Geehy SEMICONDUCTOR APM32F030x4x6x8xC, User Manual

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21 Universal Synchronous/Asynchronous
Transceiver (USART)
21.1
Full Name and Abbreviation Description of Terms
Table 64 Full Name and Abbreviation Description of Terms
Full name in English English abbreviation
Clear to Send CTS
Request to Send RTS
Most Significant Bit MSB
Least Significant Bit LSB
Guard GRD
Overrun OVR
21.2
Introduction
USART (universal synchronous/asynchronous transceiver) is a serial
communication device that can flexibly exchange full-duplex and half-duplex
data with external devices, and meets the requirements of external devices for
industry standard NRZ asynchronous serial data format. USART also provides a
wide range of baud rate for selection and supports multiprocessor
communication.
USART not only supports standard asynchronous transmission and receiving
mode, but also supports synchronous one-way communication and hardware
flow control mode. USART also supports DMA function to realize high-speed
data communication.
21.3
Main Characteristics
（
1
）
Full duplex asynchronous communication
（
2
）
Single-line half-duplex communication
（
3
）
NRZ standard format
（
4
）
Characteristics of programmable serial port:
 Data bit: 7 bits, 8 bits or 9 bits (7 bits only apply to APM32F030xC)
 Check bits: Even parity check, odd parity check, no check
 Support 1, 2 stop bits
（
5
）
Check control
 Transmit the check bit
 Check the received data
（
6
）
Select speed and clock tolerance with programmable 8 or 16-time
oversampling rate
（
7
）
Programmable high or low priority
（
8
）
Independent transmitter and receiver enable bit
（
9
）
Independent signal polarity control transmitter and receiver
（
10
）
Switch TX/RX pin