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XIO2001: IBIS model - EIO1G4A1W0_TX, pullup and pulldown information

Kawai
Guru 19785 points
Part Number: XIO2001


Hi Team,

Could you please tell me why XIO2001 IBIS model doesn't have pullup/pulldown information in this model ? It shows "NA".

Best Regards,

Kawai

  • 0
    TI__Guru 64326 points

    Kawai,

    I am in contact with our modeling team and will get back to you shortly. 

  • 0 in reply to Malik Barton57
    Guru 19785 points

    Hi Malik-san,

    Thanks for your supoort.

    I'm not much familiar to the IBIS model itself.

    Looking into this model, it seems it is calling the "high_high", "low_low", "mideum_high", or "medium_low" model using [Driver Schedule].

    Is my understanding correct ?

    If it is true, it would be helpful if you could tell us when and which model would be called.

    Best Regards,

    Kawai

  • 0 in reply to Kawai
    Guru 19785 points
    Hi Malik-san and Team,

    How is the status confirming to the modeling team ?


    Best Regards,
    Kawai
  • 0 in reply to Kawai
    TI__Guru 64326 points

    Kawai-san,

    Sorry for the late reply. After speaking with the modeling team it seems that when there is NA column in pulldown or pullup table, it implies weak and strong corners characteristic is not modeled. Only typical corner data is present. The fields you mentioned in your last post represent the corners of the simulation and will be called by the simulation software when specified. 

  • 0 in reply to Malik Barton57
    Guru 19785 points

    Hi Malik-san,

    Thanks for your support. I have additional questions.

    Q1). Regarding your information, does that mean you cannot simulate the IO characterisitc correctly with this model ?

    Q2) Isn't this model only prepared for low speed signal IOs ?

    Q3). I believe below infomation are "Voltage", "I(typ)", "I(min)", "I(max)". If correct, there is no current (Ityp=0.0). Can you say this is "Typical" Characterisitic ?

    Best Regards,

    Kawai

  • 0 in reply to Kawai
    TI__Guru 64326 points

    Kawai,

    You should be able to simulate with this model. The Pulldown and Pullup sections refer to different pins in the IBIS model, in other words this model is not meant to use the Pulldown and Pullup pins in your simulation software.

    Your earlier understanding is correct. The actual I/O characteristics are called in the "Driver Schedule" portion of the model. Are you running into issue using some software?

  • 0 in reply to Malik Barton57
    Guru 19785 points
    Hi Malik-san,

    Can I understand that [ Model EIO1G4A1W0_TX] does not uses the pullup/pulldown information in it's model, however, it will call pullup/pulldown information which is listed in the "high_high", "low_low", "mideum_high", or "medium_low" model ?

    This is customer question how it is modeled and I also wanted to deepen my understanding.

    Best Regards,
    Kawai
  • 0 in reply to Kawai
    TI__Guru 64326 points

    Kawai,

    [Driver Schedule] is used to describe a driver with pre-emphasis/de-emphasis behavior.  High_high, medium_high and etc describe timing differences between different voltage levels that constitute pre-emphasis behavior. You can find more detail regarding this driver schedule in IBIS specification document attached. the Pullup (for rising edges) and pulldown (for falling edges) information in the blue box is information that is actually called when simulating this driver. 

    Does this answer your question?

  • 0 in reply to Malik Barton57
    TI__Guru 64326 points
    Kawai

    Is there any more support needed for this issue? If so please reply with any relevant details so that I can further assist you. For now I will be marking this thread as "TI Thinks Resolved".
  • 0 in reply to Malik Barton57
    Guru 19785 points

    Hi Malik-san,

    I understood. Thank you so much for your support.

    Best Regards,

    Kawai