关键词: 延时查找表, B样条, 凸函数, 平滑, 半定规划

Abstract: Delay look-up table（LUT） of standard logic circuits are useful in applications such as auto-synthesis and static timing analysis.The accuracy along with numerical convexity and smoothness of LUT will influence the final circuit design greatly.A convex smoothing algorithm suitable for real application of such circuits is proposed in this paper.It employs tensor-product B-spline technique originated from computer-aided geometric design to approximate the delay function in LUT and retains convexity by regulating the B-spline coefficients.The solution process of these coefficients is formulated as a semidefinite programming，and hence the final model has the globally minimized fitting error.To demonstrate the efficiency and accuracy，the delay LUT of standard library cells are used as numerical examples.

Key words: delay look-up table, B-spline, convex, smoothness, semidefinite programming