What Does Universal Synchronous/Asynchronous Receiver/Transmitter Mean?
A universal synchronous/asynchronous receiver/transmitter (USART) is a type of peripheral communications hardware device that allows a computer to communicate synchronously and asynchronously with serially connected devices.
A USART provides serial data communication from the serial port and over RS 232 standardized protocol.
A USART is also known as a serial communications interface (SCI).
Techopedia Explains Universal Synchronous/Asynchronous Receiver/Transmitter
A USART works by receiving parallel data from the central processing unit (CPU), converting it to serial data for transmission to a serial port/connection. Similarly, it receives serial data from the serial connection/port, converts it to parallel data and sends it to the CPU. The USART is embedded on an integrated circuit (IC) or the motherboard and can be configured for synchronous and asynchronous transfer mode (ATM).
A USART is similar to a universal asynchronous receiver/transmitter (UART), as each supports and provides serial communication. However, UARTs only support asynchronous serial communication.