The DM9000B is a fully integrated and cost-effective low pin count single chip Fast Ethernet controller with a general processor interface, a 10/100M PHY and 4K Dword SRAM. It is designed with low power and high performance process interface that support 3.3V with 5V IO tolerance. The DM9000B supports 8-bit and 16-bit data interfaces to internal memory accesses for various processors. The PHY of the DM9000B can interface to the UTP3, 4, 5 in 10Base-T and UTP5 in 100Base-TX with HP Auto-MDIX. It is fully compliant with the IEEE 802.3u Spec. Its auto-negotiation function will automatically configure the DM9000B to take the maximum advantage of its abilities. The DM9000B also supports IEEE 802.3x full- duplex flow control.