Bounded and Unbounded Delay Synchronizers and Arbiters,

摘要

Synchronizer and arbiter malfunction can cause serious unpredictable malfunction of digital systems. It is believed that a perfect synchronizer cannot be physically realized. This view is reenforced by the close relationship among the synchronizers of bounded delay, synchronizers of unbounded delay and arbiter of bounded delay shown in this paper. Synchronizers and arbiters operate under fundamentally different conditions compared to the other elements because they encounter conflicts while other elements in a digital system can be assumed not to encounter any conflicts. The performance of synchronizers and arbiters can be measured by two parameters:an effective error window and a time delay,both of which can be derived from the parameters characterizing the behavior of a flip-flop. Even though there is difficulty with realization of synchronizers,the asynchronous arbiter can be easily realized. A very efficient realization of asynchronous arbiters is also presented in this paper.