Adaptive wire adjustment for bounded skew Clock Distribution Network

Abstract

In this paper, we suggest an adaptive approach for the clock distribution network (CDN) to cope with a modification in the VLSI system design. The CDN's wires are adjusted iteratively to reduce the skew that is resulting from a minor modification in the clock pins of a complex VLSI system. Such skew can be remedied by selecting a balancing node (BN) and adjust its edges so that the skew gets smaller. The required edge adjustments are determined using the Elmore delay model. The performance of the algorithm is investigated using different random sets of clock pins. Also, the algorithm is tested by altering some clock pins in a zero skew CDN. For small modifications in a large number of nodes in the CDN, our algorithm can achieve zero skew with less iterations than linear order algorithms.