STM32H725ZGT6 custom board hangs (Cube, Keil, ULINK2)

[TimK1]

Hello,

i am using the STM32H725ZGT6 on a custom layout.

As comparison i am also using the STM32H723ZGT6U on a NUCLEO-H723ZG Board.

I am using STM32CubeMX, Keil µVision and the ULINK2 debugger. 

To test the Serial Wire Flashing procedure, i created an empty Cube Projext (using HSI and no controller pins), compiled itand flashed it to the controller. The Nucleo Board works perfectly fine with this setup.

However when i do the exact same procedure (of corse with correct controller), my custom Board has a problem:

I can only flash the software when the BOOT0-Pin is set to +3V3 (but not use any peripherals). When the BOOT0-pin is set to GND, i cannot program anymore and there is "SWD Communication Failure" according to Keil. I also tried to toggle a GPIO but had no acces with my custom board so far.

Any ideas on this?

If you need more infos, please let me know.

See Layout files attached. Thanks.

[Imen.D]

Hello @TimK1 

Is GND connected to the debugger? Try powering the board directly from the debugger.

Check the debugger settings to set correct debugger and use SWD.

[Tesla DeLorean · Accepted solution]

Check LDO vs SMPS settings in your System Clock Configuration code.

Check VOS and PLL settings.

Check HSE_VALUE 

[TimK1]

Hello Imen,

thank you for the reply. Yes, i have connected GND and VCC to my custom board. However i think the ULINK2 is not able to power the board. It has a jumper +3V3 / VCC / ARM. But this only powers the SWD signals, not the VCC of the board (as far as i can see). I tried both jumper positions with no change of the outcome. 

Greets, Tim

[TimK1]

Hello Tesla,

thanks for your reply. This solved my problem. 

In STM Cube i had the wrong setting. (SMPS instead of LDO):

System Core -> RCC -> Parameter Settings -> Power Parameters -> PWR_LDO_SUPPLY

Thank you very much!