ACCESS: Verification, Test, and Diagnosis of Advanced Scan Infrastructures
since 08.2014, DFG-Project: WU 245/17-1
VLSI designs incorporate specialized instrumentation for post-silicon validation and debug, volume test and diagnosis, as well as in-field system maintenance. Examples of instruments for efficient localization of silicon defects and design bugs include trace buffers, performance monitors, event counters, or scan chains. Test instrumentation includes test controllers, test wrappers, scan chains and structures for pattern decompression and compaction. Such instruments are used both in manufacturing test and for in-field test. Maintenance instrumentation is mainly used in regular system operation for monitoring, error detection, and reliability management. It includes, for instance, error monitors, memory repair controllers, and structures for system reprogramming and reconfiguration. Instruments for manufacturability, e.g. process monitors, facilitate the monitoring of chip performance and reliability. Due to the increasing complexity, however, the embedded infrastructure and access mechanisms themselves become a dependability bottleneck.
While efficient verification, test, and diagnosis techniques exist for combinational and some classes of sequential circuits, Reconfigurable Scan Networks (RSNs) still pose a serious challenge. RSNs are controlled via a serial interface and exhibit deeply sequential behavior (cf. IJTAG, IEEE Std 1687). Due to complex combinational and sequential dependencies, RSNs are beyond the capabilities of existing algorithms for verification, test, and diagnosis which were developed for classical, non-reconfigurable scan networks. The goal of ACCESS is to establish a methodology for efficient verification, test and diagnosis of RSNs to meet stringent reliability, safety and security goals. This comprises:
- Unified RSN Modeling
- Verification of Model Consistency
- Formal Verification to guarantee operability, safety, and security
- Efficient Test Generation and Fault Simulation
- Post-Manufacture and In-Field Test
- Diagnosis of Scan Infrastructure Faults
- Robust Access to Faulty Scan Infrastructure
This work is supported by the German Research Foundation (DFG) under grant WU 245/17-1 (2014-2017).