Java offers several benefits that could facilitate the use of wireless Personal Digital Assistants (WPDAs) for the user. First, Java is portable, and that means that it is independent of the hardware platform it runs on, which is very important for reducing the cost of application development. As Java can be run anywhere, the development of applications can be done on a desktop without the need of a real hardware platform. | The Application of Programmable DSPs in Mobile Communications Edited by Alan Gatherer and Edgar Ausländer Copyright 2002 John Wiley Sons Ltd ISBNs 0-471-48643-4 Hardback 0-470-84590-2 Electronic 8 A Flexible Distributed Java Environment for Wireless PDA Architectures Based on DSP Technology Gilbert Cabillic Jean-Philippe Lesot Frederic Parain Michel Banatre Valerie Issarny Teresa Higuera Gerard Chauvel Serge Lasserre and Dominique D Inverno Introduction Java offers several benefits that could facilitate the use of wireless Personal Digital Assistants WPDAs for the user. First Java is portable and that means that it is independent of the hardware platform it runs on which is very important for reducing the cost of application development. As Java can be run anywhere the development of applications can be done on a desktop without the need of a real hardware platform. Second Java supports dynamic loading of applications and can significantly contribute to extend the use of WPDA. Nevertheless even if Java has a very good potential one of its main drawbacks is the need of resources for running a Java application. By resources we mean memory volume execution time and energy consumption which are the resources examined for embedded system trade-off conception. It is clear that the success of Java is conditioned by the availability of a Java execution environment that will manage efficiently these resources. Our goal is to offer a Java execution environment for WPDA architectures that enables a good trade-off between performance energy and memory usage. This chapter is composed of three different parts. As energy consumption is very important for WPDAs we first pose the problem of Java and energy. We propose a classification of opcodes depending on energy features and then using a set of representative WPDA applications we analyze what the Java opcodes are that will influence significantly the energy consumption. In the second part we present our approach to construct
