Hash index table hash generator apparatus
US4215402A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1978 |
| Grant date | Jul 29, 1980 |
| Priority date | — |
| Expiry date | Oct 23, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/9014
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention discloses an apparatus for the efficient translation of virtual addresses to main storage addresses by means of a hash index table which contains main storage addresses. Hash generator apparatus is provided for generating a uniform distribution of hash index table entry addresses from a non-uniform distribution of virtual addresses in a data processing system, where the size of the hash index table is variable and is based on the size of main storage. A field of bits within the virtual address corresponding to the page identification bits are reversed in order and aligned with two groups of bits from a field of bits within the virtual address corresponding to object identification bits, and the three groups of bits are applied to an EXCLUSIVE-OR circuit. The alignment of the three groups of bits and the size of the hash index table entry addresses generated by the present invention are based on the size of the hash index table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.