Is it possible to use the STLINK (V3) that's integrated into some of the Nucleo boards to program external devices?

[JQuan]

I have an NUCLEO-G474RE that I used for prototyping, and now I also have a custom board with a G474 on it that includes a MIPI10 debug connector. I can program and debug with the standard STLINK-V3SET just fine. However, I would like to know if it is also possible to use a Nucleo board to do this (I think this used to be possible with the previous generation). For example, if I remove the main MCU (U13) can I then use the MIPI10 (CN4) debug connector to debug another board?

https://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-mpu-eval-tools/stm32-mcu-mpu-eval-tools/stm32-nucleo-boards/nucleo-g474re.html

[Andreas Bolsch]

Probably it's quite sufficient to erase the flash of the MCU (so that the JTAG/SWD-pins are not reconfigured after reset) and then to keep NJTRST (PB4) asserted permanently.

This should keep the MCU's debug interface passive, hence it would not interfere with an externally connected MCU.

Or remove solder bridges SB40 and SB41. If you want to use SWO or VCP, remove the corresponding solder bridges (SB15, SB17, SB23), too. No need to desolder the MCU.