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.

Date of Patent:
Jan. 21, 1997

Filed:

Feb. 08, 1994
Applicant:
Inventors:

James A Kane, Newport Beach, CA (US);

Hsiao-Shih Chang, Orange, CA (US);

Graham B Whitted, III, Irvine, CA (US);

Assignee:

Meridian Semiconductor, inc., Irvine, CA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
395479 ; 395490 ; 395480 ; 395186 ; 39518701 ; 364D / ;
Abstract

A protection mechanism for a microprocessor has multiple privilege levels for tasks running on the microprocessor. A memory control unit for the microprocessor includes segment registers that identify segments of memory assigned to various tasks. When a segment register is loaded with the address of a new segment for a task, the protection mechanism within the memory control unit compares the privilege level of the task requesting the segment with the privilege level of the requested memory segment and determines whether the requested memory segment can be assigned to the requesting task. The relationship between the privilege levels is programmable to provide flexibility in generating privilege faults.


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