at91m42800 ATMEL Corporation, at91m42800 Datasheet - Page 15

• Manufacturer Part Number: at91m42800
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

User Peripherals
USART: Universal Synchronous/Asynchronous
Receiver Transmitter
The AT91M42800 provides two identical, full-duplex, uni-
versal synchronous/asynchronous receiver/transmitters
that interface to the APB and are connected to the Periph-
eral Data Controller.
The main features are:
• Programmable Baud Rate Generator with External or
• Parity, Framing and Overrun Error Detection
• Line Break Generation and Detection
• Automatic Echo, Local Loopback and Remote Loopback
• Multi-drop mode: Address Detection and Generation
• Interrupt Generation
• Two Dedicated Peripheral Data Controller channels
• 5-, 6-, 7-, 8- and 9-bit character length
TC: Timer/Counter
The AT91M42800 features two Timer/Counter blocks, each
containing three identical 16-bit Timer/Counter channels.
Each channel can be independently programmed to per-
Internal Clock, as well as Slow Clock
channel modes
form a wide range of functions including frequency
measurement, event counting, interval measurement,
pulse generation, delay timing and pulse-width modulation.
Each Timer/Counter channel has 3 external clock inputs, 5
internal clock inputs, and 2 multi-purpose input/output sig-
nals that can be configured by the user. Each channel
drives an internal interrupt signal that can be programmed
to generate processor interrupts via the AIC (Advanced
Interrupt Controller).
The Timer/Counter block has two global registers that act
upon all three TC channels. The Block Control Register
allows the three channels to be started simultaneously with
the same instruction. The Block Mode Register defines the
external clock inputs for each Timer/Counter channel,
allowing them to be chained.
Each Timer/Counter block operates independently and has
a complete set of block and channel registers.
SPI: Serial Peripheral Interface
The AT91M42800 includes two SPIs that provide commu-
nication with external devices in master or slave mode.
They are independent, and are referred to by the letters A
and B. Each SPI has four external chip selects that can be
connected to up to 15 devices. The data length is program-
mable from 8- to 16-bit.
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