DpgenDfft

• Name : DpgenDfft - Dynamic Flip-Flop with Scan-Path Macro-Generator
• Synopsys :

  Generate ( 'DpgenDfft', modelname
           , param = { 'nbit'       : n
                     , 'physical'   : True
                     , 'behavioral' : True         
                     }
           )
  

• Description : Generates a n bits dynamic flip-flop with scan-path named modelname. The two latches of this flip-flop are dynamic, i.e. the data is stored in a capacitor.
• Terminal Names :
  • scan : scan-path mode (input, 1 bit)
  • scin : scan path in (input, 1 bit)
  • wen : write enable (1 bit)
  • ck : clock signal (1 bit)
  • i0 : data input (n bits)
  • q : output (n bits)
  • vdd : power
  • vss : ground
• Parameters : Parameters are given in the map param.
  • nbit (mandatory) : Defines the size of the generator
  • physical (optional, default value : False) : In order to generate a layout
  • behavioral (optional, default value : False) : In order to generate a behavior
• How it works :
  • When scan is set to one, it enables the scan-path mode. Note that in scan-path mode, the wen signal is not effective
  • scin is the input of the scan-path. This terminal is different from i0[0]. The scout is q[N-1] (in the following example this is q[31])
  • When wen is set to one enables the writing of the flip-flop
• Example :

  from stratus import *
  
  class inst_dfft ( Model ) :
  
    def Interface ( self ) :
      self.scan = SignalIn  ( "scin", 1 )
      self.scin = SignalIn  ( "scan", 1 )
      self.ck   = SignalIn  (   "ck", 1 )
      self.wen  = SignalIn  (  "wen", 1 )
      self.i    = SignalIn  (    "i", 4 )
      self.o    = SignalOut (    "o", 4 )
  
      self.vdd = VddIn ( "vdd" )
      self.vss = VssIn ( "vss" )
      
    def Netlist ( self ) :
      Generate ( 'DpgenDfft', 'dfft_4'
               , param = { 'nbit' : 4
                         , 'physical' : True
                         }
               )      
      self.I = Inst ( 'dfft_4', 'inst'
                    , map = { "wen"  : self.wen
                            , "ck"   : self.ck
                            , "scan" : self.scan
                            , "scin" : self.scin
                            , "i0"   : self.i
                            ,  "q"   : self.o
                            , 'vdd'  : self.vdd
                            , 'vss'  : self.vss
                            }
                    )
        
    def Layout ( self ) :
      Place ( self.I, NOSYM, Ref(0, 0) )