The ICS1889 is a fully integrated physical layer device supporting 100 Megabits per second CSMA/CD Fast Ethernet fiber optic applications. It is designed to support the requirements of DTEs (adapter cards), repeaters and switches. It is compliant with the ISO/IEC 8802 Fast Ethernet standard for 100Base-FX. It provides a Media Independent Interface (MII) allowing direct chip-to-chip connection, motherboard-to-daughter board connection or connection via a cable in a similar manner to the AUI approach used with 10Base-Tsystems. A station management interface is provided to receive command information and send status information. It transmits and receives NRZI data and interfaces directly to the optical transceiver. It can operate in either half duplex or full duplex.