User`s guide

15 Model Coverage Definition
15-6
• Condition Coverage
• Decision Coverage
• MCDC Coverage
When you collect coverage for a model, you may not be able to achieve 100% MCDC
coverage. For example, if you specify to short-circuit logic blocks, you may not be able to
achieve 100% MCDC coverage for that block.
If you run the test cases independently and accumulate all the coverage results, you
can determine if your model adheres to the modified condition and decision coverage
standard. For more information about the DO-178C/DO-331 standard, see “DO-178C/
DO-331 Checks”.
For an example of MCDC coverage data in a model coverage report, see “MCDC Analysis”
on page 19-26. For an example of accumulated coverage results, see “Cumulative
Coverage” on page 19-27.
Relational Boundary Coverage
Relational boundary coverage examines blocks, Stateflow charts and MATLAB function
blocks that have an explicit or implicit relational operation.
• Blocks such as Relational Operator and If have an explicit relational operation.
• Blocks such as Abs and Saturation have an implicit relational operation.
For these model objects, the metric records whether a simulation tests the relational
operation with:
• Equal operand values.
This part of relational boundary coverage applies only if both operands are integers or
fixed-point numbers.
• Operand values that differ by a certain tolerance.
This part of relational boundary coverage applies to all operands. For integer and
fixed-point operands, the tolerance is fixed. For floating-point operands, you can
either use a predefined tolerance or you can specify your own tolerance.
The tolerance value depends on the data type of both the operands. If both operands have
the same type, the tolerance follows the following rules: