Exploring a Low-Cost and Power-Efficient Hybridization Technique for 3D NoC-Bus Hybrid Architecture Using LastZ-Based Routing Algorithms

Three-dimensional (3D) integration in which multiple active silicon layers are stacked above each other and vertically interconnected offers shorter interconnection wire for Networks-on-Chip (NoC). The simple 3D NoC architectures such as Symmetric 3D Mesh NoC could not exploit the beneficial feature of a negligible inter-layer distance in 3D chips. In order to exploit the intrinsic capability of reducing the wire length in 3D ICs, 3D NoC-Bus Hybrid architecture was proposed. This architecture suffers from naive and straightforward hybridization between NoC and bus media. In this paper, an efficient hybridization scheme is presented to enhance system performance, power consumption, and area of 3D NoC-Bus Hybrid architectures. The hybridization mechanism benefiting from a rule called LastZ enables low-cost inter-layer communication architecture. In the proposed architecture, instead of using the conventional 6 × 6 routers, 5 × 6 routers were utilized which offers many advantages. To estimate the efficiency of the proposed architecture, the system has been simulated using synthetic (uniform, hotspot 10%, and Negative Exponential Distribution) traffic patterns as well as real benchmarks, including the one with an integrated videoconference application. Compared to a conventional 3D NoC-Bus Hybrid Mesh architecture, our extensive simulations reveal significant area, power, and performance improvements for the proposed LastZ-based hybridization scheme.