Green Hills helps usher-in new era of safety-critical real-time software for multicore jetliner avionics

March 29, 2021
RCTA/DO-178C and CAST-32A certify avionics like flight computers for safety-critical uses aboard commercial passenger aircraft used throughout the world.

SANTA BARBARA, Calif. – The INTEGRITY-178 tuMP multicore real-time software represents a new chapter in certifying multicore computer processors for safety-critical commercial and military avionics systems.

The INTEGRITY-178 tuMP developer, Green Hills Software in Santa Barbara, Calif., announced this month that the INTEGRITY-178 tuMP multicore real-time operating system (RTOS) software is part of a multicore certification to RCTA/DO-178C and CAST-32A international commercial aviation standards.

The certification is part of a Technical Standing Order (TSO) authorization for the PU-3000 avionics computer from CMC Electronics Inc. in Montreal. The certification included evidence of meeting all CAST-32A requirements for multicore processors.

The RCTA/DO-178C and CAST-32A standards certify avionics subsystems like flight computers for safety-critical uses aboard commercial passenger aircraft used throughout the world. These certifications rarely, if ever, have applied to multicore processors before now.

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Historically, avionics for commercial passenger aircraft have been discouraged from using today's advanced multicore processors because of the difficulty in certifying these powerful computer chips for safe operation on commercial planes.

The PU-3000 series of avionics computers is the fourth generation of avionics computers from CMC Electronics and is fit for the civil and military retrofit markets. Modular by design, the multicore PU-3000 is suitable for use as a computer in a large variety of functions.

"CMC Electronics selected the INTEGRITY-178 tuMP RTOS after determining that it uniquely provides the robust partitioning, resource configuration, and certification support required for CMC's next-generation of multicore avionics products," says Don Paolucci, vice president of engineering, at CMC Electronics.

"INTEGRITY-178 tuMP reduces development and integration costs for CMC and our customers by providing full support for multicore processing with mixed-criticality applications up to DO-178C DAL A airborne safety requirements and certified conformance to the FACE Technical Standard," Paolucci says.

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The CMC PU-3000 enables commercial aircraft avionics to host combinations of several levels of applications simultaneously into one box varying from primary flight display, navigation display, flight management systems, radio management systems, and flight director systems.

The PU-3000-series certification came from Transport Canada Civil Aviation (TCCA), with reciprocal acceptance from the U.S. Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA).

CMC's avionics computers can host several high-performance software applications developed to design assurance levels ranging up to RTCA DO-254 and EUROCAE Document ED-80 Design Assurance Levels (DAL) A -- flight electronics hardware whose failure or malfunction could cause a catastrophic, hazardous, or severe condition that would result in the deaths of everyone aboard the aircraft.

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INTEGRITY-178 tuMP is a multicore RTOS with support for running a multi-threaded DAL A application across multiple processor cores in symmetric multi-processing (SMP) or bound multi-processing (BMP) configurations, as well as supporting the more basic asymmetric multi-processing (AMP).

INTEGRITY-178 tuMP is certified to the FACE Technical Standard, edition 3.0, and offers multicore interference mitigation for all shared resources. Multicore interference happens when more than one processor core attempts simultaneous access of a shared resource, such as system memory, I/O, or the on-chip interconnect.

For more information contact Green Hills Software online at, or CMC Electronics at

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