High speed method for maintaining cache coherency in a multi- level, set associative cache hierarchy

摘要

A cache memory system includes multiple cache levels arranged in a hierarchical fashion. A data item stored in a higher level cache level is also stored in all lower level caches. The most recent version of a data item is detected during an initial lookup of a higher level cache. The initial lookup of a higher level cache includes a comparison of address bits for the next lower level cache. Thus the most recent version of a data item is able to be detected without additional lookups to the lower level cache.