I'm trying to flash an an NUCLEO-N657X0-Q board with the STM32N6 using STM32CubeProgrammer v2.20.0. I have two NUCLEO-N657X0-Q boards here: One of them flashes just fine, the other one refuses to work. Both boards are in development mode (BOOT jumpers set accordingly as described here https://github.com/STMicroelectronics/STM32N6-GettingStarted-ImageClassification?tab=readme-ov-file#boot-modes). In STM32CubeProgrammer, I have selected the appropriate External loader to be able to write to the external flash memory.
As a simple experiment, I am trying to erase a sector of the external flash memory. I am using the exact same STM32CubeProgrammer settings for both boards. Erasing the flash works just fine on one of the boards, but on the other board, I get the following error:
Did I accidentally enable some kind of flash memory protection? How do I disable it? Or is my board broken? The board still boots the old code in the flash memory when in flash boot mode, so I don't think the flash chip is completely broken. Also, downloading code to RAM and debugging works fine with both boards, so the STM32N6 also seems to be working just fine.
Any ideas on how to proceed from here?
