PCI总线加权优先循环仲裁算法

文章介绍了在PCI系统结构中新的总线仲裁机制,提出了加权优先循环算法。该算法是基于优先算法和公平循环算法的访问策略,它的特点是避免了优先算法中高优先级的PCI主设备在重新请求访问总线时独占总线,同时也解决了公平循环算法中各主设备对总线访问的平均性问题,使得仲裁器可以根据不同设备的性能要求,分配不同设备不同加权因子,使高性能和高速度设备能及时访问总线,降低访问延迟时间。

Weighted Priority Rotational Algorithm on PCI Bus Arbitration

This paper presents a new PCI arbitrating scheduling scheme to support premium service in the PCI system architecture,called Weighted Priority Rotational Algorithm.It is based on PCI access scheduling policies such as priority and fair rotational algorithms.The key feature of the new algorithm is to avoid high-priority masters will dominate the bus to the exclusion of lower-priority masters when they are continually requesting the bus and all masters have equal access to the bus.By assigning different weights for different masters according to their performance request,the pro-posed scheme can achieve high response,low delay for high-performance masters.