The firmware structure is made up of several layers, each dealing with a different feature. The application layer engine is the general interface between the user program and all the parts of the module. It deals with the communication ports, the module peripherals such as SPI, SCI, RTC, I/Os, LEDs and timing management. It is also the interface between the PLM stack and the user program. The PLM stack, itself made up of several layers, implements and manages the power line communication, manages the conflicts, timing and repetitions, the addressing, and so on.
Some features are managed directly by the application engine, and are transparent to the user, such as the RTC management or the module parameter update, as well as the module programming and configuration, which is done by particular programming or service commands managed and acknowledged directly by the application engine.
The user layer is fully customizable by using some easy to use APIs available for user application implementation. User data can be easily addressed to the PLM or to the other communication interface by simply changing the destination channel in the user data structure.