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Explorer II
March 19, 2026
Question

stm32h503xx Clock ..

  • March 19, 2026
  • 3 replies
  • 222 views

Hello, I am using the STM32H503 MCU. When I configure the pins as follows:

  • PB2 → OUTPUT

  • PA8 → TIM1_CH1

  • PB7 → I2C1_SDA

In the RCC section, I get red warnings for Master Clock Output1 (MCO), LSCO clock output, and SAI1 External clock. I cannot disable these clock settings. Is there a way to do this in CubeMX? How can I resolve this conflict in CubeMX?

3 replies

gbm
Principal
March 19, 2026

What conflict?

These are just warnings signaling that you cannot use some function cause you activated another function on some pins.

My STM32 stuff on github - compact USB device stack and more: https://github.com/gbm-ii/gbmUSBdevice
mƎALLEm
Technical Moderator
March 19, 2026

Hello @r2-d2 and welcome to the ST community,

Please share your ioc file so we can check.

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TDK
Super User
March 19, 2026

What do the warnings say? Hover over them for context. Probably they are informational and can be ignored.

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