Jason:

In my code example, I did not save and restore the W and STATUS
registers in the interrupt routine. Please refer to the PIC16C84 data
sheet, section 8.10, for an explaination of this. You must do this!

Dave

Dave Sorlien wrote:
>
> Jason:
>
> Your code is attempting to move a single bit into the W register. A
> simpler approach is as follows:
>
>                                         ; ***** THIS CODE IS INSIDE INTERRUPT
 ROUTINE *****
> one             btfss   _porta,bit1     ; is port B pin of interest = 0?
>                 goto    bit1_is_0       ;  yes
>
> bit1_is_1                               ; insert code to be executed if
 _porta,bit1 is 1
>                 goto    one_done        ; once finished
>
> bit1_is_0                               ; insert code to be executed if
 _porta,bit1 is 0
>
> one_done                                ; if other bits need testing, insert
 code here
>
> exit_int        bcf     intcon,1        ; clear TMR0 interrupt flag
>                 retfie                  ; interrupt done
>
> There is no need to mess with intcon,7 (GIE bit) because the interrupt
> routine cannot be "interrupted".
>
> Dave
>
> Jason A Alexander wrote:
> >
> > Hello all.  I am having a problem with some code I have written.