Why to use Allegro System Capture – Extended Nets (XNets)

An eXtended Net (XNet) is a connection between two nets that are usually connected through a passive or discrete component like a resistor or capacitor.

XNets are significantly used while defining board-level constraints. Constraint Manager interprets the individual net segments as a single continuous XNet.

In System Capture, you can create XNets in the following ways:

Automatic XNet creation

• XNets are created between pins of a discrete device automatically.
• Additionally, to create XNets between pins of a non-discrete device, you can use the XNET_PINS property on component pins.

Manual XNet creation

XNets are generated when the XNET_PINS property is defined on component pins at instance level or library level.

Creation of XNets is controlled by the auto_xnets_using_gates directive defined in the CANVAS section of the project or site cpm file.

By default, the auto_xnets_using_gates directive is set to ON, meaning that XNets are created automatically. For manual creation, this directive is set to OFF.

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