The Research On Temperature And Traffic Information Sharing Mechanism In 3D NoC

Due to vertically stacking more active devices in 3D NoC, power density and length of heat transferring path are obviously increased, which brings about serious heat dissipation problem. Reducing the communication power consumption and adjusting the traffic flow distribution are the two common thermal management methods in 3D NoC and they rely on the perception of temperature and traffic information of the routing nodes. Higher accuracy and wide perception vision of state information helps to improve the overall performance while guarantees the thermal safety of the chip. However, if state information and data load were to share the same network, it would be easy to result in bandwidth contention and network congestion. Therefore, research on temperature and traffic information sharing mechanism which meets the requirements of thermal management at limited hardware cost is very important.On the basis of research and analysis of the temperature and traffic information sharing mechanism in the existing thermal management system of NoC, this paper proposes a new temperature and traffic information sharing network based on “local collection and regional exchange”. The two-dimensional planar networks in 3D NoC are divided into regions and the state information in a region is collected by an aggregation node and then exchanged through the auxiliary network between aggregation nodes. Firstly, the model of the aggregation node distribution is constructed, based on which the location of the aggregation node is optimized with Integer Linear Programming Algorithm, for the purpose of reducing the hardware cost of the information sharing network. In order to improve the transmission efficiency of the temperature and traffic information in the irregular auxiliary network, a path based multicast routing algorithm is designed in this paper, In addition, in order to reduce the extra overhead caused by the global sharing of state information and reduce the complexity of the thermal management mechanism, this paper proposes a new fusion scheme of temperature and traffic information.Simulation platform SPNT is formed by transforming the structure of Noxim. It can help to finish the performance simulation of the temperature and traffic information sharing network with different topology, different nodes distribution, different sharing cycle and different routing algorithms. Experiments show that, in 9x9x4 3D NOC, compared to the global sharing mechanism in state and load information sharing network, the designed information sharing scheme reduces the shortest period of state information transmission by 55% and the time delay by 20%. The real-time performance of network state information sharing and the overall performance of 3D NoC are improved.