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Associate II
July 27, 2024
Solved

STM32G4 and MCO pin

I am using STM32G431cbtx and enabling RCC_MCO. Since the STM32G4 supports two pins, PA8 and PG10, PA8 is being used for another function, and I am using PG10 for RCC_MCO. However, when measuring the voltage on pin PG10, it is always high.

Can anyone explain it to me?

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AScha.3
AScha.3Best answer
Super User
July 29, 2024

Ok,

so:

AScha3_0-1722241090978.png

AScha3_1-1722241140628.png

Did you set option bytes -> pg10 = not nrst, but alternate function (mco) ?

If you feel a post has answered your question, please click on " Best Answer ".

4 replies

AScha.3
Super User
July 27, 2024

Show, what you set in Cube ...

+

What frequency you want at mco ?

Set pin speed high ?

Scope probe at 10:1 ?

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Associate II
July 29, 2024

Locnvselex_vn_0-1722220590818.pngLocnvselex_vn_1-1722220704520.png

I have tested RCC_MCO on pin PA8 and it was successful. But when I tested it on PG10 (Reset Pin), it was always high

 

AScha.3
AScha.3Best answer
Super User
July 29, 2024

Ok,

so:

AScha3_0-1722241090978.png

AScha3_1-1722241140628.png

Did you set option bytes -> pg10 = not nrst, but alternate function (mco) ?

If you feel a post has answered your question, please click on " Best Answer ".
Associate II
July 30, 2024

That's correct. However, the RCC_MCO signal still cannot be measured on PG10 pin!