Ethernet controller

An Ethernet controller semiconductor chip has a system control unit, a media access control layer coupled with the system control unit, a physical layer coupled with the media access control layer, wherein the physical layer comprises a receiving port and a transmitting port, a switch control unit for providing a control signal for auto media device interface switching, and a plurality of external pins, wherein four pins are coupled with the receiving and transmitting port of the physical layer and one pin is coupled with the switch control unit for providing external access to the control signal for auto media device interface switching.