Fault Equivalence and Fault Collapsing: Fault equivalence refers to the ability of a test to detect the same fault as a larger test that contains multip...
Fault Equivalence and Fault Collapsing:
Fault equivalence refers to the ability of a test to detect the same fault as a larger test that contains multiple faults. This means that if a fault is present in the original design, it will also be present in the test, even if the individual tests are independent.
Fault collapsing is a technique used in fault testing to identify and isolate individual faults within a design. This is achieved by combining multiple tests into a single test that can detect the same set of faults. For example, a test that detects various types of logic faults could also detect a stuck gate.
Benefits of fault equivalence and fault collapsing:
Reduced test time and effort: By detecting the same faults with fewer tests, this approach can significantly reduce the amount of testing required.
Improved testability: Fault equivalence and collapsing allow designers to test individual components of a design in isolation, making them easier to test and debug.
Early detection of faults: By identifying and isolating individual faults, this technique can help identify and fix them early in the design phase.
Example:
Consider a digital circuit containing multiple logic gates connected in a logical AND (AND) configuration. If we were to test the individual gates using separate tests, we might detect the following faults:
Gate 1: stuck gate
Gate 2: stuck gate
Gate 3: stuck gate
However, if we combined these tests into a single test that checks the AND operation, we would be able to identify the same faults. This is because the test would simulate the AND operation of the gates and detect any inconsistencies or stuck gates