Proactive Thermal-Budget-Based Beltway Routing algorithm for thermal-aware 3D NoC systems

The thermal problems of three-dimensional Network-on-Chip (3D NoC) systems become more serious because of die stacking. Besides, for high-performance requirement, the minimal adaptive routing algorithms result in unbalanced traffic load and worse temperature distribution in the system. On the other hand, the conventional selection strategies determine the routing path based on the traffic information, which leads to unawareness of the potential thermal hotspot and huge performance impact. To solve the problems, in this paper, we first define a novel thermal-aware routing index, Mean Time To Throttle (MTTT), which represents the remaining active time of the node before the temperature achieves the alarming level. Based on the information of MTTT, we propose a Proactive Thermal-Budget-Based Beltway Routing (PTB³R) to balance the temperature distribution of the NoC system. The experimental results show that the proposed PTB³R can help to reduce the number of throttled nodes by 25.56%~86.95% and improve network throughput by around 15.04%~19.87%.