ASIX ELECTRONICS CORPORATION

4

AX88772

USB to 10/100 Fast Ethernet/HomePNA Controller

1.0 Introduction

1.1 General Description

The AX88772 USB to 10/100 Fast Ethernet/HomePNA/HomePlug controller is a high performance and highly integrated

ASIC with embedded 28KB SRAM for packet buffering. It enables low cost and affordable Fast Ethernet network

connection to desktop, notebook PC, and embedded system using popular USB ports. It has an USB interface to

communicate with USB host controller and is compliant with USB specification V1.1 and V2.0. It implements

10/100Mbps Ethernet LAN function based on IEEE802.3, and IEEE802.3u standards or HomePNA standard. It

integrates an on-chip 10/100Mbps Ethernet PHY to simplify system design and provides an optional media-independent

interface (MII) for implementing Fast Ethernet and HomePNA functions.

The AX88772 needs 12MHz clock for USB operation and 25Mhz clock for Fast Ethernet operation. It is in 128-pin LQFP

low profile package with CMOS process and requires only single 3.3V power supply to operate.

1.2 AX88772 Block Diagram

Figure 1: AX88772 Block Diagram

RXIP/RXIN

TXOP/TXON

MII I/F

GPIO2~0

MAC

Core

Memory Arbiter

USB to

Ethernet

Bridge

USB Core and Interface

STA

SEEPROM

Loader I/F

DP/DM

DPRS/DMRS

MDC

MDIO

EECS

EECK

EEDI

EEDO

28KB

SRAM

General

Purpose I/O

10/100

Ethernet

PHY