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Rev. 1.00
468 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
22 Universal Synchronous
Asynchronous Receiver T
ransmitter (USART)
22
22
Universal Synchronous Asynchronous
Receiver Transmitter (USART)
Introduction
The Universal Synchronous Asynchronous Receiver Transceiver, USART, provides a flexible
full duplex data exchange using synchronous or asynchronous transfer. The USART is used to
translate data between parallel and serial interfaces, and is also commonly used for RS232 standard
communication. The USART peripheral function supports a variety of interrupts.
The USART module includes an 8-level transmit FIFO, TX FIFO, and an 8-level receive FIFO, RX
FIFO. Software can detect a USART error status by reading the USART Status & Interrupt Flag
Register, USRSIFR. The status includes the condition of the transfer operations as well as several
error conditions resulting from Parity, Overrun, Framing and Break events.
The USART includes a programmable baud rate generator which is capable of dividing the USART
clock CK_APB (CK_USART) to produce a baud rate clock for the USART transmitter and
receiver.
APB
Interface
USART
Interrupt
CK_USART
RX
TX
Reference
Divisor Clock
IrDA _EN
CTS
RTS
Transmit FIFO
Transmit Shift Register
Receive Shift Register
Receive FIFO
Baud Rate
Clock
Generator
USART I/O
and IrDA
USART Control
and
Configuration
Registers
TXD
RXD
Figure 169. USART Block Diagram