Exploration Of Topology And Mapping Algorithm For Thermal-traffic Balanced 3D NoC-Bus Hybrid Architecture

Compared with 2D NoC, 3D NoC has the advantages of short global wiring, low network delay and low power consumption of communication. But the stacking way and the high density of transistor layout bring the serious problem of heat dissipation. The design of topology and mapping algorithm not only has a very important influence on the traffic, the delay and the temperature of the system, but aslo is the breakthrough to slove the problem of heat dissipation.Through improving the dynamic time division multiplex access(dTDMA) bus arbitration algorithm and the router-bus interface, this paper first studies on the vertical bus of the 3D NoC-Bus hybrid architecture and proposes a multi dynamic time division mulitiple access(md TDMA) bus, which can change the number and size at the same time dynamicly. The proposed mdTDMA bus not only inherits the high utilization rate of dTDMA, but aslo improves the real-time performance and fairness of the bus arbitration mechanism. Combined with deep analysis of the Mesh and Torus topology, this paper proposes a traffic-thermal balanced topology named BTorus and its routing algorithm. The topology can distribute more traffic to the edge of the chip, which provides a physical basis of traffic-thermal balance for 3D NoC and it is favorable for chip cooling. Based on the BTorus topology and the mdTDMA bus, a 3D No C-Bus hybrid architecture named 3D NoC-Bus BTorus is built, which has the characteristic of thermal-traffic balance. After the sufficient research on the data trasmission characteristics of energy consumption and delay in the vertical bus, a B-T mapping algorithm is proposed, which takes power and traffic into account and can ensure temperature balance from the control of traffic and power minimization of the 3D NoC hybrid architecture.A simulation of the proposed 3D NoC-Bus BTorus topology and B-T mapping algorithm is implemented, and its results show that 3D NoC-Bus BTorus has good thermal-traffic balanced performance and communication performance of low latency and high throughput. Take the 4×4×4 size of 3D NoC-Bus BTorus as example, compared with 3D Mesh, when the network closes to saturated condition, the throughput of 3D NoC-Bus BTorus is increased by 13% and the network delay of that is reduced by 17.9%. B-T mapping algorithm can compromise the two optimization objectives, the minimum power consumption and traffic balance, which is a good solution for the thermal-traffic balanced problem of 3D NoC-Bus hybrid architecture.