Virtuoso XL Layout Editor User Guide

Updating Design Data in Virtuoso XL

5. With the cursor in the layout window, press Return.

A message such as this one appears in the CIW saying that the connection has been made:

Virtuoso XL: Instance ’I1’ in cellView ’overview amp1 layout’ is renamed ’|R21’.

If the Show Incomplete Nets command is active, flight lines show that the connection has been made. If the connection cannot be made, a message box identifies the problem.

6.To cancel the command, press Escape.

Note: If you have set the ignore or lvsIgnore property on a device or the ignoreNames property on a pin and then try to make that device or pin correspond to another device, Virtuoso XL opens a dialog box asking you to verify the removal of the ignore or lvsIgnore property.

If you click OK, Virtuoso XL removes the property and sets the two devices to correspond. If you click Cancel, Virtuoso XL does not set the devices to correspond.

Creating Device Correspondence

For layout designs that have not been created using Virtuoso XL, or to bind an existing layout to another schematic use the Create – Device Correspondence command to set correspondence between a schematic and layout.

The Device Correspondence command achieves the following;

■Taking an LVS correct layout design and migrates it into Virtuoso XL.

■Updating the layout instances and nets naming convention to the Virtuoso XL naming conventions so that legacy layouts can be reused in Virtuoso XL.

■Providing you with all the benefits of connectivity driven layout editing.

Needed Mode

Needed mode supports the following;

■Enforce master match.

■Check connectivity once match is enforced.

■Mfactor and Sfactor.

Virtuoso XL Layout Editor User Guide

Updating Design Data in Virtuoso XL

Prerequisites for the Needed mode are as follows;

All selected instances must have the same master.

pins/instance in schematic must be mapped to a pin/instance in the layout.

To create device correspondence using the Needed mode;

1. Select Create – Device Correspondence.

Virtuoso XL Layout Editor User Guide

Updating Design Data in Virtuoso XL

2. The XL Create Device Correspondence form appears.

Virtuoso XL Layout Editor User Guide

Updating Design Data in Virtuoso XL

3.Leave the Show option to Instances. If you want to display the pins change the Show option to Pins.

4.By default the mode is set the Needed.

5.Change the option to Show Instance Master Name and the library, cell, and view names are displayed in the list boxes.

Use the text field to highlight a particular device or set of devices. For example P* will highlight the devices starting with P.

6.Click on a device in the left list box. Only one instance or pin can be selected. The left list box lists the schematic instances and pins.

The Message field prompts you to Select“ Layout Object(s)”.

7.Click on a corresponding layout instance(s) or pin in the right list box. Multiple instances can be selected. If multiple instances are selected, they must all be in series or parallel. Multiple selection is only permitted if the selected schematic symbol has a sFactor or a hierarchical mFactor.

The Message field prompts you to Press“ Map or Select More Layouts”.

Note: If you selected a nmos instance in the schematic list box, and a pmos instance in the layout list box then a Virtuoso XL dialog box appears. The dialog box indicates that you cannot map a nmos device to a pmos device and that you must make another selection.

The Message field at the bottom of the XL Create Device Correspondence form tells you that you must “Adjust Connectivity or Layout Selection”.

8.To create device correspondence select the Map option. Once the instances are mapped the instance names and the names of the nets attached to the layout instances mare changed according the Virtuoso XL naming convention.

The list box updates showing the instances/pins that are mapped.

9.To unmap mapped objects, select the mapped objects and select Unmap.

The objects are unmapped and placed in the schematic and layout list boxes.

10.Click Apply.

The matches are removed from the map list box.

The mapped instances will be changed to the Virtuoso XL naming convention only when you click Apply or OK. Until then the information is merely visual in the form. You can cross-select, but no names are changed.