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:
Jun. 13, 2000
Filed:
Apr. 12, 1999
Applicant:
Inventor:
Kenji Hibino, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
365168 ; 365104 ; 365210 ;
Abstract
A semiconductor multivalued read only memory device stores multivalued data in a memory cell array and multivalued reference data in reference cell arrays, and stepwise changes word lines and reference word lines to different active levels for reading out the multivalued data and the corresponding multivalued reference data at different timings so as to determine the value of each multivalued datum by comparing it to the multivalued reference data without undesirable influence of deviated threshold and unintentionally deviated active level.