Harold Hallikainen wrote:

> >What I want to do is compare the value in rmax (value increasing each
> >interrupt) with a fixed value in r1, read in at the beginning of the
> >program from some BCD switches.
> >
>         How about just setting the destination of the XOR to w instead of
> file?  this destroys w, but leaves your memory fine.
>
> >        movf    rmax,w          ; load w with max time count
> >        xorwf   r1,0           ; Set Z if equal, destroys W, maintains r1
> >        btfsc   _z              ; has the max time been reached

This will not destroy W because easy to do the same XORWF again and
restore W ;)

WBR Dmitry.
PS.
        movfw   A
        addwf   B,w
        xorwf   C,w
        skpnz
        ...             ;probably GOTO or CALL command

        xorwf   C,w     ;restore A+B in W
        ...