How to use JTAG interface instead of SWO on a NUCLEO-144?

[Gabriele1]

Hi everyone!

I'm pretty new with STM32 microcontroller and STM environment. Now I'm playing with a Nucleo-H745ZI board and developing using STM32CubeIDE. This board is equipped with the st-link V3. It should be able to use both SWO and JTAG interface to program and debug STM32 MCUs.

I was tryng to use JTAG instead of SWO (wich is the default debug configuration) but I have this error: Error: 

No STM32 target found!

ST-LINK error (DEV_CONNECT_ERR)

I've also tried with the STM32CubeProgrammer software, same error. 

What i do wrong?

Thanks 🙂

[Tesla DeLorean · Accepted solution]

Not sure full JTAG pins wired, check schematic. Use SWD.

The wrong LDO/SMPS​ settings will cause connectivity issues. Strap BOOT0 High and cycle the board several times, and erase when you have connectivity.

[Gabriele1]

Thanks for the answere.

Looking at User Manual, in the section 6.3.1 it seems that it's possible to use both JTAG and SWD. But you are right, the JTAG pins are not wierd. And also in the block diagram abore it's only specified the SWD interface.

[Tesla DeLorean]

I believe it is wired to the header for EXTERNAL targets, not the internal one.

Full JTAG isn't typically needed as you aren't going to boundary scan the device, or daisy chain them and it just interferes with the available pins on the board.

[Gabriele1]

Yes exactly! Thanks for your help!