One aspect of this work concerns the project MC3 we are involved in: definition and validation of the architecture of a new ASIC data communication circuit intended for the high level ISO protocols network, transport and session. This paper describes the definition of the specific data structure, called PnPDU, which is used for the frame memory management in the implementation of high level ISO protocols, especially when two or more of these protocols are to be implemented together on a data communication circuit and when the minimization of computational costs is an important working hypothesis. The paper also considers the microarchitecture of the transfer machine which is dedicated, inside MC3, to the interface management and to the frame emission and reception. The scanning of the PnPDU data structure and the emission of the whole frame which are done by an intelligent DMA are described. It is shown how the validation of the data structure and the dedicated hardware is carried out.