Arpad, Fangyi, All,
I need to correct an answer that I gave to Fangyi on where
Rx_Noise_PadIs applied. It is applied to the input of the Rx
Buffer. This is not at Rx AMI_GetWave as I incorrectly said in my
last e-mail. It is applied at the input to the Rx Pad which is at
the input to the Rx analog model. (Sorry for the confusion, my
mistake)
To answer Arpad, when a variable is a List, then is tells the User
that he can select any one of the values in the List, only one
gets used by a simulation. If a parameter is List and In, then
just one item in the list gets selected and passed to the model.
(If a parameter is a Table and In then all rows of the Table are
passed to the model.
So the meaning of "Rx_External_Reference_Clock" have "Allowed
Values" of "(List True False)" means that the User can ask the EDA
Tool to either pass (Rx_External_Reference_Clock True) or
(Rx_External_Reference_Clock False) to the models. The Rx Model
Maker tells the User and the EDA Tool that the model can accept
*clock_times as an input by the existence of this parameter with
an allowed value of True. If the User decides to set
Rx_External_Reference_Clock=True then he must tell the EDA tool to
generate the *clock_times vector any way the User decides to. The
EDA tool would pass these clock times into the Rx AMI_GetWave
function using *clock_times. If the User
choosesRx_External_Reference_Clock=Falsethen the user tells the
EDA tool not to create or pass in *clock_times, and therefor asks
the EDA tool to use the parameters Rx_DCD, Rx_Rj, and Rx_Sj to
correct for Jitter on the reference clock. Since the model may be
used in different channels which may affect the jitter
characteristics that end up being passed to the CDR of the
receiver the User chooses the method that he asks his EDA tool to
incorporate CDR reference clock jitter, which may be by asking the
EDA tool to generate and pass *clock_times, use Rx_DCD, Rx_Rj, and
Rx_Sj, or ask the EDA tool to incorporate CDR jitter budgets that
are defined in the specific application, such as PCIeG3, 802.3KR,
802.3-100G, or the Jitter generated by a Fowarded Clock.
You correctly point out that the Model does not call AMI_GetWave,
the EDA Tool calls AMI_GetWave. Not re, "...tells the model that
when calling AMI_GetWve the clock_times vector shall contain...".
Since the EDA Tool calls AMI_GetWave, the only possible
interpretation of this line is "...tells the model (by having
previously passed (Rx_External_Reference_Clock True) in the call
to AMI_Init)that when calling AMI_GetWve (by the EDA Tool) the
clock_times vector shall contain...".
I do not think the line needs to change in this way, but I would
have no objection to making this change either.
Walter
*From:*ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] *On Behalf Of *Muranyi, Arpad
*Sent:* Tuesday, April 12, 2011 12:12 AM
*To:* IBIS-ATM
*Subject:* [ibis-macro] Re: "Final Draft" of the Jitter BIRD 123.2
that I would like reviewed in preparation for submitting to the
Open Forum
Walter,
I am totally confused about the "Rx_External_Reference_Clock"
parameter. Why is this a "(List True False)"? My understanding
is that when something is a List, the entire list is passed into
the model. In this case, how many Boolean values are needed to let
the model know that the "clock_times vector shall contain the
transition times of an externally generated reference clock"?
I would think that this would be a TRUE or FALSE information. Why
would that be passed into the model as a list of Booleans?
The second thing that confuses me in: "...tells the model that
when calling AMI_GetWve the clock_times vector shall
contain..." is that the model doesn't call GetWave, it is the EDA
tool that calls GetWave. So why are you saying that "... tells the
model that ... clock_times vector shall contain the transition
times of an externally generated reference clock..."? Aren't
we supposed to tell the EDA tool to put these transition times into
the clock_times vector? If so, shouldn't this parameter be
(Usage Info) instead of (Usage In)?
Please explain what your intent on this.
Thanks,
Arpad
===================================================================
*From:*ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] *On Behalf Of *Walter Katz
*Sent:* Monday, April 11, 2011 2:17 PM
*To:* IBIS-ATM
*Subject:* [ibis-macro] "Final Draft" of the Jitter BIRD 123.2
that I would like reviewed in preperationg for submitting to the
Open Forum
All,
I have reviewed the comments made so far on BIRD 123 and 123.1,
and have update the BIRD (enclosed) to address these issues. All
changes since the original BIRD 123 are in Red.
I explained what is Sj when there is no Sj_Frequency (It is Sj at
any frequency).
I did not explain what an EDA is to do with these because they
describe the impairment, not how to apply it. Each EDA tool can
apply the impairment that the User or Model asked the EDA tool to
apply either to the inputs or the outputs of the model at the EDA
tools discretion. So questions on each of these parameters should
be limited to what the impairment is. I will be happy to answer
what are some of the possible ways an EDA tool can use, but not
what an EDA tool should or must do.
Finally, I added a new parameter Rx_External_Reference which
allows model makers to create Rx AMI_GetWave models that accept
*clock_times as an input that contains the clock times of an
externally generate reference clock for the Rx Clock Data Recovery
file. With this new enhancement the User can direct the EDA tool
to generate both ANY Jitter distribution as input to the Tx
AMI_GetWave and ANY Jitter distribution as input to the Rx CDR.
Walter
Walter Katz
wkatz@xxxxxxxxxx <mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 720.333-1107
