Journal of Low Power Electronics and Applications (Dec 2022)

Evaluation of Dynamic Triple Modular Redundancy in an Interleaved-Multi-Threading RISC-V Core

  • Marcello Barbirotta,
  • Abdallah Cheikh,
  • Antonio Mastrandrea,
  • Francesco Menichelli,
  • Marco Ottavi,
  • Mauro Olivieri

DOI
https://doi.org/10.3390/jlpea13010002
Journal volume & issue
Vol. 13, no. 1
p. 2

Abstract

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Functional safety is a key requirement in several application domains in which microprocessors are an essential part. A number of redundancy techniques have been developed with the common purpose of protecting circuits against single event upset (SEU) faults. In microprocessors, functional redundancy may be achieved through multi-core or simultaneous-multi-threading architectures, with techniques that are broadly classifiable as Double Modular Redundancy (DMR) and Triple Modular Redundancy (TMR), involving the duplication or triplication of architecture units, respectively. RISC-V plays an interesting role in this context for its inherent extendability and the availability of open-source microarchitecture designs. In this work, we present a novel way to exploit the advantages of both DMR and TMR techniques in an Interleaved-Multi-Threading (IMT) microprocessor architecture, leveraging its replicated threads for redundancy, and obtaining a system that can dynamically switch from DMR to TMR in the case of faults. We demonstrated the approach for a specific family of RISC-V cores, modifying the microarchitecture and proving its effectiveness with an extensive RTL fault-injection simulation campaign.

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