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:
Dec. 17, 2002
Filed:
Sep. 28, 2001
Fujitsu Limited, Kawasaki, JP;
Abstract
A redundancy information region having memory cells for retaining relief information indicating the locations of defective memory cells is arranged closer to at least one of a word driver or a plate driver than a memory cell region and a redundancy memory cell region. Since the memory cells of the redundancy information region start operation earlier, a relief/no-relief judgment can be made earlier, allowing reduction in access time. Besides, in memory cell operations, the defective memory cells are deselected in accordance with address information held in a redundancy address region. Redundancy memory cells for relieving the defective memory cells are selected in accordance with the relief information held in a redundancy flag region. Since the redundancy memory cells are selected without using the address information, it is possible to reduce the time that elapses before the redundancy memory cells are selected after the selection of word lines.