 
   May 4, 1992                                                         SIS(1)
 
   astg_flow [-x] [-l <latch-type>] [-o <out-file>]
 
     Do exhaustive token flow on an ASTG, forming a state graph using the
     ASTG signals to define the state codes.  A next-state logic function is
     extracted from the state graph in two-level form.  Then the next state
     logic is converted into a network which can be manipulated using the
     standard _S_I_S network commands.
 
     The generated network has PI and PO names which match the signal names
     specified in the ASTG.  The network has one special structural require-
     ment: for any signal which is used for feedback, the real PO is attached
     to the output of the feedback latch (i.e. connected to the fake PI for
     the latch).  This is necessary for other ASTG commands to work properly.
 
     The -l option specifies the type of latches to insert for feedback sig-
     nals.  The default is type "as" (asynchronous).
 
     The -o option writes the BLIF description of the network to a file but
     does not change the current SIS network.
 
     Normally astg_flow does a structural net check to make sure the marking
     is live-safe, using the one-token state machine condition proposed by
     T.A. Chu.  This can be extremely time consuming, so the -x option
     bypasses this check and does the token flow using the existing initial
     marking.
 
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