Allen P. Mass

An Efficient Hardware Implementation of Java Bytecodes, Threads and Processes for Embedded and Real-Time Applications

The Java platform, with its target platform neutrality, simplified object model, strong notions of safety and security, as well as multithreading support, provides many advantages for a new generation of networked embedded and real-time systems. However, the large size, nondeterministic behavior, and poor performance of the first generation of embedded Java implementations have hampered the acceptance of Java in the real-time and embedded worlds. This chapter describes a low-power hardware implementation of the Java Virtual Machine (JVM) for real-time and embedded systems, including direct support for the entire JVM instruction set and thread model. This design approach obviates the need for a Java interpreter or Just-In-Time (JIT) compiler, as well as the traditional Real-Time Operating System (RTOS). The hardware implementation also supports multiple JVM contexts executing on the same CPU, enhancing safety and security by guaranteeing space and time allotments for multiple Java applications. Combined with a Java 2 Platform, Micro Edition (J2ME) runtime and a back-end target build tool, these technologies constitute an efficient platform for the development of real-time embedded applications entirely in the Java programming language.