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:
Nov. 09, 1999
Filed:
Jun. 26, 1997
Tsukasa Ooishi, Hyogo-ken, JP;
Yoshio Matsuda, Hyogo-ken, JP;
Kazutami Arimoto, Hyogo-ken, JP;
Masaki Tsukude, Hyogo-ken, JP;
Kazuyasu Fujishima, Hyogo-ken, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor memory device comprises two memory cell arrays (1a, 1b) in which a block divisional operation is performed. Two spare rows (2a, 2b) are provided corresponding to the two memory cell arrays (1a, 1b). Spare row decoders (5a, 5b) are provided for selecting the spare rows (2a, 2b), respectively. One spare row decoder selecting signal generation circuit (18) used in common by the spare row decoders (5a, 5b) is provided. The spare row decoder selecting signal generation circuit (18) can be previously set so as to generate a spare row decoder selecting signal (SRE) when a defective row exists in either of the memory cell arrays (1a, 1b) and the defective row is selected by row decoder groups (4a, 4b). Each of the spare row decoders (5a, 5b) is activated in response to the spare row decoder selecting signal (SRE) and a block control signal.