Detect Design Errors in Controller Model

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To detect hidden design errors in your model early in the verification process, use design error detection analysis. This tutorial shows how to perform design error detection analysis, review the analysis results, and then fix the identified design errors.

Consider a controller that has three sensor inputs: SensorA, SensorB, and SensorC. The controller algorithm operates according to the equation:

The algorithm is modeled as:

Follow these steps to perform design error detection analysis:

Prepare Model for Design Error Detection

1. Open the model sldvexControllerIntegerOverflow:

sldvexControllerIntegerOverflow

2. On the Design Verifier tab, in the Mode section, select Design Error Detection.

3. Click Error Detection Settings. In the Configuration Parameters dialog box, on the Design Verifier > Design Error Detection pane, select the checks that you want to perform.

Perform Design Error Detection Analysis

To perform design error detection analysis, on the Design Verifier tab, click Detect Design Errors. The software analyzes the model for design errors and displays the results in the Results window. The results indicate that three out of six objectives were falsified.

Review the Analysis Results

You can review the analysis results by highlighting the results on the model and reviewing the analysis report.

Highlight Analysis Results on the Model

On the Design Verifier tab, in the Review Results section, click Highlight in Model.

1. Select the Sum block. The Results window displays the integer overflow objectives of the Sum block.

2. To debug the integer overflow error, click View counterexample. The harness model and the Signal Builder block open.

When the input value of SensorA is 128 and SensorB is 172, the Sum block output overflows. The accumulator data type of the Sum block is set to an incorrect integer value of uint8, it results in overflow errors and division by zero errors on the downstream Divide block.

Review Analysis Report

To view the HTML report, in Review Results, click HTML Report. The Design Error Detection Objectives section lists the objectives of each model items and their description.

Fix Design Errors

In the example, the design error detection analysis found integer overflow and division by zero errors in the model. The errors were caused due to a mismatch in the integer data type.

To fix the errors, change the Accumulator data type and Output data type to uint16 to handle the range of possible signal values. Select the Sum block, and set Accumulator data type and Output data type to uint16. When you rerun the design error detection analysis, the Results Summary window reports that 6/6 objectives are valid. When you simulate the test case for the Sum block, observe that the test case resolves the error.