56 lines
2.2 KiB
TeX
56 lines
2.2 KiB
TeX
|
\begin{itemize}
|
||
|
|
\item Name : DpgenXnor2mask -- Programmable Mask Macro-Generator
|
||
|
|
\item Description : Generates a \verb-n- bits conditionnal XNOR mask named \verb-modelname-.
|
||
|
|
\item How it works :
|
||
|
|
\begin{itemize}
|
||
|
|
\item if the \verb-cmd- signal is set to \verb-zero-, the mask is NOT applied, so the whole operator behaves like an inverter.
|
||
|
|
\item if the \verb-cmd- signal is set to \verb-one-, the mask is applied, the output is the \emph{complemented} result of the input value \emph{XORed} with the mask (suplied by \verb-constVal-).
|
||
|
|
\item The constant \verb-constVal- is given to the macro-generator call, therefore the value cannot be changed afterward : it's hard wired in the operator.
|
||
|
|
\item A common error is to give a real constant for the \verb-constVal- argument. Be aware that it is a character string.
|
||
|
|
\end{itemize}
|
||
|
|
\item Terminal Names :
|
||
|
|
\begin{itemize}
|
||
|
|
\item cmd : mask control ( 1 bit )
|
||
|
|
\item i0 : input ( \verb-n- bits )
|
||
|
|
\item nq : output ( \verb-n- bits )
|
||
|
|
\item vdd : power
|
||
|
|
\item vss : ground
|
||
|
|
\end{itemize}
|
||
|
|
\item Parameters : Parameters are given with a map called \verb-param-.
|
||
|
|
\begin{itemize}
|
||
|
|
\item nbit : Defines the size of the generator
|
||
|
|
\item const : Defines the constant
|
||
|
|
\end{itemize}
|
||
|
|
\item Behavior :
|
||
|
|
\begin{verbatim}
|
||
|
|
nq <= WITH cmd SELECT not(i0) WHEN '0',
|
||
|
|
not(i0 xor X"0000FFFF") WHEN '1';
|
||
|
|
\end{verbatim}
|
||
|
|
\item Example :
|
||
|
|
\begin{verbatim}
|
||
|
|
class myClass ( Model ) :
|
||
|
|
def Interface ( self ) :
|
||
|
|
self._in = LogicIn ( "in", 8 )
|
||
|
|
self._cmd = LogicIn ( "cmd", 1 )
|
||
|
|
|
||
|
|
self._out = LogicOut ( "out", 8 )
|
||
|
|
|
||
|
|
self._vdd = VddIn ( "vdd" )
|
||
|
|
self._vss = VssIn ( "vss" )
|
||
|
|
|
||
|
|
def Netlist ( self ) :
|
||
|
|
|
||
|
|
Inst ( 'DpgenXnor2mask'
|
||
|
|
, param = { 'nbit' : 8
|
||
|
|
, 'const' : "0b000111"
|
||
|
|
}
|
||
|
|
, map = { 'i0' : self._in
|
||
|
|
, 'cmd' : self._cmd
|
||
|
|
, 'nq' : self._out
|
||
|
|
, 'vdd' : self._vdd
|
||
|
|
, 'vss' : self._vss
|
||
|
|
}
|
||
|
|
)
|
||
|
|
\end{verbatim}
|
||
|
|
\end{itemize}
|