coriolis/stratus1/doc/stratus/man_net.tex

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2010-07-12 10:33:22 -05:00
\subsubsection{Name}
SignalIn, SignalOut ... -- Creation of nets
\subsubsection{Synopsys}
\begin{verbatim}
netA = SignalIn ( "a", 4 )
\end{verbatim}
\subsubsection{Description}
How to create and use nets.
\subsubsection{Nets}
Differents kind of nets are listed below :
\begin{itemize}
\item \verb-SignalIn- : Creation of an input port
\item \verb-SignalOut- : Creation of an output port
\item \verb-SignalInOut- : Creation of an inout port
\item \verb-SignalUnknown- : Creation of an input/output port which direction is not defined
\item \verb-TriState- : Creation of a tristate port
\item \verb-CkIn- : Creation of a clock port
\item \verb-VddIn- : Creation of the vdd alimentation
\item \verb-VssIn- : Creation of the vss alimentation
\item \verb-Signal- : Creation of an internal net
\end{itemize}
\subsubsection{Parameters}
All kind of constructors have the same parameters :
\begin{itemize}
\item \verb-name- : the name of the net (mandatory argument)
\item \verb-arity- : the arity of the net (mandatory argument)
\item \verb-indice- : for bit vectors only : the LSB bit (optional argument : set to 0 by default)
\end{itemize}
\indent Only \verb-CkIn-, \verb-VddIn- and \verb-VssIn- do not have the same parameters : there is only the \verb-name- parameter (they are 1 bit nets).
\subsubsection{Functions and methods}
Some functions/methods are provided in order to handle nets :
\begin{itemize}
\item function \verb-Cat- : Concatenation of nets, beginning with the MSB
\begin{verbatim}
Inst ( 'DpgenInv'
, map = { 'i0' : Cat ( A, B )
, 'nq' : S
, 'vdd' : vdd
, 'vss' : vss
}
)
\end{verbatim}
\indent Or :
\begin{verbatim}
tab = []
tab.append ( A )
tab.append ( B )
Inst ( 'DpgenInv'
, map = { 'i0' : Cat ( tab )
, 'nq' : S
, 'vdd' : vdd
, 'vss' : vss
}
)
\end{verbatim}
\indent If A and B are 2 bits nets, the net \verb-myNet- will be such as :
\begin{verbatim}
myNet[3] = A[1]
myNet[2] = A[0]
myNet[1] = B[1]
myNet[0] = B[0]
\end{verbatim}
\item function \verb-Extend- : Creation of a net which is an extension of the net which it is applied to
\begin{verbatim}
temp = Signal ( "temp", 5 )
tempExt = Signal ( "temp_ext", 8 )
tempExt <= temp.Extand ( 8, 'one' )
\end{verbatim}
\item method \verb-Alias- : Creation of an alias name for a net
\begin{verbatim}
cin.Alias ( c_temp[0] )
cout.Alias ( c_temp[4] )
for i in range ( 4 ) :
Inst ( "Fulladder"
, map = { 'a' : a[i]
, 'b' : b[i]
, 'cin' : c_temp[i]
, 'sout' : sout[i]
, 'cout' : c_temp[i+1]
, 'vdd' : vdd
, 'vss' : vss
}
)
\end{verbatim}
\end{itemize}
\begin{htmlonly}
\subsubsection{Example}
You can see a concrete example at : \hyperref[ref]{\emph{Example}}{}{Example}{secexample}
\end{htmlonly}
\subsubsection{Errors}
Some errors may occur :
\begin{itemize}
\item \verb-Error in SignalIn :-\\\verb-the lenght of the net must be a positive value.-\\One can not create a net with a negative lenght.
\end{itemize}
\begin{htmlonly}
\input{see_also}
\end{htmlonly}