Jop: a Java Optimized Processor for Embedded Real-time Systems

This thesis presents a Java processor designed for time-predictableexecution of real-time tasks. JOP (Java Optimized Processor) is theimplementation of the Java virtual machine in hardware. JOP isintended for applications in embedded real-time systems and theprimary implementation technology is in a field programmable gatearray. This research demonstrates that a hardware implementation ofthe Java virtual machine results in a small design forresource-constrained devices. Architectural advancements in modern processor designs increaseaverage performance with features such as pipelines, caches andbranch prediction. However, these features complicate worst-caseexecution time (WCET) analysis and lead to very conservative WCETestimates. This thesis tackles this problem from the architecturalperspective - by introducing a processor architecture in whichsimpler and more accurate WCET analysis is more important thanaverage case performance. The proposed processor and the Java real-time profile have been usedwith success to implement several commercial real-time applications.