In this work, we present an integrated approach to the SoC design problem based on a mixed (HW and SW) implementation of a system-level middleware specifically designed for SoCs: the Object-Oriented Communication Engine (OOCE). OOCE provides a high-level and homogeneous view of the SoC components based on the Distributed Object paradigm. The resulting communication infrastructure easies the integration of the HW and SW parts, allows the automatic generation of the HW/SW interfacing adapters and also enables true concurrent design methodologies. To prove the viability and efficiency of our proposal a prototype implementation on the Xilinx-V2 Pro platform has been developed.