This document introduces the concepts and principles specified within ARINC 653 to support the API, including vocabulary and definitions, and system architecture.

Both the interface and the behavior of the API services are specified in ARINC 653. Behavior is specified to the extent needed to describe functionality relevant to calling applications.

Where necessary, assumptions are made as to the support or behavior provided by the CSW and hardware. This document should not be construed as a specification for the CSW or hardware. However, where the CSW or hardware does not coincide with the stated assumptions, the API behaviors specified in ARINC 653 may not match the actual behavior.

ARINC 653 is intended for use in a partitioned software environment. In order to assure a high degree of portability, aspects of the partitioned environment are discussed and assumed. However, ARINC 653 does not define the complete system, hardware, and software requirements for partitioning nor does it provide guidance on proper implementation of partitioning, and in particular, robust partitioning. It must not be construed that compliance to ARINC 653 assures robust partitioning.

Purpose

This document provides an overview of the entire set of documents collectively referred to as ARINC 653. As this set of documents evolves, supplements to Parts 1 through 5 have been made more consistent with Part 0 in conjunction with the technical changes made in the evolution of ARINC 653. A summary of the ARINC 653 documents follows:

• Part 0 – Overview of ARINC 653

• Part 1 – Required Services

• Part 2 – Extended Services

• Part 3A – Conformity Test Specifications for ARINC 653 Required Services

• Part 3B – Conformity Test Specifications for ARINC 653 Extended Services

• Part 4 – Subset Services

• Part 5 – Core Software Recommended Capabilities

The term “this document” refers to Part 0 only, while the term “ARINC 653” or “the Specification” refers to the whole set of ARINC 653 documents, currently Parts 0 to 5.

The primary objective of ARINC 653 is to define a general purpose APplication/EXecutive (APEX) interface (Application Program Interface (API)) between the Core Software (CSW) of an Avionics Computer Resource (ACR) and the application software. Included within ARINC 653 are the interface requirements between the application software and the CSW and the list of services which allow the application software to control the scheduling, communication, and status information of its internal processing elements.

It should be noted that while ARINC 653 was developed for use in Avionics Systems, it is equally suitable for any system that requires API services, and partitioning mechanisms to enable multiple Hosted Applications (of the same or differing safety levels) to operate on platform hardware.

ARINC 653 defines the data exchanged statically (via configuration) or dynamically (via services) as well as the behavior of services provided by the CSW and used by the application. It is not the intent of the Specification to dictate implementation requirements on either the hardware or software of the system, nor is it intended to drive certain system level requirements within the system which follows this standard.

ARINC 653 Parts 1, 2, and 4 describe the runtime environment for embedded avionics software. This list of services identifies the minimum functionality provided to the application software and is, therefore, the industry standard interface. It is intended for this interface to be as generic as possible, since an interface with too much complexity or too many system specific features is normally not accepted over a variety of systems. The software specifications of this API are High Order Language (HOL) independent, allowing systems using different compilers and languages to follow this interface.

ARINC 653 is intended to complement ARINC Report 651: Design Guidance for Integrated Modular Avionics. It is expected that individual parts of ARINC 653 will evolve to contain additional functionality and capability. Supplements to ARINC Specification 653 Parts 0 to 5 will be prepared and published independently as needed by the industry. In each case, the evolution of one part must consider the potential impact on the other ARINC 653 parts.