| GENERAL DESCRIPTION The Am79C98 Twisted-Pair Ethernet Transceiver (TPEX) is an integrated circuit that implements the medium attachment unit (MAU) functions for the twisted-pair medium, as specified by the IEEE 802.3 standard (Type 10BASE-T). This device provides the necessary electrical and functional interface between the IEEE 802.3 standard attachment unit interface (AUI) and the twisted-pair cable. A network based on the 10BASE-T standard can use unshielded twisted-pair cables, providing an economical solution to networking by allowing the use of exist ing telephone wiring.The Am79C98 provides a minimal component count and cost-effective solution to the design and implementation of 10BASE-T standard networks. DISTINCTIVE CHARACTERISTICS ■ CMOS device provides compliant operation and low operating current from a single +5 V supply ■ Power Down mode provides reduced power consumption for battery-powered applications. Reset capability allows use in remote MAU applications. ■ Pin-selectable twisted-pair receive polarity detection and automatic inversion of the receive signal. Polarity indication output pin can directly drive an LED. ■ Pin-selectable twisted-pair Link Integrity Test capability conforming to the IEEE 802.3 standard for 10BASE-T. Link status pin can directly drive an LED. ■ Internal twisted-pair transmitter digital predistortion circuit reduces medium-induced jitter and ensures compliance with the 10BASE-T transmit and receive waveform requirements ■ Pin-selectable SQE Test (heartbeat) enable ■ Transmit and receive status indications are available on separate, dedicated pins ■ AUI loopback, Jabber Control, and SQE Test functions comply with the 10BASE-T standard IEEE Std 802.3i-1990 |
