Custom rotary clock router

Abstract

Timing closure and power envelopes for contemporary multi-core chips with high speed clock networks make the clock distribution design a challenging task. Resonant rotary clocking is a novel clocking technology for multi-gigahertz rate clock generation that provides minimal power dissipation. Rotary clocking implementations can easily provide independent synchronization of multiple cores as well. The traditional rotary clock design involves a regular array topology of oscillatory rings. In this paper, the rotary clock networks are designed and implemented using a custom ring topology. Custom ring topologies are advantageous as they reduce the total tapping wirelength for the registers tapping onto the oscillatory rings. A maze router based algorithm is developed for the implementation of custom topology rotary rings. In experiments performed on UCLA IBM R1-R5 benchmark circuits with the Elmore delay model, an improvement of 11.04% for register tapping wirelength is achieved on average.