robin/Robin_PHD
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

JMC proof read

Browse Source
This commit is contained in:
Robin Clark 2012-07-31 19:24:18 +01:00
parent 5dceec9b41
commit 2809e5643b
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
papers/fmea_software_hardware/software_fmea.tex
View File

@ -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}.
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
ionising radiation causing bits to be erroneously altered.
@ -512,9 +512,9 @@ We now apply FMMD starting with the hardware.
\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.
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.
{
@ -553,7 +553,7 @@ from knowledge of the software systems criteria for these.
\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}.
From the function $read\_4\_20\_input()$ we have the variables $error\_flag$,
$input\_volts$ and $value$: from the function $read\_ADC()$, $timeout$, $ADCMUX$, $ADCGO$, $dval$.