Wouter van Ooijen <wouter@voti.nl> wrote:
>Challenge (intermediate): write a JUMP <LABEL> macro for the 14-bit core
>PICs that jumps to the target address. The macro must handle code
>paging, hence it will in general expand to more than one instruction.
>When preceded by a skip instruction (for instance btfss or skpz) the
>JUMP macro must behave as a naive user would expect: the jump must not
>be taken, execution must proceed with the instruction after the JUMP.

I'd suggest something like this:

JUMP   MACRO    Target
       LOCAL    DoJump, NoJump

       goto     DoJump
       goto     NoJump
DoJump       
       PAGESEL  Target
       goto     Target
NoJump

       ENDM

It's a bit ugly, though.  The macro consumes 3-5 program words (*) each
time it is invoked, and the execution time is 4-6 cycles (*) if the jump
is taken and 3 cycles if it is skipped (excluding the skip instruction).

(*) depending on the number of the code pages in the device

Any better offers?
-- 
Ian Chapman
Chapmip Technology, UK
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