Arpad,
Here is the BIRD that I was asked to write.
Addition to spec in Red.
Comments welcome.
Thanks,
Ambrish.
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] ;
On Behalf Of Muranyi, Arpad
Sent: Thursday, June 08, 2017 12:11 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: Comments on BIRD166.3 and last week's ATM discussion
Walter,
So the question then is how we are going to document this.
In the last ATM meeting Ambrish suggested that we should just copy the
statement on pg. 178:
[cid:image001.png@01D2E057.5B189540]
to the redriver flow section to make sure no one misses it. With this
statement we would not
need to make any changes in the flows, i.e. we can forget about BIRD166. Would
you agree to
this, or do you have something else in mind?
Thanks,
Arpad
========================================================================
From: Walter Katz [mailto:wkatz@xxxxxxxxxx]
Sent: Thursday, June 8, 2017 5:42 AM
To: Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx<mailto:Arpad_Muranyi@xxxxxxxxxx>>;
ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx>
Subject: RE: [ibis-macro] Re: Comments on BIRD166.3 and last week's ATM
discussion
Arpad, Ken,
To be clear:
* If any of the models in the channel have Init_Returns_Impulse=False then
one cannot do a statistical analysis including the equalization of all of the
AMI Models unless the EDA tool creates a “proxy AMI_Init” from the input and
output of its AMI_GetWave function. SiSoft gave a paper at the 2017 DesignCon
on how to do this – divide the FFT of the AMI_GetWave output by the FFT of the
AMI_GetWave input.
* If any of the models in the channel have GetWave_Exists=False, then one
cannot do a time domain analysis using the equalization any of the AMI_GetWave
functions unless the EDA tool creates a “proxy AMI_GetWave” from the input and
output of its AMI_AMI_Inir function. IBIS 6.0 says this can be done by
deconvolving the AMI_Init output by the AMI_Init input.
The implementation of either proxy AMI_Init or proxy AMI_GetWave functions can
be problematic.
I think the debate in IBIS-ATM is what should the standard say (if anything)
about the cases that require a proxy AMI_Init or AMI_GetWave. Fangyi correctly
describes the “problematic” issues when Tx2 and Rx2 in the Redriver flow have
AMI_GetWave=False – either the proxy AMI_GetWave are incorrect because of the
non-linear nature of the Rx2 equalization or the Rx2 AMI_Init does not get the
Impulse Response of the full upstream equalization.
The only thing we can do at this point is that we document this issue. Even if
and when we implement in the standard the additional Impulse Response outputs
of AMI_Init as proposed by Keysight, we still need to document this issue for
legal legacy models.
Walter
Attachment:
Redriver_clarification.docx
Description: Redriver_clarification.docx