Yeah, I saw that thread. Oddly, I've used the same IC, I've never had Vcc up to 6.25V (the absolute maximum is 7V over VIL) and then there's the VPP that needs to spend some time at VIH before jumping to VPP (yeah, there's a pin called VPP and a programming voltage called VPP) and then back down to VIH and then to VIL. It's all about the timing of this, perhaps I was lucky? I suspect issues can occur if the programming voltage isn't at VPP at the right moment, leaving the cell only partially charged and the sense amplifiers triggering depending on the voltage on Vcc leading to either inoperable ROM or one that has errors and/or "works" sometimes and not others... (our favourite failure mode Image may be NSFW.
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)Statistics: Posted by maniacminer — Thu May 09, 2024 12:43 am
