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1、Simulator Expressions August 2005 ii Notice The information contained in this document is subject to change without notice. Agilent Technologies makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fi tness for a par
2、ticular purpose. Agilent Technologies shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material. Warranty A copy of the specifi c warranty terms that apply to this software product is available u
3、pon request from your Agilent Technologies representative. Restricted Rights Legend Use, duplication or disclosure by the U. S. Government is subject to restrictions as set forth in subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013 for DoD a
4、gencies, and subparagraphs (c) (1) and (c) (2) of the Commercial Computer Software Restricted Rights clause at FAR 52.227-19 for other agencies. Agilent Technologies, Inc. 1983-2005 395 Page Mill Road, Palo Alto, CA 94304 U.S.A. Acknowledgments Mentor Graphics is a trademark of Mentor Graphics Corpo
5、ration in the U.S. and other countries. Microsoft, Windows, MS Windows, Windows NT, and MS-DOS are U.S. registered trademarks of Microsoft Corporation. Pentium is a U.S. registered trademark of Intel Corporation. PostScript and Acrobat are trademarks of Adobe Systems Incorporated. UNIX is a register
6、ed trademark of the Open Group. Java is a U.S. trademark of Sun Microsystems, Inc. SystemC is a registered trademark of Open SystemC Initiative, Inc. in the United States and other countries and is used with permission. iii Contents 1Introduction to Simulator Expressions Simulator Expressions Syntax
7、1-4 Case Sensitivity1-4 Predefi ned Expressions .1-5 Constants and Variables.1-5 Units and Scale Factors .1-9 Mathematical Operators and Hierarchy1-12 Conditional Expressions.1-14 Functions1-16 Predefi ned Functions Reserved Names.1-16 2Using Simulator Expressions in Advanced Design System Using a V
8、AR (Variables and Equations Component)2-2 VarEqn Data Types.2-3 Editing Component Parameters2-4 Setting up a Frequency-domain Defi ned Devices (FDD)2-5 Setting up a Symbolically Defi ned Devices (SDD) .2-5 Alphabetical Listing of Simulator Functions2-6 3Data Access Functions 4Harmonic Balance Functi
9、ons 5Math Functions 6S-Parameter Analysis Functions 7Transient Source Functions 8Utility Functions Index iv 1-1 Chapter 1: Introduction to Simulator Expressions This document describes the simulator expressions that are available for use with several Agilent EEsof EDA products. For a complete list o
10、f available simulator functions, refer to the Alphabetical Listing of Simulator Functions in Chapter 2 or consult the index. Simulator expressions are functions that you defi ne before they are used internally during simulation run-time. They can be entered into the program using various methods, de
11、pending on which product you are using. Unlike the expressions described in the Measurement Expressions documentation, simulator expressions are evaluated at the beginning of a simulation, not after the simulation has completed. Although there is some overlap among many of the more commonly used fun
12、ctions, simulator expressions and measurement expressions are derived from separate sources, evaluated at different times, and can have subtle differences in their usages. Thus, these two types of expressions need to be considered separately. For an overview of how simulator expressions are evaluate
13、d, refer to Figure 1-1. Note that if a particular term is used in a simulator expression, the term must be defi ned before the simulation is run. For example, if you use the variable R in a simulator expression, and R = S(1,1), where the results of S(1,1) will not be known until after the simulation
14、 is complete, an error will be returned by the simulator. 1-2 Introduction to Simulator Expressions Figure 1-1. How Simulator Expressions are Evaluated. Start Simulation Evaluate Simulator Expressions Complete Simulation Evaluate Measurement Expressions in Data Display Open Data Display Evaluate Mea
15、surement Expressions Simulator Expressions are evaluated at simulation run-time. 1-3 Within this document you will fi nd: Information on simulator expressions syntax. A functions reference table that provides a complete list of all available simulator functions. Individual functions are also listed
16、in the index for your convenience. Information specifi c to entering simulator expressions in your product. You will also fi nd a complete list of functions that can be used as simulator expressions individually, or combined together as a nested expression. These expressions have been separated into
17、 libraries and are listed in alphabetical order within each library. The expressions available include: Chapter 3, Data Access Functions Chapter 4, Harmonic Balance Functions Chapter 5, Math Functions Chapter 6, S-Parameter Analysis Functions Chapter 7, Transient Source Functions Chapter 8, Utility
18、Functions Note All predefi ned expressions, functions, constants, and variables listed in this chapter are reserved names. You can use them in your expressions; however, you cannot redefi ne them to something else. 1-4Simulator Expressions Syntax Introduction to Simulator Expressions Simulator Expre
19、ssions Syntax Use the following guidelines when creating simulator expressions: Simulator expressions are based on the mathematical syntax in Application Extension Language (AEL). Function names, variable names, and constant names are all case sensitive in simulator expressions. Use commas to separa
20、te arguments. White space between arguments is acceptable. The general form of an expression is: expressionName = nonconstantExpression For example: x1 = 4.3 + freq; syc_a = cos(1.0+sin(pi*3 + 2.0*x1) Zin = 7.8 ohm + j*freq * 1.9 ph y = if (x equals 0) then 1.0e100 else 1/x endif Case Sensitivity Al
21、l variable names, functions names, and equation names are case sensitive in simulator expressions. Simulator Expressions Syntax1-5 Predefi ned Expressions The following expressions are predefi ned: Constants and Variables Many predefi ned constants and predefi ned global variables are available. Tab
22、le 1-1 lists the simulator constants and variables and provides a brief description of each. Constants An integer constant is represented by a sequence of digits optionally preceded by a negative sign (e.g.14,-3). A real number contains a decimal point and/or an exponential suffi x using thee notati
23、on (e.g.14.0,-13e-10). The only complex constant is the predefi ned constantj, which is equal to the square root of -1. It can be used to generate complex constants from real and integer constants (e.g., j*3,9.1 + j*1.2e-2 ). The predefi ned functions “complex()” on page 5-15 and “polar()” on page 5
24、-68 can also be used to enter complex constants into an expression. A string constant is delimited by single or double quotes (e.g.string,“this is a string“). Always use vertical quotes (e.g. ) as opposed to open quotes (e.g. ). Variables Variables can be modifi ed and swept. The main difference bet
25、ween expressions and variables is that a variable can be directly swept and modifi ed by an analysis but an expression cannot. Note however, that any instance parameter that depends on an gaussian=_gaussian_tol(10.0)default gaussian distribution nfmin=_nfmin() the minimum noise fi gure omega=2.0*pi*
26、freqthe analysis frequency rn=_rn()the noise resistance sopt=_soptthe optimum noise match tempkelvin =temp + 273.15the analysis temperature uniform=_uniform_tol(10.0)default uniform distribution 1-6Simulator Expressions Syntax Introduction to Simulator Expressions expression is updated whenever one
27、of the variables that the expression depends upon is changed (e.g. by a sweep). The general form of variables is: variableName = constantExpression Note Once a variable has been defi ned, it cannot be redefi ned with another variableName = constantExpression statement. This will create an error. For
28、 example: x1 = 4.3inches + 3mils syc_a = cos(1.0+sin(pi*3) Zin = 7.8k - j*3.2k The type of a variable is determined by the type of its value. For example,x=1 is an integer,x=1+j is complex, andx = “Tuesday“ is a string. Predefi ned Constants and Variables Reserved Names When you are using simulator
29、expressions, keep in mind that predefi ned constants and variables are reserved words. You can use these constants and variables, but you cannot redefi ne them to something else. Table 1-1 lists the simulator constants and variables available and provides a brief description of each. Table 1-1. Pred
30、efi ned Simulator Variables and Constants Reserved Names Variable/Constant NameDescription _fddFlag to indicate a new FDD instance _fdd_vFlag to indicate updated FDD state vars _ABM_Phase Phase for ABM cosim modeling (internal use) _ABM_SourceLevel Linear amplitude scaling for ABM cosim modeling (in
31、ternal use) The_i and_v variables should only be used in the context of the SDD device. Thesourcelevelvariable is used by the spectral analysis when it needs to gradually increase source power from 0 to full scale to obtain convergence. It can be used by the user to sweep the level of ALL spectral s
32、ource components, but is not recommended. The _ABM_Phase and _ABM_SourceLevel variables are only visible in an AVM/FastCosim dataset; however, they are not supported for regular use. These are used as the independent swept variables for the nonlinear characterization data. Simulator Expressions Synt
33、ax1-7 _ac_stateIs analyses in ac state _c1 to _c30Symbolic controlling current _dc_stateIs analyses in dc state _defaultUsed to set parameter to inbuilt default value. _freq1 to _freq12Fundamental frequency _harmHarmonic number index for sources and FDD _hb_stateIs analyses in harmonic balance state
34、 _i1 to _i19 State variable currents used by the sdd device _MMultiplicity factor. _p2dInputPowerPort input power for P2D simulation _sigproc_stateIs analyses in signal processing state _sm_stateIs analyses in sm state _sp_stateIs analyses in sparameter analysis state _tr_stateIs analyses in transie
35、nt state _v1 to _v19 State variable voltages used by the sdd device time = 0 sthe analysis time timestep = 1 sthe analysis time step tranorder = 1the transient analysis integration order freq = 1e+006 Hzthe analysis frequency Nsample = 0signal processing analysis sample number ScheduleCycle = 0signa
36、l processing schedule cycle number DefaultValue = -1signal processing default parameter value noisefreq = 1e+006 Hzthe spectral noise analysis frequency Table 1-1. Predefi ned Simulator Variables and Constants Reserved Names Variable/Constant NameDescription The_i and_v variables should only be used
37、 in the context of the SDD device. Thesourcelevelvariable is used by the spectral analysis when it needs to gradually increase source power from 0 to full scale to obtain convergence. It can be used by the user to sweep the level of ALL spectral source components, but is not recommended. The _ABM_Ph
38、ase and _ABM_SourceLevel variables are only visible in an AVM/FastCosim dataset; however, they are not supported for regular use. These are used as the independent swept variables for the nonlinear characterization data. 1-8Simulator Expressions Syntax Introduction to Simulator Expressions ssfreq =
39、1e+006 Hzthe small-signal mixer analysis frequency temp = 25 Cthe analysis temperature tnom = 25 Cdefault nominal temperature for models e = 2.718282.71838. jSquare root of -1 ln10 = 2.30259ln(10) pi3.14. c0 = 2.99792e+008 m/sthe speed of light e0 = 8.85419e-012vacuum permittivity u0 = 1.25664e-006v
40、acuum permeability boltzmann = 1.38066e-023Boltzmanns constant qelectron = 1.60218e-019the charge of an electron planck = 6.62608e-034Plancks constant hugereal = 1.79769e+308largest real number tinyreal = 2.22507e-308smallest real number sourceLevel = 1 used for source-level sweeping dcSourceLevel =
41、 1used for DC source-level sweeping logRshunt = 0used for DC Rshunt sweeping logNodesetScale = 0used for DC nodeset simulation logRforce = 0used for HB Rforce sweeping mcindex = 0index for Monte Carlo sweeps doeindex = 0index for Design of Experiment sweeps CostIndex = 0index for optimization cost p
42、lots Table 1-1. Predefi ned Simulator Variables and Constants Reserved Names Variable/Constant NameDescription The_i and_v variables should only be used in the context of the SDD device. Thesourcelevelvariable is used by the spectral analysis when it needs to gradually increase source power from 0 t
43、o full scale to obtain convergence. It can be used by the user to sweep the level of ALL spectral source components, but is not recommended. The _ABM_Phase and _ABM_SourceLevel variables are only visible in an AVM/FastCosim dataset; however, they are not supported for regular use. These are used as
44、the independent swept variables for the nonlinear characterization data. Simulator Expressions Syntax1-9 Units and Scale Factors The fundamental units for the simulator are shown in Table 1-2. A parameter with a given dimension assumes its value has the corresponding units. For example, for a resist
45、ance,R=10 its assumed to be 10 Ohms. mcTrial = 0trial counter for Monte Carlo based simulations optIter = 0optimization job iteration counter doeIter = 0doe experiment iteration counter DeviceIndex = 0device Index used for noise contribution or DC OP output LinearizedElementIndex = 0index for BudLin
46、earization sweep DF_Value = -1e+009 reference to corresponding value defi ned in Data Flow controller DF_ZERO_OHMS = 1e-013symbol for use as zero ohms DF_DefaultInt = -1e+009 reference to default int value defi ned in Data Flow controller Table 1-2. Fundamental Units in the Simulator DimensionFundam
47、ental Unit FrequencyHertz ResistanceOhms ConductanceSiemens CapacitanceFarads InductanceHenries Lengthmeters Table 1-1. Predefi ned Simulator Variables and Constants Reserved Names Variable/Constant NameDescription The_i and_v variables should only be used in the context of the SDD device. Thesource
48、levelvariable is used by the spectral analysis when it needs to gradually increase source power from 0 to full scale to obtain convergence. It can be used by the user to sweep the level of ALL spectral source components, but is not recommended. The _ABM_Phase and _ABM_SourceLevel variables are only
49、visible in an AVM/FastCosim dataset; however, they are not supported for regular use. These are used as the independent swept variables for the nonlinear characterization data. 1-10Simulator Expressions Syntax Introduction to Simulator Expressions Recognizing Scale Factors Variations on the fundamental units in the simulator are referred to as scale factors. A scale factor is a single word that begins with a letter or an underscore character (_). The remaining characters, if any, consist of letters, digits