Microchip Technology DM164134 Data Sheet

© 2006 Microchip Technology Inc.

DS41159E-page 203

; 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

CANCON, TempCANCON

; Save CANCON.WIN bits

; This is required to prevent CANCON

; from corrupting CAN buffer access

; in-progress while this interrupt

; occurred

MOVFF

CANSTAT, TempCANSTAT

; Save CANSTAT register

; This is required to make sure that

; we use same CANSTAT value rather

; than one changed by another CAN

; interrupt.

MOVF

TempCANSTAT, W

; Retrieve ICODE bits

ANDLW

b’00001110’

ADDWF

PCL, F

; Perform computed GOTO

; to corresponding interrupt cause

BRA

NoInterrupt

; 000 = No interrupt

BRA

ErrorInterrupt

; 001 = Error interrupt

BRA

TXB2Interrupt

; 010 = TXB2 interrupt

BRA

TXB1Interrupt

; 011 = TXB1 interrupt

BRA

TXB0Interrupt

; 100 = TXB0 interrupt

BRA

RXB1Interrupt

; 101 = RXB1 interrupt

BRA

RXB0Interrupt

; 110 = RXB0 interrupt

; 111 = Wake-up on interrupt

WakeupInterrupt

BCF

PIR3, WAKIF

; Clear the interrupt flag

;

; User code to handle wake-up procedure

;

;

; Continue checking for other interrupt source or return from here

…

NoInterrupt

…

; PC should never vector here. User may

; place a trap such as infinite loop or pin/port

; indication to catch this error.

ErrorInterrupt

BCF

PIR3, ERRIF

; Clear the interrupt flag

…

; Handle error.

RETFIE

TXB2Interrupt

BCF

PIR3, TXB2IF

; Clear the interrupt flag

GOTO

AccessBuffer

TXB1Interrupt

BCF

PIR3, TXB1IF

; Clear the interrupt flag

GOTO

AccessBuffer

TXB0Interrupt

BCF

PIR3, TXB0IF

; Clear the interrupt flag

GOTO

AccessBuffer

RXB1Interrupt

BCF

PIR3, RXB1IF

; Clear the interrupt flag

GOTO

Accessbuffer