Patent №
US 4,777,589
Granted
1988-10-11
Filed 1985
Owner
HEWLETT-PACKARD COMPANY, PALO ALTO CA., A CORP. OF
Lab
—
AI components
1
hardware
Assignment
Recorded
Dataset
AIPD
2023_r1 edition
Application
06750578
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.
AI classification
Ownership
HEWLETT-PACKARD COMPANY, PALO ALTO CA., A CORP. OF
assignment · 44780008
Assignors
BOETTNER, STEVEN C., BRYG, WILLIAM R., JAMES, DAVID V., LIU, TSO-KAI, MAHON, MICHAEL J., MILLER, TERRENCE C., WORLEY, WILLIAM S. JR.
On an employer assignment, the assignors are typically the inventors.