From: Peter L. Peres <plp@ACTCOM.CO.IL>
Date: Tuesday, October 24, 2000 6:16 PM


>  cblock
>  Ftemp
>  end cblock
>
>  decf  INDF,w ; w = (2^(N%8))-1
>  movwf Ftemp  ; idem
>  addwf INDF,w ; w = 2^((N%8)+1)-1
>  xorwf INDF,w ; w = (2^(N%8))-1
>  subwf Ftemp,f ; Ftemp = (2^(N%8))-1 - (2^(N%8))-1
>  btfsc STATUS,Z
>  retlw 0 ; yes, INDF = 2^N
>  retlw 1 ; no, INDF = 2^N + K where K > 1
>
>Note: This relies on some kind of hash that may or may not fail in
certain
>cases. ;-)
>
>Peter
>


Ah!  And here's one that'll work on those pesky 12-bit cores
that don't have a "return" opcode!

Remember: write you routines so they're word-size independent.

John
--
John Patrick -- N9OU
E-mail: jpatrick@megsinet.net
Web: http://www.megsinet.net/~jpatrick

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
"[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other "[BUY]:","[AD]:" =Ads