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:
Jun. 19, 2001
Filed:
Nov. 24, 1999
Applicant:
Inventor:
Mohamad Chehadi, Aix-en-Provence, FR;
Assignee:
STMicroelectronics S.A., Gentilly, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C 1/606 ;
U.S. Cl.
CPC ...
G11C 1/606 ;
Abstract
A secured electrically modifiable non-volatile memory includes a circuit to determine if memory cells therein have been exposed to ultraviolet radiation. The memory includes at least one additional memory cell, called a reference cell, and an associated read circuit for detecting any erasure of the reference cell by ultraviolet radiation. At each access to the memory, the reference cell is read by the associated read circuit. If the state of the reference cell is different from its initial electrical state, then operation of the memory is stopped.