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. 15, 1999
Filed:
Mar. 14, 1997
F Erich Goetting, Cupertino, CA (US);
Scott O Frake, Cupertino, CA (US);
Xilinx, Inc., San Jose, CA (US);
Abstract
A flip-flop includes non-volatile storage of a bit for encryption purposes or other applications. The non-volatile bit remains in the flip-flop, substantially unaltered, irrespective of normal flip-flop operation, and is available to be recalled whenever it is needed. The flip-flop is implemented using a pair of CMOS cells. Each cell includes a floating gate formed by connecting the gates of an n-mos transistor and a p-mos transistor. One of the two floating gates is selectively charged by hot electron injection, thereby raising the threshold of that cell. Depending upon which of the two cells is programmed by this process, the flip-flop outputs a logic one or a logic zero during a recall mode.