Digital Equipment Corporation

Cabletron Systems, Inc.

Bryan T Campbell

Ciaran B Close

Una M Quinlan

Richard A Gahan

A scheme for protecting memory stored in a DRAM using a combination of horizontal and vertical parity data to detect and correct errors in a protected space of memory in which code is stored. The DRAM memory of this scheme is architected with the code stored in horizontally contiguous bytes and the vertical parity, generated when the code is compiled, also stored in horizontally contiguous bytes, but in a row of DRAM memory separate from those in which the code is stored.

DRAM parity protection scheme

In an apparatus to couple a plurality of line interfaces with corresponding modems ports, status and control signals are time-division-multiplexed (TDM) into a data stream before being exchanged between the devices. This substantially reduces the number of communication wires required and allows for several modems to be coupled in close proximity to a line interface card. Packet recognition circuitry coupled to the modem ports insures that signals in the TDM data stream are transmitted to the appropriate modem ports.

Growing community of inventors

Galway, Ireland

Bryan T Campbell