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M0A21/M0A23 Series
May 06, 2022
Page
496
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
6.13 USCI
– UART Mode
6.13.1 Overview
The asynchronous serial channel UART covers the reception and the transmission of asynchronous
data frames. It performs a serial-to-parallel conversion on data received from the peripheral, and a
parallel-to-serial conversion on data transmitted from the controller. The receiver and transmitter being
independent, frames can start at different points in time for transmission and reception.
The UART controller also provides auto flow control. There are two conditions to wake-up the system.
6.13.2 Features
Supports one transmit buffer and two receive buffer for data payload
Supports hardware auto flow control function
Supports programmable baud-rate generator
Support 9-bit Data Transfer (Support 9-bit RS-485)
Baud rate detection by built-in capture event of baud rate generator
Supports PDMA capability
Supports Wake-up function (Data and nCTS Wakeup Only)
6.13.3 Block Diagram
Peripheral
Device
User
Interface
Control Register
Data
Buffer
Data
Shift
Unit
Protocol
Processor
Unit
(UART)
Input
Processor
Buffer
Control
Interrupt
Generation
USCIx_DAT0/1
To Interrupt
Signal
USCIx_CTL0/1
Wake-up
Control
Protocol-Relative
Clock Generator
f
PCLK
Output
Configuration
Note:
x = 0, 1
Figure 6.13-1 USCI-UART Mode Block Diagram
6.13.4 Basic Configuration
The basic configurations of USCI0_UART are as follows: