Make Cell Command in Design Planning and Analysis
The Make Cell command creates real cellviews from virtual hierarchies that are generated or manually created. During a Make Cell run, selected, generated virtual hierarchies are replaced with instances of new cellviews and bound using the same schematic correspondence as the replaced virtual hierarchies. For manually created virtual hierarchies, the schematic correspondence does not exist so these virtual hierarchies are replaced with transparent instances of new cellviews, and the instances within the made cellview are bound to the corresponding schematic instances. When the Make Cell command is run hierarchically, it uses a bottom-up approach to also create a layout view for each level of the virtual hierarchy inside the selected virtual hierarchy.
Constraints member types instances, nets, figGroups, clusters, pins, and boundary that are solely contained within the selected virtual hierarchy are transferred to the made cellview. Constraints that contain any other member types are not transferred. In addition to transferring constraints, the Make Cell command honors all net attributes, propagating the power domain information and the min/max net voltage to the made cellview .
If the made cellview has no area boundary, the command also generates a PR Boundary for the made cells using the current top-level location. If the generated PR boundary does not by default snap to the nearest grid, you can set the makeCellGridAlignment environment variable to pushGrid to snap the generated PR boundary to the nearest grid.
The made cellview has pins created for the interface nets that connect outside the virtual hierarchy being replaced by a new cellview. You can choose to invoke the congestion-aware global router to create pins on the boundary, create pins on the boundary of the virtual hierarchy ensuring the shortest possible net length, or create pins below the boundary and manually place them, as appropriate.
If routing exists, pins are created where the routes cross the boundary. If no routing exists or pin shapes are not preserved, pins are created below or on the boundary, depending on the pin creation option selected. Pins are also created below the boundary for lower-level cells when the Make Cell command is run hierarchically.
If the made virtual hierarchy was previously integrated with pins set to be preserved, the preserved pin shapes are reused to create the pins. The Make Cell command automatically updates the physConfig view to set the newly made cellview as new and available for use. You can make cell using only the single selected clone or all virtual hierarchy clones in one go.
If a virtual hierarchy contains a Modgen, the constraint is copied to the new cellview and the Modgen is created. See
Design Scenarios Not Supported by the Make Cell Command
Although some differences between the schematic and layout hierarchies are ignored during a Make Cell run for generated hierarchies, the command does not support the following cases. No such limitations exist when running the command on virtual hierarchies that are manually created.
- The selected virtual hierarchy does not contain any bound instances.
- The bound schematic instance is not in the same hierarchy as the schematic instance corresponding to the selected virtual hierarchy.
- No schematic instance exists that matches the selected virtual hierarchy name, or the schematic master does not match the master of the bound schematic instance.
To overcome these limitations, you can run the Update Components and Nets command on the selected virtual hierarchy with the Generate Virtual Hierarchy option selected. If no bound instances are available, running the Make Cell command on generated virtual hierarchies may not help.
Related Topics
Update Components And Nets Form
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