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:
Jan. 13, 1998
Filed:
Sep. 24, 1996
Applicant:
Inventor:
Toshiya Sato, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
36518529 ; 36518522 ; 36518518 ;
Abstract
In a nonvolatile semiconductor memory device, a nonvolatile counter is provided to store a number of erasing operations. A time period of a writing operation upon a memory cell is changed in accordance with the number of erasing operations. Also, a time period of an erasing operation upon memory cells is changed in accordance with the number of erasing operations.