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. 03, 2006
Filed:
May. 17, 2005
Shinji Takeda, Yokohama, JP;
Yoshiharu Hirata, Yokohama, JP;
Naokazu Kuzuno, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
Data read out from each memory cell in a memory cell array is compared with an expected value by a comparator, and the quality of a memory cell is determined by performing program verify and erase verify. Based on the comparison result of the comparator, a detected defective cell is repaired by replacing it with a spare cell. Every time a defective cell is replaced with a spare cell, information on the defective cell is stored in a register, and whether a defective cell exists and whether the repair is possible are determined on the basis of the information. When the repair is possible, a control circuit is caused to execute control, and a detected defective cell is repaired by replacing it with a spare cell. When the repair is impossible, the defect repair stops.