[ibis-macro] Re: input to jitter BIRD
- From: "Walter Katz" <wkatz@xxxxxxxxxx>
- To: <fangyi_rao@xxxxxxxxxxx>, <ibis-macro@xxxxxxxxxxxxx>
- Date: Fri, 2 Sep 2011 13:29:05 -0400 (EDT)
Fangyi,
I added "These impairments external to the receiver that are input to the
RX CDR, but are not included in the CDR clock_times output." To the
introduction of Rx_DCD, Rx_Rj, and Rx_Sj, and to each of the parameter
definitions.
It is correct, and importantly more accurate, that time domain simulations
incorporate such Rx_DCD, Rx_Rj, and Rx_Sj impairments when specified by
the model maker statistically to the output of Rx GetWave, and not using
Monte-Carlo adjustments to the clock_times returned by Rx GetWave. I
included the formulae for using Monte-Carlo techniques for reference only.
I also removed Rx_External_Reference from the BIRD based on the IBIS-ATM
decision to let someone instroduce a new BIRD just for this.
The only other open issue on the Jitter BIRD is to change all occurrences
of "Usage Info and Out" to "Usage Info". This would result in deprecating
the use of Usage Out for Tx_DCD, and removal of the following:
Note:
The EDA Tool/Simulator shall use the values of these Jitter and Noise
parameters directly if they are Usage Info. If they are Usage Out, then
the EDA Tool/Simulator shall use their values generated by AMI_Init. The
model's AMI_GetWave function may return different values for these
parameters than the values returned by AMI_Init; the EDA Tool/Simulator
may report the values of such parameters to the user, but the EDA
Tool/Simulator may not change any inputs to AMI models or change other
result of the simulation based on the values returned for the parameters
in this BIRD by AMI_GetWave.
Walter
From: fangyi_rao@xxxxxxxxxxx [mailto:fangyi_rao@xxxxxxxxxxx]
Sent: Friday, September 02, 2011 1:03 PM
To: wkatz@xxxxxxxxxx; ibis-macro@xxxxxxxxxxxxx
Subject: input to jitter BIRD
Hi, Walter;
Here is my input to the jitter BIRD after discussion in the last ATM
meeting
1. Based on discussions in this committee, it's clear that
parameters Rx_DCD, Rx_Rj & Rx_Sj should be impairments internal to Rx
instead of external as specified in the BIRD. Suggest removing words
"external" from their definition in the text. The BIRD also need to
explain why they can't be combined with parameters Rx_Clock_Recovery_DCD,
Rx_Clock_Recovery_Rj and Rx_Clock_Recovery_Sj.
2. In time domain simulation, the way Rx_DCD, Rx_Rj & Rx_Sj are
handled (by post-processing) is inconsistent with the way
Rx_Clock_Recovery_DCD, Rx_Clock_Recovery_Rj and Rx_Clock_Recovery_Sj are
handled (by clock_times). It's confusing to model part of Rx jitter in
clock_times and part of it in post processing.
3. Adding Rx Rj in post processing doesn't help to reach BER at
1e-12 in time domain simulations with a few millions bits because the low
probability events of Tx Rj , Rx_Clock_Recovery_Rj and ISI can't be
captured anyway.
Regards,
Fangyi
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