MSP430的GPIO编程？

Question

I was going through the datasheet of MSP430 series.

My doubt is :

There is a register for enabling or disabling the PULL UP and PULL DOWN registers.(PXREN)

My question is , if we configure a pin as input and disable the internal pull up and pull down registers using the register PXREN then , what would be the state of the pin at that time , will it get tri stated?

Answer 1

Yes. When you configure the pin as GPIO input it is high-Z, ie it is tri stated. That's perfect for an input pin, your external hardware will define the level.

When you enable the RXEN you get a resistor that is a pull up or down. This depends on the value in the OUT register.