Reference and change table storage system for virtual memory data processing system having a plurality of processors accessing common memory
US5155834A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1990 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Jan 11, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/08
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a multi-processor virtual memory system 10 a Reference and Change Table (RCT) 36 is located upon a Memory Control Unit (MCU) 25. The RCT 36 is responsive to accesses to any of the Memory Modules (MMs) 24-26 and generates and maintains status bits indicative of the reference and change activity of all of page frames of the system memory that are accessible by any of the CPUs 12A-12n. In that each of the CPUs 12A-12n has access to the page frames of the system memory each of the CPUs 12A-12n is further enabled, via privileged instructions, to test (read) and reset (clear) over a system bus 16 the memory page frame status bits that are generated and stored by the RCT 36. As such, the RCT provides to multiple data processors a centralized and readily accessible store of status information relating to page frames of the system memory.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.