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:
Nov. 20, 2001
Filed:
Feb. 05, 2001
Macronix International Co., Ltd., Hsinchu, TW;
Abstract
A method of controlling the multi-state NROM. A program is executed to inject electric charges that are trapped inside a nitride layer of the NROM. The amount of electric charges trapped inside the nitride layer is controlled so that the memory cell can have different threshold voltages. To read from the memory cell, a first variable voltage is applied to the gate electrode. According to the range of a second variable voltage applied to the drain terminal, three different potential levels, from the smallest to the largest, including a first potential level, a second potential level and a third potential level are set. The second input voltage is adjusted to the first potential level. When a high current is sensed, a first storage state is assumed. If little current is detected, the second input voltage is adjusted to the second potential level. When a high current is sensed, a second storage state is assumed. On the other hand, if little current is detected, the second input voltage is adjusted to the third potential level. Similarly, if a high current is sensed, a third storage state is assumed. Conversely, when little current is detected, a fourth storage state is assumed.