The AX88170 USB to Fast Ethernet/HomePNA Controller is a high performance and highly integrated Controller with embedded 5K*16 bit SRAM. The AX88170 contains a USB interface to host CPU and compliant with USB Standard V1.0 and V1.1. The interface between AX88170 and PC Host is compliant with USB Communication Class Specification 1.0. The AX88170 could be used for both 10M/100Mbps Fast Ethernet function based on IEEE802.3 / IEEE802.3u LAN standard and 1M/10M HomePNA standard. The AX88170 supports media-independent interface (MII) or RMII (Reduce MII) interface to simplify the design on implementing Fast Ethernet and HomePNA functions. The chip also provides an optional MII/RMII interface with PHY mode, combine with Ethernet repeater or switch IC can build a multiple ports USB-to-USB bridge application.