Virtuoso Schematic Composer User Guide

Creating Symbols

[@w:w=%:w is not defined;]

In Example 4, if w is not defined, the editor goes on to the next label expression,w is not defined, which is a text string. The editor evaluates the string as a value and displays the result as a label. The semicolon is part of the text string.

w is not defined;

■Example 5 – Nested label expressions

[@w:w=%;[@l:l=%]]

In Example 5, the editor returns the values for both properties if they are both defined.

For example, if the value of w is 4 and the value of l is 8, the editor generates the following label:

w=4;l=8

Adding an IL Label

To display the value of an instance property, you can add an IL label using a Cadence® SKILL language expression that can be evaluated by the SKILL language.

Using the symbol editor, do the following:

1.Choose Add – Label.

The default [@instanceName] label is attached to the cursor. The Add Symbol Label form appears.

Virtuoso Schematic Composer User Guide

Creating Symbols

2. In the Label field, type a SKILL expression or function, with the form

ilInst~>master~>libName

ilInst is a SKILL variable used to provide self-reference to an instance during graphic display of the cellview containing the instance.

3.Set the Label Choice cyclic field toinstance label.

4.In the Label Type field, clickILLabel.

5.Move the pointer into your cellview and click to place the IL label.

■Example 6 – SKILL code

ilInst~>cellView~>instancesLastChanged

The SKILL code displays a time stamp; for example,

Jun 5 15:07:33 2000

Adding Note Text and Note Shapes

You add note text and note shapes in the symbol editor in the same way you add notes in the schematic editor. Refer to “Adding Notes” on page 187.

Adding a Net Expression Label

You add a net expression label in the symbol editor in the same way you add a net expression label in the schematic editor. Refer to “AddingNet Expression Labels to Create an Inherited Connection” on page 167.

Virtuoso Schematic Composer User Guide

Creating Symbols

Setting the Symbol Origin

The origin of a symbol is the (0,0) location within a symbol. When you place instances in a schematic, the symbol origin affects the position of the symbol graphics and pins relative to the instance placement point.

Changing the origin of a symbol moves instance pins within all schematics that use that symbol. This might affect the connectivity of the schematic because schematic wires do not automatically move to the new pin locations.

To set the origin of a symbol, using the symbol editor, do the following:

1.Choose Edit – Origin.

2.Point to a location for the new origin of the symbol.

Point to a location.

[@instanceName]

Pointing to the middle of the symbol moves the symbol graphic, repositioning the X=0, Y=0 origin point of the symbol to the new location.

[@instanceName]

INV

When you use this command, it might be helpful to turn on the display of the following:

X and Y axes

Coordinates in the status banner