Settings Column

The Routing Setup dialog allows you to configure the operations in the Routing Strategy dialog. It is displayed by double-clicking in the Settings column for a relevant row. Alternatively, point the cursor at the relevant row in the Settingscolumn and click the displayed "..." button.

Figure 1: Settings

 

The most important settings are listed below for each tab in this dialog.

Item		Description
Autorouting
	Passes	Controls the number of times that the autorouter or the Refine routing command attempt to route the selected nets. The default value is "10". Click Defaults to reset all values in this tab to the default.
	Respect Fixed Fan-outs	Select this option to force the autorouter to connect to pre-existing fan-outs, or fan-outs that are generated by a previous task. If not selected, then the autorouter may connect directly to the pad of a component. The fan-outs must be fixed.
	Vias under single layer pads	Controls whether via-in-pad technology can be used. Off: it is disallowed. No Breakout: it can be used, but only if the outline of the via remains completely under the pad. Allow Breakout: the via can be placed anywhere under the pad. This includes overlapping the boundary.
	Pusher	It is recommended that the pusher is always on. This provides better performance from the autorouter.
High Speed		Allows you to configure how the Lengthen operation is handled by the Autorouter command. Click Defaults to reset all values in this tab to the default. This tab is displayed only in a High Speed environment.
	Automatic tools modify length nets	Specify whether the Autorouter can modify nets that have already been lengthened. Deselecting this setting may reduce the effectiveness of the Autorouter.
	Length-nets re-lengthened after automatic tools	Specify whether the Lengthen operation is automatically launched after certain operations are executed.
	Use pusher to make space for lengthening patterns	Specify whether other tracks can be pushed by lengthening patterns during the Lengthen operation. In the Effort box, you can set the number of times this is done in order to meet relevant constraints.
Fan-out	Fan-out sections	The following sections are in this tab. These sections are executed in the order listed. Smart Fan-out: This is used for BGA-style components. Fan-outs are automatically placed so as to avoid obstacles. This may include decoupling capacitors or terminating resistors (typically on the opposite side of the board). The direction of the fan-outs is optimized on a per-component basis. Simple Fan-out: Produces vias only at the positions that are specified in the dialog. DRC errors can be created if the Errors Allowed check box is selected in the Autorouting tab. Autorouter Fan-out: Allows much more flexibility for placement of fan-outs. They can be routed to outside the boundary of the component. Escape Routing: Generates routing that extends as far as the outside boundary of the component.
	Layer pair	Controls the desired target layers for the fan-out. The definition does not have to be changed for components on different sides of the board. The layer span always includes the surface layer of the component that is currently being operated on.
	Spiral Vias	Controls whether build-up technology is used, or whether only through hole vias can be used.
	Via Position	Controls where the via is placed in relation to the pad. For example, if it is desirable to place the via under the pad, select Absolute on the Simple fan-out tab, and set the length to "0". Ensure that vias under single layer pads are allowed.
Testpoints		If either of the check boxes in the Layers section are selected, then the autorouter generates testpoints on either the top or bottom layers, or both layers. You can also select the specific pads or padstacks that are used for these testpoints.
Via Spirals		Controls the shape of the spiral vias that are generated by the fan-out tools. The spiral vias obey the current build-up settings for the design.
Autorouting Costs		These are advanced settings, which are not described in this training.