Communication-aware task assignment algorithm for MPSoC using shared memory

In a Multi-Processor System-on-a-Chip (MPSoC) based on Network-on-Chip (NoC), which processes massive data in a distributed fashion, communication is concentrated on shared memory. This paper proposes an assignment algorithm that can minimize the total power consumption for data communication in executing application programs and a switch structure that can reduce communication congestion resulting from simultaneous accesses to the shared memory. The proposed assignment algorithm gives higher priority to the tasks transferring a larger amount of data to shared memory, so that these tasks can be assigned to the PEs close to shared memory. The proposed switch structure was designed to support multi-port memory, which is often used for shared memory. The ports of the proposed switch are dedicated to be connected with in/out ports of shared memory in order to increase communication bandwidth between PEs and shared memories. By adopting the proposed scheme, the congestion caused by the concentrated requests to the memory can be reduced. Experimental results show that power consumption for transferring data in High-Definition (HD) H.264 decoder, Motion-JPEG decoder, MP3 decoder and 2D Wavelet transform codes has been reduced by 23.9% on the average, when compared with the cases of applying the well-known FC, BN and SA algorithms. The area has been slightly increased by 1.7% compared to conventional NoC structures.