Designing efficient FPGA tiles for power-constrained ultra-low-power applications

High power consumption of Field-Programmable Gate Arrays (FPGAs) makes them a less attractive choice for ultra-low-power applications. Depending on the power source, ultra-low-power systems could either be constrained by power (energy harvesting systems) or by energy (battery-powered systems). In this work, we are evaluating four different FPGA tiles to find the one that is better suited for both power-constrained and energy-constrained systems. Ultra-low-power systems apply voltage downscaling to reduce the power consumption. However, the operational limits of different blocks do not allow conventional FPGA to be operated at very low voltage. Therefore, their logic capacity can only be increased by 2–4 times by applying voltage downscaling. In this work, we identified the blocks in FPGA tiles that are vulnerable at low voltage and replace them with alternate circuits. The results indicate that, by slight modifications in the conventional FPGA tiles, logic capacity can be increased up to 8 times, whereas power-delay-product can be reduced up to 74%.