Quincy Center for Technical Education
Computer Technology Department


     Serial devices are controlled by a Universal Asynchronous Receiver/Transmitter, or UART for short. This specialized integrated circuit is found either on the device adapter card or on the motherboard (for those that have a serial port mounted on it). The UART chip controls all the actions and functions of the serial port, including the list below.

UART Controls These Actions & Functions

Controlling all the connectors' pins and their associated signals.


Establishing the communication protocol.

Converting the parallel data bits of the data bus into a serial bit stream for transmission.


Converting the received serial bit stream into parallel data for transmission over the PC's internal bus.