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. 26, 1990
Filed:
Aug. 03, 1988
Hitachi, Ltd., Tokyo, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
A semiconductor memory device is disclosed, in which a word line address translation unit, a data line address translation unit, a first spare memory and a second spare memory are provided in addition to a main memory to relieve a defective memory cell in the main memory. Spare word line address signals for selecting a spare word line on the first spare memory are written in the word line address translation unit, spare data line address signals for selecting a spare data line on the second spare memory are written in the data line address translation unit, and each of the word line address translation unit and the data line address translation unit is constructed of an ordinary semiconductor memory of the multi-bit output type.