An Effective Approach for the Diagnosis of Transition-Delay Faults in SoCs, based on SBST and Scan Chains

In this paper, a Software-Based Diagnosis (SBD) procedure suitable for SoCs is proposed to tackle the diagnosis of transition-delay faults. The illustrated methodology takes advantage of an initial Software-Based Self-Test (SBST) test set and of the scan-chains included in the final SoC design release. In principle, the proposed methodology consists in partitioning the considered SBST test set in several slices, and then proceeding to the evaluation of the diagnostic ability owned by each slice with the aim of discarding diagnosis-ineffective test programs portions. The proposed methodology is aimed to provide precise feedback to the failure analysis process focusing the systematic timing failures characteristic of new technologies. Experimental results show the effectiveness and feasibility of the proposed approach on a suitable SoC test vehicle including an 8-bit microcontroller, 4 SRAM memories and an arithmetic core, manufactured by STMicroelectronics, whose purpose is to provide precise information to the failure analysis process. The reached diagnostic resolution is up to the 99.75%, compared to the 93.14% guaranteed by the original SBST procedure.