Gerard Mantoux <Gerard.Mantoux@BULL.NET> wrote:
>
> Hi,
> I'am following PIC list for a while now, and after some small projects
> with
> 16C84, I want to build a 9 digits frequency counter (say beyond 100
> MHz).
> something that looks like Peter Alicky's counter, but with an external
> prescaler.
> Does any of you have very efficient routines for 4 bytes 32 bits) add
> and
> substract for 16C84? I mean efficient in term of size and/or speed
> MTIA
>  Gerard Mantoux                         email: gerard.mantoux@bull.net
>  [OPINIONS ARE MY OWN & DO NOT NECESSARILY REFLECT BULL POLICIES]

My TEA encryption routines have a 32 bit math macro file that does
exactly what you need (I hope at least :-). They have 32bit add,
subtract and move with literal and/or register operands.

You can find them on my site at http://members.tripod.com/~mdileo/
following the link to CryptoPIC inside a file called TEA13.ZIP.
HTH

Ciao
  Marco