1
Note: This is a summary datasheet. A complete datasheet is
available under NDA. For more information, please contact your
local Atmel Sales Office.
Features
IEEE 802.11b MAC and Baseband for Supporting Standard Rates up to 11 Mbps
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
Wired Equivalency (WEP) in Hardware Supporting 64-bit and 128-bit Encryption
The Integrated MAC Support Unit (MSU) Supports Timing Critical MAC Functions
The WLAN and Inter-networking Functions Can be Changed and Updated Easily to
New Requirements Since They are Implemented in Microcode
Supports Automatic Fallback from 11 Mbps to 5.5, 2 and 1 Mbps
160-ball BGA Package
Low-voltage 3.3V Operation
Internal ROM Contains Hardwired CIS Information for Automatic Configuration when
Card is Inserted in the PCMCIA Slot
SPI Interface and 2 GPIO Pins
AT76C504 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
Integrated 802.11b Baseband Processor
Baseband Supports Antenna Diversity Algorithm
Baseband Supports Differential or Single-ended I- and Q-Baseband Signals
Baseband Supports Japan Filter
Block Diagram
Timers
External
Memory
Boot ROM
Interface
Internal
Memory
(SRAM)
Common Memor
y
Interf
ace Controller
ARM7TDMI
Decoder/
Arbiter/
Bridge
Interrupt
Controller
SPI Interface
WEP
802.11b
Baseband
MAC Support
Unit (MSU)
PCMCIA Interface
802.11b
Media Access
Controller
(MAC) and
Baseband for
PCMCIA Bus
AT76C504
Summary
Rev. 2218CSWLAN01/03
2
AT76C504
2218CSWLAN01/03
Description
The AT76C504 is a single-chip baseband controller that can handle IEEE 802.11b stan-
dard compliant data rates of up to 11 Mbps and provides all processing and functionality
needed for the MAC protocol of IEEE 802.11b. AT76C504 provides a glueless interface
conforming to PC Card 95 and can support a variety of RF interfaces.
The AT76C504 chip incorporates an ARM7TDMI processor using a sophisticated archi-
tecture 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 paral-
lel bus. The processor peripheral logic consists of a PCMCIA bus interface, a Serial
Peripheral Interface (SPI), a MAC unit, a 802.11b Baseband block, the common mem-
ory interface, internal boot Read Only Memory (ROM) and the normal operation stages
and common microcontroller blocks like timers, interrupt controller and bus arbiter.
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
mode. Thumb mode can be selected to exploit full
processor power with limited external memory resources. Note that ARM7TDMI operat-
ing mode can be changed at run time with negligible overhead.
Printed on recycled paper.
ATMEL
and DataFlash
are the registered trademarks of Atmel.
ARM7TDMI
and ARM
, Thumb
are the registered trademarks of ARM, Ltd.; Other terms and product
names may be the trademarks of others.
Atmel Corporation 2003.
Atmel Corporation makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty
which is detailed in Atmel's Terms and Conditions located on the Company's web site. The Company assumes no responsibility for any errors
which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does
not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Atmel are granted
by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel's products are not authorized for use as critical
components in life support devices or systems.
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