USART - Universal Synchronous Asynchronous Receiver/Transmitter

Quick Facts

What?

The USART is available in Energy Mode 0 and Energy Mode 1 and handles high-speed UART, SPI-bus, SmartCards, and IrDA communication.

Why?

Serial communication is frequently used in embedded systems and the USART allows efficient communication with a wide range of external devices.

How?

The USART has a wide selection of operating modes, frame formats and baudrates. The multi-processor mode allows the USART to remain idle when not addressed. Triple buffering and DMA support 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.

Features

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 SmartCards, and IrDA devices.

• Asynchronous and synchronous (SPI) communication
• Full duplex and half duplex
• Separate TX/RX enable
• Separate receive/transmit 2-level buffers, with additional separate shift registers
• Programmable baud rate, generated as an fractional division from the peripheral clock
• Various Asynchronous- and Synchronous mode supports
• Data can be transmitted LSB or MSB first
• Configurable number of data- and stop bits
• HW collision detection
• Multi-processor mode
• IrDA modulator on USART0
• SmartCard mode (ISO7816)
• Separate interrupt vectors for receive and transmit interrupts
• Loopback modes