Method and apparatus for achieving multilevel inclusion in multilevel cache hierarchies
US5369753A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 27, 1993 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | May 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0831
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for achieving multilevel inclusion in a computer system with first and second level caches. The caches align on a "way" basis by their respective cache controllers communicating with each other which blocks of data they are replacing and which of their cache ways are being filled with data. On first and second level cache read misses the first level cache controller provides way information to the second level cache controller to allow received data to be placed in the same way. On first level cache read misses and second level cache read hits, the second level cache controller provides way information to the first level cache controller, which places data in the indicated way. On processor writes the first level cache controller caches the writes and provides the way information to the second level cache controller which uses the way information to select the proper way for data storage. An inclusion bit is set on data in the second level cache that is duplicated in the first level cache. On a second level cache snoop hit, the second level cache controller checks the respective inclusion bit to determine if a copy of this data also resides in the first level cache. The fi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.