6 Replies Latest reply on Mar 18, 2014 1:30 AM by sandeep.kumar

    DDRx Batch Simulation

    sandeep.kumar

      Hi everyone,

       

      I have enabled the crosstalk option in DDRx Batch  Simulation but did not get any report of crosstalk.

      I tried by changing the thresholds also but no report of crosstalk is coming.

       

      Kindly help

        • 1. Re: DDRx Batch Simulation
          cristian.filip

          Although the DDRx Wizard accounts for crosstalk it does not report it. If you want to have that information you need to run the Generic Batch Simulation on the DDR nets. This is an enhancement request that I submitted a while ago through the idea website.

          • 2. Re: DDRx Batch Simulation
            sandeep.kumar

            Thanks Cristian,

             

            May i have privilege to ask one more question,

             

            I have done both quick analysis & detailed batch analysis in quick analysis the result is coming but in Detailed Batch analysis in result some errors are popping out like IC models are not assigned but i have already assigned it in beginning of simulation itself , i want to know where i am wrong??

             

             

            Thanks & Regards

            Sandeep Kumar

            • 3. Re: DDRx Batch Simulation
              cristian.filip

              I guess that you have assigned models only to the DDR nets. However the simulator requires models for the coupled nets as well. You can use the geometric threshold (advanced) feature to identify the aggressors and then assign models to them. Alternatively you can use the Advanced Batch Simulation for this task.

              • 4. Re: DDRx Batch Simulation
                sandeep.kumar

                yes i have assigned IBIS models by using Assign models through REF DES feature  to Controller & DDR .

                 

                Is there any other method to assign models to all selected nets for batch mode crosstalk

                simulation in one shot . because so many nets even from DDR nets is also giving error related to IC models.

                 

                If i will do interactively then it will consume a lot of time.

                 

                I went through tutorial too but regarding assigning models to several nets in one shot is not provided for generic batch simulation.

                • 5. Re: DDRx Batch Simulation
                  cristian.filip

                  To assign models you can use either the .REF file or the .QPL file. You can also run a quick analysis to get the complete list of aggressors. Anyway be aware that the amount of crosstalk might not necessarily be the same when using DDRx, quick analysis or Generic Batch Simulator as the first one is using IBIS models for all the DDR nets and default IC model characteristics for non DDR nets, the second one uses only the default IC model characteristics and finally the last one is using IBIS models for both DDR and non DDR nets. The stimulus and the method to calculate/simulate the crosstalk is also slightly different for each simulator.

                  • 6. Re: DDRx Batch Simulation
                    sandeep.kumar

                    Hi Cristian,

                     

                    I want to know what is the the approximate deviation of result in quick crosstalk analysis & Detailed batch analysis.

                     

                    For one of the board i when i did quick analysis i got some 283 mV of crosstalk for a net but in detailed i am not getting

                    even 50mV of crosstalk for the same net.

                     

                     

                    Thanks