Design And Evaluation Of A 3D-TC Thermal-Balanced Network On Chip

With the scaling down of VSLI chip size, the demands for the communication bandwidth are increasing quickly. With the development of TSV technology, the three-dimensional integrated circuit has become a reality. However, due to the high power consumption and high density of three dimensional network, the effect of temperature is becoming one of the key issues which must be faced in the three dimensional network system.First part of this thesis introduces the research present situation and the key technologies of Network-on –Chip, and then thermal model 3Dmesh cross switch router is propsoed. The thermal source of the network is divided into two parts. One is from routers, the other is from the temperature gradient between the adjacent routers. The thermal of router is decided by the corresponding hardware structure. Meanwhile, the thermal generated by temperature gradient is decided by the semiconductor material itself and its thermal resisitance.The temperature model of the network is determined by the temperature of each router.Then this thermal model is used to calculate the real-time temperature. The proposed thermal model is used to design a thermal-balanced routing algorithm and to avoid the deadlock problem. When data transmits to a node, its shortest transmission rout is judged in line with the destination node, then the data is sent to the router whose temperature is under the threshold. If the temperature of its adjacent router are all above threshold, then uses the zxy routing to complete data transmission.At last, the 3D-TCNo C network performance evaluation platform is developed, which uses the method of open loop interconnection network, Firstly, when packets are generated, they will be stored in an infinite queue of local input ports, and then is injected into the network according to the routed nodes. The open loop measurement network will isolate the data generation from the network data transmission. That is to say, the data generation and the working state of the network are independent. This method can accuretely measure the performance of the network.Experimental results show that the proposed method in this paper could effectively reduce the maximum temperature of the system and balance the temperature distribution compared with the traditional zxy routing algorithm. This reveals that the 3D-TCNo C routing algorithm not only can make the temperature distribution more balancede, but also improve the overall cooling efficinency.