USE OF PORTS

"Ports" 

The input-output devices are not directly connected to the CPU. Because he the IO devices are directly connected, it will reduce the number of IO devices that can be connected to CPU.
The interface between IO devices and CPU is called Port. Ports are the electronic circuits used to transfer the data to an output device and used to accept data from an input device. Each port in the computer system is identified with the help of an address called PORT ADDRESS.
Now a days the whole circuit of the port can be packed in a single integrated circuit (IC). There are so many ways to classify a port.

1. Input Port - This ports accepts data from an input device and then
supply this data to the CPU. The CPU enables this port by providing
appropriate port address and necessary control signals to the
supporting logic circuit of the port.

2. Output Port - This port accepts data from CPU and supplies this
data to output device. CPU enables this port by providing appropriate
port address and necessary control signals.