Datasheet

 2010-2012 Microchip Technology Inc. DS39977F-page 397
PIC18F66K80 FAMILY
EXAMPLE 27-2: WIN AND ICODE BITS USAGE IN INTERRUPT SERVICE ROUTINE TO ACCESS
TX/RX BUFFERS (CONTINUED)
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
RXB0Interrupt
BCF PIR3, RXB0IF ; Clear the interrupt flag
GOTO AccessBuffer
AccessBuffer ; This is either TX or RX interrupt
; Copy CANSTAT.ICODE bits to CANCON.WIN bits
MOVF TempCANCON, W ; Clear CANCON.WIN bits before copying
; new ones.
ANDLW B’11110001’ ; Use previously saved CANCON value to
; make sure same value.
MOVWF TempCANCON ; Copy masked value back to TempCANCON
MOVF TempCANSTAT, W ; Retrieve ICODE bits
ANDLW B’00001110’ ; Use previously saved CANSTAT value
; to make sure same value.
IORWF TempCANCON ; Copy ICODE bits to WIN bits.
MOVFF TempCANCON, CANCON ; Copy the result to actual CANCON
; Access current buffer…
; User code
; Restore CANCON.WIN bits
MOVF CANCON, W ; Preserve current non WIN bits
ANDLW B’11110001’
IORWF TempCANCON ; Restore original WIN bits
; Do not need to restore CANSTAT - it is read-only register.
; Return from interrupt or check for another module interrupt source