STM32H743XI silicon Y - DBGMCU dead ?

[Dan4]

Curious if anyone else encountered this: I work on a design using STM32H743XI silicon Y and DBGMCU seems to be completely dead. Reading any register returns 0 (so no REV_ID/DEV_ID). Writing to get 'timer freeze on debug' does not work either and reading back the written registers returns 0's.

The Errata does not mention anything like that.

I am aware that the Debugger is supposed to see DBGMCU at 0xE00E1000 and the CPU at 0x5C001000, but neither works.

Am I missing something ? - there is no RCC clock enabling for this class of MCUs... ; the ref manual lists DBGMCU->CR bits D1DBGCKEN and D3DBGCKEN, which are not dealt with in the standard HAL, but again trying to set them and re-read, I get back 0's...

Thanks.

[jeremi]

As I mentioned above, this issue has been fixed in Keil 5.29. LL_DBGMCU_APB1_GRP1_FreezePeriph works for me.

[Gpeti]

Sorry, I missed your post on the topic. I'm gonna try the latest MDK version.

[Simon V.]

Hello,

When the debugger is not connected and the clock gating feature is enable, the JTAG clock is automatically stop.

You must configure RCC_CKGAENR register to JTAGCKG clock gating disabled : the clock is always enabled then you can dump correctly REV_ID/DEV_ID @ 0x5C00100 address.

Regards,

Simon