before you go on to pole/zero approximation you should have an 'S' elements which directly provides the original s-parameter data either in time domain or freq domain. all the others like pole/zero are approximations, except in the case of circuit elements with analytic forms. You can add to your list controlled sources with data provided multi dimensional tables; controlled elements with hysterisis; a generic expression controlled source of the form f(v,i, parameters)=0 and so on and so forth. It is possible to reduce the controlled sources to a finite set (order of 10;s) however I am still with Arpad on this one here, unless I am not seeing something fundamental . These elements have been already implemented in equivalent forms in various flavors of spice and yes AMS and -A flavors. I fail to see how IBIS 'inventing' its own form and convince vendors and users to adopt the yet another new/even improved form. --- On Mon, 6/30/08, Walter Katz <wkatz@xxxxxxxxxx> wrote: From: Walter Katz <wkatz@xxxxxxxxxx> Subject: [ibis-macro] Re: EMD Pole-Zero Models (Why voltage controled sources?) To: bob@xxxxxxxxxxxxx Cc: "IBIS Macro" <ibis-macro@xxxxxxxxxxxxx> Date: Monday, June 30, 2008, 12:54 AM Bob, Thanks for digging this up on the use of controlled voltage source for the Laplace and Pole-Zero form of transfer functions. Is the following a correct summary: * A Touchstone file is a matrix of "Transfer Functions", where the "Transfer Function" is represented as a "Vector" of complex coefficients. o Each element of the "Vector" is the amplitude of the "Transfer Function" at a specific frequency. * Each of the "Transfer Functions" can be translated to Laplace form with a numerator and denominator polynomial. o Hspice implements the Laplace form using the E and G LAPLACE controlled voltage source. * The numerator and denominator Laplace polynomials can be factored, the numerator polynomial factored into a list of zeros, and the denominator factored into a list of poles. o Hspice implements the Pole-Zero form using the E and G POLE controlled voltage source. * Alternatively, each of "Transfer Functions" can be translated into "Impulse Responses" If this is correct, then Lossy RLGC, Touchstone, Laplace, Pole-Zero interconnect blocks can simply be represented as an EMD "Block" of the form: EMD_Block_xxxx <list of nodes> len=<length> type=<type> file=<file> * Where o EMD_Block_xxxx * Instance Designator o <list of nodes> * List of nodes o <length> * Length of interconnect in meters (applies only to RLGC) o <type> * RLGC * Touchstone * Laplace * Pole * Impulse o <file> * RLGC * Contains RLGC table data * Touchstone * sNp * Laplace * Contains Laplace polynomial coefficients * Format needs specification * Pole * Contains Pole Zero data * Format needs specification * Impulse * Contains Impulse Response data * Format needs specification It is a trivial exercise to convert any one of these "Types" of EMD_Blocks to Hspice W, S, E and G elements. If all of the above is correct, then there is no need for EMD_Blocks that are specifically voltage controlled sources. To answer your question: An EMD models for a group of interconnect pins is essentially an ICM [Nodal Path Description] where each of the N_sections is essentially an EMD_Block. The [Nodal Path Description] becomes a subckt with nodes consisting of external EMD pins and IBIS component pins. In ICM all of the N_section can either be all RLGC or all Touchstone. In EMD the EMD_Blocks can be any combination of RLGC, Touchstone, Laplace, Pole, Impulse, Resistor, Capacitor, Inductor, Conductance or K (coupling) elements. Walter -----Original Message----- From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]On Behalf Of Bob Ross Sent: Sunday, June 29, 2008 10:53 PM To: wkatz@xxxxxxxxxx Cc: IBIS Macro Subject: [ibis-macro] Re: EMD Pole-Zero Models (Why voltage controled sources?) Walter: Here are some responses to your questions 1. HSPICE and some other SPICEs implement the Laplace and pole-zero elements as a network function WITHIN controlled sources including the VCVS (E) and VCCS (G) elements. The documention is hard to find, but the HSPICE syntax is in the HSPICE Applications Manual: Exxx n+ n- LAPLACE in+ in- k0 k1 ... kn / b0 b1 ... bm Gxxx n+ n- LAPLACE in+ in- k0 k1 ... kn / b0 b1 ... bm Exxx n+ n- POLE in+ in- a {cmpl zeros) / b (cmpl poles} Gxxx n+ n- POLE in+ in- a {cmpl zeros) / b (cmpl poles} 2. I think of a pole-zero block, not as the single Laplace transfer element, but as an n-port block such as proposed in some private Touchstone-like formats and possibly implemented internally and automatically from n-port table data. My question: When you say interconnect block modules of Resistor/Inductor/ Capacitor, do you really mean a low-level SPICE or SPICE-like syntax within "SPICE" subcircuits for interconnect structures? That is where K and controlled sources are valuable for many reasons. While we have not really discussed this, I have been assuming that we need such low-level capability for EMD. We could formally add a basic SPICE-syntax subcircuit to the list below as one of the modules with its internal SPICE-like netlist used for connecting the R/L/C/K/E/F/G/H ... elements. Bob Walter Katz wrote: > All, > > > > Based on the following assumptions for an EMD: > > > > * A module as a netlist of IBIS components and external pins > * Interconnect models between these IBIS component pins consist of a > netlist of interconnect blocks > * Interconnect block models are: > o Resistors > o Inductors > o Capacitors > o Distributed RLGC models > o S parameter Models > o Impulse Response Models > o Pole-Zero Models > > > > The purpose of this e-mail is to raise the issue of what is a Pole-Zero > model and why do we need voltage controlled sources. > > > > I refer to http://www.ece.uci.edu/docs/hspice/hspice_2001_2-217.html > > > > > Understanding Pole/Zero Analysis > > In pole/zero analysis, a network is described by its network transfer > function which, for any linear time-invariant network, can be written in > the general form: > > > > In the factorized form, the general function is: > > > > It seems to me that a Pole-Zero model can either be represented as a set > of numbers like the polynomial coefficients a0, b0, a1, b1, a2, b2, .. > or the factorized form a0, b0, z1, p1, z2, p2, ? > > Where is the controlled voltage source? > > I assume that one can model the pole-zero form into Spice, Verilog, and > VHDL primitives, and doing so might utilize controlled voltage sources > and other simulator specific models. > > Why it is not sufficient to just have a Pole-Zero model (either with > polynomial coefficients and/or pole-zero coefficients). > > Walter > -- Bob Ross Teraspeed Consulting Group LLC Teraspeed Labs 121 North River Drive 13610 SW Harness Lane Narragansett, RI 02882 Beaverton, OR 97008 401-284-1827 503-430-1065 http://www.teraspeed.com 503-246-8048 Direct bob@xxxxxxxxxxxxx Teraspeed is a registered service mark of Teraspeed Consulting Group LLC --------------------------------------------------------------------- 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 --------------------------------------------------------------------- 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