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

NAME
       LooN - Local optimizations of Nets.

SYNOPSIS
       loon  [-hmxlo] input_file output_file  [lax_file]

DESCRIPTION
       loon  is	a CAD tool that	allows to remove fanout	problems within	a gate
       netlist and also	to optimize the	delay.	The netlist can	be  hierarchi-
       cal  and	 is flattened if necessary.  loon runs in batch	mode and a pa-
       rameter file can	be used	(see man lax) to parametrize  optimization  by
       adding  informations  on	outputs	(fanin), inputs	(fanout, delay)	and by
       setting general parameters such as optimization level.  loon permits to
       compute	delays	of gates in the	netlist	and gives the critical path in
       the netlist.  The global	optimization of	loon performs gate  repowering
       to  decrease  the  critical path	delay and global capacitance.  Buffers
       are only	inserted in critical path.

	 lax Parameter file description
       The lax file is common with other logic synthesis tools and is used for
       driving the synthesis process.  See lax(5) manual for more detail.

       lax  uses  a  lot  of  parameters  to guide every step of the synthesis
       process.	 Some parameters are globally used (for	example,  optimization
       level  whereas  others  are specifically	used (load capacitance for the
       netlist optimization only).  Here is the	 default  lax  file  (see  the
       user's  manual  for  further information	about the syntax of the	'.lax'
       file):

	  Optimization mode = 2	(50% area - 50%	delay)
	  Input	impedance = 0
	  Output capacitance = 0
	  Delayed input	= none
	  Auxiliary signal saved = none

OPTION
       -h	 Help mode. Displays possible uses of loon.

       -o input_file
		 Overwrites the	source file if no output_file is  given.  This
		 can be	usefull	if you don't want several netlist files.

       -m optim_mode
		 Optimization  mode.  Can  be defined in lax file, it's	only a
		 shortcut to define it on command line.	This mode  number  has
		 an array defined between 0 and	4. It indicates	the way	of op-
		 timization the	user wants. If 0 is chosen, the	 circuit  area
		 will  be  improved. On	the other hand,	4 will improve circuit
		 delays. 2 is a	medium value for optimization.

       -x xsch_mode
		 Generate a '.xsc' file. It is a color map  for	 each  signals
		 contained  in	output_file network. This file is used by xsch
		 to view the netlist. By choosing level	0 or 1 for  xsch_mode,
		 you  can  color respectively the critical path	or all signals
		 with delay graduation.

       -l lax_file
		 Just another way to show explicitely the LAX  parameter  file
		 name.

ENVIRONMENT VARIABLES
       The following environment variables have	to be set before using loon :

       MBK_CATA_LIB  gives  the	 auxiliary  paths  of the directories of input
	      files (behavioural description).

       MBK_TARGET_LIB gives the	path (single) of the directory of the selected
	      standard cell library.

       MBK_IN_LO gives the input format	of the structural description.

       MBK_OUT_LO gives	the output format of the structural description.

EXAMPLE
       You can call loon as follows :
	    loon alu alu_loon

SEE ALSO
       loon(1),	  boog(1),   boom(1),  lax(5),	vbe(5),	 proof(1),  asimut(1),
       vhdl(5),	ocp(1),	nero(1), sxlib(5).

ASIM/LIP6			 Sept 01 2000			       LOON(1)

NAME | SYNOPSIS | DESCRIPTION | OPTION | ENVIRONMENT VARIABLES | EXAMPLE | SEE ALSO

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