On Tue, 27 Jan 2004 14:56:06 -0700, Dwayne Reid wrote:
> In fact, I'd like to pose that same question to the members of the
> PIClist - Has anyone ever had a PIC verify at the normal Vdd voltage
> but fail to verify at the supply limits (either above or below the
> programming voltage)?  In other words, Vdd normal: pass, Vdd low:
> pass, Vdd high: fail (or vice versa).

Yes, back when I was first doing ICSP with my Picstart+ I had a few
16C65's that acted a little flaky after programming. I put them
aside and several months later I purchased a ProPic2 ICSP programmer
that does high/low voltage verify. I decided to check out the flaky
16C65 boards with the new ProPic2 programmer. They failed low voltage
verify. For my own curiosity I re-programmed the questionable units
(some with the ProPic2 and some with the Picstart+) and they all then
verified at low voltage (and were no longer flaky). I've seen that
happen with byte-wide EPROMS in days past also.

BTW, the ProPic2 ICSP is an excellent ICSP programmer (and it's creator
is a member of the PIClist even!) Octavio are you out there? ;-)

http://www.propic2.com

Matt Pobursky
Maximum Performance Systems

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