Test Volume and Fault Coverage Metrics Test volume and fault coverage are two crucial metrics in the testing and testability of VLSI circuits. They provide v...
Test volume and fault coverage are two crucial metrics in the testing and testability of VLSI circuits. They provide valuable insights into how well a design is tested and whether it effectively covers all potential faults.
Test volume:
This refers to the total number of individual test cases or scenarios that are executed during testing.
Increasing test volume helps to ensure that a wide range of potential faults are detected.
However, high test volume can also increase testing time and cost.
Fault coverage:
This represents the percentage of the entire design that is covered by the set of test cases.
Fault coverage is a measure of how well the test cases cover the potential fault space of the circuit.
A high fault coverage indicates that the design is well-tested, while a low fault coverage means that there are still potential faults not covered by the tests.
Importance of test volume and fault coverage:
By understanding the relationship between test volume and fault coverage, designers can determine the optimal number of test cases to execute to achieve a desired level of testing.
High test volume and fault coverage ensure that the circuit is thoroughly tested, minimizing the risk of undetected design defects.
Examples:
Consider a digital circuit with 1000 gates. Running 100 test cases with different combinations of gate connections will cover 10% of the total possible test space.
A circuit with a high fault coverage of 95% means that it is very well tested, and only 5% of the potential faults are likely to remain undetected