3 Replies Latest reply on Nov 18, 2014 4:00 PM by M_Ishikawa

    HyperLynx DRC electrical nets assignments


      Hello everybody,


      I'm doing my final project degree using HyperLynx DRC in Lear Corporation and I've several questions. I've used the PCB Expedition to create the layout from the DxDesigner schematic and then I've exported and launched the HyperLynx DRC from the PCB Expedition (Analysis --> Export and launch HyperLynx DRC 6.1) and I've evaluated some rules (the easiest’s).


      I’m going to explain my problem with an example: the SI rule Many Vias has as a prerequisites Radiation_High and Radiation_Medium object lists. So, I’ve explored these two object lists in HyperLynx DRC (Analysis Setup --> Object Lists) and I don’t have any electrical net in Radiation_High list and all the nets in Radiation_Medium list. I know that the lists are created using filters and in these cases, the filters depend on the value of the RADIATION CLASS of the electrical nets and it can be set to Medium/Low/High.


      The problem starts here, because I’ve seen that all the electrical nets of my PCB are assigned to Medium value in the Radiation Class column (as in the picture below) and for this reason I have all the electrical nets in the Radiation_Medium list. But I want to set the value of the Radiation Class depending on the information provided by the PCB Expedition or CES or DxDesigner schematic. In my case I have three net classes defined in CES: Default, Radiant and Sensitive (black circle in the picture below). The question is: how can I change the assignation of this value in order to depend on some parameter set in the schematic, PCB layout or CES? How and why is it set to Medium value?



        • 1. Re: HyperLynx DRC electrical nets assignments



          Radiation_Medium is the objects that don't meet Radiation_High or _Low.

          Radiation_High is Clock or other nets that have very fast switching edges. Radiation_Low has contant nets or reset nets.

          I'm not sure how the properties are set in CES. But anyway, you can override the CES influence with the followin ways:
          1. When you import design data, delete (or rename) .cicd file. xxx.cicd contains properties from CES.

          2. Or, on HL DRC, from the menu, Setup > Options > Constraint Manager > select "First time design loaded".
              Then, you can change settings. Otherwise, data came from CES are read-only.

              Please note you can change this setting only prior to load a design.


          Another way is to copy the rule and paste it to a new rule group. You can assign a new object list for this new rule.

          (You need to create a new object list that contains objects you want to check.)


          Hope this helps,


          • 2. Re: HyperLynx DRC electrical nets assignments

            Hello Minoru,


            You said that Radiation_High is clock or other nets that have very fast switching edges but I want to know how is it set this property. For instance, in this example, to know if a net has a very fast switching edge you should indicate this parameter and also the frequency of the net in any place, no? The question is where? In the DxDesigner schematic?


            I know that there are another ways, as copying the rule and pasting it to a new rule group and then assign a new object list for this new rule, but I would know if I can change only the assignations to Radiation_Medium changing some parameters in the PCB or indicating anywhere.


            For instance, the column Frecuency (picture below) is set to 1GHz to all my nets because it is the default value of HL DRC (Setup - Options - Default Values) but I want to change/import according to a specific attribute in the schematic (for example). It is possible? I know that I can change it manually in the HyperLynx DRC changing the corresponding value (as in the picture below) but this is not the idea.


            Thank you!


            • 3. Re: HyperLynx DRC electrical nets assignments

              Hello Ivan,


              Radiation and Susceptibility are defined through the followin steps:

              1) If a net is contant, then Radiation class=low, Susceptability class=low

              2) If a net is clock, then Radiation class=high

              3) If a net has model pin marked as Oscillator, then Radiation class=high

              4) If Radiation class is unassigned at this point, then Radiation class=medium

                  If Susceptibility class is unassigned at this point, then Susceptibility class=high.


              A net is considerd a clock net if it is included into classified object list "ClockNets"

              By default, the filtering condition is as below:



              As I explained here, the setting doesn't come from DX or CES.

              (We read some attributes/properties/assigned IBIS model in CES.)




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