STM32WB55 FUS Corrupted in a reset

[DaniStUser]

Hello,

I'm having problems with the FUS not starting and the Wireless stack not responding.

In my code, the wireless stack can be updated. In the process of updating it, the STM32WB55 was interrupted by an external reset, and the FUS was left unresponsive.

These are the option bytes:

I tried to reenable the FUS by following these steps: Unable to start FUS. FUS version is 0.0.0.0 and FUS_STATE_ERR_UNKNOWN 

Since most of the things mentioned looked almost the same. I attempted to toggle the RDP to BB apply it and back to AA, and momentarily it looked like it worked, but when I tried to update the wireless stack afterwards, it failed again and I wasnt able to make it work again.

Any help is appreciated.

[FilipKremen]

Hello,

can you please try to reset the MCU to factory settings?

Best regards,

ST support

[DaniStUser]

Thank you for answering, Is there any other way to attempt the STM32 to react?

Maybe using the SHCI functions inside the code? I can still program it and make the CPU1 run.

I read somewhere that the CPU2 could be programmable. Is there a way to restore it?

[DaniStUser]

Hello, it took me some days to fully test it.

First, I used the initial StLink/V2 that I bought, it was a clone and I thought it failed because of it.

Then, I bought an original StLink/V2. Thinking that the ID Device was something related to the programmer. But it seems that it refers to the microcontroller version.

I kept on reading in some posts regarding how to restart the CPU2, using the address 0x5800040C to start the CPU2 and to try and make the FUS respond. But this yielded no results.

 

Also, now for some reason, the FUS is no longer reacting, previously switching the RDP value allowed me to attempt something, but now it doesn't return success either on Firmware delete or firmware upgrade.

[FilipKremen]

Hello,

could please follow the steps mentioned in this document?

How to use STMicroelectronics firmware upgrade services for STM32WB MCUs - Application note

(page 37)

Also, what was the previous FUS version running on the board?

Thank you.

 

Best regards,

ST support