On Tue, 20 Aug 2002, Bob Ammerman wrote:

> Well great... and I figured you have a twelve instruction loop that would do
> 8 locations at a time.

The 12-instruction thing was just to prevent someone from writing a
program of 4096 CLRF's and claiming that's the fastest way to clear
memory. Also, 12 is that mystical number that Dmitry always manages to
encounter.

>
> Doing 4 at a time with 10 instructions:  execution time is roughly 2
> instructions per memory byte.
>
>     lfsr        0,0
>     movlw    0x0F
> loop:
>     clrf    POSTINC0
>     clrf    POSTINC0
>     clrf    POSTINC0
>     clrf    POSTINC0
>     btfsc      FSR0L,7
>     cpfseq    FSR0H
>     bra    loop

That'll do it! (Assuming that FSR0H:L rolls over from 0x000 to 0xfff).

Scott

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