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1732FS–ATARM–12-Apr-06
AT91R40008
8.2 User Peripherals
8.2.1 USART: Universal Synchronous/
Asynchronous Receiver Transmitter
The AT91R40008 microcontroller provides two identical, full-duplex, universal synchro-
nous/asynchronous receiver/transmitters.
Each USART has its own baud rate generator and two dedicated Peripheral Data Controller
channels. The data format includes a start bit, up to 8 data bits, an optional programmable par-
ity bit and up to 2 stop bits.
The USART also features a Receiver Time-out Register, facilitating variable length frame sup-
port when it is working with the PDC, and a Time-guard Register, used when interfacing with
slow remote equipment.
8.2.2 TC: Timer/Counter
The AT91R40008 microcontroller features a Timer/Counter block that includes three identical
16-bit Timer/Counter channels. It is possible to independently program each channel to per-
form a wide range of functions, including frequency measurement, event counting, interval
measurement, pulse generation, delay timing and pulse width modulation.
The Timer/Counter can be used in Capture or Waveform mode, and all three counter channels
can be started simultaneously and chained together.
