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AT76C504A

2388CS–WLAN–07/03

Description

The AT76C504A is a single-chip baseband controller that can handle IEEE 802.11b

standard compliant data rates of up to 11 Mbps and provides all processing and func-

tionality needed for the MAC protocol of IEEE 802.11b. AT76C504A provides a glueless

interface conforming to PC Card 95 and can support a variety of RF interfaces.

The AT76C504A incorporates an ARM7TDMI processor using a sophisticated architec-

ture to control the on-chip peripherals, manage the internal memory and allocate data

queue buffers as well as to communicate with the host through the PCMCIA parallel

bus. The processor peripheral logic consists of a PCMCIA bus interface, a Serial Periph-

eral Interface (SPI), a MAC unit, a 802.11b baseband controller, a WEP/TKIP engine

block, an AES engine block, two memory controllers and the ARM

ing of an Interrupt Controller, two 32-bit timers and an address decoder unit.

The ARM7TDMI core supports two alternative instruction sets. Powerful 32-bit code can

be executed by the processor in ARM operating mode. However, a 16-bit instruction

subset is also available in Thumb

processor power with limited external memory resources. Note that ARM7TDMI operat-

ing mode can be changed at run time with negligible overhead.