Use Parameter Configuration in Analysis

Parameter configuration allows Simulink^® Design Verifier™ to assess the impact of parameter ranges along with the default value during the analysis. Consider an example model that illustrates the impact of parameter configuration on analysis outcomes. The model features a switch block with its control port conditioned on > 0 and is influenced by a calibration parameter K that has a value of 0 in the base workspace.

When you configure parameters depends on which workflow you use.

• Configure parameters when you generate test cases for coverage - In this workflow, you vary the parameters after assessing whether the parameter values impact model coverage objectives.

  

• Configure parameters during design error detection analysis - In this workflow you vary parameters after detecting design errors to check if any parameter values result in a run-time error in the logic that uses these values.

  

The table below showcases how the analysis results vary with parameter configurations:

Parameter K with value 0 in base workspace	No Parameter Configuration specified	Parameter Configuration specified with K in interval [-1,1]
Analysis result	Control port with value greater than 0 is reported as dead logic. Control port with value less than 0 is reported as active logic.	No dead logic is reported. The analysis engine selects the value 1 to satisfy the condition of the control port being greater than 0.
Test cases	Parameters retain same value as specified in base workspace for all test cases.	Parameter values are reported along with input values, and they may vary from one test case to another.

The figure below shows the three basic steps involved in parameter configuration:

1. Select Parameters: Parameters are defined using Simulink.Parameter variables for calibration. You have the option to either select the parameters manually to configure or let Simulink Design Verifier automatically detect and configure these parameters. For more information, see Select Constraints for Parameter Configuration.

2. Specify Ranges: You can define ranges (maximum or minimum values) for the selected parameters. For a Simulink.Parameter variable, the default range is determined by the maximum or minimum values.

3. Run Analysis: The Simulink Design Verifier analysis uses these values to produce the results. The generated test cases include the parameter values in addition to the necessary inputs to achieve the desired coverage.

Limitations for Parameter Configurations

The following table illustrates the cases where Simulink Design Verifier does not support specifying the parameter configuration:

Parameters Based on	Limitations
Location	Simulink Design Verifier does not support parameter configuration for parameters that are: Read-only in the generated code. Defined as MATLAB® variables in Data Dictionary. Defined in mask workspace. Instance-specific parameters. Used in both design model and observer model
Data types	Simulink Design Verifier does not support parameter configuration for parameters that are: Not of the numeric, logical, or fixed-point type. With complex values. Specified by using Simulink.ValueType object. Used in Array of Buses. Converted to fixed point in the model. If your model references a base workspace parameter whose data type is auto, single, or double, and the model converts that parameter to a fixed-point data type, you must define the constraints for that parameter according to its fixed-point type.
Block types	Simulink Design Verifier does not support parameter configuration for parameters from these blocks: Variant blocks. Inport and Outport blocks Lookup, Lookup_n-D, LookupNDDirect, Lookup Table Dynamic, and Pre-lookup table blocks. Interpolation_n-D block. Saturation block. Selector block. For Iterator block. Switch case block.

Note

Simulink Design Verifier does not support parameter configuration for parameters which are present only in the replacement model. The analysis may report dead logic if you introduce new parameters in the replacement model.