Thanks for you reply Andrew,

Paul has send me another example:
DATA_1:
  SETC            ; Carry is 1
  GOTO    D0_2

DATA_0:
  CLRC            ; Carry is 0
D0_2:
  RLF     DATA,F  ; Ripple carry in.

Wish I'll try first, but although thanks for the reply!

            Joep Schroen

----- Original Message -----
From: Andrew Warren <fastfwd@IX.NETCOM.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Monday, April 17, 2000 12:46 AM
Subject: Re: Shifting in Software


> Paul B. Webster VK2BZC <paulb@midcoast.com.au> wrote:
>
> > > I've got a problem, I need to make a shifting register in software.
> >
> > Arrange your receiveing line so that it corresponds to one end or
> > other of a register, e.g., PORTA.0 then to shift a bit from that
> > into DATA, use:
> >
> >   RRF     PORTA,W ; Ignore W, it's the carry we want
> >   RLF     DATA,F  ; This time, it ends up back in the register.
>
> Paul:
>
> That's fine, except that he needs the bits to shift into the register
> the OTHER way:
>
>     RRF     PORTA,W
>     RRF     DATA
>
> Joep:
>
> If you don't want to be forced to put your input on the edge of a
> port, you can put it on ANY port pin and do this:
>
>     #DEFINE INPUT   PORTA,2  ;or any other port.
>     ....
>         CLRC
>         BTFSC   INPUT
>         SETC
>         RRF     DATA
>
> After you've executed the above code 8 times, your "DATA" register is
> full and you can copy it to wherever it needs to go.
>
> -Andy
>
>
> === Andrew Warren - fastfwd@ix.netcom.com
> === Fast Forward Engineering - San Diego, California
> === http://www.geocities.com/SiliconValley/2499
>