PIC18F258 MICROCHIP [Microchip Technology], PIC18F258 Datasheet - Page 203

• Manufacturer Part Number: PIC18F258
• Description: High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
• Manufacturer: MICROCHIP [Microchip Technology]

EXAMPLE 19-1:
 2002 Microchip Technology Inc.
WakeupInterrupt
NoInterrupt
ErrorInterrupt
TXB2Interrupt
TXB1Interrupt
TXB0Interrupt
RXB1Interrupt
; Save application required context.
; Poll interrupt flags and determine source of interrupt
; This was found to be CAN interrupt
; TempCANCON and TempCANSTAT are variables defined in Access Bank low
MOVFF
MOVFF
MOVF
ANDLW
ADDWF
BRA
BRA
BRA
BRA
BRA
BRA
BRA
BCF
;
; User code to handle wake-up procedure
;
;
; Continue checking for other interrupt source or return from here
…
…
BCF
…
RETFIE
BCF
GOTO
BCF
GOTO
BCF
GOTO
BCF
GOTO
CANCON, TempCANCON
CANSTAT, TempCANSTAT
TempCANSTAT, W
b’00001110’
PCL, F
NoInterrupt
ErrorInterrupt
TXB2Interrupt
TXB1Interrupt
TXB0Interrupt
RXB1Interrupt
RXB0Interrupt
PIR3, WAKIF
PIR3, ERRIF
PIR3, TXB2IF
AccessBuffer
PIR3, TXB1IF
AccessBuffer
PIR3, TXB0IF
AccessBuffer
PIR3, RXB1IF
Accessbuffer
WIN AND ICODE BITS USAGE IN INTERRUPT SERVICE ROUTINE TO ACCESS
TX/RX BUFFERS
Preliminary
; Save CANCON.WIN bits
; This is required to prevent CANCON
; from corrupting CAN buffer access
; in-progress while this interrupt
; occurred
; Save CANSTAT register
; This is required to make sure that
; we use same CANSTAT value rather
; than one changed by another CAN
; interrupt.
; Retrieve ICODE bits
; Perform computed GOTO
; to corresponding interrupt cause
; 000 = No interrupt
; 001 = Error interrupt
; 010 = TXB2 interrupt
; 011 = TXB1 interrupt
; 100 = TXB0 interrupt
; 101 = RXB1 interrupt
; 110 = RXB0 interrupt
; 111 = Wake-up on interrupt
; Clear the interrupt flag
; PC should never vector here. User may
; place a trap such as infinite loop or pin/port
; indication to catch this error.
; Clear the interrupt flag
; Handle error.
; Clear the interrupt flag
; Clear the interrupt flag
; Clear the interrupt flag
; Clear the interrupt flag
PIC18FXX8
DS41159B-page 201