Interconnect-aware low-power high-level synthesis
Interconnects (wires, buffers, clock distribution networks, multiplexers, and busses) consume a significant fraction of total circuit power. In this paper, we demonstrate the importance of optimizing on-chip interconnects for power during high-level synthesis. We present a methodology to integrate interconnect power optimization into high-level synthesis. It not only reduces datapath unit power consumption in the resultant register-transfer level architecture, but also optimizes interconnects for power. We take into account physical design information and coupling capacitance to estimate interconnect power consumption accurately for deep sub-micron technologies. We show that there is significant spurious (i.e., unnecessary) switching activity in the interconnects and propose techniques to reduce it. Compared with interconnect-unaware power-optimized circuits, interconnect power can be reduced by 53.1% on average, while overall power is reduced by an average of 26.8%, with negligible area overhead. Compared with area-optimized circuits, the interconnect power reduction is 72.9% and overall power reduction is 56.0%, with 44.4% area overhead. The power reductions are obtained solely through switched capacitance reduction (no voltage scaling is assumed).
interconnect high-level synthesis low power