Can't connect to STM32H755 after changing boot option byte

mt7883 · ‎2025-03-17

Hello,

after changing one of the BCM4/7 boot option bytes of my Nucleo STM32H755 board with STM32CubeProgrammer, I can't connect to the MCU any more. When trying to connect with STM32CubeProgrammer, I get

Error: Unable to read device id from ROM table

Error: ST-LINK error (DEV_CONNECT_ERR)

Is this related to the change in option bytes or did the board get damaged somehow?

Thanks and regards,

Martin

TDK · ‎2025-03-17

Try connecting using access port 3 instead of access port 0.

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TDK · ‎2025-03-17

Try connecting using access port 3 instead of access port 0.

If you feel a post has answered your question, please click "Accept as Solution".

mt7883 · ‎2025-03-18

Wow, this works, thanks a lot!

I just double checked: When I turn option BCM7 back on I can connect again on port 0. When I turn BCM7 off I can only connect on port 3.

mƎALLEm · ‎2025-03-18

Hello @mt7883 ,

Read this new article.

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