GLOBAL MODIFIED INDICATOR TO REDUCE POWER CONSUMPTION ON CACHE MISS

摘要

A processor includes a cache memory having at least one entry managedaccording to a copy-back algorithm. A global modified indicator (GMI)indicates whether any copy-back entry in the cache contains modified data. Ona cache miss, if the GMI indicates that no copy-back entry in the cachecontains modified data, data fetched from memory are written to the selectedentry without first reading the entry. In a banked cache, two or more bank-GMIs may be associated with two or more banks. In an n-way set associativecache, n set-GMIs may be associated with the n sets. Suppressing the read todetermine if the copy-back cache entry contains modified data improvesprocessor performance and reduces power consumption.