Discrete Vt assignment and gate sizing using a self-snapping continuous formulation

This paper presents a novel approach towards the simultaneous Vt-assignment and gate-sizing problem. This inherently discrete problem is formulated as a continuous problem, allowing it to be solved using any of several widely available and highly efficient non-linear optimizers. We prove that, under our formulation, the optimal solution has discrete Vts assigned to almost every gate, thus eliminating the need for a sophisticated snapping heuristic. We show that this technique performs dual-Vt assignment and gate sizing in a very efficient manner. Compared to a sensitivity based method, we achieve average leakage savings of 31% and average total power savings of 7.4% with very efficient runtimes.

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