一种改进的BFT型片上网络拓扑结构

摘要

针对片上网络(NoC)资源节点之间通信的局部性,提出改进的蝴蝶型胖树(BFT)拓扑结构XBFT及相应的路由算法.该结构在BFT结构的基础上改变边的连接关系,减少了路由节点数和物理连接链路数,理论分析表明,在64个IP核的NoC中,XBFT较BFT路由器数目减少了14.3％,物理链路数减少了10.7％,XBFT结构比BFT结构拥有较小的面积开销和较低的布线难度.实验采用gpNocsim模拟器,对64节点的网络,基于局部负载模式和均衡负载模式进行性能比较.实验结果表明,局部负载模式下,当包注入速率低于0.6时,XBFT结构与BFT性能相当,随着包注入速率继续增加,XBFT性能优于BFT.均衡负载模式下,当包注入速率低于0.4时,XBFT网络性能比BFT稍优,包注入速率大于0.4,XBFT网络性能比BFT稍差.%This paper presents an improved BFT topology, XBFT, and a touting algorithm to point at the local communication of network-on-chip. The new structure changes some edges link, substracts the number of routers on the BFT topology to form XBFT. The theoretical analysis result shows that when the network size is 64 the number of routers of XBFT topology are less 14.3% than the number of routers of BFT topology and the number of physical links of XBFT topology are less than 10.7% the physical links of BFT topology. The new structure has less area cost and less layout cost than the BFT structure. Simulator analysis bases on gpNocsim using local traffic pattern and uniform traffic pattern, when the network size is 64. The simulation result shows for local traffic pattern, the average latencies of XBFT topology is less than the average latencies of BFT topology, when the injection rate of package less than 0.6, the XBFT and BFT topology had the same performance; When the injection rate greater than 0.6, the latencies of BFT is more than XBFT topology, the performance of XBFT is better than BFT topology. For uniform traffic pattern, when the injection rate is less than 0.4, the XBFT and BFT topology had the same performance; When the injection rate is greater than 0.4, the latencies of XBFT n more than BFT topology.