Am79C987

The Am79C987 Hardware Implemented Management Information Base (HIMIB) device is a highly integrated chip that simplifies building fully managed multiport repeaters. The device integrates all the necessary counters, attributes, actions, and notifications specified by the Layer Management for 10 Mbyte/s Baseband Repeaters (IEEE 802.3k) standard, as well as additional features and enhancements, including functions specific to 10BASE-T repeaters.

The HIMIB chip Am79C987 is designed to be used in conjunction with AMD's Integrated Multiport Repeater Plus (IMR+) device. When connected to an IMR+ (Am79C981) device, the HIMIB chip provides complete repeater and per-port statistics on demand from an 8-bit parallel interface. No external processor is required to keep track of attributes locally, as full 32-bit counters are provided.

Am79C987 implements a simple 8-bit microprocessor interface, allowing multiple HIMIB devices to be used in a system. No additional logic is required for interfacing the HIMIB device to the IMR+ device.

The HIMIB chip is packaged in a 28-pin plastic leaded chip carrier (PLCC). Am79C987 is fabricated in CMOS technology and requires a single +5 V supply.