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XMEGA A [MANUAL]
8077I–AVR–11/2012
21.
USART
21.1
Features
Full-duplex operation
Asynchronous or synchronous operation
– Synchronous clock rates up to 1/2 of the device clock frequency
– Asynchronous clock rates up to 1/8 of the device clock frequency
Supports serial frames with 5, 6, 7, 8, or 9 data bits and 1 or 2 stop bits
Fractional baud rate generator
– Can generate desired baud rate from any system clock frequency
– No need for external oscillator with certain frequencies
Built-in error detection and correction schemes
– Odd or even parity generation and parity check
– Data overrun and framing error detection
– Noise filtering includes false start bit detection and digital low-pass filter
Separate interrupts for
– Transmit complete
– Transmit data register empty
– Receive complete
Multiprocessor communication mode
– Addressing scheme to address a specific devices on a multi device bus
– Enable unaddressed devices to automatically ignore all frames
Master SPI mode
– Double buffered operation
– Configurable data order
– Operation up to 1/2 of the peripheral clock frequency
IRCOM module for IrDA compliant pulse modulation/demodulation
21.2
Overview
The universal synchronous and asynchronous serial receiver and transmitter (USART) is a fast and flexible serial
communication module. The USART supports full-duplex communication and asynchronous and synchronous operation.
The USART can be configured to operate in SPI master mode and used for SPI communication.
Communication is frame based, and the frame format can be customized to support a wide range of standards. The
USART is buffered in both directions, enabling continued data transmission without any delay between frames. Separate
interrupts for receive and transmit complete enable fully interrupt driven communication. Frame error and buffer overflow
are detected in hardware and indicated with separate status flags. Even or odd parity generation and parity check can
also be enabled.
the transmitter, and the receiver, which are indicated in dashed boxes.