Virtuoso Spectre Circuit Simulator Reference - …

1 Virtuoso Spectre Circuit SimulatorReferenceProduct Version 2004 1990-2003 Cadence Design Systems, Inc. All rights in the United States of Design Systems, Inc., 555 River Oaks Parkway, San Jose, CA 95134, USAT rademarks:Trademarks and service marks of Cadence Design Systems, Inc. (Cadence) contained inthis document are attributed to Cadence with the appropriate symbol. For queries regarding Cadence strademarks, contact the corporate legal department at the address shown above or call other trademarks are the property of their respective Print Permission:This publication is protected by copyright and any unauthorized use of thispublication may violate copyright, trademark, and other laws. Except as specified in this permissionstatement, this publication may not be copied, reproduced, modified, published, uploaded, posted,transmitted, or distributed in any way, without prior written permission from Cadence.

2 This statement grantsyou permission to print one (1) hard copy of this publication subject to the following conditions:1. The publication may be used solely for personal, informational, and noncommercial purposes;2. The publication may not be modified in any way;3. Any copy of the publication or portion thereof must include all original copyright, trademark, and otherproprietary notices and this permission statement; and4. Cadence reserves the right to revoke this authorization at any time, and any such use shall bediscontinued immediately upon written notice from : Information in this publication is subject to change without notice and does not represent acommitment on the part of Cadence. The information contained herein is the proprietary and confidentialinformation of Cadence or its licensors, and is supplied subject to, and may be used only by Cadence scustomer in accordance with, a written agreement between Cadence and its customer.

3 Except as may beexplicitly set forth in such agreement, Cadence does not make, and expressly disclaims, anyrepresentations or warranties as to the completeness, accuracy or usefulness of the information containedin this document. Cadence does not warrant that use of such information will not infringe any third partyrights, nor does Cadence assume any liability for damages or costs of any kind that may result from use ofsuch Rights:Use, duplication, or disclosure by the Government is subject to restrictions as set forthin and et seq. or its Circuit Simulator ReferenceNovember 20041 Product Version Documents .. 6 Typographic and Syntax Conventions .. 6 References ..71 Introducing the Virtuoso Spectre Circuit Simulator .. 8 Improvements over SPICE .. 9 Improved Capacity .. 9 Improved Accuracy .. 9 Improved Speed .. 10 Improved Reliability.

4 11 Improved Models .. 12 Spectre Usability Features and Customer Service .. 12 Analog HDLs ..13RF Capabilities ..13 Mixed-Signal Simulation .. 15 Environments .. 152 Command Options.. 17 Default Values .. 22 Default Parameter Values .. 223 Analysis Statements.. 24AC Analysis (ac) .. 26 Alter a Circuit , Component, or Netlist Parameter (alter) .. 29 Alter Group (altergroup) .. 29 Check Parameter Values (check) .. 31 Checklimit Analysis (checklimit) .. 32 ContentsSpectre Circuit Simulator ReferenceNovember 20042 Product Version Analysis (dc) .. 33DC Device Matching Analysis (dcmatch) .. 37 Envelope Following Analysis (envlp) .. 41 Circuit Information (info) .. 46 Monte Carlo Analysis (montecarlo) .. 48 Noise Analysis (noise) .. 60 Immediate Set Options (options) .. 64 Periodic AC Analysis (pac).

5 74 Periodic Distortion Analysis (pdisto) .. 78 Periodic Noise Analysis (pnoise) .. 86 Periodic S-Parameter Analysis (psp) .. 92 Periodic Steady-State Analysis (pss) .. 98 Periodic Transfer Function Analysis (pxf) .. 112PZ Analysis (pz) .. 117 Quasi-Periodic AC Analysis (qpac) .. 122 Quasi-Periodic Noise Analysis (qpnoise) .. 125 Quasi-Periodic S-Parameter Analysis (qpsp) .. 131 Quasi-Periodic Steady State Analysis (qpss) .. 137 Quasi-Periodic Transfer Function Analysis (qpxf) .. 145 Deferred Set Options (set) .. 149 Shell Command (shell) .. 153S-Parameter Analysis (sp) .. 154 Stability Analysis (stb) .. 158 Sweep Analysis (sweep) .. 164 Time-Domain Reflectometer Analysis (tdr) .. 166 Transient Analysis (tran) .. 168 Transfer Function Analysis (xf) .. 1774 Syntax.. 182 Using analogmodel for Model Passing (analogmodel).

6 184 Behavioural Source Use Model (bsource) .. 186 Checkpoint - Restart (checkpoint) .. 191 Configuring CMI Shared Objects (cmiconfig) .. 192 Built-in Mathematical and Physical Constants (constants) .. 193 Spectre Circuit Simulator ReferenceNovember 20043 Product Version Difficulties (convergence) .. 195 Export (export) .. 196 Expressions (expressions) .. 197 User Defined Functions (functions) .. 201 Global Nodes (global) .. 202 Initial Conditions (ic) .. 203 The Structural if-statement (if) .. 203 Include File (include) .. 205 Spectre Netlist Keywords (keywords) .. 206 Library - Sectional Include (library) .. 210 Node Sets (nodeset) .. 213 Parameter Soft Limits (param_limits) .. 213 Netlist Parameters (parameters) .. 216 Parameter Set - Block of Data (paramset) .. 218 Output Selections (save).

7 219 Sensitivity Analyses (sens) .. 220 SpectreHDL Usage and Language Summary (spectrehdl) .. 221 SpectreRF Summary (spectrerf) .. 230 Subcircuit Definitions (subckt) .. 231 Verilog-A Usage and Language Summary (veriloga) .. 235.. 244 AReferences .. 245 Spectre Circuit Simulator ReferenceNovember 20044 Product Version Circuit Simulator ReferenceNovember 20045 Product Version manual assumes that you are familiar with the development, design, and simulation ofintegrated circuits and that you have some familiarity with SPICE simulation. It containsinformation about the Virtuoso Spectre Circuit is an advanced Circuit Simulator that simulates analog and digital circuits at thedifferential equation level. The Simulator uses improved algorithms that offer increasedsimulation speed and greatly improved convergence characteristics over SPICE.

8 Besides thebasic capabilities, the Spectre Circuit Simulator provides significant additional capabilities overSPICE. SpectreHDL ( Spectre High-Level Description Language) and Verilog -A usefunctional description text files (modules) to model the behavior of electrical circuits and othersystems. Virtuoso SpectreRF Simulation Option adds several new analyses that support theefficient calculation of the operating point, transfer function, noise, and distortion of commonRF and communication circuits, such as mixers, oscillators, sample holds, and switched-capacitor preface discusses the following topics: Related Documents on page Preface-6 Typographic and Syntax Conventions on page Preface-6 References on page Preface-7 Spectre Circuit Simulator ReferencePrefaceNovember 20046 Product Version DocumentsThe following can give you more information about the Spectre Circuit Simulator and relatedproducts: To learn more about the equations used in the Spectre Circuit Simulator , consult theVirtuoso Spectre Circuit Simulator Device Model Equationsmanual.

9 The Spectre Circuit Simulator is often run within the Cadence analog Circuit designenvironment, under the Cadence design framework II. To see how the Spectre circuitsimulator is run under the analog Circuit design environment, read theVirtuoso AnalogDesign Environment User Guide. For more information about using the Spectre Circuit Simulator with Verilog-A, see theVerilog-A Language Reference manual. If you want to see how SpectreRF is run under the analog Circuit design environment,readVirtuoso SpectreRF Simulation Option User Guide. For more information about RF theory, seeVirtuoso SpectreRF Simulation OptionTheory. For more information about how you work with the design framework II interface, seeDesign Framework II Help. For more information about specific applications of Spectre analyses, seeTheDesigner s Guide to SPICE & and Syntax ConventionsThis list describes the syntax conventions used for the Spectre Circuit words indicate keywords that you must enter literally.

10 These keywordsrepresent command (function, routine) or option names, filenames and paths, and any other sort of type-in in italics indicate user-defined arguments for which you must substitutea name or a value. (The characters before the underscore (_) inthe word indicate the data types that this argument can are case , Kenneth Designer s Guide to SPICE & Spectre . Boston: Kluwer Academic Publishers, Circuit Simulator ReferencePrefaceNovember 20047 Product Version |Vertical bars (OR-bars) separate possible choices for a single argument. They takeprecedence over any other character.[ ]Brackets denote optional arguments. When used with OR-bars, they enclose a list ofchoices. You can choose one argument from the list.{ }Braces are used with OR-bars and enclose a list of choices. You must choose oneargument from the dots (..) indicate that you can repeat the previous argument.)