Virtuoso Schematic Composer User Guide

Creating Schematics

Changing the Default Instance Name Prefix

Each instance requires a unique name. If you do not specify instance names on the Add

Instance form, the schematic editor generates unique names automatically. The prefix is a symbol cellview property, not an instance object property.

To change the default instance name prefix fromI to a prefix that you designate, do the following:

1.Open a symbol cellview.

2.Choose Edit – Properties – Cellview.

The Edit Cellview Properties Form appears.

3.Show the system properties on the form by choosing system.

4.Change the instNamePrefix property. You can use more than one character.

5.Click OK.

When you place new instances of this same symbol in the same cellview, the new prefix name appears.

Editing Instance Masters

To edit the master of an instance and automatically change all occurrences of the instance, do the following:

1.Open a symbol cellview.

2.Select the part of the symbol you want to edit.

You might want to select the shape, the pin, the label, or the selection box.

3.Choose Edit – Properties – Objects to edit the symbol. The Edit Objects Properties Form appears.

To edit a single instance, you edit object properties, not cellview properties. The system changes all cellviews containing instances of this master.

Virtuoso Schematic Composer User Guide

Creating Schematics

Specifying the View to Use While Placing the Instance

To change instance views (for example, from a nand2 symbol view to a nand2 symbolNeg view) as you add an instance, do the following:

1.Choose Add – Instance.

2.Before placing the instance, press the Shift key and click the right mouse button to toggle through the symbol views.

The following diagram shows an instance changing views from nand2 symbol to nand2 symbolNeg.

3.Place the instance.

Changing the View after an Instance Is Already Placed

To change instance views (for example, from a nand2 symbol view to a nand2 symbolNeg view) after you have added an instance, do the following:

1.Select the instance you want to change.

2.Choose Edit – Alternate View.

Renumbering Instances

If you deleted several instances in your cellview, you might want to renumber the instances to make the numbers consecutive.

To renumber all the instances in your hierarchy consecutively, do the following:

1. Choose Design – Renumber Instances.

Virtuoso Schematic Composer User Guide

Creating Schematics

The Renumber Instances form appears.

Renumber Instances

The default setting renumbers all instances in only the current cellview.

Only the instance names that match with the instNamePrefix property are renumbered.

Mapping of the former and new instance names appears in the Command Interpreter Window (CIW).

2.Do one of the following:

If you want to renumber instances in the your entire hierarchy, change the Scope cyclic field tohierarchy.

Renumber Instances