Oscillation period and power consumption in configurable self-timed ring oscillators

A simple and accurate analytical model for evaluating the oscillation period of Self-timed rings is proposed. Thank to this model, the designer can easily choose the number of stages and the appropriate ring initialization. The model is so simple that it can quickly provide an estimation of the oscillation period only with a paper sheet and a pen. Nevertheless it takes into account analog effect called ldquoCharlie effectrdquo. The Charlie effect is of prime importance when modeling the behavior of asynchronous rings. Moreover the relation between power consumption, ring initialization and stage implementation is showed. In order to validate our model, comparisons have been made with electrical simulations demonstrating the validity of our approach.