ARINC 653
Section 11: Aircraft & Avionics Architecture
Definition
A standard for the Application/Executive (APEX) interface in Integrated Modular Avionics, defining the software interface between hosted applications and the underlying operating system. ARINC 653 specifies robust time and space partitioning: each application executes within a partition that has guaranteed processor time windows and protected memory regions, preventing faults in one partition from propagating to others.
Where This Shows Up
ARINC 653 is fundamental to IMA certification because it provides the software mechanism for hosting multiple applications of different criticality levels on shared hardware while maintaining safety isolation. Time partitioning is achieved through a fixed, cyclic scheduling table that allocates non-overlapping time windows to each partition. Space partitioning is enforced by the hardware memory management unit (MMU) under operating system control. The ARINC 653 API provides services for partition management, process management, time management, inter-partition communication (ports, channels), and health monitoring. Commercially available ARINC 653 real-time operating systems include VxWorks 653, PikeOS, LynxOS-178, and INTEGRITY-178.
Primary Sources
Avionics Application Software Standard Interface — defines the APEX API, partitioning requirements, inter-partition communication, and health monitoring.
IMA Development Guidance — addresses ARINC 653 partitioning as a key element of IMA certification.
Related Terms
Need help navigating certification?
Understanding the terminology is the first step. If you need expert guidance on DO-178C, DO-254, ARP4754B, or any aspect of FAA, EASA, or TCCA certification, our team is here to help.