find_scenic_nets

find_scenic_nets
[ -all | -set d_setObj ] 
[ -exclude_set d_setObj ] 
[ -file s_fileName ] 
[ -max_fanout i_count ] 
[ -max_length f_userunit ] 
[ -max_ratio f_real_to_ideal ] 
[ -min_fanout i_count ] 
[ -min_length f_userunit ] 
[ -min_ratio f_real_to_ideal ] 
[ -report [ true | false ] ] 
[ -use_ideal [ true | false ] ] 
[ -use_mst [ true | false ] ] 

Description

Returns a set containing scenic nets in the entire cellview or in a given set, based on the given criteria for exact and ideal lengths.

A net is considered to be scenic if it meets all of the following conditions:

• If -min_length is set, net length >= min_length. By default, the net length is the exact length, but if -use_ideal true is given, the net’s ideal length is checked.
• If -max_length is set, net length <= max_length. By default, the net length is the exact length, but if -use_ideal true is given, the net’s ideal length is checked.
• If -min_ratio is set, exact length/ideal length >= min_ratio.
• If -max_ratio is set, exact length/ideal length <= max_ratio.
• If -min_fanout is set, fanout >= min_fanout.
• If -max_fanout is set, fanout <= max_fanout.

If none of the conditions is specified, an empty set is returned.

For all ideal lengths, use -use_mst to choose whether the length is calculated using a minimum spanning tree (default) or a Steiner tree.

The number of nets checked and the number of scenic nets found are output to the Transcript area. You can choose to have a detailed scenic net report output to the Transcript area (-report) or to a file (-file).

Arguments

-all	(Default) Searches all nets except power nets. Cannot be used with -set.
-exclude_set d_setObj	Excludes from the search the nets in this set.
-file s_fileName	Outputs the scenic net details to the specified file.
-max_fanout i_count	To be scenic, a net’s fanout count must be less than or equal to this value.
-max_length f_userunit	To be scenic, a net’s length (in user units) must be less than or equal to this value. The -use_ideal argument determines whether the net’s ideal or exact length is checked. By default, the exact length is checked.
-max_ratio f__to_ideal
	To be scenic, a net’s exact length / ideal length must be less than or equal to this value. The -use_mst argument determines whether the ideal length is calculated using a minimum spanning tree or a Steiner tree.
-min_fanout i_count	To be scenic, a net’s fanout count must be greater than or equal to this value.
-min_length f_userunit	To be scenic, a net’s length (in user units) must be greater than or equal to this value. The -use_ideal argument determines whether the net’s ideal or exact length is checked. By default, the exact length is checked.
-min_ratio f__to_ideal
	To be scenic, a net’s exact length / ideal length must be greater than or equal to this value.
-report [ true | false ]
	Outputs the scenic net details to the Transcript area.
-set d_setObj	Specifies the set of nets to operate on. Cannot be used with -all.
-use_ideal [ true | false ]
	When set to true, use the ideal length for minimum and maximum length checks. The -use_mst argument determines whether the ideal length is calculated using a minimum spanning tree or a Steiner tree. Default: (false) Use the exact length for minimum and maximum length checks.
-use_mst [ true | false ]
	When set to false, use a Steiner tree to compute the ideal length. Default: (true) Use the minimum spanning tree to compute the ideal length.

Value Returned

d_setObj	Set of scenic nets.
-1	A command syntax error occurred.

Examples

The following example creates a set of nets in the active cellview that are at least 20 user units in length and twice as long as their ideal length using a minimum spanning tree calculation. A detailed report on the scenic nets is output to scenic2.txt.

set scNet [find_scenic_nets -all -min_length 20 -min_ratio 2 -file scenic2.txt]

Opened file scenic2.txt sucessfully for scenic net report

Scenic Net Report
------------------------------------------------------------------
NetName                             Length     ScenicRatio
------------------------------------------------------------------
MULT_32_INST/i_723/n_876                   22.44         2.08939
MULT_32_INST/i_723/n_741                   24.42         2.12903
------------------------------------------------------------------
 Visited 5694 nets, and found 2 scenic nets 
sel:e8a0140

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