AX88172A接口电路

focus2009

The AX88172A is a high performance and highly integrated ASIC which enables a low cost, small form factor, and simple plug-and-play Fast Ethernet network connection capability for desktops, notebook PC's, UMPC's, cradles/port replicators/docking stations, game consoles, digital-home appliances, and any embedded system using a standard USB port.
The AX88172A features a USB interface to communicate with a USB Host Controller and is compliant with USB specification V1.1 and V2.0. The AX88172A implements 10/100Mbps Ethernet LAN function based on IEEE802.3 and IEEE802.3u standards with 24KB of embedded SRAM for packet buffering. In addition, it integrates an on-chip 10/100Mbps Ethernet PHY, simplifying system design. The AX88172A has a wide array of features including support for HP Auto-MDIX, Wake-on-LAN power management, and IEEE 802.3x/backpressure flow control. Optional serial interfaces such as I?C, SPI, and UART are provided as a control channel from the USB Host Controller to communicate with the external MCU chip.
The AX88172A, USB 2.0 to MII controller, provides an optional External Media Interface (EMI) for an external PHY or an external MAC depending on different application purposes. The EMI can be a media-independent interface (MII) for implementing 100BASE-FX Ethernet or HomePNA functions. The EMI can also be a Reverse-MII or Reverse Reduced-MII (Reverse-RMII) for glueless MAC-to-MAC connections to any MCU with Ethernet MAC MII or RMII interface. In addition, the EMI can be configured to Dual-PHY mode allowing the AX88172A to act as an Ethernet PHY or USB 2.0 PHY for external MAC devices that need Ethernet and USB interfaces in system applications. The potential and flexibility of Dual-PHY mode singles out the AX88172A as an ideal solution for growing applications such as WiMAX-to-USB modems, WiMAX ExpressCard modems, and HomePlug Powerline adapters.