(Non)parameterized Layout Cells Generation (VLGen)

For layout generation that does not need the schematic cells to have parameters or properties defined, use the Virtuoso Layout Generation (VLGen) functionality. The VLGen functionality lets you automatically generate the layout for schematic symbols that do not have an existing layout available to reuse and have no CDF parameters defined. After the layout of a schematic symbol is generated, it can be used for generating further instances of the same symbol.

The VLGen functionality is recommended when:

• Additional levels of hierarchy need to be created to match the schematic.
• Write access to the schematic is not available and a single layout needs to be used to create multiple instances of the schematic symbol.
• Limited CAD support is desired and editing of schematic symbols needs to be avoided.

You can set a schematic cell for VLGen or VPLGen, not both.

The VLGen functionality supports the following modes:

• Manual lets you specify in the LAM file or in the CPH window the schematic symbols that need to be automatically generated using the VLGen functionality.
  It is recommended to define the VLGen in a LAM file and a SKILL utility is available to help set the LAM file. But, if you prefer setting the VLGen in CPH, do this:
• In the Cells table, right-click the cell that you want to set for VLGen and choose Create/remove VLGen.
• Automatic lets you set for VLGen all schematic symbols that do not have their CDF parameters defined and have no existing layouts. To enable the automatic VLGen mode, set the vlGenAutoDetectCells and vlGenCreateCells environment variable to t before launching VLS XL.

Related Topics

Generating Parameterized Layout Cells (VPLGen)

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