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:
May. 19, 2009
Filed:
Mar. 20, 2007
Yun-sang Lee, Yongin-si, KR;
Yun-Sang Lee, Yongin-si, KR;
Samsung Electronics Co., Ltd., Suwon-si, Gyeonggi-do, KR;
Abstract
A semiconductor memory device may include a memory cell array, a redundancy address decoder, a defective address detection unit, and a defective address program unit. The memory cell array includes a plurality of memory cell groups and a predetermined number of redundancy memory cell groups. The redundancy address decoder includes a predetermined number of redundancy decoders for accessing at least one group of the redundancy memory cell groups when a first defective address is identical to an externally applied address. The defective address detection unit performs a write operation and a read operation on the memory cell array during a test operation to detect a defective address, and outputs the detected defective address as the first defective address when the same defective address is detected a predetermined number of times or more. The defective address program unit receives and programs the first defective address output from the defective address detection unit during a program operation.