loon(1alc)

1LOON(1)                    CAO-VLSI Reference Manual                   LOON(1)
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NAME

6       LooN - Local optimizations of Nets.
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ORIGIN

12       This software belongs to the  ALLIANCE CAD SYSTEM developed by the ASIM
13       team at LIP6 laboratory of Université Pierre et Marie CURIE, in  Paris,
14       France.
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16       Web : http://asim.lip6.fr/recherche/alliance/
17       E-mail : alliance-users@asim.lip6.fr
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SYNOPSIS

21       loon  [-hmxlo] input_file output_file  [lax_file]
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DESCRIPTION

25       loon  is a CAD tool that allows to remove fanout problems within a gate
26       netlist and also to optimize the delay.  The netlist can be  hierarchi‐
27       cal  and  is  flattened  if  necessary.   loon runs in batch mode and a
28       parameter file can be used (see man lax) to parametrize optimization by
29       adding  information  on  outputs (fanin), inputs (fanout, delay) and by
30       setting general parameters such as optimization level.  loon permits to
31       compute  delays  of gates in the netlist and gives the critical path in
32       the netlist.  The global optimization of loon performs gate  repowering
33       to  decrease  the  critical path delay and global capacitance.  Buffers
34       are only inserted in critical path.
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37         lax Parameter file description
38       The lax file is common with other logic synthesis tools and is used for
39       driving the synthesis process.  See lax[24m(5) manual for more detail.
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41       lax  uses  a  lot  of  parameters  to guide every step of the synthesis
42       process.  Some parameters are globally used (for example,  optimization
43       level  whereas  others  are specifically used (load capacitance for the
44       netlist optimization only).  Here is the  default  lax  file  (see  the
45       user's  manual  for  further information about the syntax of the '.lax'
46       file):
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48          Optimization mode = 2 (50% area - 50% delay)
49          Input impedance = 0
50          Output capacitance = 0
51          Delayed input = none
52          Auxiliary signal saved = none
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OPTION

57       -h        Help mode. Displays possible uses of loon.
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59       -o input_file
60                 Overwrites the source file if no output_file is  given.  This
61                 can be useful if you don't want several netlist files.
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63       -m optim_mode
64                 Optimization  mode.  Can  be defined in lax file, it's only a
65                 shortcut to define it on command line. This mode  number  has
66                 an  array  defined  between  0 and 4. It indicates the way of
67                 optimization the user wants. If 0 is chosen, the circuit area
68                 will  be  improved. On the other hand, 4 will improve circuit
69                 delays. 2 is a medium value for optimization.
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71       -x xsch_mode
72                 Generate a '.xsc' file. It is a color map  for  each  signals
73                 contained  in  output_file network. This file is used by xsch
74                 to view the netlist. By choosing level 0 or 1 for  xsch_mode,
75                 you  can  color respectively the critical path or all signals
76                 with delay graduation.
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78       -l lax_file
79                 Just another way to show explicitly the  LAX  parameter  file
80                 name.
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ENVIRONMENT VARIABLES

84       The following environment variables have to be set before using loon :
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87       MBK_CATA_LIB  gives  the  auxiliary  paths  of the directories of input
88              files (behavioural description).
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91       MBK_TARGET_LIB gives the path (single) of the directory of the selected
92              standard cell library.
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95       MBK_IN_LO gives the input format of the structural description.
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98       MBK_OUT_LO gives the output format of the structural description.
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EXAMPLE

103       You can call loon as follows :
104            loon alu alu_loon
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