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:
Jul. 16, 1996
Filed:
Dec. 06, 1994
Vincent L Fong, Cuppertino, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A flash memory system including an array of flash memory cells and at least one programmed reference cell and at least one erased reference cell disposed in a common integrated circuit. Memory array read operations are carried out by reading the two reference cells and the target cell of the memory array. The two reference cells produce a programmed reference output and an erased reference output which are averaged to provide a reference value to be compared with the read output of the target cell. In that the reference value is derived by on-chip programmed and erased cells, the reference value will automatically adapt to changes in the fabrication process, temperature, operating voltages and the like. Preferably, the reference cell outputs are also utilized to adaptively control the programming and erasing of the memory array cells so as to control the erased and programmed threshold voltages of the array cells.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile