4 Replies Latest reply on Aug 25, 2011 11:36 PM by xuezhuan.gu

    How to set differential CK when using EBD model.


      I'm using EBD model to simulate RDIMM, but I have a trouble how to set the termination of the differential CK0/CK0# in Hyperlynx 8.1.

      In EBD model, there is description about the resistor:


      | Since ebd standards do not incorporate correct modeling of differential

      | traces CK0/CK0# the differential resistors (R19) are

      | assigned as an external component for reference designator. The

      | components for the differential resistors are defined in series

      | resistor ibis model r_120.ibs. If your simulation tool does not support

      | series resistor models please add the differential resistor in the

      | simulation setup file in order to get correct results.


      | This File uses u68a.ibs file released

      | Rev 2.2: 05/24/2010

      | This file incorporates package parasitics from the u68aX8_2cob.ebd, released Rev 2.1: 02/26/2010.


      | Please select the appropriate speed grade models through [Model Selector]

      | for 800Mbps choose *_800 models.


      | This EBD represents the typical board with a nominal impedance of 60ohms

      | and a dielectric constant of 4.2



      How can I do in Hyperlynx 8.1, thanks.

        • 1. Re: How to set differential CK when using EBD model.

          If you hope to set the differantial shunt resistor with ibis file.  You should create a .ref file for the RDRAM EBD like this first


          * RefDes model Assign File*


          R19, r_120.ibs, r_120(open r_120.ibs, see what component name is it)


          Then click Menu Model - Assign Model by Reference Desinator, load your .ref file.



          • 2. Re: How to set differential CK when using EBD model.

            Thanks, Yanfeng,

            I have assigned the EBD model in "Assign Model by Reference Desinator".

            In the RLDIMM EBD model, it has included the definition for the resistor:


            [Reference Designator Map]

            | Ref Des  File name   Component name

            R11       mt18hvs25672pkz-80eh1.ibs  TerminatorNetwork2

            R15       mt18hvs25672pkz-80eh1.ibs  TerminatorNetwork1

            R19       r_120.ibs         resistor_series

            R24       mt18hvs25672pkz-80eh1.ibs  TerminatorNetwork3

            U1_U0         u68a.ibs      MT47H128M8U68A

            U1_U1         u68a.ibs      MT47H128M8U68A

            U2_U0         u68a.ibs      MT47H128M8U68A

            U2_U1         u68a.ibs      MT47H128M8U68A

            U3_U0         u68a.ibs      MT47H128M8U68A

            U3_U1         u68a.ibs      MT47H128M8U68A

            U4        inb866_v1p0.ibs   INSSTUB32866-12A

            U5        ticu877ar2p3_mt.ibs  TICDCU877AGQL_R2P3

            U6_U0         u68a.ibs      MT47H128M8U68A

            U6_U1         u68a.ibs      MT47H128M8U68A

            U7_U0         u68a.ibs      MT47H128M8U68A

            U7_U1         u68a.ibs      MT47H128M8U68A

            U8_U0         u68a.ibs      MT47H128M8U68A

            U8_U1         u68a.ibs      MT47H128M8U68A

            U9_U0         u68a.ibs      MT47H128M8U68A

            U9_U1         u68a.ibs      MT47H128M8U68A

            U10       eeprom_nc.ibs     eeprom

            U11       inb866_v1p0.ibs   INSSTUB32866-12B

            U12_U0         u68a.ibs      MT47H128M8U68A

            U12_U1         u68a.ibs      MT47H128M8U68A

            U13_U0         u68a.ibs      MT47H128M8U68A

            U13_U1         u68a.ibs      MT47H128M8U68A



            [End Board Description]


            So, if it means I don't need to set others? that is, this RDIMM EBD model has defined anything, I don't need to set others for this EBD model in Hyperlynx 8.1. And next setp I only need to run the "DDRx Batch-Mode Wizard" to do RDIMM Post-Simulation? Thanks.

            • 3. Re: How to set differential CK when using EBD model.

              If EBD itself speicifies IBIS model assignment, you have no need to select IBIS model for components inside EBD anymore. Before running DDRX wizard . I strongly you contact with Mr. Hu jianwei(he is intrumental in helping user to get hands on). Additionally, Following items you may take based on what happened

              1) you may need to set the pin direction for BI/Tri pins.

              2) don't forget copy those ibis model files under your design directory

              3) Upgrade your 8.1 to 8.1.1



              • 4. Re: How to set differential CK when using EBD model.

                Thank you, yanfeng, our hyperlynx had updated to 8.1.1.