Speculative cache snoop during DMA line update
US5802576A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1996 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Jul 1, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0835
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for facilitating the streaming of data over a system bus between a memory and a DMA device. This is accomplished by doing a speculative cache look-up, or snoop, on a next cache line during or immediately following the access of a current cache line. This is done for DMA transfers when the first DMA address is received, and before subsequent addresses are received. Thus, a determination of whether the cache line is in the cache can be done in advance, allowing the next cache line of data to stream over the bus to or from the cache without waiting for the next address from the system bus or requiring a rearbitration for the system bus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.