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JMC proof read

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Robin Clark 2012-07-31 19:24:18 +01:00
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8
papers/fmea_software_hardware/software_fmea.tex
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@ -289,7 +289,7 @@ we have yet another layer of complication.
% %
SFMEA regards, in place of hardware components, the variables used by the programs to be their equivalent~\cite{procsfmea}. SFMEA regards, in place of hardware components, the variables used by the programs to be their equivalent~\cite{procsfmea}.
The failure modes of these variables, are that they could become erroneously over-written, The failure modes of these variables, are that they could become erroneously over-written,
calculated incorrectly (due to a mistake by the programmer, or a fault in the micro-processor it is running on), or calculated incorrectly (due to a mistake by the programmer, or a fault in the micro-processor on which it is running), or
external influences such as external influences such as
ionising radiation causing bits to be erroneously altered. ionising radiation causing bits to be erroneously altered.
@ -512,9 +512,9 @@ We now apply FMMD starting with the hardware.
\section{Hardware FMEA} \section{Hardware FMEA}
The hardware FMEA requires that for each component, we consider all failure modes, The hardware FMEA requires that for each component we consider all failure modes
and the putative effect those failure modes would have on the system. and the putative effect those failure modes would have on the system.
The electronic components in our {\ft} system are, the load resistor The electronic components in our {\ft} system are the load resistor,
the multiplexer and the analogue to digital converter. the multiplexer and the analogue to digital converter.
{ {
@ -553,7 +553,7 @@ from knowledge of the software systems criteria for these.
\section{Software FMEA - variables in place of components} \section{Software FMEA - variables in place of components}
For software FMEA we take the variables used by the system, For software FMEA, we take the variables used by the system,
and examine what could happen if they are corrupted in various ways~\cite{procsfmea, embedsfmea}. and examine what could happen if they are corrupted in various ways~\cite{procsfmea, embedsfmea}.
From the function $read\_4\_20\_input()$ we have the variables $error\_flag$, From the function $read\_4\_20\_input()$ we have the variables $error\_flag$,
$input\_volts$ and $value$: from the function $read\_ADC()$, $timeout$, $ADCMUX$, $ADCGO$, $dval$. $input\_volts$ and $value$: from the function $read\_ADC()$, $timeout$, $ADCMUX$, $ADCGO$, $dval$.