lan9221/lan9221i 高性能16位非PCI 10/100以太网控制器可变电压输入输出

　　The LAN9221/LAN9221i is a full-featured， single-chip 10/100 Ethernet controller designed for embedded applications where performance， flexibility， ease of integration and system cost control are required. The LAN9221/LAN9221i has been specifically designed to provide high performance and throughput for 16-bit applications. The LAN9221/LAN9221i is fully IEEE 802.3 10BASE-T and 802.3u 100BASE-TX compliant， and supports HP Auto-MDIX. The variable voltage I/O signals of the LAN9221/LAN9221i accommodate lower voltage I/O signalling without the need for voltage level shifters. The LAN9221/LAN9221i includes an integrated Ethernet MAC and PHY with a high-performance SRAM-like slave interface. The simple， yet highly functional host bus interface provides a glue-less connection to most common 16-bit microprocessors and microcontrollers as well as 32-bit microprocessors with a 16-bit external bus. The integrated checksum offload engines enable the automatic generation of the 16-bit checksum for received and transmitted Ethernet frames， offloading the task from the CPU. The LAN9221/LAN9221i also includes large transmit and receive data FIFOs to accommodate high latency applications. In addition， the LAN9221/LAN9221i memory buffer architecture allows highly efficient use of memory resources by optimizing packet granularity.