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:
Apr. 09, 1996
Filed:
Sep. 20, 1994
Kiyoshi Fukushima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An erasable programmable read-only memory (EPROM) includes a plurality of EPROM cells arranged in a matrix having a plurality of rows and a plurality of columns, and a plurality of digit lines each connected in common to drains of the EPROM cells included in a corresponding one column of EPROM cells. A Y-selector receives a Y-address of a given address for selecting one digit line of the digit lines so as to connect the selected digit line to a sense amplifier. Each of the digit lines is connected to one of reading-inhibition circuits having a reading-inhibition information storing EPROM cell, so that when the reading-inhibition information storing EPROM cell of the reading-inhibition circuits are in a written condition, the digit line is forcibly maintained at a predetermined logic level. The EPROM can inhibit the reading of any bit or bits and any area of an EPROM.