Kunal, it is 2 pins and 1 port, you need bi-directional status.

Stephan,
So far the following has been discussed:
Soft UART (Peter):a simple solution albeit somewhat slow.
Port to port (Kunal): An excellent solution if you can spare 10 pins, which usually is not the case.
74HC646 (Peter) a good solution if you already are using memory mapped I/O. I would, however, use a CPLD instead, as that can include the memory address decode, ALE etc.
Dual port memory (Steve and yours truly): an excellent albeit somewhat costly solution.

Other options:
Shared UART: with 2 and-or gates (or similar) you can connect the UART to 2 transcievers. If both micros are on the same board, you can even connect directly, The caveat of this solution is that when you communicate with one transciever, the other is dead.
Port to port using WSI. If you can justify using the WSI chips for other reasons use Kunals solution with one of the 3 extra ports.
I2C or SPI: if you select derivatives with this interface in hardware, you can communicate very efficiently. If you choose a software solution, the soft UART is probably a better choice.
Shared RAM: STAY AWAY, I have had to rescue several projects based on shared RAM, it is a nightmare.


There may be other means, this is what comes to mind.

Have fun,

Erik