Nucleus Architecture Analysis And Research

Embedded system is one of the most favorite for Microelectronics technology and Computer technology nowadays. Embedded operation system is one of the most important constituent of embedded system. It integrates many software techniques, such as operation system, network, multimedia, characters information processing and so on. It has embedded system developed in other field and brings convenience to people's work environment and daily life. Nowadays, the popular operation systems are VxWorks, Windows CE, uClinux, Nucleus, uC/OS-II and so on. Among them, Nucleus will be very favorable because of its high real-time quality, dependability and simplified kernel. Analysis of Nucleus system structure, study of kernel arithmetic, expanding of system function and application of Nucleus will be introduced in this paper.Technique of kernel design influences the quality of embedded system directly. Therefore, analysis of Nucleus system structure takes kernel research as center. It analyzes Nucleus kernel deeply in task management, interrupt management, scheduling policy and memory management fields. This article compares Nucleus with uClinux, uC/OS-II, and gets differences and likenesses in scheduling policy, document system and system replanting fields.At this foundation on, Aiming scheduling of embedded system tasks, it is presented that a scheduling algorithm based on fuzzy theory. It makes use of fuzzy sets for describing uncertain characteristic parameters, multilevel fuzzy synthetic decision and the principle of maximum membership function for determining task priority level, an algorithm which make multilevel decision model dynamically for decreasing invalidation ratio of judging task priority level. In addition, this article discusses a technology of fault tolerance. It makes use of redundancy thought and layered method of handling faults to shield system breakdown. It improves the dependability of system and has realistic meaning.In the end, this thesis elaborates an actual application of Nucleus system, human body exam using mobile phone. Processor of mobile phone is ARM7. And embedded operation system of mobile phone is Nucleus. It gets sample data of human body physiology through UART and achieves all kinds of analytical results of human body physiology according to related arithmetic. Currently, this project is commercializing.