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6384E–ATARM–05-Feb-10
AT91SAM9G20
– By 8 or by-16 over-sampling receiver frequency
– Hardware handshaking RTS-CTS
– Optional modem signal management DTR-DSR-DCD-RI
– Receiver time-out and transmitter timeguard
– Optional Multi-drop Mode with address generation and detection
– Optional Manchester Encoding
RS485 with driver control signal
ISO7816, T = 0 or T = 1 Protocols for interfacing with smart cards
– NACK handling, error counter with repetition and iteration limit
IrDA modulation and demodulation
– Communication at up to 115.2 Kbps
Test Modes
– Remote Loopback, Local Loopback, Automatic Echo
The USART contains features allowing management of the Modem Signals DTR, DSR, DCD
and RI. In the AT91SAM9G20, only the USART0 implements these signals, named DTR0,
DSR0, DCD0 and RI0.
The USART1 and USART2 do not implement all the modem signals. Only RTS and CTS (RTS1
and CTS1, RTS2 and CTS2, respectively) are implemented in these USARTs for other features.
Thus, programming the USART1, USART2 or the USART3 in Modem Mode may lead to unpre-
dictable results. In these USARTs, the commands relating to the Modem Mode have no effect
and the status bits relating the status of the modem signals are never activated.
10.4.4
Serial Synchronous Controller
Provides serial synchronous communication links used in audio and telecom applications
(with CODECs in Master or Slave Modes, I
2S, TDM Buses, Magnetic Card Reader, etc.)
Contains an independent receiver and transmitter and a common clock divider
Offers a configurable frame sync and data length
Receiver and transmitter can be programmed to start automatically or on detection of
different event on the frame sync signal
Receiver and transmitter include a data signal, a clock signal and a frame synchronization
signal
10.4.5
Timer Counter
Two blocks of three 16-bit Timer Counter channels
Each channel can be individually programmed to perform a wide range of functions including:
– Frequency Measurement
– Event Counting
– Interval Measurement
– Pulse Generation
–Delay Timing
– Pulse Width Modulation
– Up/down Capabilities
Each channel is user-configurable and contains: