16. USART - Universal Synchronous Asynchronous Receiver/Transmitter
0 1 2 3
4
USART
RX/
MISO
TX/
MOSI
DMA
controller
RAM
CLK
CS
SPI
USART
SmartCards
IrDA
µC
Quick Facts
What?
The USART handles high-speed UART, SPI-bus,
SmartCards, and IrDA communication.
Why?
Serial communication is frequently used in embed-
ded systems and the USART allows efficient com-
munication with a wide range of external devices.
How?
The USART has a wide selection of operating
modes, frame formats and baud rates. The multi-
processor mode allows the USART to remain idle
when not addressed. Triple buffering and DMA sup-
port makes high data-rates possible with minimal
CPU intervention and it is possible to transmit and
receive large frames while the MCU remains in EM1
Sleep.
16.1 Introduction
The Universal Synchronous Asynchronous serial Receiver and Transmitter (USART) is a very flexible serial I/O module. It supports full
duplex asynchronous UART communication as well as RS-485, SPI, MicroWire and 3-wire. It can also interface with ISO7816 Smart-
Cards, and IrDA devices.
EFM32JG1 Reference Manual
USART - Universal Synchronous Asynchronous Receiver/Transmitter
silabs.com
| Smart. Connected. Energy-friendly.
Preliminary Rev. 0.6 | 447