[ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

  • From: <fangyi_rao@xxxxxxxxxxx>
  • To: <fangyi_rao@xxxxxxxxxxx>, <wkatz@xxxxxxxxxx>, <kumaran@xxxxxxxxxxxx>, <vladimir_dmitriev-zdorov@xxxxxxxxxx>, <Arpad_Muranyi@xxxxxxxxxx>, <ibis-macro@xxxxxxxxxxxxx>
  • Date: Tue, 23 Aug 2011 12:40:05 -0600

Correct a typo.

What I meant is when the Rx_Rj, Rx_Sj and Rx_DCD impairments are internal to 
Rx, model maker can combine them into Rx_Clock_Recovery_Rj, 
Rx_Clock_Recovery_Sj and Rx_Clock_Recovery_DCD for statistical simulation, and 
include them in clock_times in time-domain simulations.

Fangyi


From: Walter Katz [mailto:wkatz@xxxxxxxxxx]
Sent: Tuesday, August 23, 2011 11:31 AM
To: 'Kumaran Krishnasamy'; RAO,FANGYI (A-USA,ex1); 
vladimir_dmitriev-zdorov@xxxxxxxxxx; Arpad_Muranyi@xxxxxxxxxx; 
ibis-macro@xxxxxxxxxxxxx
Subject: RE: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Kumaran, Fangyi,

Comments below (WMK>).

Walter

From: Kumaran Krishnasamy [mailto:kumaran@xxxxxxxxxxxx]
Sent: Tuesday, August 23, 2011 1:39 PM
To: fangyi_rao@xxxxxxxxxxx; wkatz@xxxxxxxxxx; 
vladimir_dmitriev-zdorov@xxxxxxxxxx; Arpad_Muranyi@xxxxxxxxxx; 
ibis-macro@xxxxxxxxxxxxx
Subject: RE: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Hi,

To add to Fangyi's first comment, users determine the amounts of jitter from 
the standards (for example PCIe, SFI) that describe the max amounts to be used 
to stress the Rx.

WMK> You are correct. In this case the User/EDA tool will specify Rx_Rj, Rx_Sj 
and Rx_DCD from the particular standard.

Regards,
Kumaran

From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of fangyi_rao@xxxxxxxxxxx
Sent: Tuesday, August 23, 2011 10:29 AM
To: wkatz@xxxxxxxxxx; vladimir_dmitriev-zdorov@xxxxxxxxxx; 
Arpad_Muranyi@xxxxxxxxxx; ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Walter;

Thanks for the answers. Please see my further comment/question in brown.

How would a model user know how to set Rx_Rj, Rx_Sj and Rx_DCD?

The BIRD states that they are external to the receiver, so it's expected that 
model users determine and inject (through simulator) such jitters into 
simulations.

In some cases, for example a forwarded clock the User/EDA tool can analyze the 
forwarded clock signal, in which case the EDA tool would be directed to use 
these jitter impairments.

However, if the reference clock is generated inside the Rx chip, then the model 
maker does know these jitter impairments, and can set them inside the AMI model.

In that case they are not external to Rx. Can't they be combined into 
Rx_Clock_Recovery_Rj, Rx_Clock_Recovery_Sj and Rx_Clock_Recovery_DCD? (Sj could 
be tricky but can be handled)

WMK> Are only Rx_Clock_Recovery_Rj, Rx_Clock_Recovery_Sj and 
Rx_Clock_Recovery_DCD Are only used in statistical simulation (unless the 
perverse case when Rx AMI_GetWave does not return clock_times). Rx_Rj, Rx_Sj 
and Rx_DCD are used in both statistical and time domain time domain 
simulations, so cannot be combined with Rx_Clock_Recovery_Rj, 
Rx_Clock_Recovery_Sj and Rx_Clock_Recovery_DCD.


Fangyi

From: fangyi_rao@xxxxxxxxxxx [mailto:fangyi_rao@xxxxxxxxxxx]
Sent: Monday, August 22, 2011 9:02 PM
To: wkatz@xxxxxxxxxx; vladimir_dmitriev-zdorov@xxxxxxxxxx; 
Arpad_Muranyi@xxxxxxxxxx; ibis-macro@xxxxxxxxxxxxx
Subject: RE: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Hi, Walter;

I wonder why Rx_Rj, Rx_Sj and Rx_DCD are Rx model parameters. They are defined 
as impairments external to receiver and serve the purpose of jitter budget 
analyses. So they are simulation inputs but not intrinsic Rx parameters. They 
should be set by model users instead of model developers. EDA tools can include 
them in simulations by allowing users to specify their values from the 
simulator.

Regards,
Fangyi

From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Walter Katz
Sent: Wednesday, August 03, 2011 4:18 PM
To: 'Dmitriev-Zdorov, Vladimir'; 'Muranyi, Arpad'; 'IBIS-ATM'
Subject: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Vladimir,

We are planning to discuss the Jitter BIRD Tuesday. I think we can resolve all 
of the questions at that time.

Walter

From: Dmitriev-Zdorov, Vladimir [mailto:vladimir_dmitriev-zdorov@xxxxxxxxxx]
Sent: Wednesday, August 03, 2011 3:35 PM
To: wkatz@xxxxxxxxxx; Muranyi, Arpad; 'IBIS-ATM'
Subject: RE: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Walter,

After reading your comments, I'm more satisfied with the document. Otherwise 
it's hard to understand some things.
Still, I have a few remaining suggestions, shown in a few additional comments.

Vladimir

From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Walter Katz
Sent: Tuesday, August 02, 2011 5:00 PM
To: Muranyi, Arpad; 'IBIS-ATM'
Subject: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Arpad,

I am including my response to Vladimir's comments in the enclosed document. I 
stand by my earlier statement that I believe the current specification defines 
each parameter mathematically precisely and indicates how the parameters are to 
be used in either the statistical or time domain simulations. I would not 
object to adding additional words would be helpful to explain the precise 
mathematical definitions with "C" code or other standard statistical  function 
definitions.

Walter

From: Muranyi, Arpad [mailto:Arpad_Muranyi@xxxxxxxxxx]
Sent: Tuesday, August 02, 2011 5:55 PM
To: Walter Katz; 'IBIS-ATM'
Subject: RE: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Walter,

Did you look at the comments Vladimir inserted in the
attached Word document?  I think addressing those would
be a good start in this discussion.  But there are some
specifics even in the body of the email from Vladimir:

"The Bird does not seem to be logically complete (does not cover all cases, 
such as Time domain and Statistical flow), or does not provide all necessary 
parameters affecting the results (such as either giving frequency content of Tx 
Gaussian jitter, or making it defined as white uncorrelated jitter, etc.) "

Thanks,

Arpad
========================================================

From: Walter Katz [mailto:wkatz@xxxxxxxxxx]
Sent: Tuesday, August 02, 2011 4:45 PM
To: Muranyi, Arpad; 'IBIS-ATM'
Subject: RE: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Arpad, Vladimir,

There was great effort to define each of the parameters in strict mathematical 
terms. Please indicate specific parameters that the BIRD does not either define 
mathematically precisely, or indicate how the parameters are to be used in 
either the statistical or time domain simulations.

Walter

From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Muranyi, Arpad
Sent: Tuesday, August 02, 2011 4:43 PM
To: IBIS-ATM
Subject: [ibis-macro] Re: Comments on BIRD 123.2.2 from Mentor

Walter,

Here is the email (with attachment) I mentioned in the
ATM meeting today.  There was no response to it since
I posted it.  I think it would be good to get some
discussion going on these questions/comments.

Thanks,

Arpad


From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Muranyi, Arpad
Sent: Friday, July 01, 2011 11:53 AM
To: IBIS-ATM
Subject: [ibis-macro] Comments on BIRD 123.2.2 from Mentor

Walter and All,

I am forwarding Vladimir's comments on BIRD 123.2.2 to this
list for discussion.  Please look at his comments which are
in the attached Word document.  Since Vladimir is also on
this email list, please direct your answers, questions and
comments to him.  (I don't want to be the middle man in such
conversations...).

The general problem is ambiguity of given definitions when it comes to 
implementation in EDA tool.
The Bird does not seem to be logically complete (does not cover all cases, such 
as Time domain and Statistical flow), or does not provide all necessary 
parameters affecting the results (such as either giving frequency content of Tx 
Gaussian jitter, or making it defined as white uncorrelated jitter, etc.)

Thanks,

Arpad
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