[shankar]

When PORT 0 is used for input operations, both the FETs are open, that means the point is at high impedance so to pull it to Vcc, the pull up register is used. For the better understanding of PORT 0 and the concept of Pull up registers check this out.

https://www.youtube.com/watch?v=t9bN-2nFNEs

 

Thank you.

[Author]

Posts