GENERAL DESCRIPTION

The Am79C989 Quad Ethernet Switching Transceiver (QuEST?) is a four-port physical layer (PHY) device that provides all of the analog functions needed for a 10BASE-T switch, including four independent Manchester Encode/Decode units (MENDECs) and four independent 10BASE-T transceivers. If the AUI port is used for a 10BASE-2, 10BASE-5, or 10BASE-FL transceiver, one of the four 10BASE-T ports is disabled.

DISTINCTIVE CHARACTERISTICS

■ Four independent 10BASE-T transceivers compliant with the IEEE 802.3 standard

■ Four digital Manchester Encode/Decode (MENDEC) units

■ On-chip filtering enables FCC EMI compliance without external filters or common mode chokes

■ Automatic polarity Correction and Detection on 10BASE-T receivers

■ Optional Attachment Unit Interface (AUI) for non-10BASE-T transceivers

■ 10BASE-T Extended Distance option accommodate lines longer than 100 meters

■ Quad AMD Switching Interface (QuASI?) interface reduces overall pin count

■ Half-Duplex and Full-Duplex operation

■ Auto-Negotiation compliant with IEEE 802.3u Standard

■ Standard MII management interface and protocol

■ Status Change Interrupt output pin for fast response time to changed conditions

■ 44-pin PLCC CMOS device

■ 5 V supply with 3.3 V system interface compatibility