COMPANY CONFIDENTIAL • 1
Data Sheet
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PRELIMINARY
December 2010
AR9331 Highly-Integrated and Cost Effective IEEE 802.11n
1x1 2.4 GHz SoC for AP and Router Platforms
General Description
The Atheros AR9331 is a highly integrated and
cost effective IEEE 802.11n 1x1 2.4 GHz System-
on-a-Chip (SoC) for wireless local area network
(WLAN) AP and router platforms.
In a single chip, the AR9331 includes a MIPS 24K
processor, five-port IEEE 802.3 Fast Ethernet
Switch with MAC/PHY, one USB 2.0 MAC/PHY,
and external memory interface for serial Flash,
SDRAM, DDR1 or DDR2, I
2
S/SPDIF-Out audio
interface, SLIC VOIP/PCM interface, UART, and
GPIOs that can be used for LED controls or other
general purpose interface configurations.
The AR9331 integrates two Gbit MACs plus a
five-port Fast Ethernet switch with a four-traffic
class Quality of Service (QoS) engine.
The AR9331 integrates an 802.11n 1x1 MAC/BB/
radio with internal PA and LNA. It supports
802.11n operations up to 72 Mbps for 20 MHz
and 150 Mbps for 40 MHz channel respectively,
and IEEE 802.11b/g data rates. Additional
features include on-chip one-time programmable
(OTP) memory.
Features
■ Complete IEEE 802.11n 1x1 AP or router in a
single chip
■ MIPS 24K processor operating at up to
400 MHz
■ External 16-bit DDR1, DDR2, or SDRAM
memory interface
■ SPI NOR Flash memory support
■ No external EEPROM needed
■ 4 LAN ports and 1 WAN port IEEE 802.3 Fast
Ethernet switch with auto-crossover, auto
polarity, and auto-negotiation in PHYs
■ Four classes of QoS per port
■ Fully integrated RF front-end including PA
and LNA
■ Optional external LNA/PA
■ Switched antenna diversity
■ High-speed UART for console support
■ I
2
S/SPDIF-out audio interface
■ SLIC for VOIP/PCM
■ USB 2.0 host/device mode support
■ GPIO/LED support
■ JTAG-based processor debugging supported
■ 25 MHz or 40 MHz reference clock input
■ Advanced power management with dynamic
clock switching for ultra-low power modes
■ 148-pin, 12 mm x 12 mm dual-row LPCC
package
System Block Diagram
SDRAM/
DDR1/DDR2
Controller and
NOR Flas h
Memory
Interface
MIPS 24K
Processor
AR 9331
Serial Flash and SDRAM/DDR Inter face
USB MAC/PHY USB 2.0 Interface
5x Fast Ethernet
LAN/WAN Ports
5x Fast Ethernet Ports
Exter nal Interface GPIOs/LEDs
UART UART Interface
2.4 G Hz
802.11n
1x1 WLAN
MAC/BB/
Radio
RF
Front
End
25 or 40 MHz Crystal
I
2
S/SPDIF Au dio Interface
Internal
SRAM
I-Cache
D-Cache
SLIC VOIP/PCM
