Digital Equipment Corporation

Stephen R Coe

Andrew L Wu

Donald C Pierce

E William Bruce, Ii

Derrick D DaCosta

A high-density memory module has thirty-two memory integrated circuit chips, sixteen decoupling capacitors, and two resistors mounted on a double-sided multi-layer printed wiring board having a series of edge terminals for connection to a motherboard. One side of the board has a first 2.times.8 rectangular matrix of the chips, and the other side of the board has a second 2.times.8 matrix of the chips. The chips are grouped into four 'strings,' each of which includes eight chips which receive the same row address strobe and column address strobe. Each string is selected by a unique row address strobe. All four strings share a common data bus. Two of the strings share a first column address strobe and a first address bus, and the other two strings share a second column address strobe and a second address bus, to facilitate four-way interleaved memory access. Address, data, power, and ground terminals are distributed and dispersed along the series of edge terminals, but terminals for one address bus is disposed between a first half and a second half of the terminals for the other address bus. One of the two resistors is used for indicating the type of the memory chips in the memory module, and the other resistor is interconnected with similar resistors in other memory modules on the motherboard to provide a combined resistance indicating the number of memory modules on the motherboard.

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Aushburnham, MA, United States of America

Stephen R Coe