CM4 UART Compatibility question

Hello!

This is my first post here and I’m quite new to the Radxa CM3 board. I designed a custom rPi CM4 breakout board which I am testing now with 2 brand new CM3s.
I successfully created a debian OS using debos and the board runs very nice. But when connecting to my peripherals I noticed that the overlay of the UART ports seems not identical to the rPi CM4. Is this correct?

I’m missing following ports on the provided pins:

  • rPi UART3 on connector 1 pin 34 & 54
  • rPi UART4 on connector 1 pin 39 & 40
  • rPi UART5 on connector 1 pin 28 & 31

All these pins doesn’t seem to provide a UART port on the Rockchip, correct? Or am I missing something?
It would be cool if I could make my board completely compatible to the Radxa CM3.

Curious for the replies
Kind regards

Hacor

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