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:
May. 07, 1996
Filed:
Dec. 28, 1993
Applicant:
Inventors:
Assignee:
Dallas Semiconducter Corp., Dallas, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F / ; H04L / ;
U.S. Cl.
CPC ...
395750 ; 380-4 ;
Abstract
A nonvolatile microcontroller (or microprocessor) with improved security against tampering, including attempts at active intrusion. According to this invention, a battery-backed microcontroller includes encryption and power management functions, and is combined with a battery and a volatile semiconductor memory (e.g. an SRAM). The microcontroller supplies power to the semiconductor memory (either from a system power supply or from the battery). When a security violation is detected, the microcontroller wipes its encryption registers, and also grounds the power-output pin to the memory. This will destroy all data in the volatile memory.