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Patent Title: Process using virtual addressing in a non-privileged instruction to control the copying of a page of data in or between multiple media

Assignee: IBM
Patent Number: US5237668
Issue Date: 08-17-1993
Application Number:
File Date:10-20-1989

Abstract: A single non-privileged instruction copies a page of data from a source virtual address in an electronic medium to a destination virtual address in the same or in a different electronic storage medium, and without the intervention of any supervisory program when each medium and the virtual addresses are previously determined. The instruction is not required to specify which medium it will use, does not require its user to know what backing medium it will access, does not require main storage (MS) to be its backing medium, and allows different types of physical addressing to be used by different media. The instruction can lock any page for use in a multi-processor (MP). No physical direction of data movement is provided within the non-privileged machine instruction, which only designates virtual direction of movement. The separation of virtual direction from physical direction is done by avoiding instruction control over selection of electronic media. The non-privileged instruction can nevertheless express a preference for obtaining a copy of the destination page in an electronic medium in which the content of the page can be processed by further instructions. Also, the instruction can cause invocation of a privileged control program to avoid the need for a following condition code test instruction. A privileged instruction is also provided to wait for the completion of the unprivileged instruction and to invalidate a non-MS medium page whether it is unlocked or locked, either correctly or incorrectly.


Link to USPTO

IBM Pledge dated 1/11/2005