Hello,
I am following the datasheet of Silabs C8051F120DK, and having a confusion between output states and input states.

The following statement taken out of the documentation is creating the problem:

The output states of Port pins that are allocated by the Crossbar are controlled by the
digital peripheral that is mapped to those pins.

as opposed to this statement:

Because the Crossbar registers affect the pinout of the peripherals of the device, they are typically configured in the initialization code of the system before the peripherals themselves are configured.

I cannot understand what(crossbar / external device) affects what(input / output states) ?

Also how do the registers P1MDIN and P1MDOUT come into play ?