What's a PIN's (AF PP mode) status before it's peripherals ENABLE?

[Microstar]

Posted on November 08, 2014 at 07:33

For example, PA9 as USART1 TX pin, it's L, before USART1 is enabled.

[Tesla DeLorean]

Posted on November 08, 2014 at 07:45

I think the term you're looking for is undefined.

You might consider defining the pin as an input pull up/down, until you can get the peripheral in a known state before switching the pin to AF mode.

[Microstar]

Posted on November 08, 2014 at 16:31

I got you, thanks, I'll try.

[Microstar]

Posted on November 17, 2014 at 07:54

My board indicates that USART1 TX pin is Hi-Z status.