1948DS–WLAN–09/03
11-megabit
WLAN Media
Access
Controller
(MAC)
AT76C502A
Summary
Features
Wireless Interface Following the IEEE 802.11b Standard
Wireless LAN MAC Unit with ARM7TDMI
®
RISC Processor
Integrated 128-byte Transmit and 128-byte Receive FIFOs for Wireless MAC Layer
Functions
16-bit PCMCIA Bus Interface
Glueless SRAM Interface for All MAC Operations, Supporting up to 1M Byte of External
Memory
Integrated 6K x 32-bit Internal SRAM, Used for Fast Program Code Execution and
Temporary Storage of Data
Glueless Flash Memory Interface, Supporting up to 1M Byte of Nonvolatile Memory for
Permanent Storage of Program Code
Enciphering/Deciphering of Wireless Data On-the-fly by the Implementation of the
Encryption/Decryption Code Ensures Maximum Privacy of Data
The Integrated Physical Attachment Interface (PAI) Fully Supports Direct-sequence
Spread Spectrum and Frequency-hopping Spread Spectrum (2 Mbps) Physical-layer
Interfaces
The WLAN and Inter-networking Functions can be Changed and Updated Easily to New
Requirements Since They are Implemented in Microcode
Supports 11 Mbps Rates with Automatic Fallback to 5.5, 2 and 1 Mbps
144-lead TQFP Package
Low-voltage 3.3V Operation
Internal ROM Contains Hardwired CIS Information for Automatic Configuration when
Card is Inserted in the PCMCIA Slot or Reads Custom CIS Information from SPI
Memory
Offers SPI interface and 3 GPIO Pins
AT76C502A Offers the Option to Download the Whole Code from SPI DataFlash
®
or an
Option to Eliminate Flash by Downloading the Program from the Mass Storage Device
Block Diagram
Wireless Physical
Attachment
Interface (PAI)
Timers
External
Memory
Interface
Internal
Memory
Common Memor
y
Interf
ace Controller
ARM7TDMI
Decoder/
Arbiter/
Bridge
Interrupt
Controller
PCMCIA Interface
WEP
Note: This is a summary document. A complete document is avail-
able under NDA. For more information, please contact your local
Atmel sales office.