A Triple Hybrid Interconnect for Many-Cores: Reconfigurable Mesh, NoC and Barrier

Networks-on-chip (NoC) are very efficient for point-to-point communication but are also known to provide poor broadcast and multicast performance. In this paper, we propose a triple hybrid interconnect for many-cores, consisting of a reconfigurable mesh network and a wormhole routed NoC for data communication, and a barrier network for synchronization. On an FPGA many-core prototype comprising up to 30 Microblaze soft cores we show that the reconfigurable mesh network excels for multicast and broadcast operations, while the NoC performs better for larger messages and more dynamic workloads. Experiments with a parallel Jacobi algorithm demonstrate that the combined use of all three networks delivers the highest performance.