Stability analysis of active clock deskewing systems using a control theoretic approach

In this paper, a methodology for analyzing closed loop clock distribution and active deskewing networks is proposed. An active clock distribution and deskewing network is modelled as a closed loop feedback control system using state space equations. The state space models of the system were then used to simulate the clock deskewing scheme, and most importantly, to analyze the stability using the integral quadratic constraints method. Such a systematic analysis method can be very useful to designers as they will be able to determine how the deskewing network behaves, thus, avoiding repeated simulations. The proposed approach can be further extended to determine performance of such systems under different configurations. We show how the proposed method is applied to an experimental clock deskewing system for performance and stability analysis.