1 Reply Latest reply on Aug 4, 2016 9:28 PM by agxinmj

    Some warnings in DDRx Batch Simulation

    shaun.p

      Hi,

       

      After I set the ibis model and run the DDRx batch simulation, some warnings are reported in the audit, the audit seems unable to accept my differential pair settings.

      Part of the DDR_log files is as follows:


       

       

      ** WARNING ** : U11.AG17 pin of DDR2_B_CK net does not have opposite pin although net is supposed to be differential

       

      ** WARNING ** : U11.AF17 pin of DDR2_B_CK net does not have opposite pin although net is supposed to be differential

      ** WARNING ** : U11.AC15 pin of DDR2_B_LDQS net does not have opposite pin although net is supposed to be differential

      ** WARNING ** : U11.AC16 pin of DDR2_B_LDQS net does not have opposite pin although net is supposed to be differential

      ** WARNING ** : U11.Y18 pin of DDR2_B_UDQS net does not have opposite pin although net is supposed to be differential

      ** WARNING ** : U11.Y19 pin of DDR2_B_UDQS net does not have opposite pin although net is supposed to be differential

       

       

      NEXT RUN INFORMATION

       

      **********************************************************************

      Start simulation of the net: DDR2_B_CK with type: W1_Typ

      ** Error **: Too many drivers, not allowed in the DDR interface! Driving pins: U11.AF17, U11.AG17

      ** Info **: Initialization of drivers failed!

      NEXT RUN INFORMATION

      **********************************************************************

      Start simulation of the net: DDR2_B_LDQS with type: W1_Typ

      ** Error **: Too many drivers, not allowed in the DDR interface! Driving pins: U11.AC15, U11.AC16

      ** Info **: Initialization of drivers failed!

       

       

      NEXT RUN INFORMATION

       

      **********************************************************************

      Start simulation of the net: DDR2_B_UDQS with type: W1_Typ

      ** Error **: Too many drivers, not allowed in the DDR interface! Driving pins: U11.Y18, U11.Y19

      ** Info **: Initialization of drivers failed!

       

      These warnings lead to the failure of all the DQ signals.

      Can someone solve this problem?

        • 1. Re: Some warnings in DDRx Batch Simulation
          agxinmj

          Hi

          Have u created differential pairs in your board file before simulation ?

          u have to setup differential pairs and power supply before   simulation using a board file ,find the pair of DDR2_B_CK and make this two as differential pair so that when u select both nets will be selected after this try to assign the model and check