i'm now working for a couple of weeks with the Portenta H7. Until my written code gets more complicated, i bought the breakout board and the ST-LINK/V2 to debug my code.
But i am a little confused by the wiring between the ST-Link and JTAG pins on the breakout board. I have read several times in the forum, that you talking about JTAG, but i think you mean SWD.
I have looked up the schematics of the breakout board and the schematics of the Portenta and i have come to the conclusion, that we can't use the JTAG protocol, since the JTDI pin (PA15 of the STM32H747) is used for communication with the WiFi module. Also the test reset pin nJTRST isn't connected to the JTAG connector of the breakout board. The nJTRST pin is pin D3 from the SD card connector.
So my question, if we want to debug the Portenta we always use the SWD protocol. Is that correct?
Another point i didn't understand is why you think that the schematic of the brakout board is incorrect for the JTAG connector. https://forum.arduino.cc/t/portenta-breakout-documentation-appears-to-show-wrong-jtag-pinout/703004?u=eschi
If i measure the +3V3 and GND pins, the pins on the board are at the correct position. I think that pin 1 of the JTAG connector is indicated correctly on the breakout board.
The last point is, how do you connect the ST-Link to the brakout board. Do you just solder some cables to the pins or is there a ready to use connector.