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:
Nov. 30, 1993
Filed:
Dec. 26, 1990
Applicant:
Inventor:
Mitsuhiro Hamada, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C / ; G11C / ;
U.S. Cl.
CPC ...
365200 ; 36518901 ; 371 101 ; 371 102 ; 371 103 ;
Abstract
A semiconductor memory device with a redundant configuration according to the present invention includes a roll call circuit which turns an output signal of a sense amplifier compulsorily to a signal of a predetermined logical level when a portion constituting the redundant configuration is accessed, and turns an output signal of the output control circuit to that of the same predetermined logical level when a write instruction is given outside a normal level. Whether a spare memory cell is accessed can be checked in every output and the redundant configuration can operate with stability.