Flexible expansion of virtual memory addressing
US5732404A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Mar 24, 1998 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0292
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A multiple-word virtual address flexibly expands the virtual address space of a computer system without requiring the modification of the word size of the computer system. In a memory system having a virtual memory mapped to an absolute memory, the virtual memory is divided up into multiple levels each having a plurality of memory banks. Each memory bank has a plurality of words. The multiple-word virtual address provides a plurality of words for specifying the virtual memory level, memory bank, and offset word within the memory bank, to describe a selected memory location. Special instructions are added to the instruction set architecture to set up a window of program visibility, called a peephole, into a selected area of the expanded virtual memory. Existing programs are compatible with the multiple-word addressing scheme, and can also reference virtual memory through a defined peephole. New programs using multiple-word virtual addresses can still call procedures requiring single word virtual addresses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.