Using a Java Optimized Processor in a Real World Application

Java, a popular programming language on desktop systems, is rarely used in embedded systems. Some features of Java, like thread support in the language, could greatly simplify development of embedded systems, but the common implementations of the JVM (Java Virtual Machine), as interpreter or just-in-time compiler, are not practical. This paper describes an alternative approach: JOP (a Java Optimized Processor) is a hardware implementation of the JVM with short and predictable execution time of most bytecodes. JOP is implemented as a configurable soft core in an FPGA. The experiences of the first application of JOP and the benefits from using an FPGA in an embedded distributed control system are described in the second part of this paper.