REDUCING SNOOP-ENERGY IN SHARED BUS-BASED MPSOCS BY FILTERING USELESS BROADCASTS

摘要

A device and a method for reducing power for cache consistency operation in shared bus-based MPSOCs(MultiProcessor System-On-Chip) by filtering useless broadcasts are provided to reduce power needed for the cache consistency operation by referring to the data sharing status of caches before a cache consistency request is broadcasted. A snooping cache(460) stores a sharing status of cached data, and filters a cache consistency request for the data not shared by remote L1 caches(420) when the cache consistency request is received. A multi-split bus comprises bus fragments(430) and a bus splitter(440), and transfers the cache consistency request selectively to only the remote cache storing the shared status of the cached data, and sharing the data shared with the remote caches when the cache consistency request is received. Power consumption for cache consistency operation is reduced by filtering the cache consistency request if a need for broadcasting the cache consistency request to all remote caches is not found when the cache consistency operation is needed as the data is needed or changed by a memory(470).