Introduction

The Cirrus Logic CS22250 Wireless Network Controller enables high speed, 11 Mbps digital wireless data connectivity for wireless Ethernet bridge, access points, and other broadband applications.

Features

Embedded ARM Core and System Support Logic

• High Performance ARM7TDMI RISC processor core up to 77MHz

• 4KB integrated, one-way set associative, unified, write through cache

• Individual interrupt for each functional block

• Two 23-bit programmable (periodic or one-shot) general purpose timers

• 8 Dword (32-bits) memory write and read buffers for high system performance

• Abort cycle detection and reporting for debugging

• ARM performance monitoring function for system fine-tuning

• Programmable performance improvement logic based on system configuration.

Enhanced Memory Controller Unit

• Programmable memory controller unit supporting SDRAM /async SRAM/boot ROM/Flash interface

• 16-bit data bus with 12-bit address supporting up to 4MB and up to 103 MHz (100/133MHz SDRAM)

• 8-bit data bus with addressing support up to 1MB of boot ROM/Flash

• Programmable SDRAM timing and size parameters, such as CAS latencies and number of banks, columns and rows

• Flexible independent DMA engines for Ethernet MAC, Digital Radio and External Bus functional units

FEC codec

• High performance Reed-Solomon coding for error correction (255:239 block coding)

• Reduces error probability of a typical 10e-3 error rate environment to 10e-9

• Programmable rate FEC engine to optimize channel efficiency

• Low latency, fully pipelined hardware encoding and decoding. Supports byte-wise single cycle throughput up to 77MHz, with a sustain rate of 77MBps

• Double buffering (63 Dword read/write buffer) to enhance system performance

Digital Wireless Radio MAC

• Glue-less interface to 802.11b radio baseband transceiver

• 11Mbps data rate

• 32 Dword transmit/receive FIFO

• Supports clear channel assessment (CCA)

Ethernet Interface

• IEEE802.3 Ethernet MAC controller

• Two independent full-duplex DMA channels transfer between Ethernet interface to system memory

• Standard 7-pin serial interfaces to AUI or Twisted Pair 10-BaseT

• Standard half-duplex CSMA/CD and full-duplex operation

USB Device Configuration Interface

• USB 1.1 compliant