It is not possible to change the state to "Closed" when USB is connected (STM32H562)

[Artur5]

Hi.

During production, we use USB to test the board. Finally, the MCU is supposed to be password-protected against flash reads. Unfortunately, it turns out that as long as the USB cable is connected, it's impossible to program the OBK. Segger Device Provisioner returns an "Error writing OBK". Using STLink and CubeProgrammer also doesn't work. After disconnecting the USB, changing the state to Closed works. BOOT0 is connected to ground. Is there a solution?

Artur

[Jocelyn RICARD]

Hello @Artur5 ,

Not sure what can prevent from provisioning OBK.

Are you first switching to PROVISIONING state ?

Could you share a STM32CubeProgrammer CLI sequence you are using  ?

Best regards

Jocelyn

 

[Artur5]

Hi.

Yes, I'm switching the MCU to PROVISIONING state. And everything works fine as long as the USB cable is disconnected. It seems like the bootloader is blocking access to the OBK memory in some way (?) We're using the SEGGER interface and their "Device Provisioner" tool, but it seems the same applies to STMCubeProgrammer, but I'll check again and let you know.

BR

Artur

[FBL]

Hi @Artur5  @Jocelyn RICARD 

If production test firmware enables USB, you need to consider adding a command or mechanism to disable USB peripheral before OBK programming. Since it might access to flash while programming OBKs.

[Artur5]

Hi.

This also does not work after completely erasing the MCU memory.

BR

Artur

[Jocelyn RICARD]

Hello @Artur5 ,

I got internal information that issue was fixed on Segger side.

Do you confirm this?

Thank you

Best regards

Jocelyn