Research Of Communication Strategy For Multi Cores On NoC

With increasing the frequency of CPU comes to the end, it is hard to enhance the speed of single-processor. Large-scale multi-core technology as the mainstream effectively improves the performance. If sticking to single core development, chip design will face the interconnect delay, memory bandwidth, power limits and other performance bottlenecks. However, as semiconductor technology into the nanometer era, NoC (Network on Chip), represented by multi-core technology, has become a mainstream technology as the next generation of integrated circuit design. This paper designed a NoC which use open-source processors called OpenRISC1200 by Open Cores organizations and arbitrated bus. This paper focuses on establishing multi-core systems and multi-core's communication. Single-core OpenRISC1200 is based on WISHBONE bus. In order to be compatible with WISHBONE bus used in OpenRISC1200 and assure information exactly transmitting in the intermediate nodes, multi-core system needs to encapsulate the single-core's bus.Based on hypercube interconnection, NoC in the intermediate nodes uses adaptively local-identity route algorithm. Information is transmitted in the form of worm-switching. For using adaptively routing algorithm, information is prone to deadlock. Hold-release policy invalidly solves the deadlock above the route algorithm. According to The hold-release policy has defects especially in multicast. Poll-transmission policy on the basis of inputting ports solves the buffer capacity and confirming process.Through the results can be seen, based on hypercube interconnection, local-identity routing algorithm in the NoC makes the information which comes from source node to destination nodes to achieve accurately and timely. Poll-transmission policy solves the high delay happened in buffer. At last, this paper point out the deficiency and research direction.