Low-Power Snoop Architecture for Synchronized Producer-Consumer Embedded Multiprocessing

We introduce a cross-layer customization methodology where application knowledge regarding data sharing in producer-consumer relationships is used in order to aggressively eliminate unnecessary and predictable snoop-induced cache lookups even for references to shared data, thus, achieving significant power reductions with minimal hardware cost. The technique exploits application-specific information regarding the exact producer-consumer relationships between tasks as well as information regarding the precise timing of synchronized accesses to shared memory buffers by their corresponding producers and/or consumers. Snoop-induced cache lookups for accesses to the shared data are eliminated when it is ensured that such lookups will not result in extra knowledge regarding the cache state in respect to the other caches and the memory. Our experiments show average power reductions of more than 80% compared to a general-purpose snoop protocol.