Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

The Search form appears.

2.In the Search for field, type the specific words, strings, or regular expressions.

3.Click OK.

Saving Reports

To save the report in a text file, do the following:

1.From the report window, choose File – Save As. The Save As form appears.

2.In the File Name field, type a name for the text file.

Note: You can include the path to the file if you want to specify a directory other than the current working directory.

3.Click OK.

Setting Constraints

You can set constraints on nets using the Virtuoso® Constraint Manager or by writing and loading a .do file.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Using the Virtuoso Constraint Manager

Use the Virtuoso Constraint Manger to set net-based constraints which, once they are saved to the cellview, will be followed when routing.

The following are net-based constraints you can apply using the constraint manager.

Net or Class

Control the order in which nets or classes are routed.

Control the width of nets or classes.

Control the maximum and minimum voltage drops for a net or class of nets by controlling the length of the net.

Net To Net / Shielding

Set the minimum distance between two nets on different layers.

Create tandem shielding.

Create parallel shielding.

Create differential pairs.

Class To Class

Set the minimum distance between nets on different layers.

Class To Net

Set the minimum distance between nets on different layers.

Note: If you create or modify a constraint while in a wire editing command, you will need to restart the command to make the constraint active.

For more information, refer to the Virtuoso Constraint Manager User Guide.

Using .do Files

A .do file is an external ASCII file you can create using any text editor. In the Virtuoso XL environment, .do files are used to apply constraints and definitions. In contrast,.do files used in the Virtuoso Custom Router and Cadence® Chip Assembly Router environment can be used as a script to drive a batch job.

You can load a .do file or change a.do file at any time during a session. The.do file is not cumulative; once you load a new .do file or change the data within the file, the initial data is

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

lost. However, you can use the do command to load additional .do files. For example, the following line in a .do file will cumulatively load rules from both files:

do routing1.do routing2.do

.do File Commands

When wire editing is enabled, a .do file used within Virtuoso XL can include the following commands. For more information, see Appendix D, “Virtuoso XL .do File Commands”.

■circuit

■define/forget

■do

■rule

■set

Loading .do Files

To load an ASCII .do file, follow these steps:

1.From the layout window, choose Options – Route. The Route Options form appears.

2.Turn on Do File.

3.Choose the .do file by doing one of the following:

In the Do File field, type the name and path of the.do file.

Click on Browse.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

The Find File form appears.

a.Navigate to the .do file.

b.Choose the .do file.

c.Click OK.

4.In the Route Options form, click OK.

The contents of the .do file are referenced when the next command is executed.

Note: Click Refresh in the Route Options form to reload updated .do file information in the following situations:

Contents the .do file is changed.

Name of the .do file is changed.

New .do file is being used.

Note: Verify constraints and rules set in the current design by using the Verify –

Reports command. For more information, refer to “Creating Rules Reports” on page 412.