Nets with no Driving Source

Parent category: Violations Associated with Nets

Default report mode:

Summary

This violation occurs when a net in the design has been detected to have no driving source. That is, the net does not include at least one pin with one of the following electrical types:

• IO
• Output
• Open Collector
• HiZ
• Open Emitter
• Power

It is not uncommon for a net to not include a pin of one of these types, for example, it can happen when:

• A net connects from a connector pin to an input pin.
• A net connects from a series passive component (which have passive pins) to an input pin.

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

Net <NetName> has no driving source (<PinList>)

where

• NetName is the name of the offending net.
• PinList is the comma-separated list of pins in that net.

Recommendation for Resolution

There are a number of different approaches to resolving this violation, including:

1. Edit the connector/passive component pin so that it is one of the electrical types listed above.
2. Disable the Nets with No Driving Source violation check on the Error Reporting tab of the Options for Project dialog (Project » Project Options).
3. Place a No ERC marker on the net. It is recommended that the placed marker be changed from generic to specific - configured to allow this condition to exist, but that net can continue to be checked for all other possible violation conditions. This can be performed from the Suppressed Violations section of the Properties panel when viewing the properties of a currently selected No ERC object.

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).