Simulation settings
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Simulation settings

The simulation settings are enclosed in an analysis section. Example: 
analysis 
{
	TRANS( 0, 1023 ,1024,t );
	FILE("data_i.txt",VI);
	FILE("data_q.txt",VQ);
	OUTPUT("1",VI(t),VQ(t));
	OUTPUT("2",XY(VI(t),VQ(t)));
	OUTPUT("3",FFTM(VI(t),0));
}
The keyword analysis can be followed by a name declaration. It is possible to have zero, one or more analysis declaration inside a "cit" file.

TRANS
ACMOD
ACPHASE
DC
OUTPUT
OPTION
FILE
PROPORTIONAL
CONST
INITIAL

TRANS

This option tells the simulator to perform a transient analysis and to display the amplitude by using a x-lin y-lin axis view. The TRANS option accepts four parameters separated by a comma:
  • first parameter : start time expressed in seconds. Usually zero.
  • second parameter : end time expressed in seconds.
  • third parameter : number of stored points.
  • fourth parameter : name of the variable. Usually "t"

Example: TRANS( 0, 0.002, 300, t );

ACMOD

This option tells the simulator to perform an AC analysis and to display the amplitude by using a x-log y-log axis view. The ACMOD option accepts four parameters separated by a comma:
  • first parameter : frequency bottom value expressed in Hz. Usually 1K.
  • second parameter : frequency top value expressed in Hz.
  • third parameter : number of stored points.
  • fourth parameter : name of the variable. Usually "f"

Example: ACMOD( 1K, 10M, 500, f );

ACPHASE

This option tells the simulator to perform an AC analysis and to display the phase by using a x-log y-lin axis view. The ACPHASE option accepts four parameters separated by a comma:

  • first parameter : frequency bottom value expressed in Hz. Usually 1K.
  • second parameter : frequency top value expressed in Hz.
  • third parameter : number of stored points.
  • fourth parameter : name of the variable. Usually "f"

Example: ACPHASE( 1K, 10M, 500, f );

DC

The DC option has zero or more parameters:

  • zero parameters : simple DC simulation.

    Example: DC();

  • more parameters : the system will perform a DC sweep simulation.

    • The first parameter is the name of the variable that will change when performing DC sweep simulation.
    • The next parameters can be of the form start:end:point_nb :

      • start : first value
      • end : second value
      • point_nb : points number

      Example 1 : DC(VI,1m:15m:50);

      or value comma separated :

      Example 2 : DC(VI,1,2,3,4,5);

OUTPUT

The OUTPUT declaration accepts one or more parameters separated by a comma:

  • first parameter : name of the ouput chart window if between quote ( see example 2 below ). Else, first variable to display ( example 1 below ).
  • second parameter and more : list of variable to display.

Example1: OUTPUT( V1, V2, V1*V2, FFTM(V1,V2) );

Example2: OUTPUT( "output1", V1, V2, V1*V2, FFTM(V1,V2) );

It's possible to have one or more OUTPUT declaration in an analysis section.

OPTION

The OPTION declaration accepts one parameter which can be :

  • NO_DC : no DC analysis is performed before a transient of AC analysis.
  • CRAMER : tells the CAS solver to use a CRAMER-type algorithm than GAUSS-type. The CRAMER-type algorithm is the default one for AC analysis and the GAUSS-type is the one chosen by default for transient analysis.

Example: OPTION( CRAMER, NO_DC );

FILE

The FILE keyword is used to initialize a variable with values coming from a file. The first argument is the file name and the second argument, the variable.

Example : FILE( file_name, V );

PROPORTIONAL

The PROPORTIONAL keyword is used to tell the solver that some variables should be considered as const during simulation but can be changed by the user between two simulations without recompiling the design.

  • first argument : variable name
  • second argument : value for initialization
  • third argument : bottom range value
  • fourth argument : top range value

Example : PROPORTIONAL( RL, 100, 10, 1000 );

CONST

This keyword is used to tell the solver that some variables should be considered as constants during simulation. The variables inside the declaration are followed by a "=" character and a constant value or a constant equation. All the items are separated by commas.

Example : CONST(phase=PI/2,ampl=10,freq=10,temp=25);

INITIAL

This keyword is used to tell the solver that some variables should start the simulation with defaults value, usually integrals. The variables inside the declaration are followed by an "=" characters and a constant value or a constant equation. All the items are separated by commas.

Example : INITIAL(v=0.3,i=0.5);