2025-07-21 5:22 AM
Hello,
From the UM2408 document, the HSE is connected to ST-Link MCO output which is supposed to be 8MHz.
When you select Nucleo-H755ZI-Q board, the HSE input is locked to 25MHz.
Is it a CubeMX bug or does the MCO clock really 25MHz ?
Solved! Go to Solution.
2025-07-21 5:45 AM
It's grayed out, which means HSE is not enabled.
Enable HSE in the RCC tab and you can set it to 8 MHz or whatever the ST-Link is outputting, which is configurable in the ST-Link firmware upgrade.
By default, it should be set to HSE Bypass at 8 MHz.
2025-07-21 5:45 AM
It's grayed out, which means HSE is not enabled.
Enable HSE in the RCC tab and you can set it to 8 MHz or whatever the ST-Link is outputting, which is configurable in the ST-Link firmware upgrade.
By default, it should be set to HSE Bypass at 8 MHz.
2025-07-21 6:09 AM
That was an easy find, I should have a deeper look before !
Thanks a lot