SPONGE+: A NoC-based power gating scheme for overall router column opening and closing control

Abstract

Power gating, a general-purpose power saving technique, can be used to turn off inactive routers in Networks-on-Chip (NoCs) to reduce static power consumption. SPONGE is an advanced power gating scheme. When the router is dormant, SPONGE maintains the transmission of straight packets, which occupy a large percentage of the network, through a direct bypass design. At the same time, the energized router column’s can ensure the normal transmission of turning packets. However, it suffers from increased latency due to excessive detours, aggravated load imbalance, and violation of the breakeven time (BET) constraint. To address the above problems, we propose an improved energy-efficient router architecture SPONGE+. First, we design a new router bypass architecture that enables powered-off routers to have the ability to transmit straight ahead and turn in the X-to-Y direction to reduce the bypass cost of packet transmission. Secondly, we propose a congestion-aware turning routing algorithm to balance the load among powered-on routers and improve network resource utilization. Finally, we pin improves the power gating mechanism for router columns to satisfy the BET constraint and further reduce the static power expenses. Experimental results indicate that, under real application scenarios, our scheme achieves a 27.3% reduction in static power consumption and a 10.5% decrease in packet latency compared to SPONGE, with commendable scalability.