Sorry, you are wrong!
Why?

Due to weird sublw because of after sublw you have
0 if you had 9
and 9 if you had 0. So the result will be bogus.

Imre


On Thu, 11 Jun 1998, James Cameron wrote:

> Clewer,Brian wrote:
> > >        move the byte to W
> > >        swap nibbles (swapf)
> > >        and with 0x0f
> > >        or with 0x30
> > >        send that byte
> > >
> > >        move the byte to W again
> > >        and with 0x0f
> > >        or with 0x30
> > >        send that byte
> > This is ok if you use the numbers 0 to 9 but it doesn't work if you
> > need HEX values from A to F.
> > Any more ideas?
>
> Yeah, you're right.  Good observation.
>
> Okay, time to factor out the nibble to hex ASCII digit stuff into
> it's own subroutine ...
>
> hex                             ; convert nibble to ascii hex
>         andlw   0x0f            ; keep only the right bits
>         movwf   tmp1            ; save it for later
>         sublw   0x09            ; subtract from nine
>         movf    tmp1,w          ; bring it back (leave carry alone)
>         btfsc   status,c        ; test result of subtraction
>                                 ; (maybe it's btfss, not sure!)
>         addlw   0x37            ; adjust to A-F
>         return
> hex_0
>         addlw   0x30            ; adjust to 0-9
>         return
>
> byte
>         movwf   tmp2            ; save the byte for later
>         swapf   tmp2,w          ; grab the high nibble back
>         call    hex             ; encode high nibble as hex ascii
>         call    send            ; send the byte in w to serial port
>         movf    tmp2,w          ; fetch the byte again
>         call    hex             ; encode low nibble
>         call    send            ; send the byte in w to serial port
>         return
>
> I've not tested that.
> It's probably wrong somewhere.
> I'm a beginner.
> Did it work?  ;-)
>
> --
> James Cameron                              (james.cameron@digital.com)
> Digital Equipment Corporation (Australia) Pty. Ltd. A.C.N. 000 446 800
>
>