On Sun, 2004-08-22 at 20:00, Matt Pobursky wrote:
> Herbert,
>
> Check the eZ80 datasheet -- I seem to recall that the internal flash
> has is quite slow and uses a bunch of wait states. Also make sure they
> are not using RAM with wait states. The external bus cycles at 50 MHz
> are pretty short and take some darn fast (and expensive) memories to
> run with few or no wait states.
>
> I ran into this same kind of problem with the Rabbit CPUs when they
> came out with their 44MHz R3000 chip. It only ran marginally faster
> than a 22MHz R2000 CPU. The cause was adding wait states because they
> used Flash that couldn't run with 0 wait states.
>
> Matt Pobursky
> Maximum Performance Systems

BINGO!!! Thank you so much Matt, I think you nailed it on the head!

I changed the config from "run from ROM" to "run from RAM" and BOOM,
twice the speed! My little ping toggles at 2-3 times the speed. Well, at
least now I know. Thank you all again for your help.

That said, I guess it really shows how much more efficient a PIC can be
(even with a /4 of the main clock) for simple IO stuff.

This thing is still gonna run slower then I was expecting, so I guess
I'll go ahead with what I was thinking, and then move it to a
PIC/AVR+CPLD when I'm done. Thanks again, TTYL

-----------------------------
Herbert's PIC Stuff:
http://repatch.dyndns.org:8383/pic_stuff/

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