Browse Prior Art Database

Self Repairing by Pseudoduplication

IP.com Disclosure Number: IPCOM000089314D
Original Publication Date: 1977-Oct-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Palounek, LR: AUTHOR

Abstract

A system which accomplishes checking by pseudoduplication is disclosed in U.S. Patent 3,660,646. In essence, the disclosed system performs logical or arithmetic functions in separate data paths. The results obtained in the separate paths are compared. An inequality indicates error or component failure.

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Self Repairing by Pseudoduplication

A system which accomplishes checking by pseudoduplication is disclosed in U.S. Patent 3,660,646. In essence, the disclosed system performs logical or arithmetic functions in separate data paths. The results obtained in the separate paths are compared. An inequality indicates error or component failure.

A pseudoduplicated system is one in which a limited number of failing elements may be replaced by a duplicate. Typically, the system will be provided with wider data paths than required but less than a full duplicate. Where a failure occurs in one or more of the paths, up to the duplicated limit, the failing paths are bypassed, thus permitting normal circuit operations without the need for replacement of the failing component. This technique of failure correction is particularly useful with LSI, since otherwise a single component failure would require replacement of a large number of functional components.

A simplified version showing the technique applied to a shift register function is illustrated in the drawing. A multiposition shift register 10, having several extra positions, is connected to a serial data input and output by gate circuits 11. The gate circuits provide the actual stage-to-stage interconnection for shift register
10. The gates for each stage are duplicated so that a single failure within a stage module will permit a bypass for that stage. A control word register 12 controls the arrangement of the gates 11.

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