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Not able to connect to NUCLEO-H755ZI-Q

Marco.D
Associate II

Hi,

I am developing some code for a display interface on a NUCLEO-H755ZI-Q, I debug some basic code and the STM32 seem to have crashed.

Now I can not connect anymore to it, not even with the CubeProgrammer V2.5.

Is there a way to recover the Nucleo board from this?

1 ACCEPTED SOLUTION

Accepted Solutions

Most likely a SMPS/LDO or VOS setting.

Solder a two pin header between VDD and BOOT0 (BT0) pin, and use one of the spare jumpers parked on the back of the board.

Jumper VDD to BOOT0 connect/disconnect the board a couple of times (cycles power) until STM32 Cube Programmer can see the H7, and then erase the user code off it.

0693W000007EBwMQAW.jpg

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View solution in original post

4 REPLIES 4
Uwe Bonnes
Principal III

Double check jumpers, check and exchange cable and hubs.

Most likely a SMPS/LDO or VOS setting.

Solder a two pin header between VDD and BOOT0 (BT0) pin, and use one of the spare jumpers parked on the back of the board.

Jumper VDD to BOOT0 connect/disconnect the board a couple of times (cycles power) until STM32 Cube Programmer can see the H7, and then erase the user code off it.

0693W000007EBwMQAW.jpg

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

Amazing thanks,

it worked at the first attempt!

What does this trick do?

I am looking at pag 143-145 of the reference manual

The option bytes used will be from the TCM ram, is it just that?

Thanks,

Marco

The H7 is an odd bird.

NRST doesn't work as a complete chip level reset, and the device remembers things like LDO and SMPS settings across uses.

Watch very carefully the code you have in SystemClock_Config(), and especially unbounded while() loops. The code might actually be running by dies in a way you can't recover. The BOOT ROM (System Loader) provides a safe-harbour from which to connect from, and to resolve settings issues.

The method described earlier was used in the H747I-DISCO to recover it, there have been several topics about that, and H7's in general. I broken mine early by using H743ZI startup code rather than H747I-DISCO compatible code.

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Up vote any posts that you find helpful, it shows what's working..