Virtuoso XL Layout Editor User Guide

Editing Your Layout with Virtuoso XL Layout Editor

Permuting Component Pins

Virtuoso XL lets you permute (exchange the connectivity or net connections of) the pins of a component.

Pins to be permuted

■Must belong to different nets

■Must first bedefined as permutable terminals

When the Auto Permute Pins option is active (the default setting) in the Virtuoso XL Options form, Virtuoso XL automatically permutes pins in a component if doing so corrects a short caused by routing when the routing was done interactively (using auto-abutment) or done while moving or stretching a shape (or using any operation that changes connectivity).

To change the setting of the Auto Permute Pins option, follow these steps.

1.From the layout window, choose Options – Layout XL.

The Layout XL Options form appears.

Auto Permute Pins option

2.Turn on Auto Permute Pins.

3.Click OK.

Virtuoso XL automatically permutes the pins of a single component when doing so removes a short, as shown below. In the diagram below, two pins belonging to different nets (A and B) create a short when they are touching each other. If these pins are

Virtuoso XL Layout Editor User Guide

Editing Your Layout with Virtuoso XL Layout Editor

permutable, and reversing the pins of one component connects the two pins that are on the same net (B), Virtuoso XL permutes them.

marker showing short

Virtuoso XL also automatically permutes the pins of two components at the same time when doing so removes a short, as shown below. In the diagram below, two pins belonging to different nets (A and C) create a short when they are touching each other. If these pins are permutable, and reversing the pins of both components connects the two pins that are on the same net (B), Virtuoso XL permutes them.

marker showing short

Permuting Pins Manually

To manually permute pins within a component, follow these steps.

1.From the layout window, choose Connectivity – Permute Pins.

Virtuoso XL prompts you to select a pin.

2.Click on the first pin in the layout window. Virtuoso XL prompts you to select a second pin.

3.Click on the second pin in the layout window.

Virtuoso XL Layout Editor User Guide

Editing Your Layout with Virtuoso XL Layout Editor

Virtuoso XL switches the net connections of the pins you selected. If flight lines are displayed, the flight lines change to show the new nets assigned to the pins.

Note: This command is modal; that is, you can continue to select sets of pins to permute without going back to the command again each time.

4.To undo the permutation, from the layout window, choose Edit – Undo.

The pins return to their original net connection in the layout.

5.To cancel the command, press Escape.

Note: Any pin previously connected to a path, polygon, rectangle, or component pin cannot be permuted.

Checking Permutation Information

To see information about permuted pins, follow these steps.

1.From the layout window, choose Connectivity – Permute Pins.

2.Press F3.

The Permutation Information form appears.