xenial (1) loon.1.gz

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 hierarchical and is flattened if necessary.  loon runs in  batch  mode  and  a
       parameter  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
                 optimization 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).