STM32G431 connect over JTAG

[CHeck.1]

Hello,

I try to connect to a STM32G431 Device over JTAG. I got the following error. Has someone a solution for this error?

[KnarfB]

Did you upgrade to the latest tool version like STM32CuberProgrammer 2.6?

[CHeck.1]

Yes I am using V2.6

[KnarfB]

Custom board? Nucleo32 works here as expected. What probe?

[CHeck.1]

It is a self developed board. The JTAG connection works with an J-Link but not the ST-Link and STM32CubeProgrammer. Just a connection over SWD

[KnarfB]

Communication errors? You can lower the clock speed and re-check.

[Uwe Bonnes]

Firmware on the STLink recent? All STlink match JTAG ID against an internal list and reject parts they do not know(yet).

[CHeck.1]

Firmware on ST Link is recent

[Uwe Bonnes]

Does connect under reset work?

[CHeck.1]

No, it doesn't work

[Uwe Bonnes]

Double check your wiring, the problem is with 99.9% on your side. Get out the scope or LA and look at the signals.