by Dinesh Thakur

Bus Snooping: A mechanism for maintaining CACHE COHERENCY in MULTIPROCESSOR computers, under which each cpu's cache-control logic watches the external memory bus, looking for reads or writes made by other processors (that is, it 'snoops' on their transactions). Whenever such a transaction is detected, the cache logic enquires whether a copy of the target address exists in its own cache, and if so either writes that line back to memory or declares it invalid.