Virtuoso XL Layout Editor User Guide

Generating Your Layout with Virtuoso XL Layout Editor

With Shape set to Rectangle, if you do not want the design boundary’s left and bottom sides located at the default position, you can enter new values in the Left and Bottom fields.

Left lets you enter a value on the X axis to situate the left side of the rectangle.

Bottom lets you enter a value on the Y axis to situate the bottom of the rectangle.

If you set Shape to Polygon, the form changes to let you define the number and length of the sides

Points is a field that lets you enter the points where the sides meet. For example the format for a rectangle is: (0 0) (10 0) (10 10) (0 10)

Load Template File for Layout Generation allows you to load an ASCII template file in to the Layout Generation Options form.

Browse opens the Open File form, which allows you to specify a file that contains stored layout generation options.

Load loads the stored layout generation options into the Layout Generation Options form.

Note: You can set an environment variable, templateFileName, to always load the name of a template you specify.

Open File Form

Name lets you specify the name of a template file.

Pick from Schematic Form

Placement

Group As In Schematic lets you move a group of components together into the layout in the same relative position as in the schematic. In this mode, you cannot change the parameters on the components.

Place Individually lets you move each component individually.

Note: The chaining option is not available when using the Place Individually option. To interactively chain devices use the Edit – Transistor Chaining command.

Virtuoso XL Layout Editor User Guide

Generating Your Layout with Virtuoso XL Layout Editor

Options

Draglines, when active, displays rubberbanding lines that connect pins of the object you are moving to pins of the nearest objects.

Constraint Assisted, when active, allows objects to be moved only in ways that satisfy the constraints entered using the Constraint Manager, once the object has satisfied the constraint.

Transistor Chaining is only active with the Group As In Schematic option. Transistor Chaining allows a set of MOS transistors (or fingers of folded transistors) to be automatically abutted to form a stack. Transistors to be abutted must be set up for abutment first.

Transistor Folding, when active, allows MOS transistors to be automatically divided into fingers for optimum area usage. TheGroup As In Schematic option makes the Transistor Chaining and Transistor Folding options available. Transistor Folding operates independently from Transistor Chaining. The Place Individually option makes available only the Transistor Folding option.

NMOS Fold Threshold, when Transistor Folding is active, lets you type the maximum size of the folded NMOS transistor. This value defaults to the lxMaxWidth value set on the connectivity source component.

Changing this value overwrites the lxMaxWidth value you entered in the Edit Component Type form associated with the Place – Component Types command.

PMOS Fold Threshold, when Transistor Folding is active, lets you type the maximum size of the folded PMOS transistor. This value defaults to the lxMaxWidth value set on the connectivity source component.

Changing this value overwrites the lxMaxWidth value you entered in the Edit Component Type form associated with the Place – Component Types command.

Unplaced opens the Pick from Schematic Instance/Pin List form displaying a list of each component in the schematic for which there is no corresponding instance or pin in the layout.

When the Place Individually option is active, the form adds the following four fields to the Pick from Schematic form displaying information about the components you select for placement.

LibName displays the name of the library of the component you select from the list of unplaced components or from the schematic.

CellName displays the cell name of the component you select from the list of unplaced components or from the schematic.

Virtuoso XL Layout Editor User Guide

Generating Your Layout with Virtuoso XL Layout Editor

ViewName displays the view name of the component you select from the list of unplaced components or from the schematic.

InstName displays the instance name of the component you select from the list of unplaced components or from the schematic.

When a component is selected, the form adds additional fields, depending on the component and its attributes.

When a pin is selected, the form displays the following pin creation options.

Terminal Name automatically displays the name of the pin first in line to be placed

Type lets you choose the type of pin to place

Rectangle Pin lets you create a rectangular pin

Symbolic Pin changes this form to let you create symbolic pins

Layer allows you to change the layer purpose pair of the pin that has been selected.

Width allows you to change the width of the pin.

Height allows you to change the height of the pin.

Create Label attaches a label, showing the terminal name, to the pin.

Display Pin Name Options opens the Set Text Style form, which lets you set the font, height, justification, and orientation of the pin name.

I/O Type assigns a property used by routers to identify the direction of the signal into or out of this pin. The signal can be input, output, inputOutput (bidirectional), switch (carries data either in or out, but not simultaneously), or jumper (passes data through this pin).

Access Direction assigns a property used to identify the part of the pin to which routers can connect routing. The access direction can be top, bottom, left, right, any, or none.

When a device is selected, the form displays properties set for that device.

Rotate rotates the component 90 degrees counterclockwise.

Sideways mirrors the component on the Y axis (flips it horizontally).

Upside Down mirrors the component on the X axis (flips it vertically).

Virtuoso XL Layout Editor User Guide

Generating Your Layout with Virtuoso XL Layout Editor

Remove Correspondence Components Form

Identify Connectivity

Source sets the software to remove the connectivity point identified as the source when you click Apply.

Target sets the software to remove the connectivity point identified as the target when you click Apply.

Name Of Point lets you type the name of the point you want removed when you click Apply.

Set By Cursor lets you indicate by clicking on a point with the cursor the point you want removed when you click Apply.

Set Pin Label Text Style Form

Height sets the height of the label in user units (usually microns).

Font sets the text style of the label. The choices are euroStyle, gothic, math, roman, script, stick, and swedish.

Text Options

Drafting prevents the label from being rotated more than 90 degrees.

Overbar is a display option that determines how text strings containing underscore characters are displayed in a layout window.

When the overbar is disabled (default), the software displays underscore characters ( _ ) as part of the text string. When the overbar is enabled, the software interprets underscore characters ( _ ) in the text string name as toggle switches that control where overbars begin and end. Overbars appear above the text string, as shown in the examples.