AT76C503A

Features:

• IEEE 802.11b-compliant Wireless Standard
• Wireless LAN MAC Unit with ARM7TDMI™ RISC Processor
• Integrated 128-byte Transmit and 128-byte Receive FIFOs, for Wireless MAC Layer Functions
• Delivers Standard Wireless Networking to Any Host that Supports a Full-speed (12 Mbps) USB 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 Bytes of Nonvolatile Memory for Permanent Storage of Program Code
• Wired Equivalent Privacy (WEP) in Hardware Supporting 64-bit and 128-bit Encryption
• The Integrated Physical Attachment Interface (PAI) Fully Supports Direct-sequence Spread Spectrum and Frequency-hopping Spread Spectrum Physical-layer Interfaces
• The WLAN and Inter-networking Functions can be Changed and Updated Easily to New Requirements Since They are Implemented in Micro Code
• Supports 11 Mbps Data Rate with Automatic Fallback to 5.5, 2 and 1 Mbps
• 128-lead, 14 x 14 mm TQFP Package
• Low-voltage Operation (3.3V)
• Internal ROM Contains Hardwired USB Control Software for Automatic Configuration when Card is Inserted in the USB Slot
• Device Firmware Upgrade is also Included in the Internal ROM for Downloading Firmware into Internal SRAM
• Offers SPI Interface and Five GPIO Pins
• AT76C503A Offers the Option to Download the Whole Code from SPI Flash



Description

AT76C503A is a single-chip controller that provides all processing and functionality needed for the MAC protocol of wireless LANs (focusing on, but not limited to the IEEE 802.11b standard). AT76C503 A provides a glueless interface conforming to 12-Mbit Universal Serial Bus (USB) specification and can control a variety of wireless physical interfaces.

The AT76C503A chip contains a USB interface, a MAC control unit, and a PAI. The PAI supports 5.5- and 11-Mbit WLAN physical interfaces and the IEEE 802.11 (1 or 2 Mbps) direct-sequence spread spectrum and frequency-hopping spread spectrum physical interfaces, providing flexibility to end users.

The AT76C503A ARM7TDMI core supports two alternative instruction sets. Powerful 32-bit code can be executed by the proce-ssor 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 ope-rating mode can be changed at run time with negligible overhead.