Virtuoso Schematic Composer User Guide

Understanding Connectivity and Naming Conventions

This schematic shows one IOlatch iterated four times: I<0:3>. Compare this with the previous schematic.

I<0:3>

Wire Connections and Wire Naming Conventions

You can connect single-bit wires in your design using any one of the following conventions:

■Wire-to-Wire Connections on page 92

■Wire-to-Pin Connections on page 93

■Wire-by-Name Connections on page 95

■Wire-to-Iterated Instance Connections on page 95

■Global Net Name Connections on page 98

Virtuoso Schematic Composer User Guide

Understanding Connectivity and Naming Conventions

Wire-to-Wire Connections

If you draw two intersecting manhattan wires in a T configuration, the editor automatically connects the wires.

Wire 1

Wire 2

If you draw two manhattan wires that cross, you must explicitly add a solder dot to make the connection at the crossover.

If you draw two manhattan wires in an L configuration, or if you draw an angled wire and a manhattan wire that intersect at their end points, the wires are connected, but the editor does not add a solder dot.

If you connect a narrow wire to a wide wire—for example, as in a bus—you must intersect the centerline of the wide wire.

Unconnected wire at the edge of the wire

Wide wire

Connected wire at the center of the wire

Virtuoso Schematic Composer User Guide

Understanding Connectivity and Naming Conventions

If you want to connect to an angled wire, you must connect to one of its endpoints. The editor automatically adds a solder dot after you add the last wire in each of these examples.

Note: Make connections for all angled wide wires, narrow wires, and flight lines at their endpoints.

Wire-to-Pin Connections

To make wire-to-pin connections, the wire must intersect the pin.

■Draw the wire so it ends in the body of a pin.

■Draw the wire so it ends on the border or perimeter of a pin.

Wire

■Draw the wire so it passes through a pin.

Pin

Wire

Virtuoso Schematic Composer User Guide

Understanding Connectivity and Naming Conventions

■You cannot make a wire-to-pin connection by drawing an angled wire that passes through a pin.

Floating pin

Angled wire

Two mechanisms help you make an accurate connection between your wires and pins.

■As you move the pointer near a pin while you draw the wire, a small diamond appears over the pin to show you the nearest object with which you can establish electrical connectivity.

■You can zoom in on your design to see if you are making an accurate connection.