ETAS RTA-OS (operating system) is a real-time operating system for deeply embedded ECUs with the highest safety level (ISO 26262 ASIL-D). It supports the latest versions of the relevant AUTOSAR, OSEK*/VDX, ISO 26262, and MISRA C standards.

RTA-OS builds on the experience gained with the RTA-OSEK real-time operating system, which has been established in the automotive industry for many years. RTA-OS supports the use of single and multicore microcontrollers and combines the full set of AUTOSAR functions with minimal runtime overhead. By virtue of its ISO 26262 certification for ASIL-D, RTA-OS can also be used for developing functions with strict safety requirements.

RTA-OS can be combined with RTA-RTE (AUTOSAR Runtime Environment generator) and RTA-BSW (AUTOSAR Basic Software) to create an AUTOSAR-compliant runtime platform. The operating system can also be used in a non-AUTOSAR environment equally well.

Work can begin even if the target hardware is not available, as RTA-OS is delivered with a Windows PC port to allow application software development in virtual environments on the PC.


  • Best-in-class processor and memory overheads
  • ISO 26262 (ASIL-D)-certified operating system
  • Automatically generates an optimized data structure for exact configuration adapted to the specific application
  • Supports wide range of single and multicore microcontrollers
  • Includes a virtual development environment on MS Windows
  • Patented single-stack implementation, which typically reduces application stack space requirements by between 50% and 80%
  • Supports all AUTOSAR configuration levels for controlling time response behavior and memory protection
  • Features an simple-to-use intuitive graphical user interface
  • Offers easy migration from OSEK OS using the OIL2XML conversion tool
  • The code generated for the AUTOSAR operating system is smaller and faster compared to that used for RTA-OSEK despite the additional functionality
  • Implements common standards

Supported standards

  • AUTOSAR R 4.3, R4.2, R4.1, R4.0 and R3.x, including OS functions for multicore processors and memory protection
  • OSEK*/VDX OS-compliant classes
  • MISRA-C:2004


* OSEK (which stands for “Offene Systeme und deren Schnittstellen für die Elektronik in Kraftfahrzeugen” or "Open Systems and their Interfaces for Electronics in Motor Vehicles" in English) is a predecessor standard of AUTOSAR.