Can anyone help explaining the meaning of "input tap" functionality? For the example how do I need to configure the PORTB_MUX if I want to configure PORTB 00~02 as CNT0_ZM, UD and DG? Thanks a lot.
Input tap functionality enables a particular pin to act as input for particular functionality(like CNT0_ZM for PORTB 00) without configuring any of the PORT registers(from reset values). So one can directly feed the input signals to CNT0_ZM, UD and DG without changing any of PORTB settings.
Input taps lines are implicitly selected when corresponding peripheral input enables are active. So I don't think PORT_FER/MUX will have any effect, but if you want you can make FER = 0.