[ibis-macro] Re: jitter question - Info only?
- From: "Muranyi, Arpad" <Arpad_Muranyi@xxxxxxxxxx>
- To: <msteinb@xxxxxxxxxx>, <ibis-macro@xxxxxxxxxxxxx>
- Date: Thu, 24 Feb 2011 07:33:53 -0800
Mike,
As far as I can tell your statement is false because
I see this in the spec:
Notice that every one of these parameters are Reserved
Parameters, and each of these segments have a statement:
"...tells the EDA platform..." True, this doesn't define what the
EDA tool should do with the returned value, but it surely
defines what the parameter's meaning is from which the
tool developer should know what to do with it...
Thanks,
Arpad
==========================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Steinberger
Sent: Thursday, February 24, 2011 9:20 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: jitter question - Info only?
Arpad-
Since there is currently no EDA tool response defined for the output of
a jitter parameter from a model, the EDA tool cannot be expected to take
any action. However, if the information is made available to the user,
that may enable some neural processing.
Mike S.
On 02/24/2011 01:20 AM, Muranyi, Arpad wrote:
Mike,
So are you suggesting that it is perfectly OK for
a model writer to return any of these parameters
in the AMI_parameters_out argument of EITHER the
Init OR the GetWave OR BOTH functions? Do you
think that all EDA vendors are going to know what
to with these parameters if they are returned to
the tool by either of these two functions?
Quoting from the current specification from the
very bottom of pg. 145:
"It tells the EDA platform how much jitter exists at the input to the
transmitter's analog output buffer."
Do you think that if someone wrote a model in which
the Tx_Jitter is a Usage Out and the DLL returns the
value ONLY in the GetWave function that this will
work in all EDA tools?
I fully understand that a specification cannot be
written so that the model writer could never write
a nonsense model, I just want to make sure we are
fully aware of this possibility and chose the correct
actions to fix or leave the spec alone as it is...
Thanks,
Arpad
======================================================
From: Mike Steinberger [mailto:msteinb@xxxxxxxxxx]
Sent: Wednesday, February 23, 2011 10:14 AM
To: Ken Willis
Cc: Muranyi, Arpad
Subject: Re: jitter question - Info only?
Ken-
What I'm suggesting is that we _don't_ _make_ _any_ _changes_ related to
the possible output of jitter parameters from model unless/until there's
substantive information about how this information would be used.
I'm further suggesting that we devote our efforts to the BIRDs that are
already in flight.
Mike S.
On 02/23/2011 09:01 AM, Ken Willis wrote:
Arpad, Mike
I think some of the discussion yesterday was about the model writing Out
values "on the fly" for these standard parameters, which would then have
to be utilized by the EDA tool however it is defined in the spec. Mike,
are you saying that we should consider dropping the Out, and just make
them Info, as Out is never used?
In this case, the EDA tool would still need to handle all of them, but
it would not complicate the flow by making it so that you have to ping
the Init functions, get the data, then process it. It would all be there
up front and the general flow would stay the same.
If this is the case, then making them just "Info" seems like it would be
much cleaner, no?
Thanks,
Ken Willis
Sigrity, Inc.
860-871-7070
kwillis@xxxxxxxxxxx
________________________________
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Steinberger
Sent: Wednesday, February 23, 2011 5:53 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Arpad-
The reason the jitter parameters were originally allowed to have Usage
Out was that there was some thought that the model could report the
jitter it was seeing or generating. The idea at the time was that once
the model reported this jitter, the data might be used in some
unspecified way in some future simulation or analysis.
That was a couple of years ago. (My, how time flies when you're having
fun.)
I'm not aware of a single model that outputs any of the reserved jitter
parameters in this way. Therefore I have not seen any application of
this feature and have no further information on how it might be used.
Perhaps someone else does, and can give us more information to go on.
It seems to me that we have enough work to do on applications that are
already out there and in daily use. I suggest that we leave the current
spec as is rather than attempt to make decisions about applications we
haven't seen yet.
Mike S.
On 02/22/2011 11:33 PM, Muranyi, Arpad wrote:
Thanks Scott and Ambirsh for the suggestions. I will come
back to these later. I would like to respond to something
else first that was mentioned in the meeting today.
When Bob showed us the Table he compiled with the jitter
parameters, I noted that they were Usage Info or Out. This
scared me because it seemed like this was a similar situation
to what we were discussing in this thread. How would the tool
know what to do with a value like Tx_Jitter that is returned
by a DLL? After looking at the details I realized that all
of the parameters in the table Bob sowed us are Reserved
Parameters, therefore their definition (meaning) is clear
from the specification, and consequently the EDA tool will
know exactly what to do with them. So there are no issues
with these being Usage Out.
|
+------------------------+-------------------+
| | General Rules | Allowed Usage
|
|
========================================================================
| | Reserved Parameter | Required Default | Info In Out InOut
|
|
+-------------------------+------------------------+-------------------+
| | Tx_Jitter | No No Jitter | X X
|
| | Tx_DCD | No 0 | X X
|
| | Tx_Rj | No 0 | X X
|
| | Tx_Sj | No 0 | X X
|
| | Tx_Sj_Frequency | No 0 | X X
|
| | Rx_Receiver_Sensitivity | No 0 | X X
|
| | Rx_Clock_PDF | No Clock Centered | X X
|
| | Rx_Recovery_Mean | No 0 | X X
|
| | Rx_Clock_Recovery_Rj | No 0 | X X
|
| | Rx_Clock_Recovery_Sj | No 0 | X X
|
| | Rx_Clock_Recovery_DCD | No 0 | X X
|
| | Rx_Rj | No 0 | X X
|
| | Rx_Sj | No 0 | X X
|
| | Rx_DCD | No 0 | X X
|
| | Rx_Noise | No 0 | X X
|
|
+-------------------------+------------------------+-------------------+
However, looking at BIRD 123, I noticed that the BIRD does
not specify which function's AMI_parameters_out argument will
or is allowed to return these. In the discussion today it
was mentioned that only the Init function should return these
values, and the GetWave function shouldn't. The reason being
is that the EDA tool will either use these parameters to alter
the stimulus given to GetWave or the results coming from GetWave,
but these parameters should not change between GetWave calls.
Given this, it seems that we need to mention somewhere in
BIRD 123 that these parameters can only be returned by the
Init function.
Comments, questions?
Thanks,
Arpad
===================================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Scott McMorrow
Sent: Tuesday, February 22, 2011 4:33 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
I suggest a slight further clarification to that sentence
For Model_Specific parameters with Usage InOut/Out the simulation
results *must* not change, be changed, or require an AMI_INIT, as a
result of the output values of the parameters. The EDA tool is not
required to do anything with Model_Specific outputs.
In effect, if any output parameter can result in a dynamic change in the
end-to-end simulation environment (such as happens with back-channel
communication) that parameter must be standardized. Otherwise
interoperability issues may occur.
Scott McMorrow
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
(401) 284-1827 Business
(401) 284-1840 Fax
http://www.teraspeed.com
Teraspeed(r) is the registered service mark of
Teraspeed Consulting Group LLC
On 2/22/2011 5:15 PM, Ambrish Varma wrote:
Thanks for the clarification Scott, Arpad and Vladimir,
I agree, it will be tricky to legislate what the EDA tools should/could
do with Model_Specific parameter with Usage InOut/Out. I believe we
should simply clarify that the simulation results *must* not change as a
result of the output values of the parameters and that the EDA tool is
not required to do anything with it.
Thanks,
Ambrish.
Ambrish Varma | Member of Consulting Staff
P: 978.262.6431 www.cadence.com
________________________________
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Scott McMorrow
Sent: Tuesday, February 22, 2011 2:32 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Ambrish
The problem is one of "meaning". We know what clock ticks and waveforms
mean. That is well-defined within the spec. We think we know what
"Taps" mean. The meaning of Taps has not been formally defined. But
we probably all know how to present taps to the user in a way that is
meaningful. We might even provide some post processing to determine if
any tap has reached is limit stop.
What is the "meaning" of a general Model Specific Parameter output?
Scott
Scott McMorrow
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
(401) 284-1827 Business
(401) 284-1840 Fax
http://www.teraspeed.com
Teraspeed(r) is the registered service mark of
Teraspeed Consulting Group LLC
On 2/22/2011 1:53 PM, Ambrish Varma wrote:
Arpad,
I have been following this thread carefully - and am tempted to jump in
and ask a question. Would it be conceivable that the parameters of Usage
InOut/Out be considered as an output of the simulation itself and "may
be post-processed by the simulation
tool or presented to the user as is" (from BIRD 120, section 3.2) in the
same manner as clock ticks and the output waveform from GetWave? Each
EDA tool presents that data in its own way, be it eye contours, full
time domain waveform, voltage/time bathtub curves etc.
Thanks,
Ambrish.
Ambrish Varma | Member of Consulting Staff
P: 978.262.6431 www.cadence.com
________________________________
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Tuesday, February 22, 2011 12:20 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Todd,
Generally I am not opposed to plot the data, or
throw cartwheels, or reformat the hard disk or
anything you can think of, IF these expectations
or actions are documented in the specification.
Currently the spec doesn't say anything, so who
would know what to do with Bob, Carol, Ted, and
Alice or what they should do with each other... J
If we want the tools to just plot or save the data
into a file for any Out or InOut parameter, the
spec should say so. But his may not satisfy the
more intellectually advanced minds for too long.
However, we cannot have a spec that doesn't mention
anything. That opens the door to really smart
marketing claims like our tools are superior to any
other tool in the world because we are so smart that
we know what to do with such data implying that
everyone else doesn't know what they are doing,
when this situation is really caused by a badly
written specification...
Thanks,
Arpad
=====================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Todd Westerhoff
Sent: Tuesday, February 22, 2011 8:08 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Arpad,
... and so now we're ready to take the last step. Let's say that
instead of the original .ami file that used a Tap declaration, we had:
(My_RX_DLL
(Reserved Parameters
...
)
(Model _Specific
(Bob (Usage InOut)(Range 0 -10.0 10.0)(Type Float)
(Default 0)(Description "Does whatever"))
(Carol (Usage InOut)(Range 0 -20.0 20.0)(Type Float)
(Default 0)(Description " Does whatever"))
(Ted (Usage InOut)(Range 0 -5.0 5.0)(Type Float)
(Default 0)(Description " Does whatever "))
(Alice (Usage InOut)(Range 0 -99.0 99.0)(Type Float)
(Default 0)(Description " Does whatever "))
)
)
... and, for sake of discussion, we run simulation and get a table with
the same values as before:
Time Bob Carol Ted Alice
0 0.0000 0.0000 0.0000 -0.0002
2.56E-08 0.0000 0.0000 0.0000 -0.0001
5.12E-08 -0.0002 -0.0001 0.0000 -0.0001
7.68E-08 -0.0003 -0.0001 0.0000 -0.0001
1.02E-07 -0.0004 -0.0001 0.0000 -0.0001
1.28E-07 -0.0005 -0.0001 0.0000 -0.0001
1.54E-07 -0.0006 -0.0002 0.0000 -0.0001
1.79E-07 -0.0007 -0.0002 0.0000 -0.0001
2.05E-07 -0.0008 -0.0002 0.0000 -0.0001
2.30E-07 -0.0008 -0.0002 0.0000 0.0000
2.56E-07 -0.0009 -0.0002 0.0001 0.0000
2.82E-07 -0.0010 -0.0002 0.0001 0.0000
3.07E-07 -0.0011 -0.0002 0.0001 0.0001
3.33E-07 -0.0012 -0.0003 0.0000 0.0000
3.58E-07 -0.0013 -0.0003 0.0000 0.0000
3.84E-07 -0.0015 -0.0003 0.0000 0.0000
And therefore, knowing that the first column contains uniformly spaced
time points (ideal candidates for an x-axis), we can plot:
... with no specific knowledge of what this data represents. At first
glance, it seems like Bob is having a bad day, but we really need to
know what the data represents before we can conclude that.
Have I explained why it doesn't matter whether the data is (Type Tap) or
not?
If you restrict the ability to plot to (Type Tap), you're effectively
saying one of three things.
The model is not allowed to output parameters that are not of (Type Tap)
The model may output, but the simulator may not collect, output
parameters that are not of (Type Tap)
The simulator collect and output tables of data, but may not plot them
if they are not of (Type Tap)
I don't regard any of these three options as logically defensible, and I
don't expect the end-users would either.
I think it's time to take this back into an interactive discussion so we
can reach a conclusion. This email is the last of the data I wanted
to put on the table to support that discussion.
Is this a potential topic for today's IBIS-ATM meeting? Walter is
traveling and I'll be running errands, but I'll call in if needed.
Please let me know.
Todd.
________________________
Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA 01754
(978) 461-0449 x24
twesterh@xxxxxxxxxx
www.sisoft.com
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Tuesday, February 22, 2011 1:32 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Todd,
I am glad to hear that is was just a typo...
The discussion is NOT about whether there is anything non-standard
about recording and plotting the returned values the way you showed
it. The discussion is about how the EDA tool (or vendor) knows that
it is expected to do this. The specification doesn't say that, and
really CANNOT say anything about it (except for Type Tap) because
the meaning of the Model_Specific parameters is not known to anyone
except the model maker.
The ONLY exception is the Type Tap because the name of this type
carries a fairly specific meaning. Recognizing this, I am softening
my position on this and I am willing to consider allowing Usage Out
or InOut for Type Tap for this reason, but even in this case I would
mention something along the lines that the tool can present these
returned values to the user or post process it. After all, we were
able to write such things at the end of the flow descriptions in
BIRD 120...
But I have to emphasize that I am NOT ONLY talking about Type Tap
in this thread. What is the EDA tool expected to do with a
Model_Specific Usage Out or InOut of Type Float, Integer, String,
Boolean, UI parameter? Is the tool expected to plot these also
simply vs. time as with Type Tap?
I think this would get pretty boring after a while, and some clever
model makers would soon come up with an unforeseen purposes. And
if this clever model maker happens to be an EDA vendor, they could
gain a fair amount of unfair competitive advantage very quickly,
since the specification is silent about what to do with such
parameters, therefore anything goes. I am not saying that anyone
is doing it today, but the potential is definitely there. But
even if I overlook this potential for unfair competitive advantage
and focus only on the quality of the specification, I must say that
a specification that has open holes like this is not much of a
specification...
For this reason I would not allow Out or InOut for Model_Specific
parameters (other than Type Tap).
Regarding "I *am* maintaining my original position that the acquiring
and plotting
of model data is completely within the current spec", I don't think
anyone
disputed that in this thread. The spec doesn't say anything, so
anything you do is legal at this point... And regarding "and any
debate about whether or not this should be "allowed" is ... well, not a
particularly
good use of our collective time." the debate is not whether this should
be allowed or not, at least not in this context. I don't know
how I can explain it any better than the above. But it seems
that you are finally also getting the idea in what you wrote in
this sentence:
"I'm not suggesting the computer do that automatically, *unless* we want
to define
& standardize parameters that tell the simulator what to do."
You hit the nail on its head, this IS the problem we are discussing.
Other than with the Type Tap, no one knows the meaning of the
Model_Specific parameters, therefore there is no way to automate
what the tool should do with the returned values. So it simply
doesn't make sense to allow Usage Out or InOut for Model_Specific
parameters. Using your words, the computer will not be able to
process these automatically (unless someone has "insider
information"). And that is the whole point in this thread.
Thanks,
Arpad
=====================================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Todd Westerhoff
Sent: Monday, February 21, 2011 10:14 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Arpad,
That wasn't a trap, that was a typo. I was editing a 5 tap example to
make it 4 taps and forgot to take out the 5th tap in the parameter
string. The .ami file was correct, but the parameter string should have
been
(My_RX_DLL(dfe(taps(1 0)(2 0)(3 0)(4 0)))
as you point out. Sorry about that.
Here's what I've been driving at
We've agreed on how the AMI file declares Model_Specific parameters as
input and outputs
We've agreed on how those parameters are communicated in the
AMI_parameters_in string
We've agreed on how model parameters returned by the model appear in
AMI_parameters_out
We've shown how successive calls to Getwave produce additional sets of
parameter data
I'm going to assume we agree that the simulator can record data returned
by the model
We've taken the first 16 sets of parameter data returned by the model
and produced a table:
Time taps.1 taps.2 taps.3 taps.4
0 0.0000 0.0000 0.0000 -0.0002
2.56E-08 0.0000 0.0000 0.0000 -0.0001
5.12E-08 -0.0002 -0.0001 0.0000 -0.0001
7.68E-08 -0.0003 -0.0001 0.0000 -0.0001
1.02E-07 -0.0004 -0.0001 0.0000 -0.0001
1.28E-07 -0.0005 -0.0001 0.0000 -0.0001
1.54E-07 -0.0006 -0.0002 0.0000 -0.0001
1.79E-07 -0.0007 -0.0002 0.0000 -0.0001
2.05E-07 -0.0008 -0.0002 0.0000 -0.0001
2.30E-07 -0.0008 -0.0002 0.0000 0.0000
2.56E-07 -0.0009 -0.0002 0.0001 0.0000
2.82E-07 -0.0010 -0.0002 0.0001 0.0000
3.07E-07 -0.0011 -0.0002 0.0001 0.0001
3.33E-07 -0.0012 -0.0003 0.0000 0.0000
3.58E-07 -0.0013 -0.0003 0.0000 0.0000
3.84E-07 -0.0015 -0.0003 0.0000 0.0000
If I take this data and plot it in Excel, I get something like this:
My point here is that there is absolutely *NOTHING* non-standard about
the way we've recorded and plotted parameter data produced by AMI
models. The original thread, as I read it, was hypothesizing that there
was something "special" going on between the models and the simulator,
such that the simulator had some insight about what to plot and how to
display it. Hopefully, I managed to show that isn't the case - we're
merely talking about building a table of data and providing a utility
for plotting it - whether the parameters were taps or any other floating
point number, the process would be exactly the same.
When I talked about plotting one value as a function of another, I meant
that, given a table of data, I can plot it any way I want, depending on
the utility I'm using to do the plotting. I'm not suggesting the
computer do that automatically, *unless* we want to define & standardize
parameters that tell the simulator what to do. We haven't done that.
I *am* maintaining my original position that the acquiring and plotting
of model data is completely within the current spec, and any debate
about whether or not this should be "allowed" is ... well, not a
particularly good use of our collective time.
Todd.
________________________
Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA 01754
(978) 461-0449 x24
twesterh@xxxxxxxxxx
www.sisoft.com
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Monday, February 21, 2011 10:18 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Todd,
Sorry for the mistake, I failed to realize that you set a trap
for me in the first part of this exercise when you described
a four tap device and the string sent to it was for five taps...
I wasn't counting the taps, only noticed that the last one was
non zero, so I attributed that to the fifth tap. I will not
get into the debate whether this was deliberate or not, arguing
over that would be useless.
Aside from this oversight, I think we are still in agreement,
but I still don't see how all this is related to the discussion
I started. Please explain.
Thanks,
Arpad
=================================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Todd Westerhoff
Sent: Monday, February 21, 2011 7:21 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Arpad,
Actually, I think it should have been
(My_RX_DLL(dfe(taps(1 0)(2 0)(3 0)(4 -0.0002)))
Instead of
(My_RX_DLL(dfe(taps(1 0)(2 0)(3 0)(4 0)(5 -0.0002)))
Since there are only 4 taps. Depending on how you do the math, the
timestamp is either 25.575ns or 25.6ns, but close enough.
Let's say we call Getwave another fourteen times, with the model
returning updated tap parameter data through AMI_parameters_out each
time. We take the data returned through AMI_parameters_out and create a
table that looks something like this:
Time taps.1 taps.2 taps.3 taps.4
0 0.0000 0.0000 0.0000 -0.0002
2.56E-08 0.0000 0.0000 0.0000 -0.0001
5.12E-08 -0.0002 -0.0001 0.0000 -0.0001
7.68E-08 -0.0003 -0.0001 0.0000 -0.0001
1.02E-07 -0.0004 -0.0001 0.0000 -0.0001
1.28E-07 -0.0005 -0.0001 0.0000 -0.0001
1.54E-07 -0.0006 -0.0002 0.0000 -0.0001
1.79E-07 -0.0007 -0.0002 0.0000 -0.0001
2.05E-07 -0.0008 -0.0002 0.0000 -0.0001
2.30E-07 -0.0008 -0.0002 0.0000 0.0000
2.56E-07 -0.0009 -0.0002 0.0001 0.0000
2.82E-07 -0.0010 -0.0002 0.0001 0.0000
3.07E-07 -0.0011 -0.0002 0.0001 0.0001
3.33E-07 -0.0012 -0.0003 0.0000 0.0000
3.58E-07 -0.0013 -0.0003 0.0000 0.0000
3.84E-07 -0.0015 -0.0003 0.0000 0.0000
Still make sense?
Todd.
________________________
Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA 01754
(978) 461-0449 x24
twesterh@xxxxxxxxxx
www.sisoft.com
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Monday, February 21, 2011 7:28 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Time stamp at the end of the first GetWave call
having 1024 samples at 25 ps/sample should be
25.575 ns and the returned string should be:
(My_RX_DLL(dfe(taps(1 0)(2 0)(3 0)(4 0)(5 -0.0002)))
Now, can we go a little faster, please? I still
don't see how this is related to the topic we are
discussing...
Arpad
===================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Todd Westerhoff
Sent: Monday, February 21, 2011 6:14 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Arpad,
Understood. I purposely made the first question trivial to make sure we
were on the same page.
Let's move on to Getwave. To keep the math simple, let's use a 5Gb/s
link (UI = 200ps) running at 8 samples per bit (sample_interval = 25ps)
and a Getwave block size of 1024. At the end of the first Getwave call,
the DLL reports that tap parameters 1, 2, 3, 4 are 0, 0, 0, and -0.0002,
respectively. What will the timestamp be (let's assume time is measured
in seconds), and what will the AMI_parameters_out string returned by the
model be?
I know I'm still going slow, the pace picks up after this ...
Todd.
________________________
Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA 01754
(978) 461-0449 x24
twesterh@xxxxxxxxxx
www.sisoft.com
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Monday, February 21, 2011 6:23 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Todd,
Regarding: "What do you expect that string will look like?",
I would expect that string to look the same as the
string that was set into the DLL (since you said
it echoes back the received parameters):
(My_RX_DLL(dfe(taps(1 0)(2 0)(3 0)(4 0)(5 0)))
But I don't see how going through this exercise
answers the question we are discussing...
Arpad
====================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Todd Westerhoff
Sent: Monday, February 21, 2011 4:30 PM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Arpad,
Sorry for the delay in reply - today's errands ran longer than I
anticipated. I suggest we go through the tap example front to back and
then see how that compares to other cases.
The .ami file for a hypothetical RX declares the following:
(My_RX_DLL
(Reserved Parameters
...
)
(Model _Specific
(dfe
(taps
(1 (Usage InOut)(Range 0 -1.0 1.0)(Type Tap)
(Default 0)(Description "First DFE tap."))
(2 (Usage InOut)(Range 0 -1.0 1.0)(Type Tap)
(Default 0)(Description "Second DFE tap."))
(3 (Usage InOut)(Range 0 -1.0 1.0)(Type Tap)
(Default 0)(Description "Third DFE tap."))
(4 (Usage InOut)(Range 0 -1.0 1.0)(Type Tap)
(Default 0)(Description "Fourth DFE tap."))
)
)
)
Let's say the .dll is called with the default settings for the tap
parameters, which gives an AMI_parameters_in string of:
(My_RX_DLL(dfe(taps(1 0)(2 0)(3 0)(4 0)(5 0)))
Let's also say the .dll echoes back the control parameters it finds
during the AMI_Init call, using the AMI_parameters_out interface. What
do you expect that string will look like?
Todd.
________________________
Todd Westerhoff
VP, Software Products
SiSoft
6 Clock Tower Place, Suite 250
Maynard, MA 01754
(978) 461-0449 x24
twesterh@xxxxxxxxxx
www.sisoft.com
From: ibis-macro-bounce@xxxxxxxxxxxxx [
mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Monday, February 21, 2011 10:38 AM
To: ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: One MORE time without the typo ... RE: Re:
Question about Model Specific parameters
Todd,
This was exactly my point. On what bases would an EDA tool
be expected to plot Type Tap and none of the other Types?
Or, are we saying that the tool is expected to plot any Usage
InOut/Out regardless of its Type? And could any other
expectations from the tool arise for the other Types,
depending on what their meaning is? This is where the
spec is clear as mud.
If we say that the tool should plot the Type Tap, because
we know the meaning of it (Tap), people could also come up
with other rationale for the other types. But these
expectations may all be very subjective, personally biased.
We can't have such expectations and such loose ends in a
specification.
On the other hand, if we do not have such expectations, then
why would we allow to have InOut/Out for Model Specific
parameters? It just doesn't make sense...
In my opinion the specification should mention what the tool
should or could do with these InOut/Out parameters, or
prohibit them.
Thanks,
Arpad
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<SNIP>
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