75 lines
3.1 KiB
TeX
75 lines
3.1 KiB
TeX
\begin{itemize}
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\item \textbf{Name} : DpgenNand2mask -- Programmable Mask Macro-Generator
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\item \textbf{Synopsys} :
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\begin{verbatim}
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Generate ( 'DpgenNand2mask', modelname
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, param = { 'nbit' : n
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, 'const' : constVal
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, 'physical' : True
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, 'behavioral' : True
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}
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)
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\end{verbatim}
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\item \textbf{Description} : Generates a \verb-n- bits conditionnal NAND mask named \verb-modelname-.
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\item \textbf{Terminal Names} :
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\begin{itemize}
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\item \textbf{cmd} : mask control ( 1 bit )
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\item \textbf{i0} : input ( \verb-n- bits )
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\item \textbf{nq} : output ( \verb-n- bits )
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\item \textbf{vdd} : power
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\item \textbf{vss} : ground
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\end{itemize}
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\item \textbf{Parameters} : Parameters are given in the map \verb-param-.
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\begin{itemize}
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\item \textbf{nbit} (mandatory) : Defines the size of the generator
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\item \textbf{const} (mandatory) : Defines the constant (string beginning with 0b, 0x or 0o functions of the basis)
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\item \textbf{physical} (optional, default value : False) : In order to generate a layout
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\item \textbf{behavioral} (optional, default value : False) : In order to generate a behavior
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\end{itemize}
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\item \textbf{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{ANDed} 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 \textbf{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 and constVal) WHEN '1';
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\end{verbatim}
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\item \textbf{Example} :
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\begin{verbatim}
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from stratus import *
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class inst_nand2mask ( Model ) :
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def Interface ( self ) :
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self.i = SignalIn ( "i", 32 )
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self.cmd = SignalIn ( "cmd", 1 )
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self.o = SignalOut ( "o", 32 )
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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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Generate ( 'DpgenNand2mask', 'nand2mask_0x0000ffff'
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, param = { 'nbit' : 32
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, 'const' : "0x0000FFFF"
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, 'physical' : True
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}
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)
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self.I = Inst ( 'nand2mask_0x0000ffff', 'inst'
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, map = { 'i0' : self.i
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, 'cmd' : self.cmd
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, 'nq' : self.o
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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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def Layout ( self ) :
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Place ( self.I, NOSYM, Ref(0, 0) )
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\end{verbatim}
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\end{itemize}
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