Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Push Routing

When Push Routing is on, the stretched path segments will push aside other paths and vias.

Push Components

When Push Component is on, the stretched path segments will push aside components if there is insufficient space to stretch the segments.

Allow Orthogonal Jogs

When Allow Orthogonal Jogs and Push Routing are on, orthogonal jogs are created in paths that you are pushing.

Copying Routes

You can copy existing paths and vias (complete or incomplete connections, but not floating nets) to unrouted connections that have similar lengths and topologies. You can copy single paths to one or more target pins or a set of paths, and you can mirror the copied paths along the X axis and Y axis.

To copy a single route or multiple routes, follow these steps:

1.Choose Edit – Copy Route.

The layout window prompts you to select the route to be copied.

2.Select the route you want to copy.

Click once to select one segment of a route.

Shift click to add additional route segments to your selection.

Double click to select the entire route.

If rule checking is turned on, the copy is successful only if it does not cause clearance rule violations.

Note: If the copy path has a t-junction, only the path segments up to the t-junction can be selected for copying. You cannot pick the entire path. T-junctions might introduce ambiguous routing topologies that can cause the command to fail.

3.From the Layout pop-up menu, choose Mirror – X, – Y or – XY to mirror the copied route.

4.Click on a target pin to place the copied route.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

When you copy a single path to a target pin with different width or clearance rules, the tool applies these rules to the copied path.

Using Critic Wire

The Critic Wire command eliminates notches and removes extra bends in routed paths by attempting to adjust the existing paths rather than reroute the path. You can use Critic Wire on a single path or a group of paths.

To remove notches and extra bends from paths, do the following:

1.Choose Edit – Critic Wire.

2.Select a path or group of paths.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

The following figures show before and after using theCritic Wire command on all paths.

Before using the Critic Wire command

After using the Critic Wire command

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Compacting Paths Using Pull

The Pull command compacts paths and vias within a rectangular area. The compaction area is defined by digitizing a starting point and ending point, which creates a pull bar, and then digitizing a third point, which completes the definition of the compaction area. The pull bar is used to pull the routes in a vertical or horizontal direction.

To compact paths and vias within an area, do the following:

1.Choose Edit – Pull.

2.Set a pulling bar by doing one of the following:

Digitize a starting point, move the pointer vertically, and click to define the end points of a vertical pulling bar.

Digitize a starting point, move the pointer horizontally, and click to define the end points of a horizontal pulling bar.

A vertical or horizontal line represents the pulling bar.

3.Sweep the pointer away from the pulling bar in either orthogonal direction.

As you sweep the pointer, the paths and vias are pulled toward the pulling bar.

4.Click when the pointer defines the compaction area you want to use.

The following options will affect the how the paths are compacted:

Interactive Checking

When Interactive Checking is on, the compaction is limited by clearance and spacing rules. Pulling stops for a particular path or via if a violation would occur.

When Interactive Checking is off, rules are not observed, and the pulling tends to pile up the paths at or near the pulling bar.

Allow Orthogonal Jogs

When Allow Orthogonal Jogs and Push Routing are on, orthogonal jogs are created for any path segment that passes through the compaction area. Path segments within the area are pulled, while path segments outside are not.

When Allow Orthogonal Jogs is off, the entire path segment is pulled.