Virtuoso XL Layout Editor User Guide

Editing Your Layout with Virtuoso XL Layout Editor

The temporary fixed constraints are removed from the locked devices and they can then be moved by the Move or Stretch commands.

You can also remove these temporary locks using the Constraint Manager by following these steps.

1.In the Constraint Manager window, click on the Fixed category to show the individual constraints.

2.Middle-click and hold over the name of the device to unlock.

3.From the pop-up menu that appears, choose Delete.

The locked devices are no longer locked in position. The names of the locked devices disappear from the Fixed constraint category in the Constraint Manager window and in the Constraint Browser.

Using Automatic Spacing

You can assign automatic spacing properties to pins of instances so that if these pins are on different nets or the pins cannot abut for any reason (for example, they are not assigned abutment properties), the software automatically separates the instances by the distance and in the direction you specify.

You can use the layout editor user interface to enter properties on the pins in the same way that you enter the permuteRule properties.

Note: If you need to add a variable spacing rule to the pin, set the vxlInstSpacingRule to abutFunction as shown below;

dbReplaceProp(sObj~>dbId "vxlInstSpacingRule" "string" "abutFunction")

The properties to set automatic spacing are listed below.

To add the access direction to the pin:

Virtuoso XL Layout Editor User Guide

Editing Your Layout with Virtuoso XL Layout Editor

If you want automatic spacing to apply to Cadence® SKILL language or technology file parameterized cells (pcells), you can enter these properties in SKILL to add the spacing properties to the pins.

If you want automatic spacing to apply to standard cells, you can also use the layout editor to enter properties on the pins.

If the vxlInstSpacingRule value is different for two pins affected by Auto Space, the larger of the two values is used; if the value is defined for only one of two pins affected by Auto Space, the defined value is used.

1.0

To activate automatic spacing, turn on Auto Space in the Layout XL Options form (on is the default).

Using the vxlInstSpacingRule for User Defined Spacing Function

A user defined function, calledabutFunction, can be used to define a spacing offset when pins are on a different net. When you set the vxlInstSpacingRule to float, two pins of the