Matt Marsh wrote :

>         movlw   d'1'
>         subwf   SEQ,w
>         addwf   PCL,f
>         goto    Sequence1
>         goto    Sequence2
>
> Where the idea was that it would take the value of SEQ (1 or 2),
> subtracts one from it to make it 0 or 1 and adds that to the
> program counter so that if SEQ=1 the next instruction executed
> would be 'goto Sequence1', and if SEQ=2 the next instruction
> executed would be 'goto Sequence2'. Again, this is a technique I'd
> read in my book, is this not reasonable/sensible?

Not for a two-way jump.

You could use something like :

  - set SEQ to h'00' to run seq1, and to h'01' to run seq2.
  - then :

  btfsc   SEQ,0        ; is bit 0 of SEQ cleared ?
  goto    Sequence2    ; No, run seq2
  ...                  ; Yes, seq1 code start here.
  ...

  goto    wherever...

Sequence2
  ...                  ; Seq2 code start here.

Do not fiddle with the PCL if you don't have to...

Jan-Erik.

PS.
Now the question that always comes up in these cases :-)
Why start learning using the old F84 PIC ? Any special
reason ? And don't ask here, read this page instead :
http://www.voti.nl/swp/index.html. :-) :-)

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