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:
Jan. 16, 1996
Filed:
Jan. 20, 1995
Hidetoshi Iwai, Ome, JP;
Masaya Muranaka, Akishima, JP;
Takumi Nasu, Tsuchiura, JP;
Shunichi Sukegawa, Ome, JP;
Hitachi, Ltd., Tokyo, JP;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
There is provided a semiconductor memory device having a redundant column. This memory device has a redundant column disposed in the direction of the Y-system address, a ROM accessed by using an X-system address, a Y-system address signal having a defective cell included in the cells therein being electrically written into the ROM, a comparator circuit for comparing a signal read out from this ROM with a Y-system address signal and outputting a coincidence signal upon coincidence, and a defect relieving circuit responsive to output of the coincidence signal from this comparator circuit to cause selection of the redundant column of Y system instead of the Y-system address selection device.