Method and apparatus for altering data length to zero to maintain cache coherency
US6434677B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1999 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Jun 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0831
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Increased efficiency in a multiple agent system is provided by allowing all explicit writebacks to continue during a snoop phase. Upon each incoming external bus request, an agent determines if the address of that request matches an address of data within the agent. If there is a match, the agent copies this most recent data, changes the state of the data to unmodified, changes the length of the data to zero (for pending explicit writebacks), and performs an implicit writeback. Additionally, prior to each explicit writeback, an agent determines if the address of the explicit writeback and any incoming snoop request requests are the same. If there is a match, the agent changes the data length of the explicit writeback to zero prior to issuing the explicit writeback.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.