Direct input/output in a virtual memory system

Details Direct input/output in a virtual memory system Direct input/output in a virtual memory system

1985-06-28

1988-10-11

Zache, Raulfe B.

Boots, shoes, and leggings

G06F 1206, G06F 1208

Patent

active

047775890

ABSTRACT:
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.

REFERENCES:
patent: 3654621 (1972-04-01), Bock
patent: 4439830 (1984-03-01), Chueh
patent: 4442484 (1984-04-01), Childs et al.
patent: 4477871 (1984-10-01), Keshlear
patent: 4493023 (1985-01-01), Gavrin et al.
patent: 4635189 (1987-01-01), Kendall
patent: 4654777 (1987-03-01), Nakamura

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