SAM7X256_14 Datasheet, PDF (291/662 Pages) ATMEL Corporation – ARM-based Flash MCU

30. Universal Synchronous Asynchronous Receiver Transceiver (USART)
30.1 Overview
The Universal Synchronous Asynchronous Receiver Transceiver (USART) provides one full duplex universal
synchronous asynchronous serial link. Data frame format is widely programmable (data length, parity, number of stop
bits) to support a maximum of standards. The receiver implements parity error, framing error and overrun error detection.
The receiver time-out enables handling variable-length frames and the transmitter timeguard facilitates communications
with slow remote devices. Multidrop communications are also supported through address bit handling in reception and
transmission.
The USART features three test modes: remote loopback, local loopback and automatic echo.
The USART supports specific operating modes providing interfaces on RS485 buses, with ISO7816 T = 0 or T = 1 smart
card slots, infrared transceivers and connection to modem ports. The hardware handshaking feature enables an out-of-
band flow control by automatic management of the pins RTS and CTS.
The USART supports the connection to the Peripheral DMA Controller, which enables data transfers to the transmitter
and from the receiver. The PDC provides chained buffer management without any intervention of the processor.
SAM7X Series [DATASHEET]
6120K–ATARM–11-Feb-14
291