John Payson wrote:

>
> If it's okay (or desirable) to have the result in W as well as F, it can be
> done safely in 4 cycles:
>
>         movlw   1
>         btfss   scanbit,7
>          rlf    scanbit,w
>         movwf   scanbit

Another variant.

        movfw   scanbit
        addwf   scanbit,f
        skpnz
        bsf     scanbit,0

After this W contain previous scan and scanbit contain next scan.

WBR Dmitry.