☛ The port 3 can be used as simple input /output port or provides signals like interrupts.

☛ P3.0 and p3.1 are used for serial communication.

☛ P3.2 and P3.3 are used as external interrupts.

☛ P3.4 and P3.5 are used for timers.

☛ P3.6 and P3.7 are used as read write signals of external memory.