Knowledge: What is UART?

UART (Universal asynchronous transmitter ER/transmitter)
General asynchronous transceiver
UART is a chip used to control computers and serial devices. One thing to note is that it provides an interface to the RS-232C data terminal device so that the computer can communicate with the modem or other serial devices that use the RS-232C interface. As part of the interface,

UART also provides the following functions:
Converts parallel data transmitted from within a computer to the output serial data stream. Converts serial data from outside the computer into bytes for devices that use parallel data inside the computer. Add parity bits to the output serial data stream and perform parity checks on the data streams received from the outside. Add the start and stop mark to the output data stream and delete the start and stop mark from the received data stream. Handle the interrupt signal sent by the keyboard or mouse (the keyboard and mouse pass are also serial devices ). It can manage the synchronization between computers and external serial devices. Some of the more advanced uarts also provide the buffer for the input and output data. Now the newer UART is 16550, which can store 16 bytes of data in the buffer before the computer needs to process the data, generally, the UART is 8250. If you buy a built-in modem, the modem usually has a 16550 UART.