GPIO output modes wrt impedence

mikewilliamson9 · ‎2009-02-09

Posted on February 09, 2009 at 09:57

mikewilliamson9 · ‎2011-05-17

Posted on May 17, 2011 at 13:02

I have checked through the stm32 documentation especially 13902.pdf

I cannot find an explicit explanation of the GPIO output modes. The modes are for maximum output speeds of 10, 2 and 50MHz. I assume that internally the slew rate of the pin is being limited. Is this performed by impedance changing or some active method?

Particularly I am interested to know how this would affect the impedance of the pin seen from the outside.

Has anyone had any issues regarding termination and using different output modes?

Perhaps STOne-32 could shed some light on this?

Thanks.