The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 1976
Filed:
Aug. 04, 1975
Edward Mark Lerner, Glendale Heights, IL (US);
David Cartwright Peterson, Neptune, NJ (US);
Terrence Thomas Quin, Holmdel, NJ (US);
Bernard George Ruel, Belmar, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
A diagnostic system is disclosed for detecting malfunctions in the access circuitry utilized to control the reading, writing, and refreshing of a plurality of semiconductor memory modules. More specifically, a pair of access circuits are provided for each module with each access circuit only controlling the accessing of predetermined bits of each word stored in that module. During read, write and refresh operations, the output signals generated by each of the two access circuits for application to the memory elements in that module are 'compared' to ensure that the memory elements are being properly accessed. Moreover, even when one memory module is accessed, the output signals of each pair of access circuits in each of the other nonaccessed modules are compared to ensure their continued operability.