Browse Prior Art Database

Protection Mechanism

IP.com Disclosure Number: IPCOM000049424D
Original Publication Date: 1982-Apr-01
Included in the Prior Art Database: 2005-Feb-09

Publishing Venue

IBM

Related People

Authors:
Hoffman, RL Mitchell, GR Soltis, FG [+details]

Abstract

A "privileged mode" flag and a set of rules for observing the meaning of that flag are implemented as part of the hardware for controlling a general purpose computer program processing unit. When in privileged mode, any instruction may reference any page of main storage by using a virtual or real address. When in nonprivileged mode, only data or instructions in those pages of main storage addressed by a virtual address may be referenced.