Illegal Bus Range Values

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Parent category: Violations Associated with Buses

Default report mode: 


This violation occurs when at least one index in the syntax for a net associated with a bus is negative in value.


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:

Illegal bus range value <BusLabel> at <Location>


  • BusLabel is the defined bus labeling where the illegal value has been detected.
  • Location is the X,Y coordinates for the offending bus object's electrical hotspot.

Recommendation for Resolution

With the violation selected in the Messages panel, use the Details region of the panel to quickly cross probe to the offending net object (e.g., net label, port, sheet entry, etc.,) whose bus syntax is defined incorrectly. The correct syntax should appear in one of the following formats:

  • <NetName>[<LowerIndex>..<UpperIndex>]
  • <NetName>[<UpperIndex>..<LowerIndex>]

LowerIndex and UpperIndex can be zero or a positive integer, but cannot be negative in value.


  • 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). 
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