Decentralized priority encoder and its applications

This paper contains the realization of the decentralized priority encoder (DPE) and presents two application examples. DPE is constructed by placing a module for each device issuing a request and by connecting the outputs from the modules using wired‐OR. Each module has the function to modify the priority dynamically. The request signal from the corresponding device is connected to the input of the module. When the priority of the module M issuing the request is higher than those of any other modules issuing requests, M produces the priority of its request as a binary code on the bus. A data selector can be constructed using DPE, since the data with the highest priority can be selected from a set of data with priorities. This data selector is suited especially to the data selector for image data in the enhanced multiwindow system. Using DPE as the priority comparator, a decentralized independent‐request arbiter with priority is obtained.