A New Solution to Coherence Problems in Multicache Systems

A memory hierarchy has coherence problems as soon as one of its levels is split in several independent units which are not equally accessible from faster levels or processors. The classical solution to these problems, as found for instance in multiprocessor, multicache systems, is to restore a degree of interdependence between such units through a set of high speed interconnecting buses. This solution is not entirely satisfactory, as it tends to reduce the throughput of the memory hierarchy and to increase its cost.