Virtuoso Schematic Composer User Guide

Creating Schematics

Adding Wire Names

Naming a wire affects the connectivity of your design. You must follow specific naming rules.

■Naming a Wire on page 160

■Adding Wire Names on page 160

■Adding Multiple Wire Names on page 163

■Verifying Invisible Wire Names on page 165

■Using Net Name Prefixes on page 165

Virtuoso Schematic Composer User Guide

Creating Schematics

Naming a Wire

The following examples show ways you can name a wire.

■Name a wire explicitly. Assign a wire name with the Add – Wire Name command. The wire name becomes the net name. For VHDL designs, the net name must match the pin name; if not, the schematic rules checker (SRC) flags it as a VHDL violation.

TERM1 net_name

■Let the wire inherit a wire name from the system. When you do not assign a wire name, the net takes the name of the pin; for example, TERM1.

TERM1

■Let the system automatically assign a name to a wire not connected to a schematic pin. You can view the wire name by choosing Edit – Properties – Objects.

■Name a wire that consists of multiple signals (a bus) that have the same base name and subscripts.

BUS<15:8>

■Name a wire that consists of a collection of signals with different names. A bundle is represented by names separated by a comma.

DATA,BUS<0:7>

Adding Wire Names

To add wire names, do the following:

Virtuoso Schematic Composer User Guide

Creating Schematics

1.Choose Add – Wire Name.

The Add Wire Name form appears.

Add Wire Name

2.In the Names field, type the names of the wires.

To establish connectivity, use specificwire naming conventions. To name a bus, use vector expressions.

If you specify multiple names for several wires, separate each name with a space.

3.Move the pointer into your design.

The first wire name is attached to the pointer.

4.Place the name in your design by clicking near or on the wire.

If you name a vertical wire, the name rotates.

Virtuoso Schematic Composer User Guide

Creating Schematics

The text justification option displays a plus sign (+) in your cellview at the location of the justification.

If you place the wire name at a greater distance from the wire than the default offset, click on the wire that the label names.

When a wire name is associated with a wire, any action you perform with the wire affects the wire name. For example, if you stretch the wire, the wire name remains with the wire. If you delete the wire, the wire name is deleted.

If you select the entry style of fixed offset, the system uses predefined default settings to automatically calculate the position of the wire name. To change the fixed offset defaults, do the following:

1. Click Show Offset Defaults.