Built-in generation of functional broadside tests

Functional broadside tests are two-pattern scan-based tests that avoid overtesting by ensuring that a circuit traverses only reachable states during the functional clock cycles of a test. On-chip test generation has the added advantage that it reduces test data volume and facilitates at-speed test application. This paper shows that on-chip generation of functional broadside tests can be done using simple hardware, and can achieve high transition fault coverage for testable circuits. With the proposed on-chip test generation method, the circuit is used for generating reachable states during test application. This alleviates the need to compute reachable states off-line.