AT91M55800A_07 Datasheet, PDF (134/256 Pages) ATMEL Corporation – AT91 ARM Thumb-based Microcontrollers

18. USART: Universal Synchronous/ Asynchronous Receiver/Transmitter
The AT91M55800AA provides three identical, full-duplex, universal synchronous/asynchronous
receiver/transmitters which are connected to the Peripheral Data Controller.
The main features are:
• Programmable Baud Rate Generator
• Parity, Framing and Overrun Error Detection
• Line Break Generation and Detection
• Automatic Echo, Local Loopback and Remote Loopback channel modes
• Multi-drop Mode: Address Detection and Generation
• Interrupt Generation
• Two Dedicated Peripheral Data Controller channels
• 5-, 6-, 7-, 8- and 9-bit character length
Figure 18-1. USART Block Diagram
ASB
AMBA
APB
Peripheral Data Controller
Receiver Transmitter
Channel Channel
Control Logic
USART Channel
Receiver
PIO:
Parallel
I/O
Controller
RXD
USxIRQ
Interrupt Control
MCK
MCK/8
Baud Rate Generator
Baud Rate Clock
Transmitter
TXD
SCK
134 AT91M5880A
1745F–ATARM–06-Sep-07