Altium Designer Documentation

WorkspaceManager_Err-SignalsWithNoDriverSignals with no Driver_AD

Created: June 6, 2015 | Updated: August 7, 2017
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Parent category: Violations Associated with Nets

Default report mode:


This violation occurs when a pin (with I/O Type Input or IO), or a sheet entry (with I/O Type Input or Bidirectional), is not connected to a driving pin or a port on the schematic sheet.


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:

Signal <SignalName> has no driver


  • SignalName is the name of the affected signal.

Recommendation for Resolution

This error can sometimes be caused by the offending pin/sheet entry not being wired to the intended net in the circuit. If this is the case, an additional error stating that the affected signal pin/sheet entry is unconnected will also appear in the Messages panel. With the violation selected in the Messages panel, use the Details region of the panel to cross probe to the affected signal pin/sheet entry. Trace the wiring from the pin/sheet entry to ensure it is connected as required, and modify if it is not.

If the 'signal has no driver' message appears on its own, look for the component output pin to which the input pin/sheet entry is directly connected. Once identified, you can check/edit the output pin's electrical type from the Component Pin Editor dialog. Access this dialog from the associated Component Properties dialog for the part by clicking the Edit Pins button.


  1. This violation type will only be displayed when compiling an FPGA project (*.PrjFpg), a single source schematic that is part of an FPGA project, or a free schematic document.


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