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:
Jan. 31, 1995
Filed:
Aug. 05, 1993
Applicant:
Inventors:
Gyle Yearsley, Boise, ID (US);
Grant Richards, Meridian, ID (US);
Assignee:
Zilog, Inc., Campbell, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; H04L / ;
U.S. Cl.
CPC ...
380-3 ; 380-4 ; 380 23 ; 380 25 ;
Abstract
A mask value generator is used to produce a mask value for deencrypting encrypted instructions from a memory. This encryption mask generator can produce a encryption mask value from a seed value and a program counter value. The seed value can stored in a memory outside the core microprocessor. The encryption mask value can be used to deencrypt instructions in an 'exclusive or' logic section.