Hi,
I’m working with an STM32C011F6P6TR device, and after programming it via SWD using STM32CubeProgrammer, the MCU became completely stuck in reset
Symptoms
- After programming an ELF file through STCubeProgrammer, the MCU no longer runs.
- The NRST pin stays LOW permanently, even after power cycling.
- I cannot reconnect with STM32CubeProgrammer, even using “Connect Under Reset” mode.
- The tool returns: DEV_HELD_UNDER_RESET.
- Removing power, disconnecting ST-LINK, reconnecting, and trying again does not help.
Before programming, everything worked normally and I was able to connect and flash multiple times (Using VS-CODE and ST extension).
Questions:
What could cause the MCU to remain stuck in reset after flashing?
Is it possible that option bytes got corrupted or misconfigured during programming?
Is there any way to force a full chip erase or restore factory option bytes when the device cannot be accessed through SWD?
Has anyone encountered a similar issue with the STM32C0 series where NRST is permanently held low?
Any guidance on how to recover the MCU or identify the root cause would be appreciated.
Thanks!
