Wireless LAN Integrated Medium Access Controller with
The Conexant GW3887A Wireless LAN Integrated Media Access Controller
with Baseband Processor is part of both the PRISM GT™ single band and
PRISM WWR™ dual band radio chip sets. The GW3887A directly interfaces
with Conexant’s ISL3686B Single Band Direct Conversion Transceiver.
Adding Conexant’s ISL3084 5GHz VCO and ISL3980 Power Amp completes
an end-to-end WLAN chip set solution compliant with 802.11b/g standards.
Additionally, the GW3887A directly interfaces with Conexant’s ISL3692 Dual
Band Direct Conversion Transceiver. Adding Conexant’s ISL3092 11GHz
VCO and ISL3992 Dual Band Power Amp completes an end-to-end WLAN
chip set solution compliant with 802.11a/b/g/h/i/j standards. The 802.11
protocol is implemented in firmware supporting custom WLAN solutions.
The GW3887A improvements over the GW3887 include the addition of an
internal 48MHz oscillator, which eliminates several external components
from the radio design.
Software implements the full IEEE 802.11 Wireless LAN MAC protocol. It
supports BSS and IBSS operation under DCF, and operation under the
optional Point Coordination Function (PCF). Active scanning is performed
autonomously once initiated by host command. Host interface command
and status handshakes allow concurrent operations from multi-threaded I/
Orthogonal Frequency Division Multiplexing (OFDM) of 52 sub-carriers
modulated with BPSK, QPSK, 16QAM or 64QAM and a variety of
convolutional coding rates provides 8 selectable data rates at 2.4GHz and
5GHz. Differential phase shift keying modulation schemes, DBPSK and
DQPSK with data scrambling capability along with Complementary Code
Keying provide an additional 4 selectable data rates at 2.4GHz.
Built-in flexibility allows the GW3887A to be configured for a range of
applications. The MAC is based on the ARM 946E processor core that
offers a wide variety of code development support tools.
The GW3887A is housed in a thin plastic BGA package suitable for USB
2.0 Wireless LAN small form factor circuit card applications.
• Firmware implements the full IEEE
802.11a/b/g/h/i/j Wireless LAN MAC
• Internal WEP Engine allows 64 or 128 bit
• AES Hardware Accelerator
• Start-up modes allow the USB vendor and
device ID to be initialized from a small
external serial EEPROM. This allows
firmware to be downloaded from the host.
• On-chip SRAM memory
• A low frequency crystal oscillator can
maintain time, which allows the high
frequency clock source to be powered off
during sleep mode.
• Firmware controlled antenna diversity
• Data Rates: 1, 2, 5.5, 6, 9, 11, 12, 18, 24,
36, 48, & 54Mbps
• Modulation: OFDM with BPSK, QPSK,
16QAM, 64QAM; DBPSK; DQPSK and
• Convolutional coding and interleaving on
all OFDM rates
• Targeted for OFDM Multipath Delay
Spreads >800ns for 6Mbps, and >100ns
• Targeted for CCK Multipath Delay
Spreads >90ns at 11Mbps, >200ns at
5.5Mbps and >360ns at 1 and 2Mbps
• Direct interface with the ISL3692 and
ISL3686 Direct Conversion transceiver
• USB 2.0 Wireless LAN Adapters
Figure 1: Simplified Block Diagram
Preliminary Data Sheet
November 12, 2004
Conexant Systems, Inc.
Proprietary - Use Pursuant to NDA