Direct input/output in a virtual memory system

Number of patents in Portfolio can not be more than 2000

United States of America Patent

PATENT NO 4777589
SERIAL NO

06750578

Stats

ATTORNEY / AGENT: (SPONSORED)

Importance

Loading Importance Indicators... loading....

Abstract

See full text

A virtual memory system is used to control access to I/O device address space in accordance with a preferred embodiment of the present invention. In a virtual memory system, access to pages within a processor's address space are assigned to each application program. Each I/O device is assigned two pages of address space. One page is considered to be privileged, and the other unprivileged. Each I/O device register is associated with an address in each of the two pages of its I/O device address space. Address space is global. What is meant by global is that physical memory locations map to the same virtual memory space regardless of what process is running on the processor. Access codes accompanied by a write disable bit are used to control process access to various addresses.

Loading the Abstract Image... loading....

First Claim

See full text

Family

Loading Family data... loading....

Patent Owner(s)

Patent OwnerAddress
HEWLETT-PACKARD COMPANYPALO ALTO CA

International Classification(s)

  • [Classification Symbol]
  • [Patents Count]

Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Boettner, Steven C San Jose, CA 2 103
Bryg, William R Saratoga, CA 38 1713
James, David V Palo Alto, CA 72 2434
Liu, Tso-Kai Saratoga, CA 1 75
Mahon, Michael J San Jose, CA 12 449
Miller, Terrence C Menlo Park, CA 9 654
Worley, Jr William S Saratoga, CA 16 841

Cited Art Landscape

Load Citation

Patent Citation Ranking

Forward Cite Landscape

Load Citation