W5200 Fast SPI Ethernet Controller

Offloading the TCP/IP stack to relieve MCU burden, the W5200 chip is a hardwired TCP/IP embedded Ethernet controller that provides an easy Internet capability for embedded systems. The single chip W5200 IC enables a very stable Internet connectivity, implementing a TCP/IP Stack as well as 10/100 Ethernet MAC and PHY. The hardwired TCP/IP stack supports TCP, UDP, IPv4, ICMP, ARP, IGMP, and PPPoE, and other protocols, with a 32Kbyte internal buffer as its data communication memory.

The W5200 means that you can implement an Ethernet application by using a simple socket program instead of dealing with a complex Ethernet Controller.  You can even use 8 independent hardware sockets simultaneously. An SPI interface allows for easy integration with an external MCU.  For reduced system power consumption, W5200 has a WOL (Wake on LAN) feature as well as a power-down mode.