check_routability

check_routability
[ -net {s_netName…} ] 
[ -region {f_xlo f_ylo f_xhi f_yhi} ]
[ -exclude_net {s_netName…} ] 
[ -exclude_type {[power][ground][clock]} ] 
[ -clear_annotations ] 
[ -error_limit i_count ] 
[ -no_blockage_check ] 
[ -no_coverobs_check false ] 
[ -no_direction_check ] 
[ -no_floating_shape_check ] 
[ -no_grid_check ] 
[ -no_min_space_check ] 
[ -no_min_width_check ] 
[ -no_out_of_bndry_check ] 
[ -no_pin_center_on_track_check ] 
[ -no_pin_on_grid_check ] 
[ -no_pin_on_track_check ] 
[ -no_prbndry_check ] 
[ -no_via_check ] 

Description

Checks the active design for known conditions that can cause potential routing problems. Design Rule Checks applied to pins and some routability checks are performed primarily to determine the accessibility of pins. Additional routability checks address special issues, such as the presence of differential pair nets. By default, missing cover obstruction checks are excluded and must be enabled using -no_coverobs_check false. All other checks are enabled by default and can be excluded by specifying its respective argument when this command is invoked. Annotations are automatically created for violations, except cover obstruction and PR boundary violations.

If violations are reported, use the Violations Browser (Collaborate—Annotation Browser—Violations) to locate them.

The following table describes the checks that are performed and how they are categorized in the Violations Browser.

Check	Severity	Violations Browser
Pin-to-pin spacing less than minimum spacing	Error	Clearance Checks—Diff Net Checks
Pin dimensions less than minimum width	Error	Width Checks—Minimum Width Checks
Pin origin not on manufacturing grid	Warning	Grid Check—Manufacturing Grid
Pins blocked by top-level blockage or blockage of another instance	Error	Routability Checks—Blockage Checks
Pins that cannot be escaped using available vias	Error	Routability Checks—Via Checks
Floating shapes on wire:detail, wire:pin on top of wire pin shapes	Warning	Routability Checks—FloatShape Checks
Diffusion shapes on drawing purpose	Warning	Routability Checks—DiffShape Checks
Diff pair nets if present in the design, as these will be skipped during the regular flow	Warning	Routability Checks—DiffPairNets Checks

A Routability Report is output to the Transcript area that summarizes the violations that are found. For example,

+-------------------------------------------------+
| Routability Report Summary:                     |
+-------------------------------------------------+
|          0 Min Spacing violation(s)             |
|          0 Min width violation(s)               |
|          0 Grid violation(s)                    |
|         10 Via violation(s)                     |
|          0 Blockage violation(s)                |
|          0 Floating shape violation(s)          |
|          0 Diffusion shape violation(s)         |
|          2 Diff pair nets violation(s)          |
+-------------------------------------------------+
|         56 pin(s) found                         |
|         56 pin(s) checked                       |
|          0 pin(s) already connected             |
|         12 pin(s) not used (skipped)            |
+-------------------------------------------------+

More severe issues, such as DRC violations, should be dealt with before attempting to use the data.

Diffusion shapes on the drawing purpose will not be seen by Space-based Router and Chip Optimizer. To be recognized and processed, they must be mapped to either diffusion:blockage or diffusion:pin shapes using map_purpose.

Differential pair nets are not routed in the regular routing flow and require special attention. For more information on routing these nets, refer to Pair Routing Commands.

Arguments

-clear_annotations	Removes existing violation annotations of the same check type and input layers before performing this check. If not specified, existing violations are not cleared.
-error_limit i_count	Specifies the maximum number of annotations to create for each type of check.
-exclude_net {s_netName…}
	Excludes the given nets from the pin blockage checks.
-exclude_type {[power][ground][clock]}
	Excludes nets of the given types from processing.
-net {s_netName…}	Limits processing to the nets in the list. By default, all nets are processed.
-no_blockage_check	Disables blockage checks.
-no_coverobs_check false
	Enables checks for instances without a cover obstruction. By default, these checks are disabled.
-no_direction_check	Disables pin direction checks.
-no_floating_shape_check
	Disables floating shape checks.
-no_grid_check	Disables grid checks.
-no_min_space_check	Disables minimum spacing checks.
-no_min_width_check	Disables minimum width checks.
-no_out_of_bndry_check	Disables pin out of boundary checks.
-no_pin_center_on_track_check
	Disables checks for pin centers on tracks.
-no_pin_on_grid_check	Disables checks for pin centers on grid.
-no_pin_on_track_check	Disables checks for pins on tracks.
-no_prbndry_check	Disables checks for instances without a PR boundary.
-no_via_check	Disables via checks.
-region {f_xlo f_ylo f_xhi f_yhi}
	Specifies the boundary points for the area to check. If not specified, the entire design in the active artwork window is checked.

Related Topics

Verify Commands

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