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Why am I getting "No Synchronization" when trying to use trace on M4 core of STM32H747 to write to "Debug (printf) Viewer"?

john239955_stm1_st
Associate II

I'm working with the STM32h747-DISCO with Keil Development tools and an ST-LINK debugger, and I'm trying to use the Debug (printf) Viewer. I can get it to work properly on the M7 core, but am getting "No Synchronization" when I try to use the M4 core.

System setup is as follows:

  • pll1_p and pll1_q are configured to 480MHz
  • pll_r is configured to 240 MHz
  • MCO1 prescaler is 1
  • MCO2 prescaler is 2
  • MCO1 configured to run from pll1_q
  • MCO2 configured to run from pll1_p
  • System clock is configured to use pll1, meaning system clock will use pll1_p and the trace clock will use pll1_r.

From this configuration, the M7 is running at 480MHz, the M4 is running at 240MHz, and the trace clock is 240MHz.

All code is compiled to redirect stdin, stdout, and stderror to ITM.

For the M7 core, the debugger is configured as shown below.0693W000000WSjXQAW.png

For the M4, the debugger is configured as shown below (only difference is the Core Clock)

0693W000000WSjhQAG.png

On the M7, I can print to the M7 with no problem, but M4 just shows me a "No Synchronization" at the bottom of the screen and nothing prints. I've tried setting up and running from HSI at 64 MHz, which is the default with no luck.

What am I missing?

1 REPLY 1
RTira.1
Associate II

Hi John, we are facing the same problem, could you solve it?

Could some ST employee write an answer about this issue?

Thanks!