Systematic analysis of active clock deskewing systems using control theory

A formal methodology for the analysis of a closed loop clock distribution and active deskewing network is proposed. In this paper an active clock distribution and deskewing network is modeled as a closed loop feedback system using state space equations. State space analysis allows systematic analysis of any clock distribution and deskewing system to determine various conditions under which a system can overcompensate and become potentially unstable. Such an analysis can be very useful to designers as they will be able to determine analytically as to how the clock deskewing system behaves. By using the proposed approach, repeated simulations can be greatly limited and maybe entirely avoided. We applied the proposed method to an experimental clock deskewing system to illustrate the effectiveness of the proposed approach. The proposed approach can be further extended to determine performance of such systems under different configurations.