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. 29, 1999
Filed:
Mar. 18, 1998
Yasuhiro Fujii, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A semiconductor memory device according to this invention has a hierarchical bit line structure where a plurality of local bit lines are provided in parallel to each global bit line and some of the local bit lines in the column direction are connected to the global bit line. Such memory device further has an open bit line structure where global bit lines are provided on both sides of sense amplifiers, and has bit-line transfer circuits, provided between the global bit lines and the sense amplifiers, for isolating the global bit lines from the sense amplifiers when the sense amplifiers are activated. The use of the hierarchical bit line structure in combination with the open bit line structure enhances the layout efficiency of memory cells, and the provision of the bit-line transfer circuits overcomes a problem of erroneous data reading which would otherwise be caused by bit line noise inherent to the open bit line structure.