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A Time & Space Partitioned DO-178 Level A Certifiable RTOS
Supports x86, PowerPC, ARM and MIPS processors


DDC-I's Deos safety-critical RTOS is used to host DO-178B certifiable avionics software including functions such as air data computers, air data inertial reference units, cockpit video, displays and flight instrumentation, electronic flight bags, enhanced ground proximity warning, flight controls, flight management systems, maintenance systems, power distribution systems, radios, traffic collision avoidance systems and weather radar.

Deos™ is a proven, full featured DO-178 Level A certifiable real-time operating system (RTOS) which addresses the issues of high robustness and formal certifiability for avionics and safety critical applications. Built from the ground up with these goals in mind, Deos is the only certifiable time and space partitioned COTS RTOS that has been created using RTCA DO-178, Level A processes from the very first day of its product development. Deos offers several unique fundamental and patented architectural advantages over all other competing RTOS's. The result is the best performance, lowest risk, easiest to certify, and lowest cost time & space partitioned COTS RTOS for airborne avionics and safety critical applications on the market today.

Deos supports popular avionics standards and other certifiable features allowing users to customize their Deos environment by choosing from a variety of optional modules:

  • Trusted & Field Proven
    • Certified to DO-178, Design Assurance Level (DAL) A since 1998
    • Flying on hundreds of aircraft systems world-wide
  • Best in Class Performance & Technical Advantages
    • Rate Monotonic Scheduling (RMS) and patented slack scheduling enables full processor utilization
    • Patented safe scheduling and cache partitioning technologies enable safety critical multi-core applications
    • Compiler certification independence enables state-of-the-art compilers with optimization & in-lining 'on'
    • Fastest context switching available of any time & space COTS RTOS
  • Advanced Feature-set Ensures... Easy Start and Lower Risk/Cost to Certify
    • Developed using COTS hardware, and design reference boards
    • Industry standard Ethernet & TCP/IP for development & in-flight use (supports both partitioned TCP/IP stacks, and multihoming)
    • Abstraction layers significantly improve BSP creation & certification efforts
    • Binary level certifiability reduces certification risk, time, and effort
  • ARINC Specification 653 Part 1 (Optional Module)
    • Delivers the standard avionics interfaces for enhanced portability, and allows designers to take advantage of the advanced features of Deos.
  • ARINC Specification 653 Part 4 (Optional Module)
    • Delivers a streamlined subset of the standard avionics interfaces for less complex systems and the value added features of Deos.
  • Binary Coverage Tool Resolves Source-to-Object Gaps Left Behind by MCDC
  • Binary Modularity Provides a 'Plug-and-Play' for the System Design & Integration
  • XML Configuration Tools & Verification Tools Generate Verifiable Configuration Profiles
  • User Guides Direct the Integration, Use, Testing, and Verification of Deos Binary Modules
    • I/O Infrastructure (IOI) provides data conversion & I/O handling (e.g., queued, blackboard, FIFO, etc.), reducing application code
    • Networking - AFDX, UDP & TCP/IP
  • Lowest Cost of Ownership
    • Progressive, industry-leading, product license pricing models
    • Deos BSP creation & certification costs/schedules are a fraction of any other certifiable time & space COTS RTOS.
    • Deos's unique hybrid architecture makes it easy for our customers to develop ARINC 653 applications for Deos, or to migrate existing ARINC 653 applications to Deos.
    • DDC-I's open and competitive services model enables customers and third parties to create their own Deos BSP, drivers, & other Deos components.
    • Portability - Binary certifiable objects promote plug & play reuse, with minimal certification effort.
    • High-level OS facilities enable applications to migrate with minimal change (e.g., IOI resolves different I/O interfaces types).
    • Ecosystem of third party hardware, software, and services
  • Unique Hybrid Architecture
    • Combines RMS & 653 scheduling models & Application Programming Interfaces (API's) in a powerful & versatile certifiable system.

    Deos 653 Hybrid Architecture

    The Deos 653 Hybrid Architecture allows the best of both worlds with the portability of the popular avionics standards, and the value added features of Deos, such as slack scheduling, it's modular architecture, application space device drivers and more.

Deos Informaton Kit


NEW! Free On-Demand Training Videos


   Hello World Training Video

   Deos Overview

   Deos Processes and Threads

On-Demand 1 Hour Web Seminars

White Papers

Adding Slack Scheduling to RMS

  • By using slack, thread Medium might receive CPU time that would have been lost to Idle to complete its execution for period
  • Gives you the ability to budget in order to meet your safety requirement, but enable slack in order to get the most out of your processor
  • Allows a client & server to exchange data, perhaps multiple times, back-to-back, within the same period, in order to complete a transaction
  • Enables the removal of lower criticality applications from the high criticality, fixed budget time line Software designers can now leverage all the power of today's modern processors, without sacrificing the safety of space & time partitioning.

Reduced Software Development Cost

In addition to the typical RTOS services for memory management and synchronization, Deos has excellent support for hard-deadline deterministic periodic execution. Additionally, Deos provides highly efficient, deterministic inter-process/inter-processor, periodic & aperiodic communication mechanisms which enable the designer to isolate applications from changes in I/O format and bus hardware/source.

Reduced Integration Cost

It is common for resource contention conflicts, in otherwise well tested software, to manifest during integration. These errors can be difficult to locate because interactions are complex and rarely understood by any one individual. The Deos Integration Tool makes obvious, during development and design, an application's resources needs, this prevents contention while providing early warning of physical resource depletion. An application's memory, I/O, interrupt and processing time needs are defined early in the life cycle and follow it throughout development, testing & verification; thus reducing the time and cost of integration.

Reduced Recertification Cost

The cost to re-certify previously approved software is a function of the amount of change. Changing just a single module and then re-compiling / re-linking the whole system results in an entirely new executable. Deos solves this problem by supporting run-time linkable libraries and executables (i.e., it is a DO-178B Level-A Link/Loader). Consequently a change to one module within an executable impacts only that executable. The executables for the rest of the system, and even the run-time linkable libraries used by the application remain unchanged. This isolation of change impact results in a reduced re-certification cost thereby making it easier to embrace change and incrementally improve your product offerings.

Improved Programmer Efficiency

Of course, Deos comes with all the software development and debugging tools you've come to expect: IDE, Debugger, run-time system monitor/profiler, as well as integrated emulator support. Additionally, Deos provides integration and configuration tools which enable the designer to factor out what would otherwise be hard-coded constraints. This factoring ability not only speeds development, but also aids in verifying the correctness of the implementation, aided by Deos provided qualified verification tools.

Object Code Structural Coverage Tool

DO-178B indicates that, when using modern compilers for Level-A software, structural coverage "...should be performed on the object code" ( Deos provides a structural coverage tool capable of gathering structural coverage data on the executable object code in compliance with the Level-A requirement. This eliminates the need for an expensive source to object code traceability analysis.

Run-time Linkable Libraries

Decompose your applications into executables and run-time linkable libraries in order to isolate change impact. Both startup and runtime shared library loading is supported enabling maximum flexibility, configurability, and Just-In-Time function binding. Also save valuable platform memory space and ensure all your applications are using the same latest and verified library.

Decreased Software Porting Cost

The Deos 653p4 and Deos653p4-Solo products add support for the ARINC Specification 653 Part 4, scheduling model and APplication/EXecutive (APEX) interfaces to allow improved portability of avionics software from other sources that have been written to conform to that popular specification.