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Visitor II
July 22, 2026
Question

No connection with STM32U5 after unchecked nSWBOOT0 in option bytes

Hello,

I’m working on STM32U5 flash with tfm application using script “regression.sh” and “TFM_UPDATE.sh” of MB1551 example project in SBSFU. I lost the connection with the chip when I unchecked nSWBOOT0 in option bytes.

Trust Zone : activated

nBoot0 : checked

nSWBOOT0 : unchecked

RDP : 0

 

So when we try a JTAG connection, we have this error.

STM32CubeProgrammer Error connection

 

Do you know a solution to regain connection with the STM32U5 ?

Thanks for your attention,

Kind regards,