Hello, I am having similar issues with a brand new STM32H753XI-EV2 evaluation board (the big one with display). I have the board since a few days and am trying to get the printf function to work. First I tried that with the built-in USB-ST-Link interface. I did (almost)everything exactly as in an earlier project for an STM32F7 processor, where it worked perfectly (we work with the latest Keil MDK). Result: The printf only works in principle, but it is extremely unstable. If I do a slow counter o…