+85°C
VDD = 2.0V
VDD = 3.0V
FOSC = 31 kHz
(RC_RUN mode,
INTRC source)
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
FOSC = 1 MHz
(RC_RUN mode,
INTOSC source)
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
© 2007 Microchip Technology Inc.
DS39629C-page 353
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
0.6
1.7
mA
-40°C
0.6
1.6
mA
+25°C
+85°C
Supply Current (IDD)(2)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
Legend:
Note 1:
2:
3:
4:
0.6
1.5
mA
1.0
2.4
mA
-40°C
1.0
2.4
mA
+25°C
+85°C
1.0
2.4
mA
2.0
4.2
mA
-40°C
2.0
4
mA
+25°C
2.0
3.8
mA
+85°C
2.3
6.4
μA
-40°C
2.5
6.4
μA
+25°C
2.9
8.8
μA
+85°C
3.6
8.8
μA
-40°C
3.8
8.8
μA
+25°C
4.6
12
μA
+85°C
7.4
16
μA
-40°C
7.8
16
μA
+25°C
9.1
29
μA
+85°C
VDD = 2.0V
VDD = 3.0V
FOSC = 4 MHz
(RC_RUN mode,
INTOSC source)
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
FOSC = 31 kHz
(RC_IDLE mode,
INTRC source)
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
DS39629C-page 354
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
132
400
μA
-40°C
140
400
μA
+25°C
+85°C
Supply Current (IDD)(2)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
3:
4:
μA
μA
-40°C
216
600
μA
+25°C
252
+85°C
600
μA
1
mA
-40°C
0.42
1
mA
+25°C
0.44
1
mA
+85°C
272
700
μA
-40°C
280
700
μA
+25°C
288
700
μA
+85°C
PIC18LF6390/6490/8390/8490 0.416
1
mA
-40°C
0.432
1
mA
+25°C
0.464
1
mA
+85°C
.8
1.6
mA
-40°C
.9
1.6
mA
+25°C
.9
1.6
mA
+85°C
All devices
2:
400
600
All devices 0.40
PIC18LF6390/6490/8390/8490
Legend:
Note 1:
152
200
VDD = 2.0V
VDD = 3.0V
FOSC = 1 MHz
(RC_IDLE mode,
INTOSC source)
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
FOSC = 4 MHz
(RC_IDLE mode,
INTOSC source)
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
© 2007 Microchip Technology Inc.
DS39629C-page 355
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
250
500
μA
-40°C
260
500
μA
+25°C
+85°C
Supply Current (IDD)(2)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
μA
-40°C
480
650
μA
+25°C
460
650
μA
+85°C
1.2
1.6
mA
-40°C
1.1
1.5
mA
+25°C
1.4
mA
+85°C
2.0
mA
-40°C
0.74
2.0
mA
+25°C
0.74
2.0
mA
+85°C
1.3
3.0
mA
-40°C
1.3
3.0
mA
+25°C
All devices
All devices
3:
4:
μA
1.0
All devices
2:
500
650
PIC18LF6390/6490/8390/8490 0.72
PIC18LF6390/6490/8390/8490
Legend:
Note 1:
250
550
1.3
3.0
mA
+85°C
2.7
6.0
mA
-40°C
2.6
6.0
mA
+25°C
2.5
6.0
mA
+85°C
15
35
mA
-40°C
16
35
mA
+25°C
16
35
mA
+85°C
21
40
mA
-40°C
21
40
mA
+25°C
21
40
mA
+85°C
VDD = 2.0V
VDD = 3.0V
FOSC = 1 MHZ
(PRI_RUN,
EC oscillator)
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
FOSC = 4 MHz
(PRI_RUN,
EC oscillator)
VDD = 5.0V
VDD = 4.2V
FOSC = 40 MHZ
(PRI_RUN,
EC oscillator)
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
DS39629C-page 356
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
7.5
16
mA
-40°C
7.4
15
mA
+25°C
+85°C
Supply Current (IDD)(2)
All devices
All devices
All devices
All devices
Legend:
Note 1:
2:
3:
4:
7.3
14
mA
10
21
mA
-40°C
10
20
mA
+25°C
+85°C
9.7
19
mA
17
35
mA
-40°C
17
35
mA
+25°C
17
35
mA
+85°C
23
40
mA
-40°C
23
40
mA
+25°C
23
40
mA
+85°C
VDD = 4.2V
FOSC = 4 MHZ.
16 MHz internal
(PRI_RUN HS+PLL)
VDD = 5.0V
FOSC = 4 MHZ,
16 MHz internal
(PRI_RUN HS+PLL)
VDD = 4.2V
FOSC = 10 MHZ,
40 MHz internal
(PRI_RUN HS+PLL)
VDD = 5.0V
FOSC = 10 MHZ,
40 MHz internal
(PRI_RUN HS+PLL)
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
© 2007 Microchip Technology Inc.
DS39629C-page 357
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
Supply Current (IDD)(2)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
All devices
All devices
Legend:
Note 1:
2:
3:
4:
59
117
μA
-40°C
59
108
μA
+25°C
+85°C
63
104
μA
108
243
μA
-40°C
108
225
μA
+25°C
+85°C
117
216
μA
270
432
μA
-40°C
216
405
μA
+25°C
270
387
μA
+85°C
234
428
μA
-40°C
230
405
μA
+25°C
243
387
μA
+85°C
378
810
μA
-40°C
387
765
μA
+25°C
405
729
μA
+85°C
.8
1.35
mA
-40°C
.8
1.26
mA
+25°C
.8
1.17
mA
+85°C
5.4
14.4
mA
-40°C
5.6
14.4
mA
+25°C
5.9
14.4
mA
+85°C
7.3
16.2
mA
-40°C
8.2
16.2
mA
+25°C
7.5
16.2
mA
+85°C
VDD = 2.0V
VDD = 3.0V
FOSC = 1 MHz
(PRI_IDLE mode,
EC oscillator)
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
FOSC = 4 MHz
(PRI_IDLE mode,
EC oscillator)
VDD = 5.0V
VDD = 4.2V
FOSC = 40 MHz
(PRI_IDLE mode,
EC oscillator)
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
DS39629C-page 358
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
13
40
μA
-40°C
14
40
μA
+25°C
+80°C
Supply Current (IDD)(2)
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
PIC18LF6390/6490/8390/8490
PIC18LF6390/6490/8390/8490
All devices
Legend:
Note 1:
2:
3:
4:
16
40
μA
34
70
μA
-40°C
31
70
μA
+25°C
+80°C
28
70
μA
72
150
μA
-40°C
65
150
μA
+25°C
59
150
μA
+80°C
5.5
15
μA
-40°C
5.8
15
μA
+25°C
6.1
18
μA
+80°C
8.2
30
μA
-40°C
8.6
30
μA
+25°C
8.8
35
μA
+80°C
13
80
μA
-40°C
13
80
μA
+25°C
13
85
μA
+80°C
VDD = 2.0V
VDD = 3.0V
FOSC = 32 kHz
(SEC_RUN mode,
Timer1 as clock)(4)
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
FOSC = 32 kHz
(SEC_IDLE mode,
Timer1 as clock)(4)
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
© 2007 Microchip Technology Inc.
DS39629C-page 359
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔILCD, ΔIOSCB, ΔIAD)
Watchdog Timer
D022
(ΔIWDT)
D022A
(ΔIBOR)
D022B
(ΔILVD)
Brown-out Reset
High/Low-Voltage Detect
D024
(ΔILCD)
Legend:
Note 1:
2:
3:
4:
LCD Module
1.7
4
μA
-40°C
2.1
4
μA
+25°C
2.6
5
μA
+85°C
2.2
6
μA
-40°C
2.4
6
μA
+25°C
2.8
7
μA
+85°C
2.9
10
μA
-40°C
3.1
10
μA
+25°C
VDD = 2.0V
VDD = 3.0V
VDD = 5.0V
3.3
13
μA
+85°C
17
50
μA
-40°C to
+85°C
VDD = 3.0V
42
60
μA
-40°C to
+85°C
VDD = 5.0V
14
38
μA
-40°C to
+85°C
VDD = 2.0V
18
40
μA
-40°C to
+85°C
VDD = 3.0V
21
45
μA
-40°C to
+85°C
VDD = 5.0V
1.5
3
μA
-40°C
1.5
3
μA
+25°C
1.7
4
μA
+85°C
2.2
5
μA
-40°C
2.5
5
μA
+25°C
2.7
6
μA
+85°C
6.1
10
μA
-40°C
6.5
10
μA
+25°C
7.2
10
μA
+85°C
VDD = 2.0V
LCD on INTRC clock,
LCD segments enabled.
VDD = 3.0V
LCD on INTRC clock,
LCD segments enabled.
VDD = 5.0V
LCD on INTRC clock,
LCD segments enabled.
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
DS39629C-page 360
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.2
DC Characteristics:
Power-Down and Supply Current
PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Typ
Max
Units
Conditions
Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔILCD, ΔIOSCB, ΔIAD)
D025
(ΔIOSCB)
D026
(ΔIAD)
Timer1 Oscillator
A/D Converter
Legend:
Note 1:
2:
3:
4:
1.0
3.5
μA
-10°C
1.1
3.5
μA
+25°C
1.1
4.5
μA
+70°C
1.2
4.5
μA
-10°C
1.3
4.5
μA
+25°C
1.2
5.5
μA
+70°C
1.8
6.0
μA
-10°C
1.9
6.0
μA
+25°C
1.9
7.0
μA
+70°C
1.0
3.0
μA
1.0
4.0
μA
1.0
8.0
μA
VDD = 2.0V
32 kHz on Timer1(4)
VDD = 3.0V
32 kHz on Timer1(4)
VDD = 5.0V
32 kHz on Timer1(4)
—
VDD = 2.0V
A/D on, not converting
—
VDD = 3.0V
—
VDD = 5.0V
Shading of rows is to assist in readability of the table.
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 high-impedance state and tied to VDD or VSS and all features that
add delta current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin
loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have
an impact on the current consumption.
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 or VSS;
MCLR = VDD; WDT enabled/disabled as specified.
Low-power Timer1 oscillator selected.
BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be
less than the sum of both specifications.
© 2007 Microchip Technology Inc.
DS39629C-page 361
PIC18F6390/6490/8390/8490
26.3
DC Characteristics: PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS
Param
Symbol
No.
VIL
Characteristic
Min
Max
Units
Conditions
VSS
0.15 VDD
V
VDD < 4.5V
—
0.8
V
4.5V ≤ VDD ≤ 5.5V
VSS
VSS
0.2 VDD
0.3 VDD
V
V
Input Low Voltage
I/O Ports:
D030
with TTL Buffer
D030A
D031
with Schmitt Trigger Buffer
RC3 and RC4
D032
MCLR
VSS
0.2 VDD
V
D032A
OSC1 and T1OSI
VSS
0.3 VDD
V
LP, XT, HS, HSPLL
modes(1)
D033
OSC1
VSS
0.2 VDD
V
EC mode(1)
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
0.8 VDD
VDD
V
D042A
OSC1 and T1OSI
0.7 VDD
VDD
V
LP, XT, HS, HSPLL
modes(1)
D043
OSC1
0.8 VDD
VDD
V
EC mode(1)
—
±1
μA
VSS ≤ VPIN ≤ VDD,
Pin at hi-impedance
IIL
D060
Input Leakage Current(2,3)
I/O Ports
D061
MCLR
—
±5
μA
VSS ≤ VPIN ≤ VDD
D063
OSC1
—
±5
μA
VSS ≤ VPIN ≤ VDD
50
400
μA
VDD = 5V, VPIN = VSS
D070
Note 1:
2:
3:
4:
IPU
Weak Pull-up Current
IPURB
PORTB Weak Pull-up Current
In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PIC® device be driven with an external clock while in RC mode.
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.
Negative current is defined as current sourced by the pin.
Parameter is characterized but not tested.
DS39629C-page 362
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.3
DC Characteristics: PIC18F6390/6490/8390/8490 (Industrial)
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS
Param
Symbol
No.
VOL
Characteristic
Min
Max
Units
Conditions
Output Low Voltage
D080
I/O Ports
—
0.6
V
IOL = 8.5 mA, VDD = 4.5V,
-40°C to +85°C
D083
OSC2/CLKO
(RC, RCIO, EC, ECIO modes)
—
0.6
V
IOL = 1.6 mA, VDD = 4.5V,
-40°C to +85°C
VOH
Output High Voltage(3)
D090
I/O Ports
VDD – 0.7
—
V
IOH = -3.0 mA, VDD = 4.5V,
-40°C to +85°C
D092
OSC2/CLKO
(RC, RCIO, EC, ECIO modes)
VDD – 0.7
—
V
IOH = -1.3 mA, VDD = 4.5V,
-40°C to +85°C
—
8.5
V
RA4 pin
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
I2C™ Specification
D150
VOD
Open-Drain High Voltage
Capacitive Loading Specs
on Output Pins
Note 1:
2:
3:
4:
In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PIC® device be driven with an external clock while in RC mode.
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.
Negative current is defined as current sourced by the pin.
Parameter is characterized but not tested.
© 2007 Microchip Technology Inc.
DS39629C-page 363
PIC18F6390/6490/8390/8490
TABLE 26-1:
MEMORY PROGRAMMING REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC Characteristics
Param
No.
Sym
Characteristic
Min
Typ†
Max
Units
Conditions
10.0
—
12.0
V
—
—
1
mA
—
1K
—
E/W -40°C to +85°C
VMIN
—
5.5
Program Flash Memory
D110
VPP
Voltage on MCLR/VPP pin
D113
IDDP
Supply Current during
Programming
D130
EP
Cell Endurance
D131
VPR
VDD for Read
D132
VIE
V
VMIN = Minimum operating
voltage
VDD for Block Erase
2.75
—
5.5
V
Using ICSP™ port
D132A VIW
VDD for Externally Timed Erase
or Write
2.75
—
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)
2
—
—
ms
VDD > 4.5V
D133A TIW
Self-Timed Write Cycle Time
—
2
—
ms
40
100
—
D134
TIE
TRETD Characteristic Retention
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.
DS39629C-page 364
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
TABLE 26-2:
COMPARATOR SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C, unless otherwise stated.
Param
No.
Sym
Characteristics
Min
Typ
Max
Units
Comments
D300
VIOFF
Input Offset Voltage
—
±5.0
±10
mV
D301
VICM
Input Common Mode Voltage*
0
—
VDD – 1.5
V
D302
CMRR
Common Mode Rejection Ratio*
55
—
—
dB
300
TRESP
Response Time*(1)
—
150
400
ns
PIC18FXXXX
—
150
600
ns
PIC18LFXXXX,
VDD = 2.0V
—
—
10
μs
300A
301
*
Note 1:
TMC2OV
Comparator Mode Change to
Output Valid*
These parameters are characterized but not tested.
Response time measured with one comparator input at (VDD – 1.5)/2, while the other input transitions
from VSS to VDD.
TABLE 26-3:
VOLTAGE REFERENCE SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C, unless otherwise stated.
Param
No.
Sym
Characteristics
Min
Typ
Max
Units
D310
VRES
Resolution
VDD/24
—
VDD/32
LSb
D311
VRAA
Absolute Accuracy
—
—
1/2
LSb
D312
VRUR
Unit Resistor Value (R)
—
2k
—
Ω
TSET
Time(1)
—
—
10
μs
310
Note 1:
Settling
Comments
Settling time measured while CVRR = 1 and CVR3:CVR0 transitions from ‘0000’ to ‘1111’.
© 2007 Microchip Technology Inc.
DS39629C-page 365
PIC18F6390/6490/8390/8490
FIGURE 26-3:
HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
For VDIRMAG = 1:
VDD
VHLVD
(HLVDIF set by hardware)
(HLVDIF can be
cleared in software)
VHLVD
For VDIRMAG = 0:
VDD
HLVDIF
TABLE 26-4:
HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
Param
Sym
No.
D420
D423
Characteristic
HLVD Voltage on VDD
Transition High-to-Low
VBG
Band Gap Reference
Voltage Value
Min
Typ†
Max
Units
HLVDL<3:0> = 0000
2.06
2.17
2.28
V
HLVDL<3:0> = 0001
2.12
2.23
2.34
V
HLVDL<3:0> = 0010
2.24
2.36
2.48
V
HLVDL<3:0> = 0011
2.32
2.44
2.56
V
HLVDL<3:0> = 0100
2.47
2.60
2.73
V
HLVDL<3:0> = 0101
2.65
2.79
2.93
V
HLVDL<3:0> = 0110
2.74
2.89
3.04
V
HLVDL<3:0> = 0111
2.96
3.12
3.28
V
HLVDL<3:0> = 1000
3.22
3.39
3.56
V
HLVDL<3:0> = 1001
3.37
3.55
3.73
V
HLVDL<3:0> = 1010
3.52
3.71
3.90
V
HLVDL<3:0> = 1011
3.70
3.90
4.10
V
HLVDL<3:0> = 1100
3.90
4.11
4.32
V
HLVDL<3:0> = 1101
4.11
4.33
4.55
V
HLVDL<3:0> = 1110
4.36
4.59
4.82
V
HLVDL<3:0> = 1111
—
1.2
—
V
Conditions
HLVD input external.
† Production tested at TAMB = 25°C. Specifications over temperature limits ensured by characterization.
DS39629C-page 366
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.4
26.4.1
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 (High-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
© 2007 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
T13CKI
WR
P
R
V
Z
Period
Rise
Valid
High-impedance
High
Low
High
Low
SU
Setup
STO
Stop condition
DS39629C-page 367
PIC18F6390/6490/8390/8490
26.4.2
TIMING CONDITIONS
Note:
The temperature and voltages specified in Table 26-5
apply to all timing specifications unless otherwise
noted. Figure 26-4 specifies the load conditions for the
timing specifications.
TABLE 26-5:
Because of space limitations, the generic
terms “PIC18FXXXX” and “PIC18LFXXXX”
are used throughout this section to refer to
the PIC18F6390/6490/8390/8490 and
PIC18LF6390/6490/8390/8490 families of
devices specifically and only those devices.
TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC
AC CHARACTERISTICS
FIGURE 26-4:
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Operating voltage VDD range as described in DC spec Section 26.1 and
Section 26.3.
LF 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
DS39629C-page 368
CL = 50 pF
for all pins except OSC2/CLKO
and including D and E outputs as ports
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
26.4.3
TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 26-5:
EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)
Q4
Q1
Q2
Q3
Q4
Q1
OSC1
1
3
4
3
4
2
CLKO
TABLE 26-6:
Param.
No.
1A
EXTERNAL CLOCK TIMING REQUIREMENTS
Symbol
FOSC
Characteristic
Min
External CLKI Frequency(1)
DC
1
MHz
XT, RC Oscillator mode
DC
20
MHz
HS Oscillator mode
DC
31.25
kHz
LP Oscillator mode
DC
4
MHz
RC Oscillator mode
0.1
4
MHz
XT Oscillator mode
4
20
MHz
HS Oscillator mode
5
200
kHz
LP Oscillator mode
1000
—
ns
XT, RC Oscillator mode
50
—
ns
HS Oscillator mode
32
—
μs
LP Oscillator mode
250
—
ns
RC Oscillator mode
250
1
μs
XT Oscillator mode
100
250
ns
HS Oscillator mode
50
250
ns
HS Oscillator mode
5
—
μs
LP Oscillator mode
Oscillator Frequency
1
TOSC
(1)
External CLKI Period(1)
(1)
Oscillator Period
Max
Units
Conditions
2
TCY
Instruction Cycle Time(1)
100
—
ns
TCY = 4/FOSC
3
TOSL,
TOSH
External Clock in (OSC1)
High or Low Time
30
—
ns
XT Oscillator mode
2.5
—
μs
LP Oscillator mode
10
—
ns
HS Oscillator mode
4
Note 1:
TOSR,
TOSF
External Clock in (OSC1)
Rise or Fall Time
—
20
ns
XT Oscillator mode
—
50
ns
LP Oscillator mode
—
7.5
ns
HS Oscillator mode
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.
© 2007 Microchip Technology Inc.
DS39629C-page 369
PIC18F6390/6490/8390/8490
TABLE 26-7:
Param
No.
PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2V TO 5.5V)
Sym
Characteristic
Min
Typ†
Max
4
16
—
—
10
40
Units
F10
F11
FOSC Oscillator Frequency Range
FSYS On-Chip VCO System Frequency
F12
trc
PLL Start-up Time (Lock Time)
—
—
2
ms
ΔCLK
CLKO Stability (Jitter)
-2
—
+2
%
F13
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.
TABLE 26-8:
AC CHARACTERISTICS: INTERNAL RC ACCURACY
PIC18LF6390/6490/8390/8490 (INDUSTRIAL)
PIC18F6390/6490/8390/8490 (INDUSTRIAL)
PIC18LF6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
PIC18F6390/6490/8390/8490
(Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Param
No.
Device
Min
Typ
Max
Units
Conditions
INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz(1)
PIC18LF6390/6490/8390/8490
PIC18F6390/6490/8390/8490
-2
+/-1
2
%
+25°C
VDD = 2.7-3.3V
-5
—
5
%
-10°C to +85°C
VDD = 2.7-3.3V
-10
+/-1
10
%
-40°C to +85°C
VDD = 2.7-3.3V
-2
+/-1
2
%
+25°C
VDD = 4.5-5.5V
-5
—
5
%
-10°C to +85°C
VDD = 4.5-5.5V
-10
+/-1
10
%
-40°C to +85°C
VDD = 4.5-5.5V
INTRC Accuracy @ Freq = 31 kHz(2)
Legend:
Note 1:
2:
PIC18LF6390/6490/8390/8490 26.562
—
35.938
kHz
-40°C to +85°C
VDD = 2.7-3.3V
PIC18F6390/6490/8390/8490 26.562
—
35.938
kHz
-40°C to +85°C
VDD = 4.5-5.5V
Shading of rows is to assist in readability of the table.
Frequency calibrated at 25°C. OSCTUNE register can be used to compensate for temperature drift.
INTRC frequency after calibration.
DS39629C-page 370
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-6:
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)
Note:
20, 21
Refer to Figure 26-4 for load conditions.
TABLE 26-9:
Param
No.
New Value
Old Value
CLKO AND I/O TIMING REQUIREMENTS
Symbol
Characteristic
Min
Typ
Max
Units Conditions
10
TOSH2CKL OSC1 ↑ to CLKO ↓
—
75
200
ns
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
Port In Hold after CLKO ↑
17
TOSH2IOV OSC1↑ (Q1 cycle) to Port Out Valid
18
TOSH2IOI
18A
OSC1↑ (Q2 cycle) to
Port Input Invalid
(I/O in hold time)
0.25 TCY + 25
—
—
ns
(Note 1)
0
—
—
ns
(Note 1)
—
50
150
ns
PIC18FXXXX
100
—
—
ns
PIC18LFXXXX
200
—
—
ns
19
TIOV2OSH Port Input Valid to OSC1↑ (I/O in setup time)
0
—
—
ns
20
TIOR
Port Output Rise Time
20A
21
TIOF
Port Output Fall Time
21A
(Note 1)
PIC18FXXXX
—
10
25
ns
PIC18LFXXXX
—
—
60
ns
PIC18FXXXX
—
10
25
ns
PIC18LFXXXX
—
—
60
ns
22†
TINP
INTx pin High or Low Time
TCY
—
—
ns
23†
TRBP
RB7:RB4 Change INTx High or Low Time
TCY
—
—
ns
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
† 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.
© 2007 Microchip Technology Inc.
DS39629C-page 371
PIC18F6390/6490/8390/8490
FIGURE 26-7:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
VDD
MCLR
30
Internal
POR
33
PWRT
Time-out
32
Oscillator
Time-out
Internal
Reset
Watchdog
Timer
Reset
31
34
34
I/O pins
Note:
Refer to Figure 26-4 for load conditions.
FIGURE 26-8:
BROWN-OUT RESET TIMING
BVDD
VDD
35
VBGAP = 1.2V
VIRVST
Enable Internal
Reference Voltage
Internal Reference
Voltage Stable
36
TABLE 26-10: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
Symbol
No.
Characteristic
30
TMCL
MCLR Pulse Width (low)
31
TWDT
Watchdog Timer Time-out Period
(No postscaler)
32
TOST
Oscillator Start-up Timer Period
33
TPWRT
Power-up Timer Period
34
TIOZ
I/O High-Impedance from MCLR
Low or Watchdog Timer Reset
35
TBOR
Brown-out Reset Pulse Width
36
TIRVST
Time for Internal Reference
Voltage to become Stable
37
TLVD
Low-Voltage Detect Pulse Width
38
TCSD
CPU Start-up Time
39
TIOBST
Time for INTRC Block to Stabilize
DS39629C-page 372
Min
Typ
Max
Units
2
—
—
μs
3.4
4.0
4.6
ms
1024 TOSC
—
1024 TOSC
—
55.5
65.5
75
ms
—
2
—
μs
200
—
—
μs
—
20
50
μs
200
—
—
μs
—
10
—
μs
—
1
—
ms
Conditions
TOSC = OSC1 period
VDD ≤ BVDD (see D005)
VDD ≤ VLVD
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-9:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
41
40
42
T1OSO/T13CKI
46
45
47
48
TMR0 or
TMR1
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-11: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
No.
Symbol
Characteristic
40
TT0H
T0CKI High Pulse Width
No Prescaler
41
TT0L
T0CKI Low Pulse Width
No Prescaler
42
TT0P
T0CKI Period
No Prescaler
With Prescaler
With Prescaler
45
TT1H
—
ns
10
—
ns
0.5 TCY + 20
—
ns
—
ns
ns
With Prescaler
Greater of:
20 ns or
(TCY + 40)/N
—
ns
T13CKI
Synchronous, No Prescaler
High Time Synchronous,
PIC18FXXXX
with Prescaler
PIC18LFXXXX
0.5 TCY + 20
—
ns
10
—
ns
25
—
ns
30
—
ns
50
—
ns
0.5 TCY + 5
—
ns
PIC18FXXXX
T13CKI
Low Time
Synchronous, No Prescaler
Synchronous,
with Prescaler
PIC18FXXXX
10
—
ns
PIC18LFXXXX
25
—
ns
N = prescale
value
(1, 2, 4,..., 256)
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
PIC18FXXXX
30
—
ns
50
—
ns
VDD = 2.0V
Greater of:
20 ns or
(TCY + 40)/N
—
ns
N = prescale
value
(1, 2, 4, 8)
TT1P
T13CKI
Input
Period
FT 1
T13CKI Oscillator Input Frequency Range
Synchronous
TCKE2TMRI Delay from External T13CKI Clock Edge to
Timer Increment
© 2007 Microchip Technology Inc.
Conditions
PIC18LFXXXX
Asynchronous
48
0.5 TCY + 20
—
Asynchronous
47
Units
10
PIC18LFXXXX
TT1L
Max
TCY + 10
Asynchronous
46
Min
60
—
ns
DC
50
kHz
2 TOSC
7 TOSC
—
DS39629C-page 373
PIC18F6390/6490/8390/8490
FIGURE 26-10:
CAPTURE/COMPARE/PWM TIMINGS (ALL CCP MODULES)
CCPx
(Capture Mode)
50
51
52
CCPx
(Compare or PWM Mode)
53
Note:
54
Refer to Figure 26-4 for load conditions.
TABLE 26-12: CAPTURE/COMPARE/PWM REQUIREMENTS (ALL CCP MODULES)
Param
Symbol
No.
50
51
TCCL
TCCH
Characteristic
Min
Max
Units
CCPx Input Low No Prescaler
Time
With
PIC18FXXXX
Prescaler PIC18LFXXXX
0.5 TCY + 20
—
ns
10
—
ns
20
—
ns
CCPx Input
High Time
0.5 TCY + 20
—
ns
No Prescaler
With
Prescaler
52
TCCP
CCPx Input Period
53
TCCR
CCPx Output Fall Time
54
TCCF
CCPx Output Fall Time
DS39629C-page 374
Conditions
VDD = 2.0V
PIC18FXXXX
10
—
ns
PIC18LFXXXX
20
—
ns
VDD = 2.0V
3 TCY + 40
N
—
ns
N = prescale
value (1, 4 or 16)
PIC18FXXXX
—
25
ns
PIC18LFXXXX
—
45
ns
PIC18FXXXX
—
25
ns
PIC18LFXXXX
—
45
ns
VDD = 2.0V
VDD = 2.0V
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-11:
EXAMPLE SPI MASTER MODE TIMING (CKE = 0)
SS
70
SCK
(CKP = 0)
71
72
78
79
79
78
SCK
(CKP = 1)
80
bit 6 - - - - - - 1
MSb
SDO
LSb
75, 76
SDI
MSb In
bit 6 - - - - 1
LSb In
74
73
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-13: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Param
No.
Symbol
Characteristic
Min
Max Units
70
TSSL2SCH,
TSSL2SCL
SS ↓ to SCK ↓ or SCK ↑ Input
71
TSCH
SCK Input High Time
(Slave mode)
Continuous
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
SCK Input Low Time
(Slave mode)
Continuous
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
100
—
ns
1.5 TCY + 40
—
ns
100
—
ns
—
25
ns
71A
72
TSCL
72A
TCY
73
TDIV2SCH,
TDIV2SCL
Setup Time of SDI Data Input to SCK Edge
73A
TB2B
Last Clock Edge of Byte 1 to the 1st Clock Edge
of Byte 2
74
TSCH2DIL,
TSCL2DIL
Hold Time of SDI Data Input to SCK Edge
75
TDOR
SDO Data Output Rise Time
76
TDOF
SDO Data Output Fall Time
78
TSCR
SCK Output Rise Time
(Master mode)
PIC18FXXXX
PIC18LFXXXX
79
TSCF
80
TSCH2DOV, SDO Data Output Valid after
TSCL2DOV SCK Edge
Note 1:
2:
—
ns
—
45
ns
—
25
ns
PIC18FXXXX
—
25
ns
PIC18LFXXXX
—
45
ns
SCK Output Fall Time (Master mode)
Conditions
—
25
ns
PIC18FXXXX
—
50
ns
PIC18LFXXXX
—
100
ns
(Note 1)
(Note 1)
(Note 2)
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
Requires the use of Parameter #73A.
Only if Parameter #71A and #72A are used.
© 2007 Microchip Technology Inc.
DS39629C-page 375
PIC18F6390/6490/8390/8490
FIGURE 26-12:
EXAMPLE SPI MASTER MODE TIMING (CKE = 1)
SS
81
SCK
(CKP = 0)
71
72
79
73
SCK
(CKP = 1)
80
78
MSb
SDO
bit 6 - - - - - - 1
LSb
bit 6 - - - - 1
LSb In
75, 76
SDI
MSb In
74
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-14: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Param.
No.
71
Symbol
Characteristic
TSCH
SCK Input High Time
(Slave mode)
TSCL
SCK Input Low Time
(Slave mode)
73
TDIV2SCH,
TDIV2SCL
Setup Time of SDI Data Input to SCK Edge
73A
TB2B
Last Clock Edge of Byte 1 to the 1st Clock Edge
of Byte 2
74
TSCH2DIL,
TSCL2DIL
Hold Time of SDI Data Input to SCK Edge
75
TDOR
SDO Data Output Rise Time
76
TDOF
SDO Data Output Fall Time
78
TSCR
SCK Output Rise Time
(Master mode)
71A
72
72A
Continuous
Max Units
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
Continuous
1.25 TCY + 30
—
ns
Single Byte
PIC18FXXXX
PIC18LFXXXX
40
—
ns
100
—
ns
1.5 TCY + 40
—
ns
100
—
ns
—
25
ns
—
45
ns
—
25
ns
PIC18FXXXX
—
25
ns
PIC18LFXXXX
—
45
ns
79
TSCF
80
TSCH2DOV, SDO Data Output Valid after
TSCL2DOV SCK Edge
81
TDOV2SCH, SDO Data Output Setup to SCK Edge
TDOV2SCL
Note 1:
2:
Min
SCK Output Fall Time (Master mode)
PIC18FXXXX
PIC18LFXXXX
—
25
ns
—
50
ns
—
100
ns
TCY
—
ns
Conditions
(Note 1)
(Note 1)
(Note 2)
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
Requires the use of Parameter #73A.
Only if Parameter #71A and #72A are used.
DS39629C-page 376
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-13:
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
bit 6 - - - - - - 1
LSb
75, 76
MSb In
SDI
77
bit 6 - - - - 1
LSb In
74
73
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-15: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, 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
TCY
—
ns
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
Continuous
1.25 TCY + 30
—
ns
40
—
ns
100
—
ns
—
ns
100
—
ns
PIC18FXXXX
—
25
ns
PIC18LFXXXX
—
45
ns
—
25
ns
Continuous
Single Byte
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
76
TDOF
SDO Data Output Fall Time
Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40
77
TSSH2DOZ SS ↑ to SDO Output High-Impedance
78
TSCR
SCK Output Rise Time (Master mode)
79
TSCF
SCK Output Fall Time (Master mode)
80
TSCH2DOV, SDO Data Output Valid after SCK Edge PIC18FXXXX
TSCL2DOV
PIC18LFXXXX
83
Note 1:
2:
TSCH2SSH, SS ↑ after SCK Edge
TSCL2SSH
Max Units Conditions
10
50
ns
PIC18FXXXX
—
25
ns
PIC18LFXXXX
—
45
ns
—
25
ns
—
50
ns
—
100
ns
1.5 TCY + 40
—
ns
(Note 1)
(Note 1)
(Note 2)
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
Requires the use of Parameter #73A.
Only if Parameter #71A and #72A are used.
© 2007 Microchip Technology Inc.
DS39629C-page 377
PIC18F6390/6490/8390/8490
FIGURE 26-14:
EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)
82
SS
SCK
(CKP = 0)
70
83
71
72
SCK
(CKP = 1)
80
MSb
SDO
bit 6 - - - - - - 1
LSb
75, 76
SDI
MSb In
Note:
77
bit 6 - - - - 1
LSb In
74
Refer to Figure 26-4 for load conditions.
TABLE 26-16: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param
No.
Symbol
Characteristic
Min
Max Units Conditions
70
TSSL2SCH, SS ↓ to SCK ↓ or SCK ↑ Input
TSSL2SCL
71
TSCH
SCK Input High Time
(Slave mode)
TSCL
SCK Input Low Time
(Slave mode)
73A
TB2B
Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40
74
TSCH2DIL, Hold Time of SDI Data Input to SCK Edge
TSCL2DIL
75
TDOR
SDO Data Output Rise Time
76
TDOF
SDO Data Output Fall Time
77
78
71A
72
72A
TCY
—
ns
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
Continuous
1.25 TCY + 30
—
ns
Single Byte
40
—
ns
(Note 1)
—
ns
(Note 2)
100
—
ns
—
25
ns
Continuous
PIC18FXXXX
PIC18LFXXXX
—
45
ns
—
25
ns
TSSH2DOZ SS ↑ to SDO Output High-Impedance
10
50
ns
TSCR
SCK Output Rise Time
(Master mode)
—
25
ns
79
TSCF
SCK Output Fall Time (Master mode)
80
TSCH2DOV, SDO Data Output Valid after SCK
TSCL2DOV Edge
82
TSSL2DOV SDO Data Output Valid after SS ↓
Edge
83
TSCH2SSH, SS ↑ after SCK Edge
TSCL2SSH
Note 1:
2:
PIC18FXXXX
PIC18LFXXXX
—
45
ns
—
25
ns
PIC18FXXXX
—
50
ns
PIC18LFXXXX
—
100
ns
PIC18FXXXX
—
50
ns
—
100
ns
1.5 TCY + 40
—
ns
PIC18LFXXXX
(Note 1)
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
Requires the use of Parameter #73A.
Only if Parameter #71A and #72A are used.
DS39629C-page 378
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-15:
I2C™ BUS START/STOP BITS TIMING
SCL
91
93
90
92
SDA
Stop
Condition
Start
Condition
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-17: I2C™ BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
Param.
Symbol
No.
Characteristic
90
TSU:STA
Start Condition
91
THD:STA
92
TSU:STO
93
THD:STO Stop Condition
Max
Units
Conditions
4700
—
ns
Only relevant for Repeated
Start condition
ns
After this period, the first
clock pulse is generated
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
Hold Time
FIGURE 26-16:
100 kHz mode
Min
400 kHz mode
600
—
100 kHz mode
4000
—
400 kHz mode
600
—
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 26-4 for load conditions.
© 2007 Microchip Technology Inc.
DS39629C-page 379
PIC18F6390/6490/8390/8490
TABLE 26-18: I2C™ BUS DATA REQUIREMENTS (SLAVE MODE)
Param.
No.
100
Symbol
THIGH
101
TLOW
102
TR
103
TF
TSU:STA
90
Characteristic
Clock High Time
Clock Low Time
SDA and SCL Rise Time
SDA and SCL Fall Time
Min
Max
Units
Conditions
100 kHz mode
4.0
—
μs
PIC18FXXXX must operate at
a minimum of 1.5 MHz
400 kHz mode
0.6
—
μs
PIC18FXXXX must operate at
a minimum of 10 MHz
MSSP module
1.5 TCY
—
100 kHz mode
4.7
—
μs
PIC18FXXXX must operate at
a minimum of 1.5 MHz
400 kHz mode
1.3
—
μs
PIC18FXXXX must operate at
a minimum of 10 MHz
MSSP module
1.5 TCY
—
100 kHz mode
—
1000
ns
400 kHz mode
20 + 0.1 CB
300
ns
100 kHz mode
—
300
ns
400 kHz mode
20 + 0.1 CB
300
ns
CB is specified to be from
10 to 400 pF
Start Condition Setup Time 100 kHz mode
4.7
—
μs
400 kHz mode
0.6
—
μs
Only relevant for Repeated
Start condition
—
μs
91
THD:STA
Start Condition Hold Time
100 kHz mode
4.0
400 kHz mode
0.6
—
μs
106
THD:DAT
Data Input Hold Time
100 kHz mode
0
—
ns
400 kHz mode
0
0.9
μs
107
TSU:DAT
Data Input Setup Time
100 kHz mode
250
—
ns
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
Note 1:
2:
CB is specified to be from
10 to 400 pF
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
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.
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.
DS39629C-page 380
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-17:
MASTER SSP I2C™ BUS START/STOP BITS TIMING WAVEFORMS
SCL
93
91
90
92
SDA
Stop
Condition
Start
Condition
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-19: MASTER SSP I2C™ BUS START/STOP BITS REQUIREMENTS
Param.
Symbol
No.
90
TSU:STA
Characteristic
Start Condition
100 kHz mode
Setup Time
91
THD:STA Start Condition
Hold Time
92
TSU:STO Stop Condition
Setup Time
93
THD:STO Stop Condition
Hold Time
Note 1:
Min
Max
Units
2(TOSC)(BRG + 1)
—
ns
Only relevant for
Repeated Start
condition
ns
After this period, the
first clock pulse is
generated
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)
—
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
Maximum pin capacitance = 10 pF for all I2C™ pins.
FIGURE 26-18:
MASTER SSP I2C™ BUS DATA TIMING
103
102
100
101
SCL
90
106
91
107
92
SDA
In
109
109
110
SDA
Out
Note:
Refer to Figure 26-4 for load conditions.
© 2007 Microchip Technology Inc.
DS39629C-page 381
PIC18F6390/6490/8390/8490
TABLE 26-20: MASTER SSP I2C™ BUS DATA REQUIREMENTS
Param.
Symbol
No.
100
THIGH
Characteristic
Min
Max
Units
2(TOSC)(BRG + 1)
—
ms
2(TOSC)(BRG
+ 1)
—
ms
mode(1)
2(TOSC)(BRG + 1)
—
ms
Clock Low Time 100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
mode(1)
ms
Clock High Time 100 kHz mode
400 kHz mode
1 MHz
101
TLOW
1 MHz
102
103
90
91
106
107
92
TR
TF
TSU:STA
SDA and SCL
Rise Time
SDA and SCL
Fall Time
Start Condition
Setup Time
THD:STA Start Condition
Hold Time
THD:DAT Data Input
Hold Time
TSU:DAT
Data Input
Setup Time
TSU:STO Stop Condition
Setup Time
2(TOSC)(BRG + 1)
—
100 kHz mode
—
1000
ns
400 kHz mode
20 + 0.1 CB
300
ns
1 MHz mode(1)
—
300
ns
100 kHz mode
—
300
ns
400 kHz mode
20 + 0.1 CB
300
ns
1 MHz mode(1)
—
100
ns
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG
+ 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1)
2(TOSC)(BRG + 1)
—
ms
100 kHz mode
0
—
ns
400 kHz mode
0
0.9
ms
1 MHz mode(1)
—
—
ns
100 kHz mode
250
—
ns
400 kHz mode
100
—
ns
1 MHz mode(1)
—
—
ns
100 kHz mode
2(TOSC)(BRG + 1)
—
ms
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
mode(1)
2(TOSC)(BRG + 1)
—
ms
100 kHz mode
—
3500
ns
400 kHz mode
—
1000
ns
(1)
1 MHz mode
—
—
ns
100 kHz mode
4.7
—
ms
400 kHz mode
1.3
—
ms
1 MHz mode(1)
—
—
ms
—
400
pF
1 MHz
109
110
D102
Note 1:
2:
TAA
TBUF
CB
Output Valid
from Clock
Bus Free Time
Bus Capacitive Loading
Conditions
CB is specified to be from
10 to 400 pF
CB is specified to be from
10 to 400 pF
Only relevant for
Repeated Start
condition
After this period, the first
clock pulse is generated
(Note 2)
Time the bus must be free
before a new transmission
can start
Maximum pin capacitance = 10 pF for all I2C™ pins.
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.
DS39629C-page 382
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-19:
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
RC6/TX1/CK1
pin
121
121
RC7/RX1/DT1
pin
120
Note:
122
Refer to Figure 26-4 for load conditions.
TABLE 26-21: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Param
No.
Symbol
Characteristic
Min
TCKH2DTV SYNC XMIT (MASTER and SLAVE)
Clock High to Data Out Valid
PIC18FXXXX
120
PIC18LFXXXX
121
TCKRF
122
TDTRF
Max
Units
—
40
ns
—
100
ns
Clock Out Rise Time and Fall Time
(Master mode)
PIC18FXXXX
—
20
ns
PIC18LFXXXX
—
50
ns
Data Out Rise Time and Fall Time
PIC18FXXXX
—
20
ns
PIC18LFXXXX
—
50
ns
FIGURE 26-20:
Conditions
VDD = 2.0V
VDD = 2.0V
VDD = 2.0V
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
RC6/TX1/CK1
pin
125
RC7/RX1/DT1
pin
126
Note:
Refer to Figure 26-4 for load conditions.
TABLE 26-22: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Param.
No.
Symbol
Characteristic
125
TDTV2CKL SYNC RCV (MASTER and SLAVE)
Data Hold before CKx ↓ (DTx hold time)
126
TCKL2DTL
Data Hold after CKx ↓ (DTx hold time)
© 2007 Microchip Technology Inc.
Min
Max
Units
10
—
ns
15
—
ns
Conditions
DS39629C-page 383
PIC18F6390/6490/8390/8490
TABLE 26-23: A/D CONVERTER CHARACTERISTICS: PIC18F6390/6490/8390/8490 (INDUSTRIAL)
PIC18LF6390/6490/8390/8490 (INDUSTRIAL)
Param
Symbol
No.
Characteristic
Min
Typ
Max
Units
ΔVREF ≥ 3.0V
A01
NR
Resolution
—
—
10
A03
EIL
Integral Linearity Error
—
—
<±1
LSb ΔVREF ≥ 3.0V
A04
EDL
Differential Linearity Error
—
—
<±1
LSb ΔVREF ≥ 3.0V
A06
EOFF
Offset Error
—
—
<±1
LSb ΔVREF ≥ 3.0V
A07
EGN
Gain Error
—
—
<±1
LSb ΔVREF ≥ 3.0V
A10
—
Monotonicity
A20
ΔVREF
Reference Voltage Range
(VREFH – VREFL)
A21
VREFH
A22
A25
Guaranteed(1)
bit
Conditions
—
3
—
AVDD – AVSS
V
For 10-bit resolution
Reference Voltage High
AVSS + 3.0V
—
AVDD + 0.3V
V
For 10-bit resolution
VREFL
Reference Voltage Low
AVSS – 0.3V
—
AVDD – 3.0V
V
For 10-bit resolution
VAIN
Analog Input Voltage
VREFL
—
VREFH
V
A30
ZAIN
Recommended Impedance of
Analog Voltage Source
—
—
2.5
kΩ
A50
IREF
VREF Input Current (Note 2)
—
—
—
—
±5
±150
μA
μA
Note 1:
2:
During VAIN acquisition.
During A/D conversion
cycle.
The A/D conversion result never decreases with an increase in the input voltage and has no missing codes.
VREFH current is from RA3/AN3/VREF+/SEG17 pin or AVDD, whichever is selected as the VREFH source.
VREFL current is from RA2/AN2/VREF-/SEG16 pin or AVSS, whichever is selected as the VREFL source.
DS39629C-page 384
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
FIGURE 26-21:
A/D CONVERSION TIMING
BSF ADCON0, GO
(Note 2)
131
Q4
130
132
A/D CLK
9
A/D DATA
8
7
...
...
2
1
0
NEW_DATA
OLD_DATA
ADRES
TCY
ADIF
GO
DONE
SAMPLING STOPPED
SAMPLE
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.
TABLE 26-24: A/D CONVERSION REQUIREMENTS
Param
Symbol
No.
130
TAD
Characteristic
A/D Clock Period
Min
Max
Units
PIC18FXXXX
0.7
25.0(1)
μs
TOSC based, VREF ≥ 3.0V
PIC18LFXXXX
1.4
25.0(1)
μs
VDD = 2.0V;
TOSC based, VREF full range
PIC18FXXXX
TBD
1
μs
A/D RC mode
PIC18LFXXXX
TBD
3
μs
VDD = 2.0V; A/D RC mode
11
12
TAD
1.4
TBD
—
—
μs
μs
131
TCNV
Conversion Time
(not including acquisition time) (Note 2)
132
TACQ
Acquisition Time (Note 3)
135
TSWC
Switching Time from Convert → Sample
—
(Note 4)
TBD
TDIS
Discharge Time
0.2
—
Legend:
Note 1:
2:
3:
4:
Conditions
-40°C to +85°C
0°C ≤ to ≤ +85°C
μs
TBD = To Be Determined
The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
ADRES register may be read on the following TCY cycle.
The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale
after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50Ω.
On the following cycle of the device clock.
© 2007 Microchip Technology Inc.
DS39629C-page 385
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 386
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
27.0
DC AND AC
CHARACTERISTICS GRAPHS
AND TABLES
Graphs and tables are not available at this time.
© 2007 Microchip Technology Inc.
DS39629C-page 387
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 388
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
28.0
PACKAGING INFORMATION
28.1
Package Marking Information
64-Lead TQFP
Example
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
PIC18F6490
-I/PT e3
0710017
Example
80-Lead TQFP
XXXXXXXXXXXX
XXXXXXXXXXXX
YYWWNNN
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
PIC18F8490-E
/PT e3
0710017
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.
© 2007 Microchip Technology Inc.
DS39629C-page 389
PIC18F6390/6490/8390/8490
28.2
Package Details
The following sections give the technical details of the
packages.
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DS39629C-page 393
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 394
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
APPENDIX A:
REVISION HISTORY
Revision A (July 2004)
Original data sheet for PIC18F6390/6490/8390/8490
devices.
APPENDIX B:
DEVICE
DIFFERENCES
The differences between the devices listed in this data
sheet are shown in Table B-1.
Revision B (August 2004)
Updated preliminary “electrical characteristics” data.
Revision C (November 2007)
Revised I2C™ Slave Mode Timing figure. Updated DC
Power-Down and Supply Current table and package
drawings.
TABLE B-1:
DEVICE DIFFERENCES
Features
PIC18F6390
PIC18F6490
PIC18F8390
PIC18F8490
Number of Pixels the LCD Driver
can Drive
128 (4 x 32)
128 (4 x 32)
192 (4 x 48)
192 (4 x 48)
I/O Ports
Flash Program Memory
Packages
© 2007 Microchip Technology Inc.
Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E,
F, G
F, G
F, G, H, J
F, G, H, J
8 Kbytes
16 Kbytes
8 Kbytes
16 Kbytes
64-Pin TQFP
64-Pin TQFP
80-Pin TQFP
80-Pin TQFP
DS39629C-page 395
PIC18F6390/6490/8390/8490
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
DS39629C-page 396
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
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
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
PIC18C442.” 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
PIC18CXXX Migration.” This Application Note is
available as Literature Number DS00726.
This Application Note is available as Literature Number
DS00716.
© 2007 Microchip Technology Inc.
DS39629C-page 397
PIC18F6390/6490/8390/8490
NOTES:
DS39629C-page 398
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
INDEX
A
A/D ................................................................................... 231
A/D Converter Interrupt, Configuring ....................... 235
Acquisition Requirements ........................................ 236
ADCON0 Register .................................................... 231
ADCON1 Register .................................................... 231
ADCON2 Register .................................................... 231
ADRESH Register ............................................ 231, 234
ADRESL Register .................................................... 231
Analog Port Pins, Configuring .................................. 238
Associated Registers ............................................... 240
Automatic Acquisition Time ...................................... 237
Configuring the Module ............................................ 235
Conversion Clock (TAD) ........................................... 237
Conversion Status (GO/DONE Bit) .......................... 234
Conversions ............................................................. 239
Converter Characteristics ........................................ 384
Discharge ................................................................. 239
Operation in Power-Managed Modes ...................... 238
Special Event Trigger (CCP) .................................... 240
Use of the CCP2 Trigger .......................................... 240
Absolute Maximum Ratings ............................................. 349
AC (Timing) Characteristics ............................................. 367
Load Conditions for Device Timing
Specifications ................................................... 368
Parameter Symbology ............................................. 367
Temperature and Voltage Specifications ................. 368
Timing Conditions .................................................... 368
Access Bank ...................................................................... 73
Mapping with Indexed Literal Offset Mode ................. 86
ACKSTAT ........................................................................ 187
ACKSTAT Status Flag ..................................................... 187
ADCON0 Register ............................................................ 231
GO/DONE Bit ........................................................... 234
ADCON1 Register ............................................................ 231
ADCON2 Register ............................................................ 231
ADDFSR .......................................................................... 338
ADDLW ............................................................................ 301
Addressable Universal Synchronous Asynchronous
Receiver Transmitter (AUSART). See AUSART.
ADDULNK ........................................................................ 338
ADDWF ............................................................................ 301
ADDWFC ......................................................................... 302
ADRESH Register ............................................................ 231
ADRESL Register .................................................... 231, 234
Analog-to-Digital Converter. See A/D.
ANDLW ............................................................................ 302
ANDWF ............................................................................ 303
Assembler
MPASM Assembler .................................................. 346
AUSART
Asynchronous Mode ................................................ 222
Associated Registers, Receive ........................ 225
Associated Registers, Transmit ....................... 223
Receiver ........................................................... 224
Setting up 9-Bit Mode with
Address Detect ........................................ 224
Transmitter ....................................................... 222
© 2007 Microchip Technology Inc.
Baud Rate Generator (BRG) ................................... 220
Associated Registers ....................................... 220
Baud Rate Error, Calculating ........................... 220
Baud Rates, Asynchronous Modes ................. 221
High Baud Rate Select (BRGH Bit) ................. 220
Operation in Power-Managed Modes .............. 220
Sampling ......................................................... 220
Synchronous Master Mode ...................................... 226
Associated Registers, Receive ........................ 228
Associated Registers, Transmit ....................... 227
Reception ........................................................ 228
Transmission ................................................... 226
Synchronous Slave Mode ........................................ 229
Associated Registers, Receive ........................ 230
Associated Registers, Transmit ....................... 229
Reception ........................................................ 230
Transmission ................................................... 229
Auto-Wake-up on Sync Break Character ......................... 210
B
Bank Select Register (BSR) .............................................. 71
Baud Rate Generator ...................................................... 183
BC .................................................................................... 303
BCF ................................................................................. 304
BF .................................................................................... 187
BF Status Flag ................................................................. 187
Block Diagrams
A/D ........................................................................... 234
Analog Input Model .................................................. 235
AUSART Receive .................................................... 224
AUSART Transmit ................................................... 222
Baud Rate Generator .............................................. 183
Capture Mode Operation ......................................... 150
Comparator Analog Input Model .............................. 245
Comparator I/O Operating Modes ........................... 242
Comparator Output .................................................. 244
Comparator Voltage Reference ............................... 248
Compare Mode Operation ....................................... 151
Device Clock .............................................................. 36
EUSART Receive .................................................... 208
EUSART Transmit ................................................... 206
External Power-on Reset Circuit
(Slow VDD Power-up) ........................................ 53
Fail-Safe Clock Monitor ........................................... 290
Generic I/O Port Operation ...................................... 109
HLVD Module (with External Input) ......................... 252
Interrupt Logic ............................................................ 94
LCD Clock Generation ............................................. 262
LCD Driver Module .................................................. 257
LCD Resistor Ladder Connection ............................ 263
MSSP (I2C Master Mode) ........................................ 181
MSSP (I2C Mode) .................................................... 166
MSSP (SPI Mode) ................................................... 157
On-Chip Reset Circuit ................................................ 51
PLL (HS Mode) .......................................................... 33
PWM Operation (Simplified) .................................... 153
Reads from Flash Program Memory ......................... 88
Single Comparator ................................................... 243
Table Read Operation ............................................... 87
Timer0 in 16-Bit Mode ............................................. 132
DS39629C-page 399
PIC18F6390/6490/8390/8490
Timer0 in 8-Bit Mode ................................................ 132
Timer1 ...................................................................... 136
Timer1 (16-Bit Read/Write Mode) ............................ 136
Timer2 ...................................................................... 142
Timer3 ...................................................................... 144
Timer3 (16-Bit Read/Write Mode) ............................ 144
Voltage Reference Output Buffer Example .............. 249
Watchdog Timer ....................................................... 287
BN .................................................................................... 304
BNC .................................................................................. 305
BNN .................................................................................. 305
BNOV ............................................................................... 306
BNZ .................................................................................. 306
BOR. See Brown-out Reset.
BOV .................................................................................. 309
BRA .................................................................................. 307
Break Character (12-Bit) Transmit and Receive .............. 211
BRG. See Baud Rate Generator.
Brown-out Reset (BOR) ............................................. 54, 281
Disabling in Sleep Mode ............................................ 54
BSF .................................................................................. 307
BSR .................................................................................... 86
BTFSC ............................................................................. 308
BTFSS .............................................................................. 308
BTG .................................................................................. 309
BZ ..................................................................................... 310
C
C Compilers
MPLAB C18 ............................................................. 346
MPLAB C30 ............................................................. 346
CALL ................................................................................ 310
CALLW ............................................................................. 339
Capture (CCP Module) ..................................................... 150
Associated Registers ............................................... 152
CCP Pin Configuration ............................................. 150
CCPR2H:CCPR2L Registers ................................... 150
Software Interrupt .................................................... 150
Timer1/Timer3 Mode Selection ................................ 150
Capture/Compare/PWM (CCP) ........................................ 147
Capture Mode. See Capture.
CCP Mode and Timer Resources ............................ 148
CCPRxH Register .................................................... 148
CCPRxL Register ..................................................... 148
Compare Mode. See Compare.
Interaction of CCP1 and CCP2 for
Timer Resources .............................................. 149
Interconnect Configurations ..................................... 148
Module Configuration ............................................... 148
Clock Sources .................................................................... 36
Selecting the 31 kHz Source ...................................... 37
Selection Using OSCCON Register ........................... 37
CLRF ................................................................................ 311
CLRWDT .......................................................................... 311
Code Examples
16 x 16 Signed Multiply Routine ................................ 92
16 x 16 Unsigned Multiply Routine ............................ 92
8 x 8 Signed Multiply Routine .................................... 91
8 x 8 Unsigned Multiply Routine ................................ 91
Changing Between Capture Prescalers ................... 150
Computed GOTO Using an Offset Value ................... 68
Fast Register Stack .................................................... 68
How to Clear RAM (Bank 1) Using
Indirect Addressing ............................................ 81
Implementing a Real-Time Clock Using
a Timer1 Interrupt Service ............................... 139
DS39629C-page 400
Initializing PORTA .................................................... 109
Initializing PORTB .................................................... 112
Initializing PORTC ................................................... 115
Initializing PORTD ................................................... 118
Initializing PORTE .................................................... 120
Initializing PORTF .................................................... 122
Initializing PORTG ................................................... 125
Initializing PORTH ................................................... 127
Initializing PORTJ .................................................... 129
Loading the SSPBUF (SSPSR) Register ................. 160
Reading a Flash Program Memory Word .................. 89
Saving STATUS, WREG and BSR
Registers in RAM ............................................. 108
Code Protection ............................................................... 281
COMF .............................................................................. 312
Comparator ...................................................................... 241
Analog Input Connection Considerations ................ 245
Associated Registers ............................................... 245
Configuration ........................................................... 242
Effects of a Reset .................................................... 244
Interrupts ................................................................. 244
Operation ................................................................. 243
Operation During Sleep ........................................... 244
Outputs .................................................................... 243
Reference ................................................................ 243
External Signal ................................................ 243
Internal Signal .................................................. 243
Response Time ........................................................ 243
Comparator Specifications ............................................... 365
Comparator Voltage Reference ....................................... 247
Accuracy and Error .................................................. 248
Associated Registers ............................................... 249
Configuring .............................................................. 247
Connection Considerations ...................................... 248
Effects of a Reset .................................................... 248
Operation During Sleep ........................................... 248
Compare (CCP Module) .................................................. 151
Associated Registers ............................................... 152
CCP Pin Configuration ............................................. 151
CCPR2 Register ...................................................... 151
Software Interrupt .................................................... 151
Special Event Trigger .............................. 145, 151, 240
Timer1/Timer3 Mode Selection ................................ 151
Computed GOTO ............................................................... 68
Configuration Bits ............................................................ 281
Configuration Register Protection .................................... 292
Context Saving During Interrupts ..................................... 108
Conversion Considerations .............................................. 396
CPFSEQ .......................................................................... 312
CPFSGT .......................................................................... 313
CPFSLT ........................................................................... 313
Crystal Oscillator/Ceramic Resonator ................................ 31
Customer Change Notification Service ............................ 409
Customer Notification Service ......................................... 409
Customer Support ............................................................ 409
D
Data Addressing Modes .................................................... 81
Comparing Addressing Modes with the
Extended Instruction Set Enabled ..................... 85
Direct ......................................................................... 81
Indexed Literal Offset ................................................ 84
Indirect ....................................................................... 81
Inherent and Literal .................................................... 81
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
Data Memory ..................................................................... 71
Access Bank .............................................................. 73
and the Extended Instruction Set ............................... 84
Bank Select Register (BSR) ....................................... 71
General Purpose Registers ........................................ 73
Map for PIC18F6X90/8X90 Devices .......................... 72
Special Function Registers ........................................ 74
DAW ................................................................................. 314
DC and AC Characteristics
Graphs and Tables .................................................. 387
DC Characteristics ........................................................... 362
Power-Down and Supply Current ............................ 352
Supply Voltage ......................................................... 351
DCFSNZ .......................................................................... 315
DECF ............................................................................... 314
DECFSZ ........................................................................... 315
Development Support ...................................................... 345
Device Differences ........................................................... 395
Device Overview .................................................................. 7
Features (table) ............................................................ 9
New Core Features ...................................................... 7
Special Features .......................................................... 8
Direct Addressing ............................................................... 82
E
Effect on Standard Instructions .......................................... 84
Effect on Standard PIC MCU Instructions ........................ 342
Electrical Characteristics .................................................. 349
Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART). See EUSART.
Equations
A/D Acquisition Time ................................................ 236
A/D Minimum Charging Time ................................... 236
Calculating the Minimum Required
Acquisition Time .............................................. 236
Errata ................................................................................... 5
EUSART
Asynchronous Mode ................................................ 206
12-Bit Break Transmit and Receive ................. 211
Associated Registers, Receive ........................ 209
Associated Registers, Transmit ....................... 207
Auto-Wake-up on Sync Break ......................... 210
Receiver ........................................................... 208
Setting up 9-Bit Mode with
Address Detect ........................................ 208
Transmitter ....................................................... 206
Baud Rate Generator (BRG) .................................... 201
Associated Registers ....................................... 201
Auto-Baud Rate Detect .................................... 204
Baud Rate Error, Calculating ........................... 201
Baud Rates, Asynchronous Modes ................. 202
High Baud Rate Select (BRGH Bit) ................. 201
Operation in Power-Managed Modes .............. 201
Sampling .......................................................... 201
Synchronous Master Mode ...................................... 212
Associated Registers, Receive ........................ 214
Associated Registers, Transmit ....................... 213
Reception ......................................................... 214
Transmission ................................................... 212
Synchronous Slave Mode ........................................ 215
Associated Registers, Receive ........................ 216
Associated Registers, Transmit ....................... 215
Reception ......................................................... 216
Transmission ................................................... 215
© 2007 Microchip Technology Inc.
Extended Instruction Set
ADDFSR .................................................................. 338
ADDULNK ............................................................... 338
CALLW .................................................................... 339
MOVSF .................................................................... 339
MOVSS .................................................................... 340
PUSHL ..................................................................... 340
SUBFSR .................................................................. 341
SUBULNK ................................................................ 341
External Clock Input ........................................................... 32
F
Fail-Safe Clock Monitor ........................................... 281, 290
Interrupts in Power-Managed Modes ...................... 291
POR or Wake from Sleep ........................................ 291
WDT During Oscillator Failure ................................. 290
Fast Register Stack ........................................................... 68
Firmware Instructions ...................................................... 295
Flash Program Memory ..................................................... 87
Associated Registers ................................................. 89
Control Registers ....................................................... 88
TABLAT (Table Latch) Register ........................ 88
TBLPTR (Table Pointer) Register ...................... 88
Reading ..................................................................... 88
Table Reads .............................................................. 87
FSCM. See Fail-Safe Clock Monitor.
G
GOTO .............................................................................. 316
H
Hardware Multiplier ............................................................ 91
Introduction ................................................................ 91
Operation ................................................................... 91
Performance Comparison .......................................... 91
High/Low-Voltage Detect ................................................. 251
Applications ............................................................. 254
Typical Low-Voltage Detect (diagram) ............ 254
Associated Registers ............................................... 255
Characteristics ......................................................... 366
Current Consumption .............................................. 253
Effects of a Reset .................................................... 255
Operation ................................................................. 252
During Sleep .................................................... 255
Setup ....................................................................... 253
Start-up Time ........................................................... 253
HLVD. See High/Low-Voltage Detect. ............................. 251
I
I/O Ports .......................................................................... 109
I2C Mode (MSSP)
Acknowledge Sequence Timing .............................. 190
Associated Registers ............................................... 196
Baud Rate Generator .............................................. 183
Bus Collision
During a Repeated Start Condition .................. 194
During a Start Condition .................................. 192
During a Stop Condition .................................. 195
Clock Arbitration ...................................................... 184
Clock Stretching ...................................................... 176
10-Bit Slave Receive Mode (SEN = 1) ............ 176
10-Bit Slave Transmit Mode ............................ 176
7-Bit Slave Receive Mode (SEN = 1) .............. 176
7-Bit Slave Transmit Mode .............................. 176
DS39629C-page 401
PIC18F6390/6490/8390/8490
Effect of a Reset ...................................................... 191
General Call Address Support ................................. 180
I2C Clock Rate w/BRG ............................................. 183
Master Mode ............................................................ 181
Operation ......................................................... 182
Reception ......................................................... 187
Repeated Start Condition Timing ..................... 186
Start Condition ................................................. 185
Transmission .................................................... 187
Transmit Sequence .......................................... 182
Multi-Master Communication, Bus Collision
and Arbitration .................................................. 191
Multi-Master Mode ................................................... 191
Operation ................................................................. 170
Read/Write Bit Information (R/W Bit) ............... 170, 171
Registers .................................................................. 166
Serial Clock (RC3/SCK/SCL) ................................... 171
Slave Mode .............................................................. 170
Addressing ....................................................... 170
Reception ......................................................... 171
Sleep Operation ....................................................... 191
Stop Condition Timing .............................................. 190
Transmission ............................................................ 171
ID Locations ............................................................. 281, 293
INCF ................................................................................. 316
INCFSZ ............................................................................ 317
In-Circuit Debugger .......................................................... 293
In-Circuit Serial Programming (ICSP) ...................... 281, 293
Indexed Literal Offset Addressing Mode .......................... 342
and Standard PIC18 Instructions ............................. 342
Indexed Literal Offset Mode ......................................... 84, 86
Indirect Addressing ............................................................ 82
INFSNZ ............................................................................ 317
Initialization Conditions for all Registers ...................... 59–64
Instruction Cycle ................................................................. 69
Clocking Scheme ....................................................... 69
Instruction Flow/Pipelining ................................................. 69
Instruction Set .................................................................. 295
ADDLW .................................................................... 301
ADDWF .................................................................... 301
ADDWF (Indexed Literal Offset mode) .................... 343
ADDWFC ................................................................. 302
ANDLW .................................................................... 302
ANDWF .................................................................... 303
BC ............................................................................ 303
BCF .......................................................................... 304
BN ............................................................................ 304
BNC ......................................................................... 305
BNN ......................................................................... 305
BNOV ....................................................................... 306
BNZ .......................................................................... 306
BOV ......................................................................... 309
BRA .......................................................................... 307
BSF .......................................................................... 307
BSF (Indexed Literal Offset mode) .......................... 343
BTFSC ..................................................................... 308
BTFSS ..................................................................... 308
BTG .......................................................................... 309
BZ ............................................................................ 310
CALL ........................................................................ 310
CLRF ........................................................................ 311
CLRWDT .................................................................. 311
COMF ...................................................................... 312
CPFSEQ .................................................................. 312
CPFSGT .................................................................. 313
CPFSLT ................................................................... 313
DS39629C-page 402
DAW ........................................................................ 314
DCFSNZ .................................................................. 315
DECF ....................................................................... 314
DECFSZ .................................................................. 315
Extended Instructions .............................................. 337
and Using MPLAB IDE Tools .......................... 344
Considerations when Enabling ........................ 342
Syntax .............................................................. 337
General Format ........................................................ 297
GOTO ...................................................................... 316
INCF ........................................................................ 316
INCFSZ .................................................................... 317
INFSNZ .................................................................... 317
IORLW ..................................................................... 318
IORWF ..................................................................... 318
LFSR ....................................................................... 319
MOVF ...................................................................... 319
MOVFF .................................................................... 320
MOVLB .................................................................... 320
MOVLW ................................................................... 321
MOVWF ................................................................... 321
MULLW .................................................................... 322
MULWF .................................................................... 322
NEGF ....................................................................... 323
NOP ......................................................................... 323
POP ......................................................................... 324
PUSH ....................................................................... 324
RCALL ..................................................................... 325
RESET ..................................................................... 325
RETFIE .................................................................... 326
RETLW .................................................................... 326
RETURN .................................................................. 327
RLCF ....................................................................... 327
RLNCF ..................................................................... 328
RRCF ....................................................................... 328
RRNCF .................................................................... 329
SETF ....................................................................... 329
SETF (Indexed Literal Offset mode) ........................ 343
SLEEP ..................................................................... 330
Standard Instructions ............................................... 295
SUBFWB ................................................................. 330
SUBLW .................................................................... 331
SUBWF .................................................................... 331
SUBWFB ................................................................. 332
SWAPF .................................................................... 332
TBLRD ..................................................................... 333
TBLWT .................................................................... 334
TSTFSZ ................................................................... 335
XORLW ................................................................... 335
XORWF ................................................................... 336
Summary Table ....................................................... 298
INTCON Register
RBIF Bit ................................................................... 112
INTCON Registers ............................................................. 95
Inter-Integrated Circuit. See I2C.
Internal Oscillator Block ..................................................... 34
Adjustment ................................................................. 34
INTIO Modes ............................................................. 34
INTOSC Output Frequency ....................................... 34
OSCTUNE Register ................................................... 34
Internal RC Oscillator
Use with WDT .......................................................... 287
Internet Address .............................................................. 409
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
Interrupt Sources ............................................................. 281
A/D Conversion Complete ....................................... 235
Capture Complete (CCP) ......................................... 150
Compare Complete (CCP) ....................................... 151
Interrupt-on-Change (RB7:RB4) .............................. 112
INTx Pin ................................................................... 108
PORTB, Interrupt-on-Change .................................. 108
TMR0 ....................................................................... 108
TMR0 Overflow ........................................................ 133
TMR1 Overflow ........................................................ 135
TMR2 to PR2 Match (PWM) .................................... 153
TMR3 Overflow ................................................ 143, 145
Interrupts ............................................................................ 93
Interrupts, Flag Bits
Interrupt-on-Change (RB7:RB4) Flag
(RBIF Bit) ......................................................... 112
INTOSC Frequency Drift .................................................... 34
INTOSC, INTRC. See Internal Oscillator Block.
IORLW ............................................................................. 318
IORWF ............................................................................. 318
IPR Registers ................................................................... 104
MOVWF ........................................................................... 321
MPLAB ASM30 Assembler, Linker, Librarian .................. 346
MPLAB ICD 2 In-Circuit Debugger .................................. 347
MPLAB ICE 2000 High-Performance
Universal In-Circuit Emulator ................................... 347
MPLAB Integrated Development
Environment Software ............................................. 345
MPLAB PM3 Device Programmer ................................... 347
MPLAB REAL ICE In-Circuit Emulator System ............... 347
MPLINK Object Linker/MPLIB Object Librarian ............... 346
MSSP
ACK Pulse ....................................................... 170, 171
Control Registers (general) ..................................... 157
I2C Mode. See I2C Mode.
Module Overview ..................................................... 157
SPI Master/Slave Connection .................................. 161
SPI Mode. See SPI Mode.
SSPBUF .................................................................. 162
SSPSR .................................................................... 162
MULLW ............................................................................ 322
MULWF ............................................................................ 322
L
N
LCD
NEGF ............................................................................... 323
NOP ................................................................................. 323
Associated Registers ............................................... 279
Bias Types ............................................................... 263
Clock Source Selection ............................................ 262
Configuring the Module ............................................ 278
Frame Frequency ..................................................... 264
Interrupts .................................................................. 276
LCDCON Register ................................................... 258
LCDDATA Register .................................................. 258
LCDPS Register ....................................................... 258
LCDSE Register ....................................................... 258
Multiplex Types ........................................................ 263
Operation During Sleep ........................................... 277
Pixel Control ............................................................. 264
Prescaler .................................................................. 262
Segment Enables ..................................................... 263
Waveform Generation .............................................. 264
LCDCON Register ........................................................... 258
LCDDATA Register .......................................................... 258
LCDPS Register ............................................................... 258
LP3:LP0 Bits ............................................................ 262
LCDSE Register ............................................................... 258
LFSR ................................................................................ 319
Liquid Crystal Display (LCD) Driver ................................. 257
Look-up Tables .................................................................. 68
M
Master Clear (MCLR) ......................................................... 53
Master Synchronous Serial Port (MSSP). See MSSP.
Memory Organization ......................................................... 65
Data Memory ............................................................. 71
Program Memory ....................................................... 65
Memory Programming Requirements .............................. 364
Microchip Internet Web Site ............................................. 409
Migration from Baseline to Enhanced Devices ................ 396
Migration from High-End to Enhanced Devices ............... 397
Migration from Mid-Range to Enhanced Devices ............ 397
MOVF ............................................................................... 319
MOVFF ............................................................................ 320
MOVLB ............................................................................ 320
MOVLW ........................................................................... 321
MOVSF ............................................................................ 339
MOVSS ............................................................................ 340
© 2007 Microchip Technology Inc.
O
Opcode Field Descriptions ............................................... 296
Oscillator Configuration ..................................................... 31
EC .............................................................................. 31
ECIO .......................................................................... 31
HS .............................................................................. 31
HSPLL ....................................................................... 31
Internal Oscillator Block ............................................. 34
INTIO1 ....................................................................... 31
INTIO2 ....................................................................... 31
LP .............................................................................. 31
RC ............................................................................. 31
RCIO .......................................................................... 31
XT .............................................................................. 31
Oscillator Selection .......................................................... 281
Oscillator Start-up Timer (OST) ........................... 39, 55, 281
Oscillator Switching ........................................................... 36
Oscillator Transitions ......................................................... 37
Oscillator, Timer1 ..................................................... 135, 145
Oscillator, Timer3 ............................................................. 143
P
Packaging ........................................................................ 389
Details ...................................................................... 390
Marking .................................................................... 389
PICSTART Plus Development Programmer .................... 348
PIE Registers ................................................................... 101
Pin Functions
AVDD .......................................................................... 29
AVDD .......................................................................... 19
AVSS .......................................................................... 29
AVSS .......................................................................... 19
COM0 .................................................................. 17, 25
LCDBIAS1 ........................................................... 17, 25
LCDBIAS2 ........................................................... 17, 25
LCDBIAS3 ........................................................... 17, 25
MCLR/VPP/RG5 ................................................... 12, 20
OSC1/CLKI/RA7 .................................................. 12, 20
OSC2/CLKO/RA6 ................................................ 12, 20
RA0/AN0 .............................................................. 13, 21
DS39629C-page 403
PIC18F6390/6490/8390/8490
RA1/AN1 .............................................................. 13, 21
RA2/AN2/VREF-/SEG16 ....................................... 13, 21
RA3/AN3/VREF+/SEG17 ...................................... 13, 21
RA4/T0CKI/SEG14 .............................................. 13, 21
RA5/AN4/HLVDIN/SEG15 ................................... 13, 21
RB0/INT0 ............................................................. 14, 22
RB1/INT1/SEG8 ................................................... 14, 22
RB2/INT2/SEG9 ................................................... 14, 22
RB3/INT3/SEG10 ................................................. 14, 22
RB4/KBI0/SEG11 ................................................. 14, 22
RB5/KBI1 ............................................................. 14, 22
RB6/KBI2/PGC .................................................... 14, 22
RB7/KBI3/PGD .................................................... 14, 22
RC0/T1OSO/T13CKI ........................................... 15, 23
RC1/T1OSI/CCP2 ................................................ 15, 23
RC2/CCP1/SEG13 ............................................... 15, 23
RC3/SCK/SCL ..................................................... 15, 23
RC4/SDI/SDA ...................................................... 15, 23
RC5/SDO/SEG12 ................................................ 15, 23
RC6/TX1/CK1 ...................................................... 15, 23
RC7/RX1/DT1 ...................................................... 15, 23
RD0/SEG0 ........................................................... 16, 24
RD1/SEG1 ........................................................... 16, 24
RD2/SEG2 ........................................................... 16, 24
RD3/SEG3 ........................................................... 16, 24
RD4/SEG4 ........................................................... 16, 24
RD5/SEG5 ........................................................... 16, 24
RD6/SEG6 ........................................................... 16, 24
RD7/SEG7 ........................................................... 16, 24
RE4/COM1 ........................................................... 17, 25
RE5/COM2 ........................................................... 17, 25
RE6/COM3 ........................................................... 17, 25
RE7/CCP2/SEG31 ............................................... 17, 25
RF0/AN5/SEG18 .................................................. 18, 26
RF1/AN6/C2OUT/SEG19 .................................... 18, 26
RF2/AN7/C1OUT/SEG20 .................................... 18, 26
RF3/AN8/SEG21 .................................................. 18, 26
RF4/AN9/SEG22 .................................................. 18, 26
RF5/AN10/CVREF/SEG23 .................................... 18, 26
RF6/AN11/SEG24 ................................................ 18, 26
RF7/SS/SEG25 .................................................... 18, 26
RG0/SEG30 ......................................................... 19, 27
RG1/TX2/CK2/SEG29 ......................................... 19, 27
RG2/RX2/DT2/SEG28 ......................................... 19, 27
RG3/SEG27 ......................................................... 19, 27
RG4/SEG26 ......................................................... 19, 27
RG5 ...................................................................... 19, 27
RH0/SEG47 ............................................................... 28
RH1/SEG46 ............................................................... 28
RH2/SEG45 ............................................................... 28
RH3/SEG44 ............................................................... 28
RH4/SEG40 ............................................................... 28
RH5/SEG41 ............................................................... 28
RH6/SEG42 ............................................................... 28
RH7/SEG43 ............................................................... 28
RJ0/SEG32 ................................................................ 29
RJ1/SEG33 ................................................................ 29
RJ2/SEG34 ................................................................ 29
RJ3/SEG35 ................................................................ 29
RJ4/SEG39 ................................................................ 29
RJ5/SEG38 ................................................................ 29
RJ6/SEG37 ................................................................ 29
RJ7/SEG36 ................................................................ 29
VDD ............................................................................. 29
VDD ............................................................................. 19
DS39629C-page 404
VSS ............................................................................ 29
VSS ............................................................................ 19
Pinout I/O Descriptions
PIC18F6X90 .............................................................. 12
PIC18F8X90 .............................................................. 20
PIR Registers ..................................................................... 98
PLL .................................................................................... 33
HSPLL Oscillator Mode ............................................. 33
Use with INTOSC ................................................ 33, 34
PLL Lock Time-out ............................................................. 55
POP ................................................................................. 324
POR. See Power-on Reset.
PORTA
Associated Registers ............................................... 111
LATA Register ......................................................... 109
PORTA Register ...................................................... 109
TRISA Register ........................................................ 109
PORTB
Associated Registers ............................................... 114
LATB Register ......................................................... 112
PORTB Register ...................................................... 112
RB7:RB4 Interrupt-on-Change Flag
(RBIF Bit) ......................................................... 112
TRISB Register ........................................................ 112
PORTC
Associated Registers ............................................... 117
LATC Register ......................................................... 115
PORTC Register ...................................................... 115
RC3/SCK/SCL Pin ................................................... 171
TRISC Register ........................................................ 115
PORTD
Associated Registers ............................................... 119
LATD Register ......................................................... 118
PORTD Register ...................................................... 118
TRISD Register ........................................................ 118
PORTE
Associated Registers ............................................... 121
LATE Register ......................................................... 120
PORTE Register ...................................................... 120
TRISE Register ........................................................ 120
PORTF
Associated Registers ............................................... 124
LATF Register .......................................................... 122
PORTF Register ...................................................... 122
TRISF Register ........................................................ 122
PORTG
Associated Registers ............................................... 126
LATG Register ......................................................... 125
PORTG Register ...................................................... 125
TRISG Register ....................................................... 125
PORTH
Associated Registers ............................................... 128
LATH Register ......................................................... 127
PORTH Register ...................................................... 127
TRISH Register ........................................................ 127
PORTJ
Associated Registers ............................................... 130
LATJ Register .......................................................... 129
PORTJ Register ....................................................... 129
TRISJ Register ........................................................ 129
Postscaler, WDT
Assignment (PSA Bit) .............................................. 133
Rate Select (T0PS2:T0PS0 Bits) ............................. 133
Switching Between Timer0 and WDT ...................... 133
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
Power-Managed Modes ..................................................... 41
and Multiple Sleep Commands .................................. 42
Effects on Clock Sources ........................................... 39
Entering ...................................................................... 41
Exiting Idle and Sleep Modes
by Reset ............................................................. 48
by WDT Time-out ............................................... 48
Without a Start-up Delay .................................... 48
Exiting Idle or Sleep Modes ....................................... 48
by Interrupt ......................................................... 48
Idle Modes ................................................................. 45
PRI_IDLE ........................................................... 46
Run Modes ................................................................. 42
PRI_RUN ........................................................... 42
RC_RUN ............................................................ 44
SEC_RUN .......................................................... 42
Selecting .................................................................... 41
Sleep Mode ................................................................ 45
Summary (table) ........................................................ 41
Power-on Reset (POR) .............................................. 53, 281
Oscillator Start-up Timer (OST) ................................. 55
Power-up Timer (PWRT) ................................... 55, 281
Time-out Sequence .................................................... 55
Power-up Delays ................................................................ 39
Power-up Timer (PWRT) ............................................. 39, 55
Prescaler, Capture ........................................................... 150
Prescaler, Timer0 ............................................................. 133
Assignment (PSA Bit) .............................................. 133
Rate Select (T0PS2:T0PS0 Bits) ............................. 133
Switching Between Timer0 and WDT ...................... 133
Prescaler, Timer2 ............................................................. 154
Program Counter ............................................................... 66
PCL, PCH and PCU Registers ................................... 66
PCLATH and PCLATU Registers .............................. 66
Program Memory
and Extended Instruction Set ..................................... 84
Instructions ................................................................. 70
Two-Word .......................................................... 70
Interrupt Vector .......................................................... 65
Map and Stack (diagram) ........................................... 65
Reset Vector .............................................................. 65
Program Verification and Code Protection ....................... 292
Associated Registers ............................................... 292
Programming, Device Instructions ................................... 295
Pulse-Width Modulation. See PWM (CCP Module).
PUSH ............................................................................... 324
PUSH and POP Instructions .............................................. 67
PUSHL ............................................................................. 340
PWM (CCP Module)
Associated Registers ............................................... 155
Duty Cycle ................................................................ 154
Example Frequencies/Resolutions .......................... 154
Period ....................................................................... 153
Setup for PWM Operation ........................................ 155
TMR2 to PR2 Match ................................................ 153
Q
Q Clock ............................................................................ 154
R
RAM. See Data Memory.
RC Oscillator ...................................................................... 33
RCIO Oscillator Mode ................................................ 33
RCALL ............................................................................. 325
RCON Register
Bit Status During Initialization .................................... 58
© 2007 Microchip Technology Inc.
Reader Response ............................................................ 410
Reading Program Memory and Other Locations ............. 292
Register File ....................................................................... 73
Register File Summary ................................................ 76–79
Registers
ADCON0 (A/D Control 0) ......................................... 231
ADCON1 (A/D Control 1) ......................................... 232
ADCON2 (A/D Control 2) ......................................... 233
BAUDCON1 (Baud Rate Control 1) ......................... 200
CCPxCON (CCPx Control) ...................................... 147
CMCON (Comparator Control) ................................ 241
CONFIG1H (Configuration 1 High) .......................... 282
CONFIG2H (Configuration 2 High) .......................... 284
CONFIG2L (Configuration 2 Low) ........................... 283
CONFIG3H (Configuration 3 High) .......................... 284
CONFIG4L (Configuration 4 Low) ........................... 285
CONFIG5L (Configuration 5 Low) ........................... 285
CVRCON (Comparator Voltage
Reference Control) .......................................... 247
DEVID1 (Device ID 1) .............................................. 286
DEVID2 (Device ID 2) .............................................. 286
HLVDCON (High/Low-Voltage
Detect Control) ................................................ 251
INTCON (Interrupt Control) ....................................... 95
INTCON2 (Interrupt Control 2) .................................. 96
INTCON3 (Interrupt Control 3) .................................. 97
IPR1 (Peripheral Interrupt Priority 1) ....................... 104
IPR2 (Peripheral Interrupt Priority 2) ....................... 105
IPR3 (Peripheral Interrupt Priority 3) ....................... 106
LCDCON (LCD Control) .......................................... 258
LCDDATAx (LCD Datax) ......................................... 261
LCDPS (LCD Phase) ............................................... 259
LCDSEx (LCD Segmentx Enable) ........................... 260
OSCCON (Oscillator Control) .................................... 38
OSCTUNE (Oscillator Tuning) ................................... 35
PIE1 (Peripheral Interrupt Enable 1) ....................... 101
PIE2 (Peripheral Interrupt Enable 2) ....................... 102
PIE3 (Peripheral Interrupt Enable 3) ....................... 103
PIR1 (Peripheral Interrupt Request (Flag) 1) ............. 98
PIR2 (Peripheral Interrupt Request (Flag) 2) ............. 99
PIR3 (Peripheral Interrupt Request (Flag) 3) ........... 100
RCON (Reset Control) ....................................... 52, 107
RCSTA1 (EUSART Receive
Status and Control) .......................................... 199
RCSTA2 (AUSART Receive
Status and Control) .......................................... 219
SSPCON1 (MSSP Control 1, I2C Mode) ................. 168
SSPCON1 (MSSP Control 1, SPI Mode) ................ 159
SSPCON2 (MSSP Control 2,
I2C Master Mode) ............................................ 169
SSPSTAT (MSSP Status, I2C Mode) ...................... 167
SSPSTAT (MSSP Status, SPI Mode) ...................... 158
STATUS .................................................................... 80
STKPTR (Stack Pointer) ............................................ 67
T0CON (Timer0 Control) ......................................... 131
T1CON (Timer1 Control) ......................................... 135
T2CON (Timer2 Control) ......................................... 141
T3CON (Timer3 Control) ......................................... 143
TXSTA1 (EUSART Transmit
Status and Control) .......................................... 198
TXSTA2 (AUSART Transmit
Status and Control) .......................................... 218
WDTCON (Watchdog Timer Control) ...................... 288
RESET ............................................................................. 325
DS39629C-page 405
PIC18F6390/6490/8390/8490
Reset .................................................................................. 51
MCLR Reset, during Power-Managed Modes ........... 51
MCLR Reset, Normal Operation ................................ 51
Power-on Reset (POR) .............................................. 51
Programmable Brown-out Reset (BOR) .................... 51
Stack Full Reset ......................................................... 51
Stack Underflow Reset .............................................. 51
Watchdog Timer (WDT) Reset ................................... 51
Resets .............................................................................. 281
RETFIE ............................................................................ 326
RETLW ............................................................................. 326
RETURN .......................................................................... 327
Return Address Stack ........................................................ 66
Return Stack Pointer (STKPTR) ........................................ 67
Revision History ............................................................... 395
RLCF ................................................................................ 327
RLNCF ............................................................................. 328
RRCF ............................................................................... 328
RRNCF ............................................................................. 329
S
SCK .................................................................................. 157
SDI ................................................................................... 157
SDO ................................................................................. 157
Serial Clock, SCK ............................................................. 157
Serial Data In (SDI) .......................................................... 157
Serial Data Out (SDO) ..................................................... 157
Serial Peripheral Interface. See SPI Mode.
SETF ................................................................................ 329
Slave Select (SS) ............................................................. 157
SLEEP .............................................................................. 330
Sleep
OSC1 and OSC2 Pin States ...................................... 39
Software Enabled BOR ...................................................... 54
Software Simulator (MPLAB SIM) .................................... 346
Special Event Trigger. See Compare (CCP Module).
Special Features of the CPU ............................................ 281
Special Function Registers ................................................ 74
Map ...................................................................... 74–75
SPI Mode (MSSP)
Associated Registers ............................................... 165
Bus Mode Compatibility ........................................... 165
Effects of a Reset ..................................................... 165
Enabling SPI I/O ...................................................... 161
Master Mode ............................................................ 162
Master/Slave Connection ......................................... 161
Operation ................................................................. 160
Serial Clock .............................................................. 157
Serial Data In ........................................................... 157
Serial Data Out ........................................................ 157
Slave Mode .............................................................. 163
Slave Select ............................................................. 157
Slave Select Synchronization .................................. 163
Sleep Operation ....................................................... 165
SPI Clock ................................................................. 162
Typical Connection .................................................. 161
SS .................................................................................... 157
SSPOV ............................................................................. 187
SSPOV Status Flag .......................................................... 187
SSPSTAT Register
R/W Bit ............................................................. 170, 171
Stack Full/Underflow Resets .............................................. 68
STATUS Register ............................................................... 80
SUBFSR ........................................................................... 341
SUBFWB .......................................................................... 330
SUBLW ............................................................................ 331
DS39629C-page 406
SUBULNK ........................................................................ 341
SUBWF ............................................................................ 331
SUBWFB ......................................................................... 332
SWAPF ............................................................................ 332
T
T0CON Register
PSA Bit .................................................................... 133
T0CS Bit .................................................................. 132
T0PS2:T0PS0 Bits ................................................... 133
T0SE Bit .................................................................. 132
Table Pointer Operations (table) ........................................ 88
Table Reads ...................................................................... 68
TBLRD ............................................................................. 333
TBLWT ............................................................................. 334
Time-out in Various Situations (table) ................................ 55
Timer0 .............................................................................. 131
16-Bit Mode Timer Reads and Writes ...................... 132
Associated Registers ............................................... 133
Clock Source Edge Select (T0SE Bit) ..................... 132
Clock Source Select (T0CS Bit) ............................... 132
Operation ................................................................. 132
Overflow Interrupt .................................................... 133
Prescaler. See Prescaler, Timer0.
Timer1 .............................................................................. 135
16-Bit Read/Write Mode .......................................... 137
Associated Registers ............................................... 139
Interrupt ................................................................... 138
Operation ................................................................. 136
Oscillator .......................................................... 135, 137
Layout Considerations ..................................... 138
Overflow Interrupt .................................................... 135
Resetting, Using a Special Event Trigger
Output (CCP) ................................................... 138
TMR1H Register ...................................................... 135
TMR1L Register ....................................................... 135
Use as a Real-Time Clock ....................................... 138
Timer2 .............................................................................. 141
Associated Registers ............................................... 142
Interrupt ................................................................... 142
Operation ................................................................. 141
Output ...................................................................... 142
PR2 Register ........................................................... 153
TMR2 to PR2 Match Interrupt .................................. 153
Timer3 .............................................................................. 143
16-Bit Read/Write Mode .......................................... 145
Associated Registers ............................................... 145
Operation ................................................................. 144
Oscillator .......................................................... 143, 145
Overflow Interrupt ............................................ 143, 145
Special Event Trigger (CCP) ................................... 145
TMR3H Register ...................................................... 143
TMR3L Register ....................................................... 143
Timing Diagrams
A/D Conversion ........................................................ 385
Acknowledge Sequence .......................................... 190
Asynchronous Reception ................................. 209, 225
Asynchronous Transmission ............................ 207, 223
Asynchronous Transmission
(Back-to-Back) ......................................... 207, 223
Automatic Baud Rate Calculation ............................ 205
Auto-Wake-up Bit (WUE) During
Normal Operation ............................................ 210
Auto-Wake-up Bit (WUE) During Sleep ................... 210
Baud Rate Generator with Clock Arbitration ............ 184
BRG Overflow Sequence ......................................... 205
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
BRG Reset Due to SDA Arbitration
During Start Condition ..................................... 193
Brown-out Reset (BOR) ........................................... 372
Bus Collision During a Repeated
Start Condition (Case 1) .................................. 194
Bus Collision During a Repeated
Start Condition (Case 2) .................................. 194
Bus Collision During a Start
Condition (SCL = 0) ......................................... 193
Bus Collision During a Start
Condition (SDA Only) ...................................... 192
Bus Collision During a Stop
Condition (Case 1) ........................................... 195
Bus Collision During a Stop
Condition (Case 2) ........................................... 195
Bus Collision for Transmit and Acknowledge ........... 191
Capture/Compare/PWM (All CCP Modules) ............ 374
CLKO and I/O .......................................................... 371
Clock Synchronization ............................................. 177
Clock/Instruction Cycle .............................................. 69
Example SPI Master Mode (CKE = 0) ..................... 375
Example SPI Master Mode (CKE = 1) ..................... 376
Example SPI Slave Mode (CKE = 0) ....................... 377
Example SPI Slave Mode (CKE = 1) ....................... 378
External Clock (All Modes Except PLL) ................... 369
Fail-Safe Clock Monitor ............................................ 291
High/Low-Voltage Detect Characteristics ................ 366
High-Voltage Detect Operation (VDIRMAG = 1) ...... 254
I2C Bus Data ............................................................ 379
I2C Bus Start/Stop Bits ............................................. 379
I2C Master Mode (7 or 10-Bit Transmission) ........... 188
I2C Master Mode (7-Bit Reception) .......................... 189
I2C Master Mode First Start Bit ................................ 185
I2C Slave Mode (10-Bit Reception, SEN = 0) .......... 174
I2C Slave Mode (10-Bit Reception, SEN = 1) .......... 179
I2C Slave Mode (10-Bit Transmission) ..................... 175
I2C Slave Mode (7-Bit Reception, SEN = 0) ............ 172
I2C Slave Mode (7-Bit Reception, SEN = 1) ............ 178
I2C Slave Mode (7-Bit Transmission) ....................... 173
I2C Slave Mode General Call Address
Sequence (7 or 10-Bit Addressing Mode) ........ 180
I2C Stop Condition Receive or Transmit Mode ........ 190
LCD Interrupt Timing in Quarter-Duty Cycle Drive ... 276
LCD Sleep Entry/Exit When SLPEN = 1 or
CS1:CS0 = 00 .................................................. 277
Low-Voltage Detect Operation (VDIRMAG = 0) ...... 253
Master SSP I2C Bus Data ........................................ 381
Master SSP I2C Bus Start/Stop Bits ........................ 381
PWM Output ............................................................ 153
Repeat Start Condition ............................................. 186
Reset, Watchdog Timer (WDT), Oscillator Start-up
Timer (OST) and Power-up Timer (PWRT) ..... 372
Send Break Character Sequence ............................ 211
Slave Synchronization ............................................. 163
Slow Rise Time (MCLR Tied to VDD,
VDD Rise > TPWRT) ............................................ 57
SPI Mode (Master Mode) ......................................... 162
SPI Mode (Slave Mode, CKE = 0) ........................... 164
SPI Mode (Slave Mode, CKE = 1) ........................... 164
Synchronous Reception
(Master Mode, SREN) ............................. 214, 228
Synchronous Transmission .............................. 212, 226
Synchronous Transmission
(Through TXEN) ...................................... 213, 227
© 2007 Microchip Technology Inc.
Time-out Sequence on POR w/PLL Enabled
(MCLR Tied to VDD) .......................................... 57
Time-out Sequence on Power-up
MCLR Not Tied to VDD, Case 1 ......................... 56
MCLR Not Tied to VDD, Case 2 ......................... 56
MCLR Tied to VDD, VDD Rise < TPWRT ............. 56
Timer0 and Timer1 External Clock .......................... 373
Transition for Entry to PRI_IDLE Mode ..................... 46
Transition for Entry to SEC_RUN Mode .................... 43
Transition for Entry to Sleep Mode ............................ 45
Transition for Two-Speed Start-up
(INTOSC to HSPLL) ........................................ 289
Transition for Wake from Idle to Run Mode ............... 46
Transition for Wake from Sleep (HSPLL) .................. 45
Transition from RC_RUN Mode to
PRI_RUN Mode ................................................. 44
Transition from SEC_RUN Mode to
PRI_RUN Mode (HSPLL) .................................. 43
Transition to RC_RUN Mode ..................................... 44
Type-A in 1/2 MUX, 1/2 Bias Drive .......................... 266
Type-A in 1/2 MUX, 1/3 Bias Drive .......................... 268
Type-A in 1/3 MUX, 1/2 Bias Drive .......................... 270
Type-A in 1/3 MUX, 1/3 Bias Drive .......................... 272
Type-A in 1/4 MUX, 1/3 Bias Drive .......................... 274
Type-A/Type-B in Static Drive ................................. 265
Type-B in 1/2 MUX, 1/2 Bias Drive .......................... 267
Type-B in 1/2 MUX, 1/3 Bias Drive .......................... 269
Type-B in 1/3 MUX, 1/2 Bias Drive .......................... 271
Type-B in 1/3 MUX, 1/3 Bias Drive .......................... 273
Type-B in 1/4 MUX, 1/3 Bias Drive .......................... 275
USART Synchronous Receive (Master/Slave) ........ 383
USART Synchronous Transmission
(Master/Slave) ................................................. 383
Timing Diagrams and Specifications
A/D Conversion Requirements ................................ 385
AC Characteristics - Internal RC Accuracy .............. 370
Capture/Compare/PWM Requirements
(All CCP Modules) ........................................... 374
CLKO and I/O Requirements ................................... 371
Example SPI Mode Requirements
(Master Mode, CKE = 0) .................................. 375
Example SPI Mode Requirements
(Master Mode, CKE = 1) .................................. 376
Example SPI Mode Requirements
(Slave Mode, CKE = 0) .................................... 377
Example SPI Slave Mode Requirements
(CKE = 1) ......................................................... 378
External Clock Requirements .................................. 369
I2C Bus Data Requirements (Slave Mode) .............. 380
I2C Bus Start/Stop Bits Requirements
(Slave Mode) ................................................... 379
Master SSP I2C Bus Data Requirements ................ 382
Master SSP I2C Bus Start/Stop Bits
Requirements .................................................. 381
PLL Clock ................................................................ 370
Reset, Watchdog Timer, Oscillator Start-up
Timer, Power-up Timer and Brown-out
Reset Requirements ........................................ 372
Timer0 and Timer1 External
Clock Requirements ........................................ 373
USART Synchronous Receive
Requirements .................................................. 383
USART Synchronous Transmission
Requirements .................................................. 383
DS39629C-page 407
PIC18F6390/6490/8390/8490
Top-of-Stack Access .......................................................... 66
TSTFSZ ............................................................................ 335
Two-Speed Start-up ................................................. 281, 289
Two-Word Instructions
Example Cases .......................................................... 70
TXSTA1 Register
BRGH Bit ................................................................. 201
TXSTA2 Register
BRGH Bit ................................................................. 220
W
V
Watchdog Timer (WDT) ........................................... 281, 287
Associated Registers ............................................... 288
Control Register ....................................................... 287
During Oscillator Failure .......................................... 290
Programming Considerations .................................. 287
WCOL ...................................................... 185, 186, 187, 190
WCOL Status Flag ................................... 185, 186, 187, 190
WWW Address ................................................................ 409
WWW, On-Line Support ...................................................... 5
Voltage Reference Specifications .................................... 365
X
XORLW ............................................................................ 335
XORWF ........................................................................... 336
DS39629C-page 408
© 2007 Microchip Technology Inc.
PIC18FXX90
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
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To register, access the Microchip web site at
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© 2007 Microchip Technology Inc.
DS39629C-page 409
PIC18FXX90
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
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Device: PIC18F6390/6490/8390/8490
Literature Number: DS39629C
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?
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7. How would you improve this document?
DS39629C-page 410
© 2007 Microchip Technology Inc.
PIC18F6390/6490/8390/8490
PIC18F6390/6490/8390/8490 PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
X
/XX
XXX
Device
Temperature
Range
Package
Pattern
Examples:
a)
b)
Device(1), (2)
PIC18F6390/6490/8390/8490,
PIC18F6390/6490/8390/8490T;
VDD range 4.2V to 5.5V
PIC18LF6390/6490/8390/8490,
PIC18LF6390/6490/8390/8490T;
VDD range 2.0V to 5.5V
Temperature Range
I
E
Package
PT =
Pattern
QTP, SQTP, Code or Special Requirements
(blank otherwise)
=
=
c)
PIC18LF6490-I/PT 301 = Industrial temp.,
TQFP package, Extended VDD limits,
QTP pattern #301.
PIC18F8490-I/PT = Industrial temp., TQFP
package, normal VDD limits.
PIC18F8490-E/PT = Extended temp., TQFP
package, normal VDD limits.
-40°C to +85°C (Industrial)
-40°C to +125°C (Extended)
TQFP (Thin Quad Flatpack)
© 2007 Microchip Technology Inc.
Note 1:
2:
F = Standard Voltage Range
LF = Wide Voltage Range
T = In tape and reel
DS39629C-page 411
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10/05/07
DS39629C-page 412
© 2007 Microchip Technology Inc.