Walter, Too bad that I didn't save that half done flow I put on the screen a week ago Tuesday. (Does Live Meeting save it under the share area by any chance, so we could retrieve it and look at it once again)? In that version I started with the "final flow" from last November, and deleted the Init_Returns_Filter Boolean. When I got done with that, I had pages 2 and 3 (I believe) on which the flow wouldn't have worked without deconvolution to get the results as indicated on the final flow. When I brought this problem up in last week's teleconference, Ambrish and/or Fangy (I am not sure) made the suggestion to "go back to the original flow" as described on pg. 1-2 of: http://www.vhdl.org/pub/ibis/macromodel_wip/archive/20091009/arpadmurany i/AMI%20flows:2009%20Sept%2029%20proposal%20-%20fixed/AMI_Flows_2fixed.p df and then everything will be "nice and clean" without needing deconvolution. This is exactly what I did for the flow I showed in today's meeting. Pg. 2 of the above presentation was perceived as the ONLY change we needed to make to correct the error in the 5.0 specification, and the rest of the changes were perceived as "new features" that belonged to another BIRD. Regardless of how hard I tried to argue that what was perceived as new features in the final flow from last fall were just corrections to a flawed flow, the group voted 4 against 3 last week saying that those features were new features. So the question I want to get answer for from everyone on this list is this: What additional flaws exist in the spec flow (if any), other than the reversal of the order between steps 4 and 5 as shown on pg 1 in the above presentation? It seems that as long as we do not agree on this question we will not have an agreement on how to fix it either... Thanks, Arpad ================================================================== ________________________________ From: Walter Katz [mailto:wkatz@xxxxxxxxxx] Sent: Tuesday, April 20, 2010 5:52 PM To: Muranyi, Arpad; Ambrish Varma; IBIS-ATM Subject: RE: [ibis-macro] Re: AMI_Flows_6.pdf for today's ATM teleconference Ambrish, Arpad, You neglected to include the beginning of section 2.3. You also seam to have forgotten that I proved that this flow was fundamentally flawed and that it required that the Tx GetWave be LTI. This is the fundamental reason why SiSoft uses the flow that we presented two years ago, and again last year. All models that SiSoft has developed, and are currently being distributed by IC Vendors, comply with the flow that Arpad presented last November, support both statistical and time domain flows, and do not use Init_Returns_Filter. I can assure you that this is required in order to correlate with IC Vendor simulation and measurement data. I strongly recommend that we revert to the flow we developed together last November, and simply modify it to choose all of the decision branches that applied when Init_Returns_Filter is True. Walter | | 2.3 Reference system analysis flow | | System simulations will commonly involve both TX and RX algorithmic | models, each of which may perform filtering in the AMI_Init call, the | AMI_Getwave call, or both. Since both LTI and non-LTI behavior can be | modeled with algorithmic models, the manner in which models are | evaluated can affect simulation results. The following steps are | defined as the reference simulation flow. Other methods of calling | models and processing results may be employed, but the final simulation | waveforms are expected to match the waveforms produced by the reference | simulation flow. | | The steps in this flow are chained, with the input to each step being | the output of the step that preceded it. | | Step 1. The simulation platform obtains the impulse response for the | analog channel. This represents the combined impulse response | of the transmitter's analog output, the channel and the | receiver's analog front end. This impulse response represents | the transmitter's output characteristics without filtering, for | example, equalization. Walter Katz 303.449-2308 Mobile 720.333-1107 wkatz@xxxxxxxxxx www.sisoft.com -----Original Message----- From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]On Behalf Of Muranyi, Arpad Sent: Tuesday, April 20, 2010 6:38 PM To: IBIS-ATM Subject: [ibis-macro] Re: AMI_Flows_6.pdf for today's ATM teleconference Ambrish, I think you meant "Time-variant" in a few places where you wrote "Time-invariant"... but aside from that I am not sure what this has to do with Walter's comment about what goes into Rx_Init. Can you explain how these two topics are related? Thanks, Arpad ================================================================== ________________________________ From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Ambrish Varma Sent: Tuesday, April 20, 2010 5:32 PM To: IBIS-ATM Subject: [ibis-macro] Re: AMI_Flows_6.pdf for today's ATM teleconference Hi Arpad, The spec is very clear in delineating between Linear, Time-invariant model and Nonlinear, and /or Time-invariant models. (section 2, chapter 10). It was expected that a non linear/time-invariant model would not try and model an approximation of the same algorithm in the Init function. Also, a linear model would not have a getwave function. Thanks, Ambrish. ________________________________ From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad Sent: Tuesday, April 20, 2010 6:08 PM To: IBIS-ATM Subject: [ibis-macro] Re: AMI_Flows_6.pdf for today's ATM teleconference Walter, Thanks for your feedback. I think you just made us discover another discrepancy in the spec. Contrast what you quoted with this from the IBIS specification: What do you suggest we should do about this? Arpad ======================================================================== ________________________________ From: Walter Katz [mailto:wkatz@xxxxxxxxxx] Sent: Tuesday, April 20, 2010 4:27 PM To: Muranyi, Arpad; IBIS-ATM Subject: RE: [ibis-macro] Re: AMI_Flows_6.pdf for today's ATM teleconference Arpad, In the IBIS 5.0 specification: | Use_Init_Output: | | Use_Init_Output is of usage Info and type Boolean. When | Use_Init_Output is set to "True", the EDA tool is | instructed to use the output impulse response from the | AMI_Init function when creating the input waveform | presented to the AMI_Getwave function. | | If the Reserved Parameter, Use_Init_Output, is set to | "False", EDA tools will use the original (unfiltered) | impulse response of the channel when creating the input | waveform presented to the AMI_Getwave function. | | The algorithmic model is expected to modify the waveform in | place. | | Use_Init_Output is optional. The default value for this | parameter is "True". | | If Use_Init_Output is False, GetWave_Exists must be True. In what was agreed to in November, the input the Rx_Init was always hAC(t) X hTEI(t). In what you presented this week, the input to Rx_Init is either hAC(t) or hAC(t) X hTEI(t), depending on the value of Tx Use_init_Output. I believe based on the IBIS 5.0 specification above that the November flow is correct and the Spec. correction flow that you presented this week is incorrect. Walter Walter Katz 303.449-2308 Mobile 720.333-1107 wkatz@xxxxxxxxxx www.sisoft.com -----Original Message----- From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]On Behalf Of Muranyi, Arpad Sent: Tuesday, April 20, 2010 12:48 AM To: IBIS-ATM Subject: [ibis-macro] Re: AMI_Flows_6.pdf for today's ATM teleconference Here is the AMI_Flows_6.pdf file once again. I made the changes which were suggested to me in the last ATM meeting. This flow includes only the correction we wanted to make on the existing spec flow. I am not sure what the decision was about the last two slides which deal with the Rx pad waveform. Did we say we would delete these slides altogether and not address this capability in this BIRD? As far as I can tell, we can't achieve this flow without deconvolution... Please familiarize yourselves with these slides, because I would like to achieve closure on this flow in the ATM teleconference tomorrow. Comments are welcome before or at the meeting. Thanks, Arpad ========================================================= ________________________________ From: Muranyi, Arpad Sent: Tuesday, April 13, 2010 1:39 PM To: 'IBIS-ATM' Subject: AMI_Flows_6.pdf for today's ATM teleconference For those who are unable to join the meeting via LiveMeeting, here is a new flow diagram to aid the discussion on the subject. Arpad ==================================================