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:
Oct. 01, 1996
Applicant:
Inventors:
Assignee:
Sharp Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
36518503 ; 36518518 ; 36518519 ; 36518527 ;
Abstract
There is provided a method for writing a multiple value into a nonvolatile memory capable of writing multiple value data into a floating gate type memory cell in an equal time even when the data are varied. With a specified voltage applied to a control gate of a memory cell, a drain voltage which is varied according to each of data values '11', '10' and '01' to a drain so that a write time required for setting a varied threshold voltage is equalized. By moving electrons between a floating gate and a drain through a gate insulating film, the threshold voltage of the memory cell is set.