The last several years have seen significant progress on two related fronts in hardware and software design for electronic systems. The first is the rapid growth in the design of complex System-on-Chip devices (SoC). The second is progress in adding capabilities to the Unified Modeling Language (UML) to better support the design of real-time and embedded systems, culminating in the UML 2.0 specification which is nearing final approval. It is thus an excellent time to evaluate the combination of these two topics into a unified theme: UML for SoC design. At DAC 2004, we organized a UML and SoC workshop as a discussion forum to bring hardware, SoC, and UML experts together. For that workshop, we received great international interest and contributions from Asia, Europe, and North America. The success of the workshop has demonstrated that there is a great interest in both academia and industry to create and investigate joint efforts in SoC design and UML. This book is a collection of the main contributors of the DAC 2004 UML and SoC workshop, providing the first set of papers for such a joint effort. Some additional contributions to the book were made by other experts who did not present at the workshop. The selected chapters present approaches to executable UML, UML translations for FPGA synthesis and SystemC simulation, as well as UML-specific SoC methodologies. They give insights into the current state of the art, and the most recent advances in applying UML to SoC design. They provide a representative overview of current UML activities in SoC design and give an excellent introduction to UMLs application in hardware and hardware/software codesign.