Removable processor board having first, second and third level cache system for use in a multiprocessor computer system
US5829027A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1997 |
| Grant date | Oct 27, 1998 |
| Priority date | — |
| Expiry date | Mar 31, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0897
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system which utilizes processor boards including a first level cache system integrated with the microprocessor, a second level external cache system and a third level external cache system. The second level cache system is a conventional, high speed, SRAM-based, writeback cache system. The third level cache system is a large, writethrough cache system developed using conventional DRAMs as used in the main memory subsystem of the computer system. The three cache systems are arranged between the CPU and the host bus in a serial fashion. Because of the large size of the third level cache, a high hit rate is developed so that operations are not executed on the host bus but are completed locally on the processor board, reducing the use of the host bus by an individual processor board. This allows additional processor boards to be installed in the computer system without saturating the host bus. The third level cache system is organized as a writethrough cache. However, the shared or exclusive status of any cached data is also stored. If the second level cache performs a write allocate cycle and the data is exclusive in the third level cache, the data is provided directly from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.