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:
Oct. 09, 2007
Filed:
May. 09, 2005
Shigekazu Yamada, Kawasaki, JP;
Shigekazu Yamada, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A transmission transistor transmitting a drain voltage is connected to an electrically rewritable nonvolatile memory cell. An operation control circuit controls program operation for increasing a threshold voltage of the memory cell, and verify operation which is performed before and after the program operation in order to verify the threshold voltage of the memory cell. A drain switching circuit connects during the verify operation a gate of the transmission transistor to a first voltage line through which a first voltage is supplied, and it connects during the program operation the same to a second voltage line through which a second voltage is supplied. Since the second voltage can be supplied to the transmission transistor only by the switching operation (selecting operation) of the drain switching circuit, the program operation can be started shortly after the verify operation. This can shorten the data write time to the memory cell.