The serial communication port is one of the communication medium available in almost all microcontrollers. It is the most effective communication method available with a microcontroller. The serial port of the microcontroller provides the easiest way by which the user and the microcontroller can write their data in the same medium and both can read each other’s data. When the serial port of the microcontroller is connected to the PC and the incoming and outgoing data is monitored using software and displayed in a window, it forms the simplest text user interface (TUI) setup for the microcontroller. Serial communication is a very useful debugging tool in the code development process. It can send back the run time status of the internal registers, value of the variables etc.