Universal serial bus implementation in an integrated access chip for ISDN systems

The universal serial bus technology comes as a response to the increasing demands for unified interfaces and the need for flexible easy-to-use products for personal computers. Integrating this technology into PBXs and ISDN ICs can play an important role in the integration of telecommunications and computer technologies. The paper reports the findings of a research project called COPARIS for ISDN chip design with the additional USB interface. It also presents the software and hardware design approaches for implementing USB functions in the COPARIS chip. The research indicates that a balanced approach is the best, where the computationally intensive functions should be implemented in hardware and the rest in software