Ultra-low Energy, High Performance and Programmable Magnetic Threshold Logic

Abstract: We propose magnetic threshold-logic (MTL) design based on non-volatile spin-torque switches. A threshold logic gate (TLG) performs summation of multiple inputs multiplied by a fixed set of weights and compares the sum with a threshold. MTL employs resistive states of magnetic tunnel junctions as programmable input weights, while, a low-voltage domain-wall shift based spin-torque switch is used for thresholding operation. The resulting MTL gate acts as a low-power, configurable logic unit and can be used to build fully pipelined, high-performance programmable computing blocks. Multiple stages in such a MTL design can be connected using energy-efficient ultralow swing programmable interconnect networks based on resistive switches. Owing to memory-based compact logic and interconnect design and low-voltage, high-speed spintorque based threshold operation, MTL can achieve more than two orders of magnitude improvement in energy-delay product as compared to look-up table based CMOS FPGA.