Michael S. Hagberg wrote:

> thanks scott, i made the change and am reposting, your message, i did a
> reply and forgot to see who it was being sent to, you must have your reply
> to set in the mail, i leave mine blank.
>
> here is an idea (not tested) 12 bytes of code no looping, and leaves x
> alone.
>
> michael
>
>     swapf    x,w
>     xorwf    x,w        ; xor nibbles, now we have only 4 bits to test
>     andlw    0F0h    ; clear lower nibble for counter
>     movwf    parity
>     btfsc    parity,4    ; test bits now
>     incf    parity,f
>     btfsc    parity,5
>     incf    parity,f
>     btfsc    parity,6
>     incf    parity,f
>     btfsc    parity,7
>     incf    parity,f
>
>     btfsc    parity,0    ; use this to test for parity

        rrf     x,w             ;x.A.B.C.D.E.F.G
        xorwf   x,w             ;x^A.A^B.B^C.C^D.D^E.E^F.F^G.G^H
        movwf   parity

        rrf     parity,w
        rlf     parity,f
        xorwf   parity,f

        swapf   parity,w
        xorwf   parity,f

        btfsc   parity,5
;...

WBR Dmitry.