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