Apparatus for cache compression engine for data compression of on-chip caches to increase effective cache size

摘要

A compression engine for a cache memory subsystem has a pointer into cache tag memory and cache data memory and an interface coupled to the pointer and capable of being coupled to cache tag memory, and cache data memory. The interface reads tag information and uncompressed data from the cache and writes modified tag information and compressed data to the cache. The compression engine also has compression logic for generating compressed data and generate compression successful information, and tag line update circuitry for generating modified tag information according to the compression successful information and the tag information. Also disclosed is a cache subsystem for a computer system embodying the compression engine, and a method of compressing cache using the compression engine.