Hi,
I was testing with the Nucleo STM32L476RG board, BSP example project FLASH_DualBoot.
I made small changes in the example code (LED blink stuff) and programmed bank 1 and 2 several times. I also manually checked/toggled the option bytes BFB2 bit a few times.
When I tried to program the MCU flash bank 2 again with STM32 ST-LINK Utility it said that it's not possible because of read/write protection. I didn't configure it any time before, only using the BFB2 bit in the example code. In the option bytes window I discovered that "Read/Write Protection Bank B" was activated. I couldn't uncheck it, because it says:
"To disable Read/Write protection of BANK B, you must set PCROP_RDP bit, and switch RDP from Level 1 to Level 0".
Well, both we're in desired state. Power cycle doesn't help. So I tried to trick the MCU by switching from Level 0 to Level 1 to be able to revert from 1 to 0.
But it doesn't let me revert from 1 to 0:
"ERROR: Could not set Option bytes! Please reset the target and retry."
"Warning: Can not read memory! Disable Read Out Protection and retry."
I retried several times, tried to load some code, tried to update the onboard ST-Link of the Nucleo board, power cycle...what's the matter with this problem? Is the MCU lost in a broken state? Any suggestions?
STM32 ST-LINK Utility V4.4.0; STM32Cube_FW_L4_V1.14.0
Regards,
Alex
