No cache-coherence: A single-cycle ring interconnection for multi-core L1-NUCA sharing on 3D chips

Consistent with the trend towards the use of many cores in SOC and 3D chip techniques, this paper proposes a ldquosingle-cycle ringrdquo interconnection (SC_Ring) with ultra-low latency and minimal complexity. The proposed SC_Ring allows multiple single-cycle transactions in parallel. The main features of the circuit-switched design include a set of 3-ported circuit-switched routers (4~16) and a performance/timing effective arbiter. The arbiter, called ldquoBTPCrdquo, features single-cycle arbitration and routing-control by means of the novel binary-tree paths convergence and path-prediction mechanisms, to provide a highly reduced time complexity. By combining this with the integration of 3D chips, the proposed ring-based interconnection offers several advantages for hierarchical clustering in future many-core systems, in terms of cost, latency, and power reductions. Moreover, based on the proposed SC_Ring, this work realizes a ldquolevel-1 non-uniform cache architecturerdquo (L1-NUCA) for fast data communication without cache-coherency in facilitating multithreading/multi-core as a case study. Finally, experimental results show that our approach yields promising performance.