Nucleo MB1364 as standalone ST-Link V3

[DrDro]

Hi there,

I have developed my project long time with MB1364E, exactly with H723ZG.

Now I have got my own PCB with H743. I would like to use ST-Link V3 (SWD) from Nucleo board just the same as it works for cuttable ST-Link from L4 Nucleos, e.g.:
https://community.st.com/t5/stm32-mcus-boards-and-hardware/how-to-use-the-standalone-st-link-capability-of-my-nucleo-after/td-p/306461

I have removed JP4 "Idd measurement", JP2 "Power source selection" and JP5 "Power selection".

But it seems that Nucleo ST-Link is hardcoded to support only this board.
Log from CubeProgrammer:

  07:59:18:504 : UR connection mode is defined with the HWrst reset mode
  07:59:20:007 : ST-LINK SN  : 003600453331510B33323639
  07:59:20:007 : ST-LINK FW  : V3J12M3
  07:59:20:008 : Board       : NUCLEO-H723ZG
  07:59:20:008 : Voltage     : 3.29V
  07:59:20:008 : Error: ST-LINK error (DEV_TARGET_HELD_UNDER_RESET)
  07:59:20:024 : Disconnected

 However, when my PCB is not supplied I get another error from CubeProgrammer, the voltage is correctly 0.00V detected:

  08:03:06:200 : UR connection mode is defined with the HWrst reset mode
  08:03:06:234 : ST-LINK SN  : 003600453331510B33323639
  08:03:06:234 : ST-LINK FW  : V3J12M3
  08:03:06:235 : Board       : NUCLEO-H723ZG
  08:03:06:235 : Voltage     : 0.00V
  08:03:06:235 : Error: No STM32 target found! If your product embeds Debug Authentication, please perform a discovery using Debug Authentication
  08:03:06:249 : Disconnected

Yes, I can still work with external ST-Link V3 and my board. But I also want to reuse part of not anymore used NUCLEO board.

Let's say, just to reduce garbage and save the world.
Is there a way to free the ST-Link V3 from NUCLEO board?

[AScha.3 · Accepted solution]

looking at the circuit (MB1364) , the H723 is fix connected to the st-link F723.

so no easy way to use it.

you could try cutting the connections swdio, swclk, swo (sb32) close to the H723 and use the CN5 pinheader to connect a cable.

but maybe it expect just a H723 as target...and refuses to work with other.

[FBL]

Hello @DrDro 

Check the user manual STM32H7 Nucleo-144 boards (MB1364) - User manual

It should be helpful as well.

[Mike_ST]

>> but maybe it expect just a H723 as target...and refuses to work with other.

I'm not aware about such a limitation, so far...

Anyways, for that board, the use case is that you can only bring an external probe to debug the H723, but can't debug an external MCU with the on-board ST-Link V3.

Maybe it is possible, but as you said, there is some work to do with cutter/soldering iron.