3 Replies Latest reply on Jan 26, 2011 3:54 PM by olivier_arnaud

    DRC-103: Un-loaded net


      Is it correct, that DxDesigner's DRC does not considers a bidirectional pin to have an input function and

      that's why give a DRC-103 warning if 2 bidirectional pins are connected together ?

        • 1. Re: DRC-103: Un-loaded net

          DRC-103 only reports any input pin which is not connected to (driven by) an output pin. By input and output pins we mean pins of "Pin Type" IN and OUT as shown in the Properties windows. DRC-103 should not report bidirectional pins connected together. I do not observe the behavior you report.

          In the coming release (7.9.2) there will be an option to eliminate from the reported input pins those connected to pins of ANALOG Pin Type.

          • 2. Re: DRC-103: Un-loaded net

            May be you mixed DRC-103 up with DRC-105: Un-driven net. The latter shows IN pins which are not connected to any OUT pins (as an error).

            DRC-103 shall report OUT or BI pins which are unconnected to any input pin (as a warning).


            I double-checked the warnings I got and can confirm that there is no DRC-103 warning given for 2 bidirectional pins.

            • 3. Re: DRC-103: Un-loaded net

              Sorry for the confusion. I misread the original message. I confirm that bidirectional pins are not considered in DRC-103. Only nets driven by an output pin (Pin Type = OUT) are checked if they are connected to an input pin (Pin Type = IN). So inn the current implementation of DRC-103:

              - A bidirectional pin is not considered as a driver so any net driven by a bidirectional pin (Pin Type = BI) on one end and not connected on the other end will not be reported.

              - A bidirectional pin is not considered as a load either, so a net driven by an output (Pin Type = OUT) connected to a bidirectional will be flagged as un-loaded.

              Note that it is probably a good idea to extend the check to treat bidirectional pins as valid input and output.


              In 7.9.2 release, there will be an option to treat a analog pin (Pin Type = ANALOG) as a valid load to remove erroneous messages about nets which are connected to a serial resistor (with analog pins).


              I hope it is clearer now.