8.5
User Peripherals
8.5.1
USART: Universal Synchronous/Asynchronous Receiver Transmitter
The AT91M40800 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 parity
bit and up to 2 stop bits.
The USART also features a Receiver Timeout register, facilitating variable length frame support
when it is working with the PDC, and a Time Guard register, used when interfacing with slow
remote equipment.
8.5.2
TC: Timer Counter
The AT91M40800 microcontroller features a Timer Counter block that includes three identical
16-bit timer counter channels. Each channel can be independently programmed to perform a
wide range of functions including frequency measurement, event counting, interval measure-
ment, 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.
12
AT91M40800
1348FS–ATARM–13-Apr-06
ATMEL [ ATMEL ]
