Missing Negative Net in Differential Pair

Parent category: Violations Associated with Nets

Default report mode:

Summary Copy Link Copied

This violation appears when a negative polarity net has not been detected for a particular differential pair object within a design. The positive polarity net for the pair does exist.

Notification Copy Link Copied

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. A notification is also displayed in the Messages panel in the following format:

Missing Negative Net for differential pair <PairName>, positive net <NetName>

where:

• PairName is the name of the differential pair for which a positive polarity net has already been defined (e.g. V_RX1)
• NetName is the name of the positive polarity net (e.g. V_RX1_P).

Recommendation for Resolution Copy Link Copied

This violation typically arises in the following situations:

• A differential pair directive has not been attached to the negative polarity wire of the signal pairing. The required net label (e.g. V_RX1_N) has been attached to the wire as required.
• An appropriately-named net label (e.g. V_RX1_N) has not been attached to the negative polarity wire of the signal pairing. The required differential pair directive has been attached to the wire as required.

To resolve this violation, simply locate the negative wire object for the pair and ensure that both the net label and differential pair directive are attached and that the name of the net label is specified as required. The net label for the negative wire will be essentially the same as that for the positive wire, but with an _N suffix instead of an _P.