All,
One unanimous agreement reached at the May 9 ATM that is missing in Walter's
summary is that BIRD166.2 introduces artificial inflation of redirver
nonlinearity (e.g. limiting mode and compression), noise and crosstalks.
BTW, GetWave-only is a model problem but not a flow problem.
Regards,
Fangyi
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] ;
On Behalf Of Walter Katz
Sent: Wednesday, May 10, 2017 5:16 AM
To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
Subject: [ibis-macro] Summary of discussion about BIRD 166.2
All,
Let me summarize the discussion we had on May 9 about BIRD 166.2 by describing
five scenarios, and then some concluding remarks.
Scenario 1, all four AMI models in the Redriver flow (Tx1, Rx1, Tx2, Rx2) are
Init Only models.
The current flow in IBIS 6.1 is flawed because the Rx2 AMI_Init function does
not receive the complete IR input to properly determine its equalization.
There is unanimous agreement that BIRD 166.2 fixes this for statistical
simulations.
Scenario 2, all four AMI models in the Redriver flow (Tx1, Rx1, Tx2, Rx2) are
Dual models.
The current flow in IBIS 6.1 is flawed because the Rx2 AMI_Init function does
not receive the complete IR input to properly determine its equalization.
There is unanimous agreement that BIRD 166.2 fixes this for both statistical
and time domain simulations.
Scenario 3, the Tx1 and Rx1 AMI models are Dual Models and the Tx and Rx2) are
Init Only models.
The current flow in IBIS 6.1 is flawed because the Rx2 AMI_Init function does
not receive the complete IR input to properly determine its equalization.
There is unanimous agreement that BIRD 166.2 fixes the statistical flow, but
the time domain flow remains problematic.
Scenario 4, all four AMI models in the Redriver flow (Tx1, Rx1, Tx2, Rx2) are a
combination of Init Only and Dual models.
The current flow in IBIS 6.1 is flawed because the Rx2 AMI_Init function does
not receive the complete IR input to properly determine its equalization.
There is unanimous agreement that BIRD 166.2 fixes the statistical flow, but
the time domain flow remains problematic.
Scenario 5, one or more of the four AMI models in the Redriver flow (Tx1, Rx1,
Tx2, Rx2) are GetWave Only models.
There is no valid statistical flow.
The conclusion is that BIRD 166.2 is the correct statistical flow when all four
AMI models in the Redriver flow (Tx1, Rx1, Tx2, Rx2) are a combination of Init
Only and Dual models, and is the correct time domain flow when all four models
are Dual Models.
What I believe IBIS should do is:
1. Approve BIRD 166.2
2. Recommend that all four AMI models in the Redriver flow (Tx1, Rx1, Tx2,
Rx2) are Dual Models in order to support Time Domain flow.
* Note that any Init Only AMI model can easily be upgraded by the model
maker to a Dual Model.
3. Enhance IBIS AMI by adding additional IR outputs to the AMI_Init function
that contain the linear (CTLE) and non-linear (DFE) equalization of the model.
(Keysight AMI_Init Enhancement)
Which leads to the following questions:
1. Is the Keysight AMI_Init Enhancement necessary if all AMI Models are
Dual Models?
2. Is it easier for a model maker to implement the Keysight AMI_Init
Enhancement instead of making Dual Models?
3. If a model maker is too lazy to make a Dual Model, will he be too lazy to
implement the Keysight AMI_Init Enhancement?
4. Will the EDA tools that are used by model makers implement the Keysight
AMI_Init Enhancement?
Note that the Keysight AMI_Init Enhancement does not address the problem of
AMI_GetWave only models.
Walter
Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 303.335-6156
