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:
Feb. 21, 1995
Filed:
Dec. 16, 1992
Taira Iwase, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A mask read only memory (ROM) has a small chip size and realizes high-speed operation and a large capacity by reducing a wiring capacity of a main bit line and a virtual ground line. Between the main bit line and the virtual ground line are three bit lines, and between the main bit line and the virtual ground line are formed two columns of memory cell transistor columns in the direction of the word line, Furthermore, the main bit line and the virtual ground line do not have zig-zag wiring, and can be configured so that the lines are in parallel straight lines so that the connections between the bit lines and the main bit lines, and between the bit lines and the virtual ground lines can be suitably made or broken by a drive current supplied via a selector line and using transistors as gates, to therefore enable the selection of a required memory cell transistor column by on-off control,