VISA synthesis: Variation-aware Instruction Set Architecture synthesis

We present VISA: a novel Variation-aware Instruction Set Architecture synthesis approach that makes effective use of process variation from both software and hardware points of view. To achieve an efficient speedup, VISA selects custom instructions based on statistical static timing analysis (SSTA) for aggressive clocking. Furthermore, with minimum performance overhead, VISA dynamically detects and corrects timing faults resulting from aggressive clocking of the underlying processor. This hybrid software/hardware approach generates significant speedup without degrading the yield. Our experimental results on commonly used ISA synthesis benchmarks demonstrate that VISA achieves significant performance improvement compared with a traditional deterministic worst case-based approach (up to 78.0%) and an existing SSTA-based approach (up to 49.4%).