B-U585I-IOT02A definitely locked?

[ELuca.2]

Hello STM32U5 community,

I was making a few attemps with my B-U585I-IOT02A demo board and TF-M. I am afraid I have irreversibly locked the MCU.

Here is what I did:

• run regression.sh
• set RDP level 1 with the Programmer despite the warnings, because I forgot that regression.sh had erased the Secure and NSecure applications.

Now I fail to reconnect with the MCU by any means. What can I do? TZEN/RDP regression with boot from RSS? AN5347 says "a small rework" must be done. I would appreciate a step by step instruction.

Regards.

[Aime]

Hi @ELuca.2​ 

To solve the issue you need to:

• Switch the BOOT0 pin to 1 with the connector SW1 on your board
• Connect your board with STM32CubeProgrammer
• In the option bytes section :
  • Switch the RDP value to Level 0, no protection in the Read Out Protection panel
  • Uncheck the TZEN value to disable it, in the User Configuration panel
• Then click on Apply to program the Option bytes.
• You can now disconnect and switch BOOT0 to 0 with SW1 and connect again
•  

You need to Switch the RDP value to Level 0 and Uncheck the TZEN value before programming the option bytes, otherwise it won't work.

Best Regards,

A.MVE

[ELuca.2]

Thanks A. MVE.

It worked! I was a bit confused because CubeProgrammer raised some reading error messages at connection time. But apparently it was still able to change RDP/TZEN.

[Aime]

Hi @ELuca.2​ ,

I am glad to heard it ;) .

To let the others STM32U5's users find the thread, select the answer as best.

Best Regards,

A.MVE