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Progress on AppNote 011

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Clifford Wolf 2013-12-07 11:58:55 +01:00
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manual/APPNOTE_011_Design_Investigation.tex
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@ -686,15 +686,16 @@ of the module and wants to carefully read all the debug output created by the
commands in order to spot a problem. This kind of troubleshooting is much easier
if the circuit under investigation is encapsulated in a separate module.
\begin{figure}[b]
\includegraphics[width=\linewidth,trim=0 0cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_00.pdf} \\ \centerline{\tt memdemo} \vskip1em
\includegraphics[width=\linewidth,trim=0 0cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_01.pdf} \\ \centerline{\tt scramble} \vskip1em
\includegraphics[width=\linewidth,trim=0 0cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_02.pdf} \\ \centerline{\tt outstage} \vskip1em
\includegraphics[width=\linewidth,trim=0 0cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_03.pdf} \\ \centerline{\tt selstage} \vskip1em
Fig.~\ref{submod} shows how the {\tt submod} command can be used to split the
circuit from Fig.~\ref{memdemo_src} and \ref{memdemo_00} into its components.
The {\tt -name} option can is used to specify the name of the new module and
also the name of the new cell in the current module.
\begin{figure}[t]
\includegraphics[width=\linewidth,trim=0 1.3cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_00.pdf} \\ \centerline{\tt memdemo} \vskip1em\par
\includegraphics[width=\linewidth,trim=0 1.3cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_01.pdf} \\ \centerline{\tt scramble} \vskip1em\par
\includegraphics[width=\linewidth,trim=0 1.3cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_02.pdf} \\ \centerline{\tt outstage} \vskip1em\par
\includegraphics[width=\linewidth,trim=0 1.3cm 0 0cm]{APPNOTE_011_Design_Investigation/submod_03.pdf} \\ \centerline{\tt selstage} \vskip1em\par
\begin{lstlisting}[basicstyle=\ttfamily\scriptsize]
select -set outstage y %ci2:+$dff[Q,D] %ci*:-$mux[S]:-$dff
select -set selstage y %ci2:+$dff[Q,D] %ci*:-$dff @outstage %d
@ -707,8 +708,61 @@ submod -name selstage @selstage
\label{submod}
\end{figure}
\subsection{Evaluation of combinatorial circuits}
\FIXME{} --- submod, eval, sat
The {\tt eval} command can be used to evaluate combinatorial circuits.
For example (see Fig.~\ref{submod} for the circuit diagram of {\tt selstage}):
{\scriptsize
\begin{verbatim}
yosys [selstage]> eval -set s2,s1 4'b1001 -set d 4'hc -show n2 -show n1
9. Executing EVAL pass (evaluate the circuit given an input).
Full command line: eval -set s2,s1 4'b1001 -set d 4'hc -show n2 -show n1
Eval result: \n2 = 2'10.
Eval result: \n1 = 2'10.
\end{verbatim}
\par}
So the {\tt -set} option is used to set input values and the {\tt -show} option
is used to specify the nets to evaluate. If no {\tt -show} option is specified,
all selected output ports are used per default.
If a necessary input value is not given, an error is produced. The option
{\tt -set-undef} can be used to instead set all unspecified input nets to
undef ({\tt x}).
The {\tt -table} option can be used to create a truth table. For example:
{\scriptsize
\begin{verbatim}
yosys [selstage]> eval -set-undef -set d[3:1] 0 -table s1,d[0]
15. Executing EVAL pass (evaluate the circuit given an input).
Full command line: eval -set-undef -set d[3:1] 0 -table s1,d[0]
\s1 \d [0] | \n1 \n2
---- ------ | ---- ----
2'00 1'0 | 2'00 2'00
2'00 1'1 | 2'xx 2'00
2'01 1'0 | 2'00 2'00
2'01 1'1 | 2'xx 2'01
2'10 1'0 | 2'00 2'00
2'10 1'1 | 2'xx 2'10
2'11 1'0 | 2'00 2'00
2'11 1'1 | 2'xx 2'11
Assumend undef (x) value for the following singals: \s2
\end{verbatim}
}
\subsection{Solving combinatorial SAT problems}
\FIXME
\subsection{Solving sequential SAT problems}
\FIXME
\section{Conclusion}
\label{conclusion}