Option Statements

As its name implies, option statements are used to set various options to appropriate values. More than one option statement can appear in the input file. The format of an option statement is:

.OPTIONS  opt1  opt2 ...
where opt1, opt2, and ..., are various options. Some options only take on the values of ON or OFF. The defaults values for such options are OFF and the option values are turned ON by having the corresponding keyword present in an option statement. Some other options assume the form of the parameter assignment outlined in . Option statements are not allowed to be placed within the scope of definition of any subcircuit because the options apply to the entire system under study. The various options and their meanings are:
EMSG_MAX = k Sets the Maximum number of error messages that are generated before the syntax checking of the input file is suspended. "EMSG_MAX=" is the nine-character keyword "EMSG_MAX=" and k is a positive integer. For very severe syntax errors, the syntax checking is suspended before the number of error messages reaches this maximum limit. The default value for k is 20.
EXPAND Show the entire circuit after all subcircuit calls have been instantiated. The listing of this expanded circuit is shown in the file "XXXX.lst" where XXXX is the name of the input file. The default is not to show the expanded circuit.
MAPNODE0 By default, node 0 is not allowed to appear as an external node in the definition of a subcircuit and node 0 in a subcircuit is considered the same node as node 0 in the main circuit. If MAPNODE0 is specified as an option, node 0 in a subcircuit would not be considered as the same node as node 0 in the main circuit. In such a case, node 0 in the subcircuit is appropriately mapped for each subcircuit instantiation and it is allowed to appear as an external node in the subcircuit definition.
PSP_START = t1 For time-domain transient analysis, the print variables are generated for time values larger than or equal to the value of t1. "PSP_START=" is the ten-character keyword "PSP_START=" and t1 is a nonnegative floating-point number. If this option is not specified, the default value for t1 is the time the simulation starts saving data for the transient analysis. Refer to the .TRAN statement for details of the transient analysis.
PSP_END = t2 For time-domain transient analysis, the print variables are generated for time values up to but not larger than the value of t2. "PSP_END=" is the eight-character keyword "PSP_END=" and t2 is a positive number larger than the value of t1. If this option is not specified, the default value for t2 is the stop time of the transient analysis as specified in the .TRAN statement. If the value of t2 in PSP_END is smaller than the value for t1 in PSP_START, no output print file will be generated for the transient analysis.
PSP_NPT = n Set the minimum number of data points generated for printing the output variables during the transient analysis. "PSP_NPT=" is an eight-character keyword and n is an integer between 2 and 100000001, inclusively. (PSP_END - PSP_START)/(PSP_NPT - 1) is the step size of the time variable in the print file generated for the transient analysis. If PSP_NPT is not specified, no output print file will be generated for the transient analysis.
POP_ITRMAX = n POP Iteration Limit. This option sets the maximum number of iterations for the POP analysis.

If set, the option value must be a positive integer between 1 and 200, inclusively.

If this option is not set, it defaults to 20.

Example:

.OPTIONS POP_ITRMAX=50
POP_USE_TRAN_SNAPSHOT This option instructs POP to take advantage of the last data point of a previous transient simulation, assuming the circuit and the initial conditions remained the same between the two simulation runs.

This option does not take on any value. It is either turned ON or turned OFF. If it is turned ON, the POP analysis will use the last data point of a previous transient simulation as the initial condition to start the POP analysis. Usually this leads to a faster POP analysis.

Example:

.OPTIONS POP_USE_TRAN_SNAPSHOT
POP_OUTPUT_CYCLES=n Number of cycles of steady-state POP Data to show. After a successful POP analysis, SIMPLIS will generate the steady-state time-domain waveforms for an integral number switching cycles.

If set, the option value must be a positive integer between 1 and 16, inclusively.

If this option is not set, it defaults to 5.

Example:

.OPTIONS POP_OUTPUT_CYCLES=3
POP_SHOWDATA Display POP Data. In general, this option is turned on as a debugging aid if a Periodic Operating Point (POP) analysis fails.

This option does not take on any value. It is either turned ON or turned OFF. If it is turned ON, the progress of the periodic operating point analysis is output and the resulting waveforms may be viewed in the same manner as for the POP cycles. To turn this option ON, the line in the following example should be output to the SIMPLIS simulation input deck.

Example:

.OPTIONS POP_SHOWDATA
SNAPSHOT_INTVL Minimum duration between snapshots. This instructs SIMPLIS to save a snapshot of the internal state of the simulation at intervals no smaller than the option value set for SNAPSHOT_INTVL.

If set, the option value must be a positive floating-point number. Engineering prefixes are allowed.

If this option is not set, it defaults to zero. If this option is not set, or if the option is set to zero, SIMPLIS will only save snapshots at t=0 and the end time of the simulation.

Example:

.OPTIONS SNAPSHOT_INTVL = 100u
SNAPSHOT_NPT Maximum number of saved snapshots. This sets the maximum number of snapshots that SIMPLIS saves. If there is a conflict between the values set for the SNAPSHOT_NPT and SNAPSHOT_INTVL options, the value set for the SNAPSHOT_NPT option will override the value set for the SNAPSHOT_INTVL option.

If set, the option value must be a positive integer between 11 and 2001, inclusively.

If this option is not set, SIMPLIS will only save snapshots at t=0 and the end time of the simulation.

Example:

.OPTIONS "SNAPSHOT_NPT=30
NEW_ANALYSIS Force new analysis. This option does not take on any value. It is either turned ON or turned OFF. If it is turned ON, SIMPLIS will ignore any relevant data files from a previous simulation, even if the circuit and the initial conditions between the two simulation runs are the same. If this option is turned OFF, SIMPLIS will try to take advantage of any relevant data files from the previous simulation if the circuit and the initial conditions have not changed from the previous simulation run.

To turn ON this option, the line in the following "Example" section should be output to the SIMPLIS simulation input deck. .OPTIONS NEW_ANALYSIS
FREQ_DOMAIN Domain in small-signal AC analysis. The small-signal AC analysis can be carried out in the continuous (s-) domain or in the discrete (z-) domain.

If set, the option value must be either the character 'S' or 'Z.'

If this option is not set, it defaults to 'S.'

Example: .OPTIONS FREQ_DOMAIN = Z
IGNORE_UNITS Ignore Units. This option does not take on any value. It is either turned ON or turned OFF. If it is turned ON, SIMPLIS will ignore any trailing units or strings when it is looking for a floating-point number. For example, in specifying the voltage of a DC voltage source, SIMPLIS would not complain the trailing 'V' here 1.23V if this options is turned ON.

The default is to not to turn ON this option and SIMPLIS would then complain about the trailing string or units. To turn ON this option, the line in the following "Example" section should be output to the SIMPLIS simulation input deck.

Example:

.OPTIONS IGNORE_UNITS
NO_FORCED_DATA Disable forcing data points before and after each switching instant. This option does not take any value. It is either turned ON (option present) or turned OFF (option not present). If it is turned ON, SIMPLIS will not generate data points before and after each switching instant. If it is turned OFF, SIMPLIS will create data points each side of a switching instant.

Example - turn option ON:

.OPTIONS NO_FORCED_DATA

Under most circumstances, this option should remain turned OFF. For very long simulations that generate extremely large data sets, the waveform viewer may be slow responding to user commands. In such cases, turning ON the NO_FORCED_DATA option will reduce the number of simulation data points displayed in the waveform viewer during each switching cycle. For long simulations that involve many switching instants in one switching cycle this reduction can be significant. Enabling this option in no way degrades the accuracy of the SIMPLIS solution, but it can potentially reduce the fidelity of the displayed waveforms within each switching cycle.
MIN_AVG_TOPOLOGY_DUR SIMPLIS calculates the average time it spends in each toplogy over a number of topologies defined by AVG_TOPOLOGY_DUR_MEASUREMENT_WINDOW. If this value falls below MIN_AVG_TOPOLOGY_DUR, the simulation aborts. The default value is 1e-18.

The purpose of this is to resolve problems with the simulation apparently getting 'stuck' in situations where there are unexpected very high speed oscillations.
AVG_TOPOLOGY_DUR_MEASUREMENT_WINDOW Default value = 128. See MIN_AVG_TOPOLOGY_DUR above for details