[ibis-macro] Re: Truth table taken to the next level

Hi Arpad,

 

My apologies for missing the meeting yesterday, I just returned from vacation and was digging out.

 

I am concerned that we are going in entirely the wrong direction with this, in that it is becoming far too EDA-centric and not IP supplier-centric enough. And I think the latter is what we need to focus on if we are ever to have a robust pool of Serdes models available for the SI engineering community to use.

 

I have spoken with a lot of Serdes IP suppliers, and have never heard any mention of supporting statistical or LTI TD or non-LTI TD or partial statistical or full non-LTI TD or any other specific kind of analysis. What I hear is things much more like this:

 

- What IBIS-AMI API do I need to use for my Serdes Tx / Rx? I want to use the most straightforward approach to model my filter.

- Does the filtering in my Serdes IO do a one-time adaptation to my channel? If it does I will use the modified impulse response approach, since that is simplest.

- Does my filtering do real-time dynamic kind of adaptation? If it does, I will need to use the GetWave approach and process waveforms directly.

 

This is admittedly a little over-simplified, but I think is basically on target. I think we would do much better to think more along these lines rather than add all the complexity I see in these tables below. To be successful, I think we need to keep this as simple as possible, and enable models to be developed. I would even go as far as to say that the most practical approach for a given Serdes IO would be to use either the impulse response or GetWave API, but not both together.

 

I would be interested to hear opinions on these ideas from the people on this list.

 

Thanks,

 

Ken Willis

Sigrity, Inc.

860-871-7070

kwillis@xxxxxxxxxxx

 

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From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Wednesday, April 28, 2010 1:57 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Truth table taken to the next level

 

Dear AMI experts,
 
I cleaned up the spreadsheet with the truth table that we discussed
in our ATM meeting today.  It looks like this now:

I hope I got it right this time.

The next thing I would like to do is to extend this table
and spell out how these conditions can be applied to Tx
and Rx independently.  In other words, I don't believe
that our intent was to require these Booleans to be the
same for both Tx and Rx.  But how many combinations are
valid?

We have four (4) combinations per buffer, and we have two
buffers, which could theoretically allow 4^2 = 16 total
possibilities.  Are they all valid?

Thanks,

Arpad
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