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Can someone provide pointers on how to make use of ibis models?

T

Teece

Jan 1, 1970
0
Hi,

I have been doing designs, digital and analog, for over 20 years, without
making use of ibis data, but I think that is about to end.

I was doing a design with one of the newer Altera BGA's and could not find
the ususal "rise time", "fall time" data, so I inquired to Altera. Altera
told me that they provide ibis models for more cases than I could count but
that the "old style" specifications were no longer applicable.

What I am trying to do is match the output of an Altera device to a
transmission line. If I don't know the rise time and the output impedance
then I have little chance of making a good match.

I tried using the freeware tool from Intusoft that can translate ibis models
to spice models (I have used spice for a long, long time) but the translator
would only translate models up to ibis version 3.0. The ibis models
provided by Altera were based upon ibis 3.2 and there were errors in the
translation.

The whole process of making use of ibis models must be easier than I am
making it.

I would think that if I had an ibis simulator, then I could use the ibis
models provided by manufacturers and then creat ibis models of my own to
simulate the transmission lines in my design.

1) Is that last assumption correct?
2) Are there freeware ibis simulators?
3) Can someone recommend an inexpensive ibis simulator?
4) What am I missing in all this that makes the process seem more complex
than it probably is?

Thank You
Tom
 
Hi,

I have been doing designs, digital and analog, for over 20 years, without
making use of ibis data, but I think that is about to end.

I was doing a design with one of the newer Altera BGA's and could not find
the ususal "rise time", "fall time" data, so I inquired to Altera. Altera
told me that they provide ibis models for more cases than I could count but
that the "old style" specifications were no longer applicable.

What I am trying to do is match the output of an Altera device to a
transmission line. If I don't know the rise time and the output impedance
then I have little chance of making a good match.

I tried using the freeware tool from Intusoft that can translate ibis models
to spice models (I have used spice for a long, long time) but the translator
would only translate models up to ibis version 3.0. The ibis models
provided by Altera were based upon ibis 3.2 and there were errors in the
translation.

The whole process of making use of ibis models must be easier than I am
making it.

I would think that if I had an ibis simulator, then I could use the ibis
models provided by manufacturers and then creat ibis models of my own to
simulate the transmission lines in my design.

1) Is that last assumption correct?
2) Are there freeware ibis simulators?
3) Can someone recommend an inexpensive ibis simulator?
4) What am I missing in all this that makes the process seem more complex
than it probably is?

Thank You
Tom


try to ask in comp.arch.fpga, Austin from Xilinx is usually pushing
for people to do ibis sims

-Lasse
 
R

Rich Grise

Jan 1, 1970
0
Hi,

I have been doing designs, digital and analog, for over 20 years, without
making use of ibis data, but I think that is about to end.

I was doing a design with one of the newer Altera BGA's and could not find
the ususal "rise time", "fall time" data, so I inquired to Altera. Altera
told me that they provide ibis models for more cases than I could count but
that the "old style" specifications were no longer applicable.

What I am trying to do is match the output of an Altera device to a
transmission line. If I don't know the rise time and the output impedance
then I have little chance of making a good match.

I tried using the freeware tool from Intusoft that can translate ibis models
to spice models (I have used spice for a long, long time) but the translator
would only translate models up to ibis version 3.0. The ibis models
provided by Altera were based upon ibis 3.2 and there were errors in the
translation.

The whole process of making use of ibis models must be easier than I am
making it.

I would think that if I had an ibis simulator, then I could use the ibis
models provided by manufacturers and then creat ibis models of my own to
simulate the transmission lines in my design.

1) Is that last assumption correct?
2) Are there freeware ibis simulators?
3) Can someone recommend an inexpensive ibis simulator?
4) What am I missing in all this that makes the process seem more complex
than it probably is?

I know nothing at all about Altera, but I _did_ have an opportunity to
poke around with the Xilinx development kit, and one thing I noticed in
the I/O circuits is a "rise time/fall time" control of some kind. You
might look for something like that.

Good Luck!
Rich
 
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