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:
Oct. 05, 1993
Filed:
Sep. 28, 1990
James M Sibigtroth, Round Rock, TX (US);
Michael W Rhoades, Austin, TX (US);
George G Grimmer, Jr, Austin, TX (US);
Susan W Longwell, Austin, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A data processor with memory within a single integrated circuit package provides a programmable 'secure mode' of operation to selectively restrict access and protect information stored in its memory. The secure mode of operation is included in addition to a 'single chip mode' wherein the data processor accesses both data and instructions strictly from within the single integrated circuit package. An 'expanded mode' of operation also exists wherein the data processor may access either internal or external memory for both instructions and data. The secure mode of operation restricts accesses of instructions to memory contained within the single integrated circuit while allowing data accesses to memory either internal or external to the integrated circuit. The secure mode is accomplished by selectively isolating internal data/instruction bus transfer activity from an external data/instruction bus.