Mike, These emails might have been flying around too fast, but I think I have stated it clearly what problem I am trying to solve. I will attempt to summarize it again: We have an unfinished discussion topic on Model_Specific parameters and InOut/Out. This was tabled, but it will soon flare up again (if it hasn't yet with this email thread). This topic deals with the issue whether InOut and Out should ever be allowed in the spec for Model_Specific parameters, because Model_Specific parameters can't be adequately described by the spec, and consequently the EDA tool would not have enough information to know how to deal with them. One of the main reasons this notion is being questioned is the tap parameters, because if the model has optimization, than it would be desirable to return the optimized values to the tool so it can display it to the user. Up to now we (I) thought that tap parameters can only be described as Model_Specific parameters, and concluded that for that reason we must not eliminate Model_Specific parameters of InOut and Out from the spec. The idea of making the tap parameters Reserved parameters was sparked in my mind by the BIRD 123 thread, in which the question of making them Out or not was brought up. It occurred to me that there might be a way to make the tap parameters Reserved parameters too with the Table syntax. I do not have any examples for the "added benefit" on what else the EDA tool could do with them if they were Reserved parameters, but that is not the main point of this discussion. The main point is to eliminate the reason for needing InOut and Out Model_Specific parameters. Let me know if this doesn't answer your question about my intent. Thanks, Arpad ================================================================== From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Steinberger Sent: Monday, December 12, 2011 1:54 PM To: ibis-macro@xxxxxxxxxxxxx Subject: [ibis-macro] Re: How to make tap coefficients Reserved Parameters with Table Arpad- It's not at all clear what problem you're trying to solve. If you want models to be able to report their tap values to the EDA tool so that they can be displayed to the user then, as Walter says, we've already had that since IBIS 5.0. For this purpose, what we have in IBIS 5.0 is actually better than what you propose because the model can choose to report its state using exactly the parameter definitions which most directly apply to the model. The point is that what Reserved parameters are really useful for is communicating directly with the EDA tool and not directly with the user. In that context, what would you have the EDA tool do other than report the tap values to the user? Thanks. Mike S. On 12/12/2011 01:43 PM, Muranyi, Arpad wrote: Walter, I wasn't talking about added functionality. The reason I got into this brain storming is to find a way to make tap parameters Reserved parameters. This is motivated by the discussion of whether InOut and Out should be allowed with Model_Specific parameters. Your reason for wanting that was the tap coefficient example. Your argument is that these can be only Model_Specific, and these need to have the Out capability so that the model can return its optimized tap coefficients to the EDA tool. The idea I am proposing is an attempt to make tap parameters Reserved and thereby being able to make them Out and InOut without sacrificing the integrity of the specification. If I understand it correctly, currently we are making the tap parameters Model_Specific because the number of taps and their names might be specific to each model which is hard to make Reserved. Regarding the "removed functionality", I do not intend to do that. This is in the brain storming stage at this point. However, the second example indicates that there might be ways to come up with syntax that includes Range, Increment, List, and the like. I don't see a limitation there, we would just have to define each of these representations in the spec. Thanks, Arpad ======================================================== From: Walter Katz [mailto:wkatz@xxxxxxxxxx] Sent: Monday, December 12, 2011 1:32 PM To: Muranyi, Arpad; ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx> Subject: RE: [ibis-macro] How to make tap coefficients Reserved Parameters with Table Arpad, What you are proposing does not give any additional functionality to what is in BIRD 5.0, and in fact removes functionality. The existing structure allows List, Increment, ... for each Tap. This is important because taps does have constrained values. Also taps be InOut or Out. Although Table now support "Out", they return the full table, not just the tap value. What in your proposal adds functionality to what already is in IBIS 5.0? Walter From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx> [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]<mailto:[mailto:ibis-macro-bounce@xxxxxxxxxxxxx]> On Behalf Of Muranyi, Arpad Sent: Monday, December 12, 2011 2:24 PM To: ibis-macro@xxxxxxxxxxxxx<mailto:ibis-macro@xxxxxxxxxxxxx> Subject: [ibis-macro] How to make tap coefficients Reserved Parameters with Table All, I just couldn't leave this idea alone, and looked at BIRD 132 to see how Tables could be used for taps. Here is an example that I can imagine: (DFE_taps (Usage InOut) (Type String Float) (Table (Labels "Tap name" "Tap value") ("tp-1" -0.1) ("tp0" 0.8) ("tp1" 0.1) ) (Description "Initial DFE tap coefficients.") ) I don't see why this couldn't be under the Reserved parameters section. Note that it doesn't have to be a required parameter because not all models may have a DFE. The specification can provide a detailed description on when/how/why this parameter is used by the EDA tool and model, etc... A more elaborate version of the above example is an equivalent of the example on pg. 150 of the v5.0 spec (including Range and Default): (DFE_taps (Usage InOut) (Type String Float Float Float Float) (Table (Labels "Tap name" "Typ value" "Min value" "Max value" "Default value") ("-2" 0.1 -0.1 0.2 0.1) ("-1" 0.2 -0.4 0.4 0.2) ("0" 1 -1 2 1) ("1" 0.2 -0.4 0.4 0.2) ("2" 0.1 -0.1 0.2 0.1) ) (Description "DFE tap coefficients.") ) Comments? Questions? Thanks, Arpad ================================================================