A Novel FPGA Architecture Based on Ultrafine Grain Reconfigurable Logic Cells

In this paper, we investigate the opportunity brought by controllable-polarity transistors to design efficient reconfigurable circuits. Controllable-polarity transistors are devices whose polarity can be electrostatically programmed to be either n- or p-type. Such devices are used to build ultrafine grain computation cells. These cells are arranged into regular matrices, called MClusters, with a fixed and incomplete interconnection pattern, employed to minimize the reconfigurable interconnection overhead. We subsequently use them into field-programmable gate arrays (FPGAs). To assess this architectural scheme in an efficient and objective manner, we present a complete benchmarking tool flow and focus on the packing algorithm developed to handle the architecture. We finally perform the evaluation with widely used benchmark circuits. Leveraging the ultrafine grain cells compactness from a system-level perspective, we show that FPGAs exploiting MClusters demonstrate average savings of 43% and 23% in area and delay, respectively, as compared with the CMOS lookup table FPGA counterpart at 22-nm technological node.