Temporal Memory With Magnetic Racetracks

Hamed Vakili,Matthew W. Daniels,Advait Madhavan,Avik W. Ghosh,Mark D. Stiles,Mircea Stan,Samiran Ganguly,Mohammad Nazmus Sakib

doi:10.1109/jxcdc.2020.3022381

Abstract

Race logic is a relative timing code that represents information in a wavefront of digital edges on a set of wires in order to accelerate dynamic programming and machine learning algorithms. Skyrmions, bubbles, and domain walls are mobile magnetic configurations (solitons) with applications for Boolean data storage. We propose to use current-induced displacement of these solitons on magnetic racetracks as a native temporal memory for race logic computing. Locally synchronized racetracks can spatially store relative timings of digital edges and provide non-destructive read-out. The linear kinematics of skyrmion motion, the tunability and low-voltage asynchronous operation of the proposed device, and the elimination of any need for constant skyrmion nucleation make these magnetic racetracks a natural memory for low-power, high-throughput race logic applications.

Highlights

W HEN energy efficiency becomes the predominant metric in computing systems, the choice of information representation becomes increasingly important
We construct a complete circuit model using the 45- and 16-nm technology node obtained from the predictive technology model [28] for the driving transistors and the module discussed in Section II for the dynamics of the skyrmions in the magnetic racetracks
In this work, we utilize a novel technology based on skyrmions in magnetic racetracks to provide energy-efficient memory for temporal computing

Summary

DISPLACEMENT-BASED MAGNETIC MEMORIES AND ARRIVAL TIME CODES

W HEN energy efficiency becomes the predominant metric in computing systems, the choice of information representation becomes increasingly important. One major impediment in implementing race-logic-based temporal computing systems is the need for a memory that can store such temporally coded information. Such storage would enable more complicated processing than can be done with simple logic gates. We present a design (see Fig. 2) of a temporal memory cell that linearly converts information from the time domain to a displacement domain This is done by using current pulses of varying lengths in time to translate skyrmions corresponding distances in space. A discussion of nonidealities from imperfections in material properties and how they affect the operation of this memory

DOMAIN WALLS AND SKYRMIONS FOR MEMORY

RECOVERY OPERATION

RESULTS AND DISCUSSION

CONCLUSION