Optimal switching time to minimize store energy in MTJ-based flip-flops under process and temperature variations

Kimiyoshi Usami, Daiki Yokoyama, Aika Kamei, Hideharu Amano

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Introducing a magnetic tunneling junction (MTJ) into a flip-flop enables non-volatile power gating but large store energy to MTJ is a critical concern. A two-step store (TSS) to first perform a short store for all non-volatile flip-flops and then perform a long store only at the failed ones is an effective approach to reduce energy under switching time variation. However, properties of the optimal short-store time Tshort_opt to minimize the total store energy in TSS and physical/statistical parameters affecting Tshort_opt have not been studied yet. In this paper, we propose an analytical expression for Tshort_opt,assuming that the switching time variation follows a normal distribution. The derived expression revealed that Tshort_optis affected only by μ and σ of the distribution and the long store time. Results with fabricated chips in a 40nm CMOS/MTJ hybrid process demonstrated that the analytical Tshort_optshows a good agreement with the measured value (within 8% difference) under process and temperature variations. The TSS with Tshort_optreduced energy for the store operation to 0.32X of that of the conventional long-store-only technique.

Original languageEnglish
Title of host publication2022 IEEE Nordic Circuits and Systems Conference, NORCAS 2022 - Proceedings
EditorsJari Nurmi, Dag T. Wisland, Snorre Aunet, Kristian Kjelgaard
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9798350345506
DOIs
Publication statusPublished - 2022
Event8th IEEE Nordic Circuits and Systems Conference, NORCAS 2022 - Oslo, Norway
Duration: 2022 Oct 252022 Oct 26

Publication series

Name2022 IEEE Nordic Circuits and Systems Conference, NORCAS 2022 - Proceedings

Conference

Conference8th IEEE Nordic Circuits and Systems Conference, NORCAS 2022
Country/TerritoryNorway
CityOslo
Period22/10/2522/10/26

Keywords

  • analytical expression
  • energy minimization
  • MTJ
  • non-volatile flip-flop
  • process variation
  • store energy
  • temperature fluctuation

ASJC Scopus subject areas

  • Hardware and Architecture
  • Signal Processing
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Optimal switching time to minimize store energy in MTJ-based flip-flops under process and temperature variations'. Together they form a unique fingerprint.

Cite this