Honored Contributor
Honored ContributorYou only need to issue the 3 (or more) cycle 'unlock' sequence when you're writing/erasing a FLASH device but not when you're reading from it. Any operation that changes the contents must be preceded by the unlock sequence (unless you've already activated the unlock bypass - I suggest you get something working before experimenting with that). There are some other special commands that require unlock codes. However, you don't need to unlock the device to read from it, just present the address and assert CE# & OE# (WE# de-asserted).
If you haven't already, I suggest you start by looking to implement a command like 'Manufacturer ID' to prove your basic code sequence. This should return you a known, fixed value which, I hope, should help consolidate the basic timings your code generates. Cheers, Alex
