Smart Cards are some of the smallest computing platforms in use today. They have limited resources, but a huge number of functional requirements. The requirement for multi-application cards increases the demand for high performance and security even more. Great efforts have been taken to find methodologies for developing and implementing low-power hardware, but almost no state-of-the-art software engineering techniques are used to design and implement the software layers – if software is layered at all. Smart card operating systems (e.g. Java CardTM Technology) were designed to let smart cards benefit from the advantage of modern software engineering techniques. Applications are developed in a high level language; the resulting code is interpreted by a virtual machine. These additional layers require even more performance, requiring the use of HW/SW codesign techniques to better support software parts in hardware. This project aims to realize a HW/SW codesign methodology for designing entire smart card systems with regard to power awareness and performance.