How to Ignore Components in Physical Hierarchy

You can use Configure Physical Hierarchy to specify ignore properties at the cell-level, in which case all the instances of that cell are ignored, or you can override the cell-level setting for one or more instances or individual occurrences of instances in your design.

The value of the propsUsedToIgnoreObjs property set on a device in the schematic design is used as the default value for the Ignore for generation and Ignore for check attributes in the Configure Physical Hierarchy window.

If you do not change the value of these properties in the Configure Physical Hierarchy window, the Generate All From Source command honors the value set for the propsUsedToIgnoreObjs in the schematic design and any changes made to the value of that property in the schematic design.

If you change a value in the Configure Physical Hierarchy window to specify that certain components are to be ignored either during layout generation and/or check, Generate All From Source respects the changed value and disregards any changes made to the propsUsedToIgnoreObjs property in the schematic design.

To restore the default, select the value and click the Revert to default button on the right.

Generate All From Source again honors the value on the propsUsedToIgnoreObjs property in the schematic design and any changes made to the value of that property in the schematic design.

The table below shows the inheritance rules for ignore values on cells and instances.

Inheritance Rules for Ignore Properties

Cell	Instance	Instance is ignored?
No ignore property	ignore = true	Yes.
No ignore property	ignore = true lvsIgnore = false	Yes, because lvsIgnore OR ignore => true
ignore = true	No ignore property	Yes, because it inherits the ignore property setting from the cell
ignore = true	lvsIgnore = false	Yes, because the ignore property is inherited from the cell meaning that lvsIgnore OR ignore => true
ignore = true	ignore = false	No, because the ignore property exists on the instance and its setting overrides the setting on the cell.

Related Topics

Ignoring an Instance or Occurrence for Generation or Check

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