use ITM (printf) with GD32E505 (CortexM33)

Hello,

I can compile, flash and debug code for a GigaDevice GD32E505. Debug Probe is a ULINK Pro.

Now I want to use debug output via ITM. As soon as I enable the checkbox for "Trace Enable" I can't start the debugger anymore. Instead I get a Error Message:

ULINKpro - ARMv8-M Error
Cannot access Memory (@ 0xe0040010, Write, Acc Sice: 4 Byte)

I assume µVision tries to send configuration bytes to the target to enable the ITM debug output.

If I try to start the debugger a second time (without reset of the target) I get:

ULINKpro - ARMv8-M Error
Device could not be powered up

I assume with the first attempt the CPU crashed, and with the second attempt the target did not respond any more at all.

Maybe this is a CortexM33-specific problem and some setup code is required before µVision can send these configuration bytes?

Does anyone have in idea what else I could try?