MINC: Multistage interconnection network with Cache control mechanism

A novel approach to the cache coherent Multistage Interconnection Network (MIN) called the MINC (MIN with Cache control mechanism) is proposed. In the MINC, the directory is located only on the shared memory using the Reduced Hierarchical Bit-map Directory schemes (RHBDs). In the RHBD, the bit map directory is reduced and carried in the packet header for quick multicasting without accessing directory in each hierarchy. In order to reduce unnecessary packets caused by compacting the bit map in tile RHBD, a small cache called tile pruning cache is introduced in the switching element. Through the simulation, it appears that the pruning cache works mast effectively when it is provided in every switching element of the first stage, and it reduces the congestion from 50% to 90% only with 4 entries.