Am79C985

The enhanced Integrated Multiport Repeater Plus (eIMR+) device is a VLSI integrated circuit that provides a system-level solution to designing managed multiport repeaters. Am79C985 integrates the repeater functions specified in Section 9 of the IEEE 802.3 standard and Twisted Pair Transceiver functions complying with the 10BASE-T standard.

Am79C985 provides four Twisted Pair (TP) ports and one reversible AUI (RAUI) port for direct connection to a MAC. The total number of ports per repeater unit can be increased by connecting multiple eIMR+ devices through their expansion ports, hence, minimizing the total cost per repeater port.

The eIMR+ device Am79C985 also provides a connection to the Am79C987 HIMIB device. The HIMIB device monitors all the necessary counters, attributes, actions, and notifications specified by IEEE 802.3, Section 19 (Layer Management for 10 Megabit per second (Mbps) Baseband Repeaters). When the eIMR+ and HIMIB devices are used together as a chip set, they provide a cost-effective solution to the problem of designing 10BASE-T basic managed multiport repeaters.

Am79C985 is fabricated in CMOS technology and requires a single +5-V supply.