W5100 is a kind of multifunctional monolithic network interface chip, internal integrated 10/100 ethernet controller, mainly used in high integrated, high-stability, high performance and low-cost embedded system. Using W5100 can realize internet connection without operating system, W5100 and IEEE802.3 10BASE-T, 802.3u 100BASE-TX compliant. W5100 internal integrates full hardware and TCP/IP protocol stack, MAX, PHY. Using W5100 do not need consider Ethernet control, just need proceeding simple Socket program.