Software Canaries: Software-based Path Delay Fault Testing for Variation-aware Energy-efficient Design

Software-based path delay fault testing (SPDFT) has been used to identify faulty chips that cannot meet timing constraints due to gross delay defects. In this paper, we propose using SPDFT for a new purpose – aggressively selecting the operat-ing point of a variation-affected design. In order to use SPDFT for this purpose, test routines must provide high coverage of potentially-critical paths and must have low dynamic perfor-mance overhead. We describe how to apply SPDFT for select-ing an energy-efficient operating point for a variation-affected processor and demonstrate that our test routines achieve ample coverage and low overhead. 1