Circuit-Level Evaluation of the Generation of Truly Random Bits with Superparamagnetic Tunnel Junctions

Many emerging alternative models of computation require massive numbers of random bits, but their generation at low energy is currently a challenge. The superparamagnetic tunnel junction, a spintronic device based on the same technology as spin torque magnetoresistive random access memory has recently been proposed as a solution, as this device naturally switches between two easy to measure resistance states, due only to thermal noise. Reading the state of the junction naturally provides random bits, without the need of write operations. In this work, we evaluate a circuit solution for reading the state of superparamagnetic tunnel junction. We see that the circuit may induce a small read disturb effect for scaled superparamagnetic tunnel junctions, but this effect is naturally corrected in the whitening process needed to ensure the quality of the generated random bits. These results suggest that superparamagnetic tunnel junctions could generate truly random bits at 20 fJ/bit, including overheads, orders of magnitudes below CMOS-based solutions.

[1]  Brian M. Sutton,et al.  Stochastic p-bits for Invertible Logic , 2016, 1610.00377.

[2]  Witold Pedrycz,et al.  A true random number generator based on parallel STT-MTJs , 2017, Design, Automation & Test in Europe Conference & Exhibition (DATE), 2017.

[3]  A. Rukhin,et al.  Statistical Testing of Random Number Generators , 1999 .

[4]  Hiroshi Imamura,et al.  Spin dice: A scalable truly random number generator based on spintronics , 2014 .

[5]  Himanshu Kaul,et al.  2.4 Gbps, 7 mW All-Digital PVT-Variation Tolerant True Random Number Generator for 45 nm CMOS High-Performance Microprocessors , 2012, IEEE Journal of Solid-State Circuits.

[6]  E. Vianello,et al.  Bio-Inspired Stochastic Computing Using Binary CBRAM Synapses , 2013, IEEE Transactions on Electron Devices.

[7]  Andrew S. Cassidy,et al.  A million spiking-neuron integrated circuit with a scalable communication network and interface , 2014, Science.

[8]  Hitoshi Kubota,et al.  Magnetic Stochastic Oscillators: Noise-Induced Synchronization to Underthreshold Excitation and Comprehensive Compact Model , 2015, IEEE Transactions on Magnetics.

[9]  Kaushik Roy,et al.  Generating true random numbers using on-chip complementary polarizer spin-transfer torque magnetic tunnel junctions , 2014, 72nd Device Research Conference.

[10]  Hitoshi Kubota,et al.  Controlling the phase locking of stochastic magnetic bits for ultra-low power computation , 2016, Scientific Reports.

[11]  Stefano Ambrogio,et al.  True Random Number Generation by Variability of Resistive Switching in Oxide-Based Devices , 2015, IEEE Journal on Emerging and Selected Topics in Circuits and Systems.

[12]  Jacques Droulez,et al.  Bayesian Inference With Muller C-Elements , 2016, IEEE Transactions on Circuits and Systems I: Regular Papers.

[13]  Weisheng Zhao,et al.  High Speed, High Stability and Low Power Sensing Amplifier for MTJ/CMOS Hybrid Logic Circuits , 2009, IEEE Transactions on Magnetics.

[14]  André van Schaik,et al.  Stochastic Electronics: A Neuro-Inspired Design Paradigm for Integrated Circuits , 2014, Proceedings of the IEEE.

[15]  Andrew S. Cassidy,et al.  Cognitive computing systems: Algorithms and applications for networks of neurosynaptic cores , 2013, The 2013 International Joint Conference on Neural Networks (IJCNN).

[16]  Chris H. Kim,et al.  A Magnetic Tunnel Junction based True Random Number Generator with conditional perturb and real-time output probability tracking , 2014, 2014 IEEE International Electron Devices Meeting.

[17]  Joseph S. Friedman,et al.  Low-Energy Truly Random Number Generation with Superparamagnetic Tunnel Junctions for Unconventional Computing , 2017, 1706.05262.

[18]  Hitoshi Kubota,et al.  Noise-enhanced synchronization of stochastic magnetic oscillators , 2014, 1405.4360.

[19]  John P. Hayes,et al.  Survey of Stochastic Computing , 2013, TECS.

[20]  Kang L. Wang,et al.  Design of high-throughput and low-power true random number generator utilizing perpendicularly magnetized voltage-controlled magnetic tunnel junction , 2017 .