[ibis-macro] Re: An AMI Overview
- From: "C. Kumar" <kumarchi@xxxxxxxxx>
- To: ibis-macro@xxxxxxxxxxxxx, Arpad_Muranyi@xxxxxxxxxx
- Date: Thu, 15 Oct 2009 12:02:08 -0700 (PDT)
what i meant was te eda tool has to call getwave multiole times with blocks of
waveform.
--- On Thu, 10/15/09, Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx> wrote:
From: Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
Subject: [ibis-macro] Re: An AMI Overview
To: ibis-macro@xxxxxxxxxxxxx
Date: Thursday, October 15, 2009, 2:40 PM
Kumar,
I can see why you want to split the task of
GetWave
into different blocks of algorithms. But that
could
still be done within a single function called
GetWave
which may have different partitions (or sub
function
calls) inside. I don't see how this would justify
Init,
(a truly initializing function) to perform
signal
processing...
Arpad
========================================================
From: C. Kumar [mailto:kumarchi@xxxxxxxxx]
Sent: Thursday, October 15, 2009 1:35 PM
To:
ibis-macro@xxxxxxxxxxxxx; Muranyi, Arpad
Subject: Re: [ibis-macro] Re:
An AMI Overview
algorithms using getwave are usually more complicated and
may not be required for all devices. Further more getwave is usually
called multiple times and so programming is also more involved and
there is a need to use persistent data structures
that is the
reason the api is split into two main calls
--- On Thu,
10/15/09, Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
wrote:
From:
Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
Subject: [ibis-macro]
Re: An AMI Overview
To: ibis-macro@xxxxxxxxxxxxx
Date: Thursday,
October 15, 2009, 2:28 PM
Why can't the channel info be fed directly into
GetWave?
Why can't the parameters be fed into GetWave
directly?
Why does the Init function do any convolutions (i.e.
signal
processing) if its purpose is the above
two?
Arpad
============================================================
From: C. Kumar
[mailto:kumarchi@xxxxxxxxx]
Sent: Thursday, October 15, 2009
1:24 PM
To: ibis-macro@xxxxxxxxxxxxx; Muranyi,
Arpad
Subject: Re: [ibis-macro] Re: An AMI
Overview
i do not thing that the fundamental issue
here is the question of doing lti or non lti analysis. the init
function gives the device the channel info (impulse response).
another important function of the init is to deliver the device
parameters.
This delivery of parameters is equally or even
more important. if the device has getwave then it simply returns
the wave form. it may elect to choose the channel information it
obtained in the init or may not.
--- On Thu, 10/15/09,
Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
wrote:
From:
Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
Subject:
[ibis-macro] Re: An AMI Overview
To:
ibis-macro@xxxxxxxxxxxxx
Date: Thursday, October 15, 2009,
2:08 PM
Oh well... I will throw in my $
0.02 worth on this topic.
I think we are mixing two things here,
and our terminology
doesn't help either. One is that
we have this notion of
"Init", meaning initializing the
computer memory, etc... in
a computer science sense, and the other
is the two types of
flows, LTI and non-LTI. To be
honest, I never liked the idea
of calling the "Init" function "Init",
when its purpose was
to execute the LTI
algorithms.
If this flow topic is now becoming such
a big deal regarding
Init and GetWave, why don't we give
things a little more
descriptive names? Let's have an
Init (if necessary) to
really do nothing but initializing
memory, etc... and then
have another function, say
"LTI_algorithms" to do the LTI
signal processing, and a third function
that will do the
non-LTI signal
processing.
The reason I am suggesting this is
because it seems that the
most confusing thing in this discussion
is that the GetWave
functions are not complete by
themselves, they rely on Init
to do part of the algorithms. But
Init may do different
things depending on whether there is a
GetWave or not. Why
don't we just have a function that does
a complete LTI
analysis, and another function that
does a complete non-LTI
analysis?
Arpad
============================================================
From:
ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of
fangyi_rao@xxxxxxxxxxx
Sent: Thursday, October 15,
2009 11:57 AM
To: dkirsanov@xxxxxxxxxx;
ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: An
AMI Overview
Hi,
Danil;
I
think we are on the same page. The fundamental problem is that
current AMI spec allows two usages of Init and GetWave as
stated
at the end of the BIRD.
Further
discussion identified that
two
different styles of modeling were possible and should be
supported. In the default case, the
AMI_Init and
AMI_Getwave calls represent filtering performed by sequential
stages of a device, and
the results
should therefore be chained together. In the second case,
the AMI_Init and AMI_Getwave
calls each
represent the overall device. For example, the AMI_Init
call could provide an LTI model
for the
device while the AMI_Getwave call provides a time-varying
model. In this case, results from
the AMI_Init
and AMI_Getwave calls should be treated as
independent.
The
first case obviously can’t support statistical
simulation.
There
are different approaches to make the AMI standard to support
both time domain (pattern depend) and statistical simulations.
The two-model approach suggested by Kumar is one of them.
Walter
and Arpad prefer to stay with one model by dropping support to
the first case in AMI since practically no model of this usage
exists.
I
want to take this opportunity to suggest another solution with
one model. In AMI we should separate the interface for time
domain simulation from that for statistical by adding a third
function named GetImpulseForStatistical(). It takes impulses of
victim and aggressors and returns modified impulses.
Regards,
Fangyi
From:
ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of
Danil Kirsanov
Sent: Thursday, October 15, 2009
8:30 AM
To:
ibis-macro@xxxxxxxxxxxxx
Subject: [ibis-macro] Re: An
AMI Overview
Fangyi,
Could
you please clarify it? I agree that it might be reasonable to
put the linear part of the model in Init and non-linear part in
Getwave, so that together they characterize the model
(statistical simulator uses only the linear part, while the
pattern-dependent always uses both).
But
I strongly disagree that inside one model Init and
GetWave can provide different approximations of the same
algorithm (i.e. introducing double-counting), where statistical
simulator uses Init and pattern-dependent simulator uses
GetWave. I believe this behavior should be prohibited, since it
makes the flow more complicated, and we can easily achieve the
same result providing two different models (or having internal
option to switch the model between the statistical and
non-linear mode).
If
we have this simple rule (non-linear simulator we always uses
Init and Getwave), the behavior of the EDA does not depend on
the fact whether GetWave exists or not, and GetWaveExists flag
becomes unnecessary (if the Simulator at some point figures out
there is no GetWave, it just does not use it).
Are
we on the same page here?
Best,
Danil
From:
fangyi_rao@xxxxxxxxxxx [mailto:fangyi_rao@xxxxxxxxxxx]
Sent: Wednesday, October 14, 2009 7:48
PM
To: kumarchi@xxxxxxxxx; ibis-macro@xxxxxxxxxxxxx;
dkirsanov@xxxxxxxxxx
Subject: RE: [ibis-macro] Re: An
AMI Overview
Hi,
Kumar;
What
if a model wants to support non-linear time domain simulation
by
GetWave and statistical simulation by returning a LTI
approximation in Init?
Thanks,
Fangyi
From:
ibis-macro-bounce@xxxxxxxxxxxxx
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of C.
Kumar
Sent: Wednesday, October 14, 2009 4:23
PM
To: ibis-macro@xxxxxxxxxxxxx;
dkirsanov@xxxxxxxxxx
Subject: [ibis-macro] Re: An AMI
Overview
i agree..
if the model modifies the
init it is the only thing it should be doing. there
should
not be any getwave
--- On Wed, 10/14/09, Danil
Kirsanov <dkirsanov@xxxxxxxxxx>
wrote:
From:
Danil Kirsanov <dkirsanov@xxxxxxxxxx>
Subject:
[ibis-macro] Re: An AMI Overview
To:
ibis-macro@xxxxxxxxxxxxx
Date: Wednesday, October 14,
2009, 6:59 PM
Dear colleagues,
I would like to clarify one basic
principle of AMI modeling, hoping that all of us agree
with it.
I believe that the model writer should
never do a double-counting: if he modified the channel
impulse response in Init() to model some effect, he
should
not model this effect in Getwave(). So he cannot put the
“true” model in GetWave() and it’s linear approximation
in
Init(). If both types of behavior are expected, there
should be two models (or some internal flag that changes
the behavior of the model).
If this assumption is true, statistical
(linear) simulator always works with Init() function of
the model, while pattern-dependent (non-linear) simulator
works with both Init() and GetWave() and I do not see any
necessity for Get_Wave_Exists flag.
Best,
Danil
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