Hierarchical compactor design for diagnosis in deterministic logic BIST

Scan-based tests created by automatic test pattern generators (ATPG) can be efficiently compressed and applied in a deterministic built-in self-test (DBIST) architecture. However, the BIST environment adds significant complexity to failure diagnosis. We present a simple scan-compatible diagnosis solution - streaming DBIST (SDBIST), which is based on a low-overhead hierarchical compactor SDBIST allows continuously monitoring streaming scanout data for reduced-volume expect-data diagnosis, on-line fail-data collection and selective scan cell masking.