Re: [SI-LIST] : Best type of models, edge rates & load

Mark Nass (markn@rccorp.com)
Tue, 20 Jul 1999 16:56:52 +0100

We are not a foundry, just design the logic and rely on the foundry to
provide
HSPICE models. No magic with the models just use HSPICE models and vary the
process and temperature.

Weak models are > Slow process, high temp and low voltage
typical models are > typical process, nominal temp & voltage
Strong models are > Fast process, low temp and high voltage

I have no control over the accuracy of the HSPICE models, they come from the
foundry. I am just curious if any knowledgeable people out there have definite
ideas on which parameters are best for generating Tco values and IBIS models
that they have had good results with. I think I hear everybody agreeing that
40pf is not useful, so then my question is what is useful?

Mark

At 04:58 PM 7/20/99 -0500, you wrote:
>
>
>Mark Nass wrote:
>>
>> There has been some discussion recently about parameters of parts
>> specified into 40pf caps and accuracy of models. I generate this type
>> of data for our devices for our own use and our customers. So I am
>> curious as to what people think would be the optimal way to generate
>> Tco, Tsu, jitter parameters and IBIS models so that they would be confident
>> they were getting exactly what they needed for signal integrity and timing
>> analysis. Any feedback?
>>
>> Mark Nass
>
>
>Mark,
>
>Can your provide the SI community some insight on how you generate these
>parameters now. Specifically, do you take measurements on a number
>of different samples over temp/voltage ranges and with different loads?
>Are they SPICE derived? Do you specify a certain amount of 'cushion'
>in the parameters? This might be helpful to those of us who don't know
>how vendors derive the numbers.
>
>Thanks,
>David Haedge
>Raytheon
>
>**** To unsubscribe from si-list: send e-mail to
majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
si-list, for more help, put HELP. si-list archives are accessible at
http://www.qsl.net/wb6tpu/si-list ****
>
>
>

**** To unsubscribe from si-list: send e-mail to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****