Same Net used in Multiple Differential Pairs

Parent category: Violations Associated with Nets

Default report mode:

Summary

This violation occurs when the same polarity net (positive or negative) has been detected in multiple differential pair objects within the design.

Notification

If compiler errors and warnings are enabled for display on the schematic (enabled on the Schematic - Compiler page of the Preferences dialog), an offending object will display a colored squiggle beneath it. Hovering over the object will display a pop-up hint that summarizes the violation. AA notification is also displayed in the Messages panel in the following format:

Net <NetName> is used in more than one differential pair objects: <ObjectList>

where:

• NetName is the name of the positive or negative polarity net being used in multiple differential pair objects (e.g., V_RX1_N or V_RX1_P).
• ObjectList is a list of the differential pair objects in which the offending net is used. As the differential pair name is taken as the root of the net name, the names in this list will be identical (e.g., V_RX1 V_RX1).

Recommendation for Resolution

This violation typically arises when the same net label has been attached to multiple wire objects upon which differential pair directives have also been attached. Locate the offending net label objects (use the Details region of the Messages panel to cross-probe to the relevant area of the source schematic document) and amend the names as required.

The positive and negative wires in a pairing should have associated net labels with the same root name for the net, along with a _P and _N suffix respectively. For example, if two wires in a particular pair have the same net label, V_RX1_N, change the positive wire's net label to V_RX1_P.

Tip

• Object hints will only appear provided the Enable Connectivity Insight option is enabled on the System - Design Insight page of the Preferences dialog. Use the controls associated with the Object Hints entry in the Connectivity Insight Options region of the page to determine the launch style for such hints (Mouse Hover and/or Alt+Double Click).