Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

7. To complete the shape, press Return.

Note: The Virtuoso compactor does not compact nonorthogonal shapes or shapes other than paths, except for pins.

Checking Connectivity with Flight Lines

To see nets for which connectivity has not yet been made, you can use the

Show Incomplete Nets command to turn on flight lines in the layout window. Flight lines show uncompleted electrical connections between devices in each net. The Command Interpreter Window (CIW) reports how many uncompleted nets you have.

If you draw a path between two components that completes the connection, the flight lines disappear. If the path does not complete the connection, the flight lines remain.

To see flight lines in the layout window, from the layout window, chooseConnectivity –

Show Incomplete Nets.

Checking Connectivity with Markers

Markers are flashing boxes in the layout window that indicate electrical shorts or invalid overlaps. When the Show Incomplete Nets command is active (flight lines are displayed), the markers might be more difficult to see.

Finding Markers

To find markers, follow these steps.

1. From the layout window menu, choose Verify – Markers – Find.

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

The Find Marker form appears.

2.Turn on Zoom To Markers.

3.Click Apply.

Virtuoso XL zooms in on the error and warning markers one by one.

Explaining Markers

To find out what each marker means, follow these steps.

1.From the layout window, choose Verify – Markers – Explain.

The layout window prompts you to point at a marker.

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

2.Click on the marker to explain.

A dialog box appears identifying the location and explaining the short.

location: ("overview" "feedbackAmp" "layout")

reason: Warning: Overlap between path on layer ‘metal1 drawing’ on net ’vcc!’ and instance ‘|R17’ creates a short.

3. Click on another marker to explain, or press Escape to exit the command.

Deleting Single Markers

To delete (turn off) a single marker, follow these steps.

1.From the layout window, choose Verify – Markers – Delete.

The layout window prompts you to point at a marker.

2.Click on the marker to delete. The marker disappears.

3.Click on another marker to delete or press Escape to exit the command.

Deleting All Markers

To delete all the markers, follow these steps.

1. From the layout window, choose Verify – Markers – Delete All.

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

The Delete All Markers form appears. It lets you choose the type of markers to delete and the levels of hierarchy from which you want to delete them.

2.Indicate your choices on the form.

3.Click OK.

All the markers disappear.

Defining Physical Vias

If you need vias that have special shapes not supported by symbolic vias or if you need more than five layers in a via, you can build physical vias using the layout editor.

To define a physical via, follow these steps.

1. From the CIW, choose File – New – Cellview.

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

The Create New File form appears.

2.In the Library Name cyclic field, choose the library you want.

3.In the Cell Name field, type the cell name you want.

4.In the View Name field, typelayout.

5.In the Tool cyclic field, chooseVirtuoso or another layout editor.

6.Click OK.

A new layout window appears.

7.Create one via shape.

8.Define one pin on each of the two layers you want to connect.

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

The two pin names (one on each layer) must be identical and the pins must be created as rectangles.

Via shape

Shape defined as pin with name “A” on layer 1

Shape defined as pin with name “A” on layer 2

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

12. The form changes to show properties and include the Add button.

13. Click Add.

Virtuoso XL Layout Editor User Guide

Preparing Your Design for Routing in the Virtuoso XL Layout Editor

14. The Add Property form appears.

15.Use the Add Property form to define the following properties:

The lvsIgnore property as a Boolean with a value of true

The function property as a string with a value of via

16.To add each property, click Apply.