EP0200198A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

An arrangement for expanding memory capacity

Assignee: Digital Equipment Corp

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Filing: 1986-04-29

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Granted: —

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Expires: 2006-04-29

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Abstract

Abstract The invention includes one or more circuit cards, each of which can be plugged into a data processing system and each of which can have multiple banks of memory thereon. In a preferred embodiment, a system can have up to two cards and each card can have one, two, or four banks of memory located thereon. In addition each circuit card includes signal generating circuitry which generates a plurality of electrical signals, which signals, when considered together, represent a code that indicates the amount of memory located on the circuit card. Further, in addition, each circuit card has combining circuitry thereon which is connected to receive the last mentioned coded signals as well as coded signals from a second circuit card if the same be plugged into the data processing system. The combining circuitry combines the two sets of coded signals to provide a resultant set of coded signals which are indicative of the total amount of memory on the two cards and the addressable location of such memory. The data processing system with which the circuit cards are used provides the circuit path to connect the circuit cards.

Inventors

👤 Jesse B. Lipcon
👤 Barry A. Maskas

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-10-25 04:42

CPC Classifications

G; G06; G06F; G06F12/00; G06F12/02; G06F12/06; G06F12/0646; G06F12/0684

Claims Analysis

Total Claims: 4

Claim 1

Independent Claim 144 words

CLAIM 1 - An expandable memory circuit to be used with a data processing system which is capable of generating memory address signals and which has interconnecting circuitry connected thereto, comprising in combination: X groups of memory units formed to be part of said expandable memory circuit, where X is equal to or less than Y, and Y is the maximum possible number of groups of memory units which can be part of said expandable memory circuit; code generating circuit means formed to be part of said expandable memory circuit and formed to generate N voltage signals, which when considered together form a code representing said X groups of memory units; and connecting means formed and disposed to connect said N voltage signals to said interconnecting circuitry means to transmit said N voltage signals thereto to be ultimately used by said data processing system.

Claim 2

Dependent Claim 56 words

CLAIM 2 - An expandable memory circuit according to Claim 1 wherein there is further included decoding circuitry means connected to said interconnecting circuitry means to receive said N voltage signals as well as address signals from said data processing system to provide signals indicating which of said X groups of memory units is being addressed.

Claim 3

Dependent Claim 227 words

CLAIM 3 - An expandable memory circuit to be used with a system which has interconnecting circuitry means formed to connect said expandable memory circuit to a similar expandable memory circuit and to a data processor means, comprising in combination: X units of memory formed to be part of said expandable memory circuit, where X is equal to, or less than Y, and Y is the maximum possible number of memory units which can be part of said expandable memory circuit; first electrical circuit means formed to be part of said expandable memory circuit and formed to generate N voltage signals which when considered together form a code representing said X units of memory; connecting means formed and disposed to connect said N voltage signals to said interconnecting circuitry means to transmit said N voltage signals thereto; and coded signals combining means connected to said first electrical circuit means and to said interconnecting circuitry means and formed to receive transmitted N voltage signals from a similar expandable memory circuit in the event such transmitted N voltage signals should be present and combine said transmitted N voltage signals with said N voltage signals generated by said first electrical circuit means to provide a set of combined N voltage signals representing the combined memory units which are part of said expandable memory circuit and said similar expandable memory circuit.

Claim 4

Dependent Claim 57 words

CLAIM 4 - An expandable memory circuit according to claim 3 wherein there is further included decoding circuitry means connected to said interconnecting circuitry means to receive said combined N voltage signals as well as address signals from said data processor system to provide signals indicating which of said X groups of memory units is being addressed.

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