Portenta H7: external debugger

Official Hardware Portenta Family Portenta H7
1

FYI, if you want to connect an external (ST-LINK) debugger: most of the STM NUCLEO boards have ST-LINK onboard. You can "hijack":
Some boards, e.g. I use NUCLEO-H743ZI, provide a 6-pin SWD header. Open two jumpers on NUCLEO board and have a cable from this NUCLEO to Portenta H7 JTAG.
Is provides an ST-LINK V2 debugger via USB on NUCLEO (Portenta H7 needs still USB-C for power).

Portenta_H7_debugger
Portenta_H7_debugger1488×1984 230 KB

Here the schematics for it:

P7_Debugger
P7_Debugger2402×1756 226 KB

It is just a bit tricky to solder a cable on this small-pitch female connector for Portenta H7. And bear in mind:

  • the 3V3 signal is not for power: it is used by the debugger to sense the target voltage

  • wire also the RESET signal: debugger will use it in order to release the target

  • The SWO signal is optional (not needed to flash, debug): it is used as SWD Viewer (SWV), with sending print messages via ITM (like a read-only serial connection to host, I use to monitor debug messages on a running system)

2

Thanks @tjaekel for the details on the debugger setup!
What kind of connector did you use for the mini JTAG connection?

I have ended up buying the ST-LinkV3 and the provided cable works perfectly.