SAM7S256_14 Datasheet, PDF (359/775 Pages) ATMEL Corporation – ARM-based Flash MCU

31. Universal Synchronous Asynchronous Receiver Transceiver (USART)
31.1
Overview
The Universal Synchronous Asynchronous Receiver Transceiver (USART) provides one full duplex universal syn-
chronous 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 han-
dling 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, and 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 trans-
mitter and from the receiver. The PDC provides chained buffer management without any intervention of the
processor.
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
359