Methods and apparatus for performing a write/load cache protocol
US5611070A · kind A · utility
Inventors
Key dates
| Filing date | Oct 13, 1993 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Oct 13, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0862
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A Write/Load cache protocol is described which may be used for maintaining cache coherency and performing barrier synchronization in multiprocessor computer systems, and for cooperating with prefetch mechanisms to allow data to be loaded into a central processor unit's (CPU) cache (in both single and multiprocessor systems) in anticipation of future memory references. The new protocol is defined such that when a cache observes a Write/Load command (and associated data item) on a bus to which the cache is attached, the cache is accessed and (a) if the data item is in the cache, the new value of the data item from the bus is copied into and replaces the data item in cache; and (b) if the data item is not in the cache, a new data item is created therein (preferably using the normal cache replacement policy), and the value of the data item on the bus is loaded into the cache. Thus, a protocol is provided which allows cache to be loaded via an external entity, i.e., other than the processor being directly serviced by the cache.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.