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:
Feb. 23, 1988
Filed:
Mar. 02, 1987
Masahiro Yoshida, Tachikawa, JP;
Kanji Oishi, Koganei, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The semiconductor memory device includes at least two memory arrays, a first selection circuit which selects a memory cell from either one of the memory arrays in accordance with address signals, preferably two spare memory arrays and a second selection circuit which selects a memory cell from either one of the spare memory arrays. If a defective memory cell or cells are contained in one of the two memory arrays, the second selection circuit can select a spare memory cell or cells from any of the two spare memory arrays in place of the defective memory cell or cells. Thus, the spare memory arrays can be used effectively. Two sets of main amplifiers are also disposed and only one of them, which receives the data from the memory cell selected from the memory arrays or spare memory arrays, is operated. Thus, lower power consumption can be realized.