PROBA-3 is a technology mission of the European Space Agency (ESA), devoted to the in-orbit demonstration of formation flying techniques and technologies. Presently at the end of phase B, PROBA-3 will implement a coronagraph (called ASPIICS, “Association de Satellites Pour l'Imagerie et l'Interferometrie de la Couronne Solaire”) that will both demonstrate and exploit the capabilities and performance of formation flying. The ASPIICS Coronagraph Control Box (CCB) which has the central role and controls all the activities of the coronagraph instrument sub-systems while being the only I/F with the spacecraft, is composed of the Coronagraph Control Module (CCM) which is in charge of the command and control of the entire instrument, of the image data compression unit and of the interface with the spacecraft, the Power Converter Module (PCM) which provides the power to all modules of the CCB, the Motor Control Module (MCM) which controls and commands all motors inside the Coronagraph Optical Box (COB), and the Ancillary Electronics Module (AEM) which is in charge of the Shadow Position Sensor (SPS) data acquisition and treatment and of the active thermal control. In this paper after a brief overview of the PROBA-3 ASPIICS coronagraph, the typical observation sequences and derived requirements, a detailed description of the architectural definition of the ASPIICS Coronagraph Control Box (CCB) electronics at the Preliminary Design Review (PDR) status, is provided.