OK, thanks!
Bob
On Tue, Jun 20, 2017 at 1:02 PM, RAO,FANGYI (K-USA,ex1) <
fangyi_rao@xxxxxxxxxxxx> wrote:
Hi Bob,
My proposal does solve the adaptation problem (rx2 init needs the
complete upstream info in it's impulse_in) because the Rx input impulse
matrix includes the cumulative IR that represents the complete upstream
channel.
Regards,
Fangyi
*From:* ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@
freelists.org] *On Behalf Of *Bob Miller
*Sent:* Tuesday, June 20, 2017 9:49 AM
*To:* Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
*Cc:* ibis-macro@xxxxxxxxxxxxx
*Subject:* [ibis-macro] Re: Response to BIRD-190
Does Fangyi's proposal solve the adaptation problem (rx2 init needs the
complete upstream info in it's impulse_in)? I don't think so unless I've
forgotten something therein...
Bob
On Tue, Jun 20, 2017 at 10:32 AM, Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>
wrote:
Good question. Let’s discuss it in ATM today…
But there were a few “implementation options” to Fangyi’s proposed
solution too.
For example, instead of adding more IR inputs and outputs to the Init
function, we
could execute the Init functions multiple times to generate the different
IRs that
are needed for the “correct flow”. This might work without changing the
models,
as far as the IR input/output is concerned. However, we would need to
figure out
how to prevent the Init functions to initialize/optimize twice, though… I
didn’t think
all this through in detail yet. This is why we need all the experts come
together and
find a good way to do this…
The fundamental concept in Fangyi’s proposal that we need to aim to
implement is
that we need to find a way to have the Init functions generate “self IR-s”
and
“cumulative IR-s” in each channel. Without having both of these, I don’t
think we
can solve the problems we are discussing…
Thanks,
Arpad
=================================================================
*From:* Walter Katz [mailto:wkatz@xxxxxxxxxx]
*Sent:* Tuesday, June 20, 2017 10:59 AM
*To:* Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>; ibis-macro@xxxxxxxxxxxxx
*Subject:* RE: [ibis-macro] Re: Response to BIRD-190
Arpad,
If we approve Fangyi’s BIRD today, what do we do in the Redriver flow for
legacy models that do not return the new IR from the AMI_Init function.
Walter
Walter Katz
wkatz@xxxxxxxxxx
Phone 303.449-2308 <(303)%20449-2308>
Mobile 303.335-6156 <(303)%20335-6156>
*From:* ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@
freelists.org <ibis-macro-bounce@xxxxxxxxxxxxx>] *On Behalf Of *Muranyi,
Arpad
*Sent:* Tuesday, June 20, 2017 11:44 AM
*To:* ibis-macro@xxxxxxxxxxxxx
*Subject:* [ibis-macro] Re: Response to BIRD-190
Walter,
I don’t think any of us is trying to block innovation here. But there are
reasons to have
a specification and have consistency in it. We can twist the rules and
intent of a spec
only so far before chaos takes over. But in the name of serving the user
and innovation,
let’s approve and implement Fangyi’s proposal right now! This is the only
proposal at
this time that I am aware of that solves the problem as it should be
solved.
You keep saying that BIRD166 does this and that while BIRD190 doesn’t, but
you seem
to forget that it has been demonstrated that while BIRD166 may fix the
statistical flow,
it introduces problems in the time domain flow which weren’t there
before. Also, you
haven’t responded to some of the questions related to your latest version
regarding
the “8b” paragraph, which basically says that if any of the GetWave
functions are missing,
the analysis should be done with all of the Init functions. It is not
guaranteed that all
models will have Init_Returns_Impulse=true. If any of the models has a
false for that,
and any of the other models have no GetWave function, you won’t be able to
simulate
at all. BIRD166 needs some work. It simply can’t be approved as it
stands today.
Thanks,
Arpad
=====================================================================
*From:* Walter Katz [mailto:wkatz@xxxxxxxxxx ;<wkatz@xxxxxxxxxx>]
*Sent:* Tuesday, June 20, 2017 7:20 AM
*To:* Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx>; ibis-macro@xxxxxxxxxxxxx
*Subject:* RE: [ibis-macro] Re: Response to BIRD-190
Arpad,
As you said, I was trying to answer your question about original intent.
IBIS is a triangle with three corners:
1. EDA Tool
2. IC Vendor
3. User
We can dissect original intent, and history of a standard that is 22 years
old and has gone through 11 factors of two (according to Moore’s law). We
have gone from 25 Megahertz to 56 Gigahertz. It is amazing that 2^11
=56G/25M, and now designing 116 Gigahertz for two years from now.
Ultimately, we are here to serve the User, and his requirements. It is our
duty as EDA vendors and IC Vendors to deliver models and tools that serve
Users well. This is not accomplished by dissecting original intent, or is
DFE LTI, and how LTI is it. We do not serve our Users well if we try to
block innovation that is demonstrably and successfully being used today to
design systems that are driving technology such as autonomous driving,
WebEx, Facebook, and Google.
IBIS-AMI was specifically designed to support innovation: InOut Parameters
and Model Specific Parameters. Innovation has let IBIS-AMI meet the needs
of the SerDes (and now DDR5) market with relatively few substantive changes
over a 10 year life span.
Ultimately, IBIS-AMI Users require a solution that “Predicts the
operations of a channel with sufficient accuracy to design robust products”.
We should be making sure that the IBIS standard allows IC Vendors to
produce “Compliant” models that allow EDA vendors to deliver a software
product that Users can use to address this requirement. I believe BIRD 166
does that, I believe BIRD 190 does not. I also support the extensions that
Keysight has proposed does additional things in line with this fundamental
User requirement.
Walter
Walter Katz
wkatz@xxxxxxxxxx
Phone 303.449-2308 <(303)%20449-2308>
Mobile 303.335-6156 <(303)%20335-6156>
