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:
Aug. 21, 1990
Filed:
May. 23, 1988
Keniti Imamiya, Yokohama, JP;
Sumio Tanaka, Oomorinishi, JP;
Junichi Miyamoto, Yokohama, JP;
Shigeru Atsumi, Tokyo, JP;
Yumiko Iyama, Yokohama, JP;
Nobuaki Ohtsuka, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A nonvolatile semiconductor memory according to this invention is so constructed that different data readout references are used in an ordinary readout mode and in a program verification mode. The different read-out references can be set by changing reference input potential VREF supplied to a differential sense amplifier for amplifying a potential derived onto a bit line from a memory cell, or by changing an input threshold level of a circuit for sensing the potential on the bit line. In this case, the readout reference in the program verification mode is set severe, or high, in comparison with that in the ordinary readout mode.