On Tue, May 04, 2004 at 11:14:19AM -0800, Dave Baldwin enlightened us
thusly
> > Is there any reason why the behaviour of a uP should vary from reset
> > to reset? I need repeatability over clock cycles for some range;
> > about 10 clock cycles might be enough.
>
> I can think of a lot of reasons from power supply conditions to reset
> circuit variations. Also, what kind of uP? Don't some have to wait
> for internal circuits to settle? Some only sample the reset line
> periodically like they do the interrupts.
No uP was mentioned on purpose. I had several in mind. Right now,
The HD6303xp & HD 6303YP are in mind.
>
> > I want to test using clock cycle for clock cycle sampling. The
> > digital signature analysers (HP5004, 5005, & 5006) manufactured by
> > HP offer a checksum of a data stream, but very poor triggering
> > options, which I am seeking to extend :-D.
> >
> > But if the cpu took an extra clock cycle to settle after a reset,
> > the result would be screwed. Is this a possibility?
>
> Note that power on reset can take hundreds to thousands of clock
> cycles waiting for the oscillator/clock to settle, I think it's very
> likely to happen.
>
> > The idea is to take a checksum of the data lines while a board wakes
> > up and checks everything.
>
> That may take a lot to get that idea to work. Lots of variation in
> that process.
>
Back to the drawing board ...
The DSA is a great test device at the money, if one could apply it. I
certainly didn't pay the �10k than HP want for it!
--
With best Regards,
Declan Moriarty.
--
Author: Declan Moriarty
INET: [EMAIL PROTECTED]
Fat City Hosting, San Diego, California -- http://www.fatcity.com
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB CHIPDIR-L
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
