Optimal Useful Clock Skew Scheduling In the Presence of Variations Using Robust ILP Formulations

This paper exploits useful skew to improve system performance and robustness. We formulate a robust integer linear programming problem considering the interactions between data and clock paths on a microprocessor chip to improve clock frequency. The timing slack is optimized for each path to determine a clock schedule. The percentage of timing violations, obtained from a 1000 point Monte Carlo simulation, is highlighted as yield predictions and conveys the robustness of the clock schedule. The results show performance improvement of up to 9.747% with 20% yield and up to 6.682% with 100% yield. The novelty of the proposed method is its ability to tradeoff between performance improvement in frequency and robustness, via a single variable in the formulation