Virtuoso XL Layout Editor User Guide

Preparing Your Connectivity Source for the Virtuoso XL Layout Editor

place layout devices and create pins in positions that correspond to the positions of their schematic symbols.

■Use consistent parameter defaults for comparable symbols

Virtuoso XL applies the parameters of the symbols to the layout devices.

Virtuoso XL does not pass CDF parameters that are not evaluated (are not AEL expressions), and have cdfParamRec~>storeDefault=nil. These are master parameters and are expected to match for both schematic and layout master.

Virtuoso XL does not pass them to the layout instance even when lxUseCell is used. If you require the parameters to be passed set cdfParamRec- >storeDefault to t for the schematic master parameters.

Note: When transferring information from the schematic to the layout, Virtuoso XL flattens the schematic (expands schematic symbols into corresponding devices) if you provide a view list or a stop list to show Virtuoso XL which view of the lower-level instances to use.

Virtuoso XL also supports the use of

■Design variables

■One-to-many mapping

■Many-to-many and many-to-one mapping

If you are preparing a hierarchical design, you also need to make sure the symbol view of each top-level design element is mapped to the correct layout view of the corresponding layout element for generating the layout.

Using Design Variables

You can use the following design variables with Virtuoso XL:

■Netlist Processor (NLP) expressions

■Analog Expression Language (AEL) expressions

■Simulation design variables

Netlist Processor Expressions

NLP expressions are properties that specify parameter values. These expressions are used by the Open Simulation System (OSS) in netlisting.