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GD32F403xx User Manual
398
17.
Universal
synchronous/asynchronous
receiver
/transmitter (USART)
17.1.
Overview
The Universal Synchronous/Asynchronous Receiver/Transmitter (USART) provides a f lexible
serial data exchange interface. Data f rames can be transferred in f ull duplex or half duplex
mode, synchronously or asynchronously through this interface. A programmable baud rate
generator divides the UCLK(PCLK1 or PCLK2) to produce a dedicated baud rate clock for
the USART transmitter and receiver.
Besides the standard asynchronous receiver and transmitter mode, the USART implements
several other types of serial data exchange modes, such as IrDA (infrared data association)
SIR mode, smartcard mode, LIN (local interconnection network) mode, half-duplex mode and
synchronous mode. It also supports multiprocessor communication mode, and hardware flow
control protocol (CTS/RTS). The data frame can be transferred from LSB or MSB bit. The
polarity of the data bits and the TX/RX pins can be configured independently and flexibly.
The USART supports DMA function for high-speed data communication, except UART4.
17.2.
Characteristics
◼
NRZ standard format.
◼
Asynchronous, full duplex communication.
◼
Programmable baud-rate generator
–
Divided from the peripheral clocks, PCLK2 for USART0, PCLK1 for USART1/2 and
UART3/4.
–
Oversampling by 16
–
Maximum speed up to 10.5 MBits/s (PCLK2 168M and oversampling by 16).
◼
Fully programmable serial interface characteristics:
–
Even, odd or no-parity bit generation/detection.
–
A data word length can be 8 or 9 bits.
–
0.5, 1, 1.5 or 2 stop bit generation.
◼
Transmitter and receiver can be enabled separately.
◼
Hardware f low control protocol (CTS/RTS).
◼
DMA request for data buffer access.
◼
LIN break generation and detection.
◼
IrDA support
◼
Synchronous mode and transmitter clock output for synchronous transmission.
◼
ISO 7816-3 compliant smartcard interface
–
Character mode (T=0)