STM32F7xx: How to read DBGMCU_IDCODE from bootloader?

fckruegel_opto · ‎2025-06-20

Hi;

In order to determine exactly the chip type I'd like to read the DBGMCU_IDCODE register. When I try to do this the bootloader hangs. RM0410 44.6.1 says "Only 32 bit access support". I guess the bootloader uses byte access.

Is there a workaround?

Reading UID and FLASHSIZE works just fine.

Andrew Neil · ‎2025-06-20

Which bootloader are you referring to?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

fckruegel_opto · ‎2025-06-20

the internal ROM bootloader

Andrew Neil · ‎2025-06-20

But that's fixed code, which you can't modify - so how does you reading DBGMCU_IDCODE relate to that?

Perhaps you show a minimum but complete example which illustrates the issue.

How to insert source code.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.