实时微处理器体系结构综述

实时应用已经成为嵌入式应用中一类快速崛起的典型应用。作为实时系统的核心部件,实时微处理器体系结构是微处理器领域的一个重要研究方向。与通用处理器追求最大吞吐量不同,实时处理器要求具有紧凑且可计算的最坏执行时间。传统的实时处理器往往采用较为简单的处理器结构,避免复杂结构引入执行时间的不确定性。随着实时应用对处理器性能需求越来越高,实时处理器正逐渐向多线程与多核结构发展。在多线程与多核处理器中,共享资源竞争导致实时系统的确定性变差,对实时处理器体系结构带来了更大挑战。对实时微处理器体系结构进行综述,首先从指令集、微体系结构、存储、I/O、任务调度等多个方面对传统实时处理器进行分析;然后分别对采用多线程与多核结构的高性能实时处理器展开分析;最后对几种商用实时处理器结构进行比较,总结实时处理器发展现状与未来发展趋势。

Technologies of real-time processor architecture:a survey

As real time applications have become a kind of important embedded applications,the real time microprocessor architecture,the core component of real time systems,attracts much more attention.Unlike general purpose processors,real time processors require a tight and predictable worst case execution time.To meet the requirement,traditional real time processors often adopt a relatively simple structure so as to avoid uncertain execution time.To meet the increasing performance demand of real time applications,real time processors also gradually shift towards multi threading and multi core. In the multi threaded and multi core processors,there are a large number of shared resources leading to deterioration of deterministic real time systems.In this paper we summarize the technologies of real time processor architecture.We first analyze the traditional real time processor architecture from the aspects of instruction set architecture, micro architecture,memory,I/O,and real time task scheduling.Then,we analyze the high performance real time processor architectures employing multithreaded and multi core structures.Finally,we compare two commercial real time processors,and summarize the status and trends of real time processors.