Exploring a low-cost inter-layer communication scheme for 3D networks-on-chip

In this paper, a low-cost 3D NoC architecture based on Bidirectional Bisynchronous Vertical Channels (BBVC) is proposed as a solution to mitigate high area footprints of vertical interconnects. Dynamically self-configurable BBVCs, which can transmit flits in either direction, enable a system to benefit from a high-speed bidirectional channel instead of a pair of unidirectional channels for inter-layer communication. In this architecture, low-latency attribute of the interconnect TSVs enables the system to support a higher frequency for vertical channels, better bandwidth utilization, lower area footprint, and improved routability. In addition, an enhanced BBVC-based communication scheme, called Direct Vertical Channel Access, is presented to enable an express inter-layer communication. Experimental results verify that the proposed architecture can reduce up to 47% TSV area footprint with a negligible performance degradation.