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[802.3_100GEL] Measuring Tx compliance ay a variable TP0a - Collaborate in developing methodology - CFI



Hi All,

Last week I have withdrawn my comments addressing measurement of Tx parameters at a variable TP0a.

I did not have the methodology ready to address this fully and announced I will be welcoming additional people interest in forming the required methodology together with me.

I hereby call every interested personnel to answer me directly on this Email and I will include him/her in the discussions that will follow.

 

Why have this?

  • Measuring at a pre-defined TP0a becomes extremely challenging in 100Gbps signal
    • Was shown by Rich a few month back
    • Will extremely limit the amount of lanes to be measured, if any
    • The variance of TP0-TP0a interconnects can extremely cripple ability to forecast TP0a anticipated parameters

What is suggested?

  • Have a methodology developed (and included in the spec.) to enable extrapolating the parameters to TP0a according to the specific fixture that will be measured per TP0a case
  • We will go over Tx parameters one by one and come up with the appropriate methodology on a per parameter basis
  • Once we have this methodology the current TP0a parameters can still be achieved from TP0 parameters and extrapolating according to the methodology with the ideal TP0-TP0a used to get these first (can be supplied as a reference if we find fit).
  • In the future it will be possible to measure the Tx signal at a specific TP0a, extrapolate the parameters to this point of measurement. Extrapolate according to the specific  

Is it feasible?

  • Currently simulations are used to come up with TP0a and TP2 parameters and put into the spec, so it is possible, but we need to generate the required procedure and not use simulation tools
  • ERL may need to be defined in a strict TP0a location to have appropriate data

Can we avoid doing this work?

  • Another possibility is just add a note that measuring at a specific different TP0a should be addressed by the one doing so and allow thus to run simulations. Not a all around solution, since it may result with different target parameters according to simulators, etc.

 The original presentation for the withdrawn comments can be found here

I feel very strongly that this is the appropriate path forward, but lack the time (and possibly some knowledge) to tend to this all by myself.

Best regards,

--Liav

 

 

 

Liav Ben-Artsi 
Signal Integrity Engineering Group

Physical System Engineering team
Marvell Israel Ltd
6 Hamada Street
Mordot HaCarmel Industrial Park
Yokneam 20692, ISRAEL
Email -
liav@xxxxxxxxxxx
Tel - + 972 4 9091623
Cell - 972-54-2490802
Fax - + 972 4 9091501
WWW Page:
http://www.marvell.com

 

 

 


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