ARINC 653 (ARINC 653-1)

ARINC 653-1 is an abbreviation for the Draft 3 of Supplement 1 to ARINC Specification 653: Avionics Application Standard Software Interface, published July 15, 2003. The ARINC 653-1 specification became a standard in October, 2003.

The ARINC 653 specification for system partitioning and scheduling is often required in safety- and mission-critical systems, particularly in the avionics industry.

ARINC 653 defines an APplication EXecutive (APEX) for space and time partitioning that may be used wherever multiple applications need to share a single processor and memory, in order to guarantee that one application cannot bring down another in the event of application failure.

Each partition in an ARINC 653 system represents a separate application and makes use of memory space that is dedicated to it. Similarly, the APEX allots a dedicated time slice to each, thus creating time partitioning. Each ARINC 653 partition supports multitasking.

Because the ARINC 653 specification forces applications to be isolated, ARINC 653 conformance can be a step toward DO-178B certification. In some cases, ARINC 653 conformance makes it possible for DO-178 certified applications of different levels to run isolated from each other on the same computer.

As well, applications that use the ARINC 653 application programming interface (API) can be more easily ported from one ARINC 653 operating system to another than those which do not.

ARINC standards allow aircraft manufacturers to ensure that new installations are compatible and interchangeable. A study called "The Economic Impact of Avionics Standardization on the Airline Industry," from Georgia State University's Aviation Policy Research, Aviation and Transport Studies, estimates annual savings by the airlines industry of more than $291 million annually through the use of ARINC standards.

ARINC 653 services

The LynxOS-178 RTOS and LynxOS-SE RTOS conform to the ARINC 653-1 Application Executive Software (APEX) Interface defined by the ARINC 653-1 standard. LynxOS-178 and LynxOS-SE provide the following system service groups in accordance with the ARINC 653-1 standard:

• ARINC 653 Partition Management: services related to partition management. GET_PARTITION_STATUS and SET_PARTITION_MODE are Partition Management service requests.
• ARINC 653 Process Management: services related to process management. GET_PROCESS_ID and GET_PROCESS_STATUS are Process Management service requests.
• ARINC 653 Time Management: services related to time management. TIMED_WAIT and PERIODIC_WAIT are Time Management service requests.
• ARINC 653 Interpartition Communication: services responsible for communication between processes residing in different partitions. There are two types of Interpartition Communication services:
  1. Sampling Port Services: A sampling port is a communication object allowing a partition to access a channel of communication configured to operate in sampling mode. CREATE_SAMPLING_PORT and WRITE_SAMPLING_MESSAGE are Sampling Port Services service requests.
  2. Queuing Port Services: A queuing port is a communication object allowing a partition to access a channel of communication configured to operate in queuing mode. CREATE_QUEUING_PORT and SEND_QUEUING_MESSAGE are Queuing Port Services service requests.
• ARINC 653 Intrapartition Communication: services responsible for communication between processes residing in the same partition. There are four types of Intrapartition Communication service requests:
  1. Buffer Services: A buffer is a communication object used by processes of a same partition to send or receive messages. CREATE_BUFFER and SEND_BUFFER are Buffer Services service requests.
  2. Blackboard Services: A blackboard is a communication object used by processes of the same partition to send or receive messages. CREATE_BLACKBOARD and DISPLAY_BLACKBOARD are Blackboard Services service requests.
  3. Semaphore Services: A counting semaphore is a synchronization object commonly used to provide access to partition resources. CREATE_SEMAPHORE and WAIT_SEMAPHORE are Semaphore Service service requests.
  4. Event Services: An event is a synchronization object used to notify the occurrence of a condition to processes that may wait for it. CREATE_EVENT and SET_EVENT are Event Services service requests.
• ARINC 653 Health Monitoring: The Health Monitor (HM) is invoked by an application calling the RAISE_APPLICATION_ERROR service or by the OS or hardware detecting a fault.