On Thu, Jun 26, 2003 at 05:43:23AM +0100, Sergio Masci wrote:
> If I understand correctly you are clocking in all bit 7's followed by all bit
> 6's down to all bit 0's
>
> Try the following:
>
>         acc = 0
>
>         for (int j=0; j<8; j++)
>         {        acc = (acc << 1) + count_one_bits(read_port())
>         }
>
> count_one_bits() could be implemented as a lookup table

It's more efficient to do directly. Each loop iteration can be
done in 15 cycles, if you unroll it and add the "acc=0" at the
begining, you get 15*8+1 = 121 cycles (and 121 program words).

Seems that it's the faster version.

    Daniel.

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