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. 30, 2012
Filed:
Oct. 17, 2008
Hiroyuki Nagashima, Yokohama, JP;
Koichi Kubo, Yokohama, JP;
Yasuyuki Fukuda, Kamakura, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device comprises a memory cell array of electrically erasable programmable nonvolatile memory cells arranged in matrix, each memory cell using a variable resistor. A pulse generator generates plural types of write pulses for varying the resistance of the variable resistor based on write data. A selection circuit applies write pulses generated by the pulse generator to the memory cell. A sense amplifier executes verify read to the memory cell. A status decision circuit decides the verify result based on the output from the sense amplifier. A control circuit executes additional write to the memory cell based on the verify result from the status decision circuit.