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:
Sep. 15, 1998
Filed:
Oct. 15, 1996
Applicant:
Inventors:
Donald A Dorsey, Vernon Hills, IL (US);
Joseph M Hansen, Lake Villa, IL (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
711163 ; 34082534 ; 39518701 ;
Abstract
A microcontroller (100) with an expansion port (112) includes internal ROM (110) and EEPROM (109) and an external expansion port. The EEPROM internal to the microcontroller is programmable only when the CPU (102) is executing instructions within the internal ROM. Additionally, instructions associated with a secure operation stored in the internal ROM may not be accessed without first executing the beginning instruction of the secure operation. Attempts to begin execution of the secure operation at any point other than the legal entry address will cause the internal ROM (110) to be disabled.