All, I believe that what Kumar is saying is that there is no need for a Tx or Rx to output Init Impulse Response that is to be combined with the output of GetWave or the input of Rx GetWave. So in this respect I believe Kumar agrees with me that there is no need for a second Impulse Response output of Init in a model that supports both Init Statistical and GetWave time domain processing. Of course I have always objected, and will continue to object to requiring that model makers have separate AMI models for Init statistical processing and GetWave time domain processing. Such a change would deprecate an important feature that many models use today and is allowed in the original IBIS 5.0 specification. Bottom line: Can anyone can express a compelling reason for Init returning two impulse responses (other than there may be some model makers that are incapable of implementing the Overlap -save method described in http://en.wikipedia.org/wiki/Overlap%E2%80%93save_method)? Walter . -----Original Message----- From: ckumar [mailto:ckumar@xxxxxxxxxxx] Sent: Thursday, June 14, 2012 8:00 AM To: wkatz@xxxxxxxxxx Cc: Taranjit Kukal; ibis-macro@xxxxxxxxxxxxx Subject: Re: [ibis-macro] Re: AMI-init should pass modified IR to getwave.... my views and original intent are when a model implements getwave it should closely approximate the real device . ie. it should input waveform as a continuous waveform and do what is necessary. Real devices do not do anything to impulse response because it is an analytic construct not available naturally. If statistical processing is desired a separate init model should do. This is analogous in circuit modeling where we have a analytic/semi analytic behavior model and more "real" and complex? silicon level model. On Thu, 14 Jun 2012 07:35:40 -0400 (EDT), "Walter Katz" <wkatz@xxxxxxxxxx> wrote: > Kukal, > > > > So you want to make it easy for the model makers by having Init return two > impulse responses, the current ones that is used for the “Init” flow, > and a > second one that the EDA tool would presumably use in the following way: > > For Tx, the EDA tool would convolve this second impulse response with the > output of Tx GetWave. > > For Rx, the EDA tool would convolve this second impulse response with the > input to Rx GetWave. > > > > 1. Please confirm that this is what you propose to do with the > second > impulse response that you want the Init function to return. > > 2. And if you do confirm this, cannot the model maker pass this > Impulse Response to its GetWave, and have its GetWave do this convolution. > > > > Assume you confirm 1., then what is the compelling reason for us to change > the outputs of Init to make it simpler for a model maker to eliminate > a trivial convolution that he can do in his GetWave function? > > > > Walter > > > > > > From: Taranjit Kukal [mailto:kukal@xxxxxxxxxxx] > Sent: Thursday, June 14, 2012 6:53 AM > To: wkatz@xxxxxxxxxx; 'ibis-macro@xxxxxxxxxxxxx' > Subject: Re: [ibis-macro] AMI-init should pass modified IR to getwave.... > > > > Hi Walter, > I meant model-makers who want to use both init and getwave in conjunction > for transient flow v/s those who want to do everything in getwave. > > Apologize if this statement was confusing.. > > Rgds > > > > From: Walter Katz [mailto:wkatz@xxxxxxxxxx] > Sent: Thursday, June 14, 2012 02:25 PM > To: Taranjit Kukal; 'IBIS-ATM' <ibis-macro@xxxxxxxxxxxxx> > Subject: RE: [ibis-macro] AMI-init should pass modified IR to getwave.... > > > Kukal, > > > > Who are “those” in you statement “those who want to leverage init as > complement to getwave and those who want to keep statistical-flow > purely > independent.” > > > > Walter > > > > From: ibis-macro-bounce@xxxxxxxxxxxxx > [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Taranjit Kukal > Sent: Thursday, June 14, 2012 2:04 AM > To: 'IBIS-ATM' > Subject: [ibis-macro] AMI-init should pass modified IR to getwave.... > > > > Hi All, > > When I was implementing AMI model, I found a situation where it was > important that Rx ami_init needed to pass modified-IR to getwave function. > > Reason was that Chip-RDL-routing was available as Impulse-Responses. > > Removal for “Use_Init_Output” to make Statistical-flow independent of > Transient-flow, is going to break the original intent where init and > getwave were supposed to work in conjunction with each other handling > linear and non-linear filtering portions respectively (as shown below) > > > > cid:image001.png@01CD49C5.F040DCA0 > > > > I would go back to Arpad’s suggestion (year 2010) for having two > Impulse-responses coming out of ami_init > > - One that goes to EDA tool for statistical flow > > - One that gets passed to getwave to allow splitting of > modeling-effort across init and getwave and make things easy for > linear filters. > > > > BIRD120 was brought up that deprecates use of “use_init_output” with a > view > to keep statistical and time-domain simulations independent. But as I > think more, we need to allow both capabilities. It absolutely does not > make sense to implement simple linear filters within getwave when we > can convolute the filter-IR with channel-IR. We should take all steps > to make modeling easy > and ensure enough flexibility. > > > > This way, we cover both the scenarios – those who want to leverage init > as > complement to getwave and those who want to keep statistical-flow > purely > independent. Since this does not bring any disadvantage, I strongly > feel > that we all re-consider outputting two modified-IRs out of init > function – one for statistical-flow and another one to complement > getwave filtering. > > > > > > Rgds > > ..kukal --------------------------------------------------------------------- IBIS Macro website : http://www.eda.org/pub/ibis/macromodel_wip/ IBIS Macro reflector: //www.freelists.org/list/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe