[ibis-macro] Re: [IBIS] BIRD123.1: IBIS-AMI New Reserved Parameters for Jitter/Noise
- From: "Ken Willis" <kwillis@xxxxxxxxxxx>
- To: "'IBIS-ATM'" <ibis-macro@xxxxxxxxxxxxx>
- Date: Wed, 30 Mar 2011 15:34:37 -0400
Hi,
This BIRD has a number of unresolved questions and clarifications that need
to be made before it is ready for a vote in the Open Forum. Each of these
jitter parameters needs to be clearly spelled out as to its meaning and
implementation in order for EDA vendors to consistently handle these
parameters to the expectations of the AMI model developers. Some of the
initial questions we have:
- There was already a parameter Tx_Jitter in the IBIS 5.0 spec. Is
this superceded by all the Tx-related jitter sub-components spelled out in
this BIRD? Or is it intended to still be used?
- There is a whole question of Usage with these parameters. If the
EDA tool is expected to do some well-defined thing with the parameters, we
should probably introduce a new Usage type like (Usage Tool) so that it is
unambiguous as to what is the intent for that parameter.
- Each of these items needs to be spelled out in detail as to what
is to be done with the various parameters. Incorporate into the bit stream?
Add jitter post-simulation in some manner? Post-process statistically into
bathtubs? Needs to be defined for each.
- There is a Tx_Sj parameter with a companion Tx_Sj_Frequency
parameter. But there is also an Rx_Sj that does not have a Rx_Sj_Frequency
counterpart. Was this intentional?
- Can there be multiple Sj's, or can you only have a single one?
- Does it even make sense to have all the Rx_ jitter parameters, if
they are all just ignored anyway if an Rx model with AMI_GetWave returns
clock ticks? Don't we expect Rx models that emulate real device behavior to
have their own clock recovery algorithms as part of the model?
Our recommendation is treat this BIRD as a starting point, and bring it back
into the IBIS-ATM committee for clarification. There is still work to be
done here.
Thanks,
Ken Willis
Sigrity, Inc.
860-871-7070
kwillis@xxxxxxxxxxx
_____
From: owner-ibis@xxxxxxx [mailto:owner-ibis@xxxxxxx] On Behalf Of Mirmak,
Michael
Sent: Tuesday, March 29, 2011 2:09 PM
To: ibis@xxxxxxxxxxxxxx
Subject: [IBIS] BIRD123.1: IBIS-AMI New Reserved Parameters for Jitter/Noise
The enclosed revised BIRD 123.1, IBIS-AMI New Reserved Parameters for
Jitter/Noise, is submitted on behalf of Walter Katz, Mike Steinberger and
Todd Westerhoff of Signal Integrity Software (SiSoft). It will be discussed
at the next IBIS Open Forum teleconference.
A complete list of BIRDs, along with each BIRD's current status, is
available at http://www.eda.org/ibis/birds/.
Michael Mirmak
Intel Corp.
Chair, IBIS Open Forum
http://www.eda.org/ibis/
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