Storage-Based Logic Built-In Self-Test With Partitioned Deterministic Compressed Tests
Irith Pomeranz · IEEE Transactions on Very Large Scale Integration (VLSI) Systems · 2023
Logic built-in self-test (LBIST) is important for in-field testing. In a storage-based LBIST approach, deterministic test data are stored on-chip and used for applying tests that are closer to deterministic tests than pseudorandom tests. Using the same stored test data for applying several different tests allows the volume of test data stored on-chip to be reduced, and the fault coverage to be increased. This observation was applied earlier in two ways: 1) by complementing bits of stored test data or applied tests to form additional tests and 2) by forming different tests from different combinations of stored test data entries that are obtained by partitioning deterministic tests. Partitioning was applied earlier to uncompressed deterministic tests. In this article, partitioning is applied for the first time to compressed deterministic tests. Under the resulting LBIST approach, tests are formed on-chip using pseudorandom combinations of partitioned compressed tests. A software procedure is described for deriving a reduced set of test data entries for on-chip storage. With compressed tests, the storage requirements are already reduced, and they are reduced further by the software procedure. Experimental results demonstrate the effectiveness of this LBIST approach considering both single stuck-at and single-cycle gate-exhaustive faults in benchmark circuits.