Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Route Options Form

General Tab

Interactive Checking prevents conflict and clearance violations between routing objects, such as paths, vias, and pins. Also prevents routing outside of the boundary area.

Via Assistance controls whether visual and interactive assistance is available to search for legal via locations when you are routing a connection and want to add a via.

Snap either snaps the path you are routing to the closest via site or displays nearby via sites, depending on the distance of the closest legal via site to the last digitized point on the path.

If the last digitized point is within one via radius of a legal via site, the path is automatically routed to the closest via site and a via is added.

If the last digitized point is not close to a legal via site, nearby via sites are displayed as concentric circles but no via is added.

Display adds a via if the last digitized point is on a via site. If the last digitized point is not at a legal via site, nearby via sites are displayed as concentric circles and no via is added.

With both the Snap and Display options, when via sites are displayed you can move the pointer to a via site and click to add a via.

Allow Orthogonal Jogs, when Allow Orthogonal Jogs and Push Routing are on, permits orthogonal jogs in paths that are pushed using the Create Path, Stretch, Split, and

Pull commands.

Show Timing/Length Rule Constraints displays length rule indicators as you are editing a path with a length rule.

Meter displays the current path length relative to the minimum or maximum length rules of the path.

Octagons displays an octagon showing the minimum or maximum length rule of the path you are editing.

Route To Cursor when on, paths are created by following the direction of the cursor from the previously digitized point. This option is not available when you are routing a bus, bundle, or differential pair.

Single Layer multiple path segments are routed on the current active layer.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Multiple Layers paths are routed using multiple layers. Vias are added automatically as layers change.

Follow Layer Direction controls whether the layer direction set in the rules file is strictly followed.

Snap to Pin Origin controls whether routing connections snap to pin origins when you route them. If Snap to Pin Origin is on, a path snaps to the origin of pins when you click anywhere inside the pin. If Snap to Pin Origin is off, a connection to a pin is considered complete if it is within the boundary of the pin shape.

Push Routing controls whether path segments and vias can push aside other paths and vias in order to comply with current width and clearance rules.

Same Net Checking prevents same net rule violations such as gaps and notches which occur when the exposed facing edges of objects on the same net are closer than the minimum clearance rules permit. Also prevents loops or self intersecting nets.

Check Region check path segments at region boundaries during routing operations.

■When Check Region is on (the default), path segments are blocked from extending across a region boundary until you click at the boundary. If you are routing the paths, the router inserts a pseudopin for each net. Then you can continue routing or moving the path segments into or out of the region. If you are routing multiple paths and the applicable path width or clearance rules are different inside the region, the paths fan out if necessary to accommodate these rules.

■When Check Region is off, region boundaries and region rules are ignored during routing and move operations.

Auto Adjust Length attempts to meet minimum length rules when finishing a connection with Finish Route and highlights the connection if any rule violations occur.

Multiple Component Connection when on, the Create Path command connects same net instance pins and top level instance pins that are in alignment. The resulting path contains connections to each pin and separate path segments between each adjacent pair of pins. When off or the pins are not in alignment, a single path is created with connections only to the pins that are clicked on.

Push Component controls whether path segments or vias can push aside components in order to comply with current clearance rules.

Allow Floating Nets routes paths that do not begin or end on terminal objects.

Auto Shield when on, nets that have a shielding constraint attached to them are automatically shielded. Shields are generated when the Create Path operation is completed.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Allow Redundant Wiring On Enabled Nets allows wire loops and extra vias on selected nets for increased current capacity. Redundant wiring is permitted on selected nets when

Allow Redundant Wiring On Enabled Nets is turned on and the allow_redundant_wiring on rule is attached to the net.

Rules lets you load a technology process rules file.

Do File lets you load a specified.do file. When the wire editor is enabled, the.do file is used for setting constraints within your design and also for setting definitions, such as defining bundles and classes.

Refresh reloads updated rules and .do files. Use this when you manually edit an ACSII rules file ordo. file and want to reload the new file.

Browse opens the Find File form, which lets you navigate to the rules file or.do file you want to load.

BusTab

Enable Bus Routing controls whether you can simultaneously route multiple paths.

Enable Tandem Pair controls whether the router lets you simultaneously route paths on different layers.

Fit Via Pattern controls whether the router automatically adjusts the locations of the vias to fit in the available space when you place a via pattern.

Spacing For Gathering Bus Wires controls the minimum wire clearance during a multiple wire gathering operation. The options are Wire-Wire, Wire-Via, Via-Via, Specify Clearance, and None

Override Spacing For Gathering Bus Wires change the current bus spacing when you are routing multiple wires

Override Value lets you set a new bus spacing value.

Use Override the override value will take effect immediately on the current routing layer.

Use Override On Next Via the override value will take effect on the next routing layer after you add a via pattern.

Ignore Override returns to the default spacing value while routing the multiple wires.

Virtuoso XL Layout Editor User Guide

Wire Editing in the Virtuoso XL Layout Editor

Save As Form

File Name lets you type the name of the file to which you want to save the report.