[Nucleo-N657X0-Q ]How to use swv printf in Keil arm mdk 5.39

[bioak]

I would like to use SWV for debugging on the Nucleo-N657X0-Q board.

I first enabled SWV debugging and also change the CPU clock to 400 MHz.

Then, I added some code to main.c (as reference here ).

At the same time, I also set the core clock to 50 MHz in the TRACE configuration of Keil.

But i can't see any string in Debug Viewer.

Does anyone know what else I should check?

Thank's