Because of ambitions applications, future smart cards will require more power are and software point of view. In case of smart cards, hardware and software application are closely interdependent and the final performance evaluation must be a new code resulting from a good balance between response time, speed, complexity of the processor and memory size (ROM, RAM). The OCEAN tool (Outil de Conception et d'Evaluation d'Architectures Nouvelles) provides: - a methodology to design a model of programming and an architecture of instructions set. - facilities to evaluate the best appropriateness. Unlike the others HDLs, OCEAN includes the application code as an important component of the evaluation.