ARINC 653 API and its application - An insight into Avionics System Case Study

Traditionally automated systems in aircraft were realised using well defined functions that are implemented as federated functional units. Each functional units possesses its own resources with fault containment compared to multiple functions in single processing node. Integrated architectures are structured over the avionics cabinets or processing cabinets which house the hardware modules and software application partitions along with system software. These integrated modular avionics (IMA) applications supports distributed multiprocessor architecture. Both time and memory is shared among multiple avionics functionalities across the same platform with good protection mechanisms provided by ARINC 653. ARINC 653 is an additional layer of protection being embedded as part of real time operating systems supporting the partitioning protections using well defined application executive, and application programming interfaces (API). IMA uses set of partitions, which are scheduled across a major frame M consisting set of partitions P-tn and each partition having set of task/process tau(n)/P-sn. The number of partitions and number of processes in each partition is a trade-off between the real time requirements and the resource. The paper also presents in brief, the API functionalities, its components, implementation, required interfaces, restrictions based on criticality of the avionics application. Error detection, control mechanisms for data integrity and validity for reconfiguration is also addressed. The experimental and simulation studies related to the API utilization as part of case study is addressed with four partitioned case study demonstrating the normal and failure scenario.