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:
Jun. 05, 2001
Filed:
Dec. 13, 1999
Tomoya Kawagoe, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
After writing data into a memory cell array according to an internal address signal, data read out from each memory cell is compared with expected value data in a read out operation. When there are two spare rows and two spare columns provided, a replacement determination unit is provided for each of the sixth types of sequences sequentially replacing a memory cell row and a memory cell column. A defective address is written into four sets of storage cell trains provided corresponding to each replacement determination unit only when a defective memory cell is detected having an address differing from at least one of a row address and column address of a defective memory cell that is already stored.