I prefer to extend the final slope. That gives maximum flexibility, since it can be used to mimic HE too. About triggered sources, is this the Cadence "DATAPOINTS timecoeff ..." format we are talking about? We would need to have the description in front of us, and it's up to Cadence whether or not that's OK. Mike ________________________________ From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad Sent: Tuesday, November 01, 2005 1:17 PM To: ibis-macro@xxxxxxxxxxxxx Subject: [ibis-macro] Question on PWL building block implementations Importance: High Hello everyone, I need to ask a few questions regarding the PWL sources in our library, so I thought I would write this message before the meeting so people could get ready for the discussion on this topic in the meeting. One question is general. What should the PWL sources do when the input is outside the range of the table definition? The two options I can think of are: 1) Repeat the first or last points, which amounts to a horizontal extrapolation (HE), or 2) use the first or last slope and extrapolate with that, which I call slope extrapolation (SE). The easier way of doing it is the second way, because the $table_model keyword in Verilog-A(MS) which is used for this in our library can only do it that way. This is how the library has it now. However, with a few IF statements I found a relatively easy way to implement HE, and I am leaning towards implementing this in our library. The reason I am asking, though, is because I would like to be compatible with existing SPICE implementations while also serving the needs of the macro modeling engineers. My understanding of HSPICE is that the PWL tables in it use HE. How about other SPICE tools? How about the practical usage of these PWL building blocks? The second question is regarding the event triggered PWL sources. So far the only tool that I know has these PWL sources is Cadence's K-SPICE. Is it OK if I implemented it the same way they do it? My current implementation is somewhat different from it in the library, but I think using their implementation would make a lot of sense. I can explain the details verbally in the meeting, but first I wanted to find out whether there are any other SPICE tools which have such an animal, and if so who's implementation we should pick... Thanks, Arpad ========================================================== --------------------------------------------------------------------- IBIS Macro website: http://www.sisoft.com/ibis-macro IBIS Macro archives: //www.freelists.org/archives/ibis-macro To unsubscribe send an email: To: ibis-macro-request@xxxxxxxxxxxxx Subject: unsubscribe