Rapid and accurate latch characterization via direct Newton solution of setup/hold times

Characterizing setup/hold times of latches and registers, a crucial component for achieving timing closure of large digital designs, typically occupies months of computation in industries such as Intel and IBM. We present a novel approach to speed up latch characterization by formulating the setup/hold time problem as a scalar nonlinear equation h(τ) = 0 derived using state-transition functions, and then solving this equation by Newton-Raphson (NR). The local quadratic convergence of NR results in rapid improvements in accuracy at every iteration, thereby significantly reducing the computation needed for accurate determination of setup/hold times. We validate the fast convergence and computational advantage of the new method on transmission gate and C2MOS latch/register structures, obtaining speedups of 4-10× over the current standard of binary search.

• Type: Conference
• Year: 2007
• Where: DATE
• Authors: Shweta Srivastava, Jaijeet S. Roychowdhury
• Keywords: DATE 2007, Hardware, Local Quadratic Convergence, Scalar Nonlinear Equation, Setup/hold Times