Error: No STM32 target found in STM32CubeProgrammer

[binarybee]

Hi guys, I disabled flashing core M7 in STM32CubeProgrammer option bytes to run just M4, but now I cant connect to the board and the tool says Error: No STM32 target found!. Is there some possibility how to reset the option bytes to again run M7?

Thanks a lot!

[TDK]

By "disabled flashing core M7" do you mean you set BOOT_CM7=0?

If so, short BOOT0 to 3V3 during reset to enter the bootloader. Use bootloader functions to reset the option bytes.

[binarybee]

Yes BOOT_CM7, sorry the menu was not possible to reopen again so I didnt know exactly the name. What are the bootloader functions which I should use to reset the option bytes?

[Bouraoui Chemli]

Hi @binarybee​ 

Core M7 is connected to access port 0, Core M4 is connected to access port 3.

Since you disabled core M7, choose access port 3 in STM32CubeProgrammer to connect to M4, then you can reset the option bytes to again run M7.

You can refer to AN5286 for more details about STM32H7 dual core debugging.

Best regards

Bouraoui

[binarybee]

Hi I tried it with port 3 but its still the same problem.

[TDK]

See the answer for "How do I regain ST-Link connectivity with Nucleo-H745ZI-Q with BOOT_CM7 = 0 and BOOT_CM4 = 1":

https://community.st.com/s/question/0D50X0000CAsx3kSQB/how-do-i-regain-stlink-connectivity-with-nucleoh745ziq-with-bootcm7-0-and-bootcm4-1

There is also this FAQ entry:

https://community.st.com/s/article/FAQ-Unable-to-connect-to-STM32H7-devices

[Bouraoui Chemli]

Hi @binarybee​ 

There is a limitation on Cube Programmer it will be fixed in next release, as alternative today you can use st-link utility.

Best regards,

Bouraoui

[binarybee]

Hi yes I jumped to that limitation probably, with st link utility it worked and I can again reach M7 core.

Thanks!

[binarybee]

For everyone who is struggeling I followed these instructions:

-Download the STM32 ST-LINK Utility tool and try to connect to the board.

STM32 ST-LINK Utility:

www.st.com/.../stsw-link004.html

-If the Utility tool fails to connect with the board try tying your boot0 pin high, resetting the board, and reconnecting. On my board this meant using one of the extra jumpers from CN11/12 and connecting pins 7 (boot0) and 5 (VDD) together. Your board's User Manual will tell you where the boot0 pin is and might also tell you how to tie it high. Ofcourse you need to select correct port (in my case it was 3 because I tried to connect to M4 core).