Zoom-In Feature for Storage-Based Logic Built-In Self-Test

Storage-based logic built-in self-test (LBIST) does not require a tester, and enhances the security of a chip. By storing deterministic test data on-chip, it allows a special type of random tests to be applied, where random combinations of deterministic test data are used to form tests. Such tests are more suitable for complex fault models than tests where all the bits are determined randomly. In this context, the paper suggests a zoom-in feature where subsets of the stored test data are used for forming tests. With tests that combine test data from a limited subset, the tests are more focused on detecting target faults. Experimental results for single-cycle gate-exhaustive faults in benchmark circuits demonstrate the effectiveness of the zoom-in feature.