Hy-BTree: An efficient Tree based topology for FPGA based NoC implementation

Due to their hierarchical structure, Binary Tree (BTree) topology can be employed in Network-on-Chip (NoC) applications. Because of its lower bisection bandwidth, the performance degradation is observed in communication intensive applications. The Fat tree topology has been proposed to overcome the disadvantages of the BTree topology. But, the complexity of the Fat Tree topology's router becomes more complicated as we move towards the root node of the tree and occupying a huge amount of hardware resources compared to the BTree variant. Instead of going for Fat Tree topology, the number of hops taken by a packet in the BTree topology can be reduced by introducing new links in the network with an increase in the bisection bandwidth. In this work, we propose a variant of BTree topology called Hy-BTree by introducing additional links at the intermediate levels of the network to reduce the number of hops taken for the communication. The proposed design is implemented on the FPGA and compared with the other topologies from state-of-the-art the FPGA based NoC architectures. A reduction in average latency and an improvement in throughput have been observed in Hy-BTree with respect to the BTree network with negligible overhead.