Abstract:

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.

Key words: realtime processor;predictability;timeliness;architecture;multithreading;multicore