table of contents
LOON(1) | CAO-VLSI Reference Manual | LOON(1) |
NAME¶
- LooN - Local optimizations of Nets.
-
ORIGIN¶
This software belongs to the ALLIANCE CAD SYSTEM developed by the ASIM team at LIP6 laboratory of Université Pierre et Marie CURIE, in Paris, France.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.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 :SEE ALSO¶
loon(1), boog(1), boom(1), lax(5), vbe(5), proof(1), asimut(1), vhdl(5), ocp(1), nero(1), sxlib(5).BUG REPORT¶
This tool is under development at the ASIM department of the LIP6 laboratory.Sept 01 2000 | ASIM/LIP6 |