Hello, I have problem with a custom stm32f437 based board. It was working for few days then suddenly stopped working and can't program it anymore From keil/St-Link setup.
Installed the ST-Link utility (V4.0) and updated firmware on ST-Link. When I try to connect it says
"Can not read memory!
Disable Read Out Protection and retry."
Not sure how it got into "Read Out Protection Level 1" as I had never even used ST-Link Utility.
When I try to switch to ROP level 0 and deselect all sector and apply, it complains
"Could not set Option bytes!
Please reset the target and retry."
Already reset/retry many time with no improvement!
The board is unusable now. Please help.