XYZ-ZXY: A minimal routing algorithm for dynamic thermal management in 3D NoCs

This paper proposes and evaluates an efficient routing algorithm for dynamic thermal management in 3D NoCs. The proposed routing algorithm conducts packets toward routers which either have lower traffic or have more cooling efficiency. To do this, the proposed routing algorithm utilizes the horizontal and the vertical traffic distribution techniques to uniformly distribute generated heat over the chip area. In the first technique, i.e., the horizontal technique, packets are routed by XY or YX routing algorithm to conduct packets to the borders of the chip to generate more uniform heat density. The second technique selects one of XYZ or ZYX routing algorithms for a packet to divert the packet form the overheated layers of the chip. The proposed routing algorithm is analyzed by turn model to achieve deadlock freedom without requiring any hardware support in NoC routers. Traffic-thermal co-simulation platform is used to evaluate the performance/thermal behavior of the proposed routing algorithm in a wide range of working conditions. Results show that the proposed routing algorithm 1) relieves at least 60% of overheated routers, 2) improves the temperature variance by at least 38% and 3) improves the traffic variance by at least 25%. These are achieved at the cost of at most 37% overhead in the average packet latency in the network.