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@@ -14,12 +14,16 @@ These systems are also known as intermittent systems, since the computation happ
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Intermittent systems require software support to maintain volatile system states across power failures.
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The volatile system states (e.g., register and memory) should be saved to Non-Volatile Memory (NVM) during the execution and be recovered upon power restoration.
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When designing such technique, software designers rely on an \emph{execution model}, which abstracts the operations in the hardware and describes how intermittent system works.
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Fig.~\ref{fig:introduction} illustrates this model.
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The voltage of energy storage increases while the system collects energy from environmental sources.
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When the capacitor voltage reaches a certain threshold voltage, the computing system is powered on and starts execution.
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When the capacitor voltage hits a power-off threshold later, the computing system is powered off and energy starts to be collected again.
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The goal of software designers is to implement techniques to sustain system states across power failures with minimal overhead under such execution model.
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+Recent techniques have aimed frequent power failures.
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+This is typically considered good, better reactiveness.
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However, this model is not precise enough for recent techniques that aim frequent power failures where power failure frequency is of tens of milliseconds or even in nanosecond scale.
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The major source of inconsistency is the decoupling capacitors in the system.
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Decoupling capacitors are on-board capacitors attached to the power input/output terminal.
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