It could maybe be related to the CS issue - hence my debug suggestion of going even slower on the clock to see if that makes it go away.That is concerning, I thought it was related to the CS issue. I have done a whole board redesign and moved the flash right next to the RP2040, along with having all the traces on the top layer and the resistor right next to the flash. I will double-check the pinout in case something is wrong. It would suck to not have it run at full speed.
Certainly your new flash layout looks good.
I do wonder why you are using super-wide tracks for digital signals on the inner layer (they look a width more appropriate for power connections). No reason to think it will stop it working, just seems a bit odd.
Statistics: Posted by arg001 — Thu Feb 06, 2025 12:30 am