Instruction register in (II) problem

[mafrmt00]

I really had fun building this project, thank you a lot for that!

While testing I came upon the following problem: The instruction register copies every value that comes from memory. If a pop is used, the value goes to the instruction register e.g. It does not matter if II is set.

It seems that my Flash (AM29J040B-90JD) has a very short undefined state on it's data pins while the address changes.

A 10nF capacitor between II and GND solves the problem at most speed settings.

To you have a suggestion for a specific flash type that does not show this behaviour?

Regards
Manfred

[vascofazza]

Hi Manfred, Thank you, really appreciate the feedback. I am glad you’re liking it! I had similar issues (fixed in the current review) never with the flashes, I am using this particular one: SST39SF010A-70-4C-NHE You should be fine with those, you can find them on Mouser.