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. 28, 1994
Filed:
Dec. 24, 1992
Toshiya Sato, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A semiconductor memory device uses a memory cell array having of a plurality of cell array blocks, a redundancy cell array as a replacement for a cell array block containing a faulty memory cell, a replacement-information memory circuit for holding faulty-cell detection information and discrimination information of a cell array block containing a faulty cell in a plurality of memory transistors each, in normal mode, with source and control gate electrodes kept at ground potential and a drain electrode kept at a specified voltage of lower potential than the supply voltage. Each is forced into depletion or enhancement mode depending on the accumulated charge on the floating gate. The memory also includes a redundancy selector for outputting the redundancy signal which goes to active level by the decision based on an information held in this replacement-information memory circuit that a cell array block containing a faulty cell has been selected.