Subject: RE: Simulating IBIS models using XTK
From: Chris Rokusek (crokusek@innoveda.com)
Date: Thu Jan 24 2002 - 16:04:35 PST
Khalid,
Perhaps your timestep isn't small enough when generating the waveform
that is used to create the IBIS model? Check that there is are at least
10 points capturing the "shape" of the transition within the IBIS .ibs
model itself. Also try decreasing time step when simulating the .ibs
model. Just guessing...
Chris Rokusek
Innoveda
> -----Original Message-----
> From: owner-ibis-users@eda.org
> [mailto:owner-ibis-users@eda.org] On Behalf Of Khalid Ansari
> Sent: Thursday, January 24, 2002 2:44 PM
> To: ibis-support@nqesv1.nms.nec.co.jp; ibis-users@eda.org
> Subject: RE: Simulating IBIS models using XTK
>
>
> Hi all,
>
> I am using the B element of HSPICE ( as recommended by
> the gurus) to simulate my IBIS model that I created. This
> IBIS model is for TTL I/Os that I created using the s2ibis
> utility. The complete model looks fine but when I simulate
> one of the macro models I see a digital signal rather than an
> analog signal that I should see at the output. When I take
> the hspice deck for the TTL I/O and simulate it I see a nice
> analog signal at the end. This, I believe but the B element
> simulation of the IBIS model I do not believe. Basically this
> is what it looks like:
>
> ---------------
> *
> *
> *
> -----------------------------
> for the hspice output and
>
> --------------
> *
> *
> *
> ----------------------------------
> for the IBIS output.
>
> What could I be doing wrong here? Any inputs will be appreciated.
>
> My hspice deck with the b element looks like this:
>
> .option post probe
> .option accurate
> .opt dv=1
> vin nd_in 0 pulse(0.8 2.0 2.0ns 1ns 1ns 2ns 6ns)
> b1 nd_pc nd_gc nd_in nd_out_of_in
> + file = '871.ibs' model = 'pnl_it2nn8'
> rpadx nd_in nd_inx 2
> .op all
> cload nd_out_of_in 0 20ff
> .probe tran v(nd_in)
> .probe tran v(nd_out_of_in)
> .tran 5ps 5ns
> .end
>
>
> Thanks,
> Khalid
>
>
> At 12:42 PM 1/23/02 -0800, Muranyi, Arpad wrote:
> Khalid,
>
> You don't need to do any conversion if you want to use HSPICE
> with IBIS models. They have now a B-element which can read
> IBIS files directly.
>
> Arpad Muranyi
> Intel Corporation
> ==============================================================
>
> -----Original Message-----
> From: Khalid Ansari [mailto:khalida@vitesse.com]
> Sent: Wednesday, January 23, 2002 10:23 AM
> To: Alan Hilton-Nickel
> Cc: ibis-users@eda.org; ibis-support@nqesv1.nms.nec.co.jp
> Subject: Re: Simulating IBIS models using XTK
>
>
> Alan, Bill, Tadashi and others,
>
> Thank you all for your responses.
>
> I use HSpice quite a bit. I guess I can run the simulations
> in Hspice too since I don't have Scratchpad. When converting
> IBIS models to Hspice compatible using ibis2spice is there
> any chances of me loosing any important part of the IBIS model?
>
> Khalid
>
>
>
>
>
>
>
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