GENERAL DESCRIPTION

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.

DISTINCTIVE CHARACTERISTICS

■ Provides repeater management functions, complying with all options detailed in the layer management for 10 Mbyte/s Baseband Repeaters (IEEE 802.3k) standard

■ Fully compatible with the Novell Hub Management Interface (HMI) specification

■ Provides additional IEEE MAU management functions (802.3p draft)

■ Interfaces directly with AMD’s Am79C981 Integrated Multiport Repeater Plus™ (IMR+™) device to build a fully managed repeater

■ Multiple HIMIB/IMR+ devices can be used in a system

■ 8-bit microprocessor interface allows attribute access, interrupt control, and management control

■ Maskable interrupts for notification of status/error reporting

■ Internal “receive only” MAC tracks all address information and monitors exception conditions

■ Supports mapping of node source addresses to port numbers, through implementing source address match function

■ Full 32-bit hardware-implemented counters incur no additional software overhead to keep network statistics

■ Pinout allows simple board layout between IMR+ and HIMIB devices

■ 28-pin PLCC device in CMOS technology for low power with a single +5 V supply