W5100 Hardwired TCP/IP Embedded Controller WIZnet W5100 Hardwired TCP/IP Embedded Ethernet Controller is a full-featured, single-chip Internet-enabled 10/100 Ethernet controller designed for embedded applications where ease of integration, stability, performance, area, and system cost control are required. The W5100 has been designed to facilitate easy implementation of Internet connectivity without an OS, and it is IEEE 802.3 10BASE-T and 802.3u 100BASE-TX compliant. WIZnet W5100 Hardwired TCP/IP Embedded Ethernet Controller includes a fully hardwired, market-proven TCP/IP stack and integrated Ethernet MAC and PHY. The hardwired TCP/IP stack supports TCP, UDP, IPv4, ICMP, ARP, IGMP, and PPPoE, and 16Kb internal buffer is included for data transmission. For easy integration, three different interfaces--direct, indirect bus, and SPI--are supported on the MCU side.