Heterogeneous energy-sparing reconfigurable logic: spin-based storage and CNFET-based multiplexing

Field programmable gate array (FPGA) attributes of logic configurability, bitstream storage, and dynamic signal routing can be realised by leveraging the complementary benefits of emerging devices with complementary metal oxide semiconductor (CMOS)-based devices. A novel carbon/magnet lookup table (CM-LUT) is developed and evaluated by trading off a range of mixed heterogeneous technologies to balance energy, delay, and reliability attributes. Herein, magnetic spintronic devices are employed in the configuration memory to contribute non-volatility and high scalability. Meanwhile, carbon nanotube field-effect transistors (CNFETs) provide desirable conductivity, low delay, and low power consumption. The proposed CM-LUT offers ultra-low power and high-speed operation while maintaining high endurance re-programmability with increased radiation-induced soft-error immunity. The proposed four-input one-output CM-LUT utilises 41 CNFETs and 20 magnetic tunnel junctions for read operations and 35 CNFET to perform write operations. Results indicate that CM-LUT achieves an average four-fold energy reduction, eight-fold faster circuit operation and 9.3% reconfiguration power delay product improvement in comparison with spin-based look-up tables. Finally, additional hybrid technology designs are considered to balance performance with the demands of energy consumption for near-threshold operation.