IAR Embedded Workbench for Renesas RX

Complete development solution to create smaller, faster, smarter code for all RX devices.



User-friendly IDE

Integrated development environment with project management tools and editor. Included is linker and library tools, configuration files for all devices in the RX family, example projects and code templates as well as Renesas FIT integration.


Powerful build tools

IAR C/C++ Compiler is a highly optimizing C and C++ compiler for RX. It offers a relocating RX assembler and run-time libraries, and is compliant with Renesas RX ABI and the INCITS/ISO/IEC 9899:2018 standard.


Comprehensive debugger

The C-SPY Debugger is a comprehensive debugger with RX simulator, support for RTOS-aware debugging on hardware, timeline visualizing power consumption, call stack and interrupt activity as well as oower debug support with power profiling.


Integrated code analysis

IAR Embedded Workbench for RX provides integrated code analysis through the add-on for static analysis C-STAT, ensuring code quality as well as proving alignment with standards such as MISRA C:2012. In addition, the add-on product C-RUN featuring runtime analysis is also available.


On-demand training included

When you buy a license of IAR Embedded Workbench for Renesas RX, you get access to free training courses through our IAR Academy on Demand offering.

Latest releases

We are constantly updating and refining our tools with new features, new device support and extended capabilities.

Latest release: 5.10

  • Library support for the C++17 language standard

    The toolset includes a new C++ library that supports C++17 library features.

    Additional GNU C language extensions

    The IAR C/C++ Compiler supports a number of new GCC-style operators, attributes and expressions in extended language mode.

    Editor and IDE enhancements

      • Editor themes - a new way to set up the colors and fonts in the text editor
      • Syntax feedback - instant syntax suggestions while typing
      • Improved parameter hints
      • Window color themes - dark mode
      • Gray out inactive code support

    RX660 and RX26T supported

    The RX660 and RX26T groups of microcontrollers are now supported.

    Iarbuild enhancements

    The iarbuild command line build utility now supports:

      • Generating a Ninja build file based on the IAR Embedded Workbench project format
      • Generating a JSON description of the Embedded Workbench project
      • More C-STAT reporting and configuration methods

    64-bit Windows application

    IAR Embedded Workbench now runs as a 64-bit Windows application.

    Visual Studio Code support

    The IAR Build and IAR C-SPY Debug extensions available on Microsoft Marketplace enable you to work in Visual Studio Code (with IAR Embedded Workbench installed) to:

      • Build IAR Embedded Workbench projects
      • Run the C-STAT static analysis tool
      • Debug applications using the same range of hardware/debug probes as in IAR Embedded Workbench.

    C-STAT enhancements

      • MISRA C:2012 Amendment 2
        The static analysis tool C-STAT has extended its coverage of the MISRA C:2012 Coding Standard and now fully supports MISRA C:2012 Amendment 2. This Amendment adds two additional rules to MISRA C:2012 and introduces support for ISO/IEC 9899:2011, commonly referred to as "C11".
      • Improved performance
        Depending on the project, the analysis can be up to 40% faster and memory consumption reduced by up to 20%, compared to the previous version of C-STAT.

    Updated device support

    The device support files have been updated to the most recent version from Renesas.

    Updated user documentation

    The C/C++ Development Guide, C-SPY Debugging Guide, and IDE Project Management and Building Guide have been updated to reflect the product changes.

Read complete release notes

Version 4.20

  • C-STAT enhancements

    • MISRA C:2012 Amendment 1
      The static analysis tool C-STAT has extended its coverage of the MISRA C:2012 Coding Standard and now fully supports MISRA C:2012 Amendment 1. This amendment adds 14 additional rules to MISRA C:2012 with a focus on security concerns highlighted by the ISO C Secure Guidelines. Several of these address specific issues pertaining to the use of untrustworthy data, a well-known security vulnerability.
    • Extended coverage of CERT C
      The static analysis tool C-STAT has extended its coverage of the SEI CERT C Coding Standard. The SEI CERT C Coding Standard's goal is to provide rules for developing safe, reliable, and secure systems in the C programming language, with support for C11 constructs. C-STAT covers all rules in the different CERT C sections listed on the CERT C wiki as of January 2020, with the exception of the API, CON, POS, and WIN sections, which are not applicable to IAR Systems products, yielding a total of 90 covered rules.
    • Link analysis trace information
      The link analysis messages now display trace information when relevant. For checks looking for conflicting symbol names, all conflicting declarations are now listed in the trace information instead of each pair of conflicts being described in a separate message. This might lead to fewer reported messages for the same number of found issues.

    IAR Build Tools for Linux

    A new product, IAR Build Tools for Renesas RX is available. It contains the IAR C/C++ Compiler, IAR Assembler, Linker and library tools, C-STAT, IARBuild, and runtime libraries. Get product info

    Renesas Smart Configurator update

    The Renesas Smart Configurator (included) has been updated to V2.7.0.

Read complete release notes

Wide support for MCU devices

Supported Renesas RX devices

IAR Embedded Workbench for Renesas RX enables you to take full advantage of the performance and power-efficient capabilities of Renesas RX MCUs.

See all supported devices

What type of license do you need?

Our tools are available in a flexible license model to suit your company needs. Together with our support and update agreements, you get the support you need in multiple time zones and multiple languages. Send a request for quote or contact sales to get started.

Get started using this product

We are here to help you in your next embedded development project. Get started now by downloading a free trial version or requesting a price quote for your specific needs.

IAR Embedded Workbench for Renesas RX - Free trial version

The evaluation license is free of charge and allows you to try the software for 14 days to evaluate its efficiency and ease of use. 

You will be asked to register to get your license when you click download.

Please note the following for the 14-day time-limited version:

  • Time limit for evaluation license is 14 days
  • Not allowed to be used for product development or any commercial use
  • Source code for runtime libraries is not included
  • No support for MISRA C
  • C-RUN is size-limited to 12 Kbytes of code, excluding constant data.
  • Limited technical support

Complete this form and we will get back to you with a price quote tailored for the needs of your project and company. 

We look forward to your request! 

User guides and documentation

Hardware debugging and RTOS support

  • Debugging system support

    • Renesas E1 Emulator
    • Renesas E2 Emulator
    • Renesas E2 Emulator Lite
    • Renesas E20
    • Segger J-Link
    • C-SPY Debugger plugin SDK available for 3rd party debuggers

    RTOS support

    • OSEK Run Time Interface ORTI
    • Express Logic
    • Micrium
    • FreeRTOS
    • CMX
    • embOS
    • UNISON

    The RTOS plugin installs a number of new windows in C-SPY, most importantly the task or thread list windows where task-specific breakpoints can be specified and task-specific steps executed. Different inspector windows display the contents of the internal data structures of the RTOS such as timers, queues, semaphores, resources and mailboxes.

Languages and standards

  • The IAR C/C++ compilers offer different dialects of the C and C++ programming languages, as well as different extensions specific for embedded programming (please note that not all language standards are supported for all target implementations). The compiler can be instructed to disable extensions for strict conformance to the standards. 

    A wide range of industry-standard debug and image formats compatible with most popular debuggers and emulators are supported. This includes ELF/DWARF where applicable.

    ISO/ANSI C/C++ Compliance

    The IAR C/C++ compilers adhere to a freestanding implementation of the following C programming language standards:

    • INCITS/ISO/IEC 9899:2018, known as C18 (Latest version only).
    • The compiler supports all C++17 features. The C++ library supports C++14 with no C++17 additions.  (Latest version only).
    • ISO/IEC 14882:2015, known as C++14
    • INCITS/ISO/IEC 9899:2012, known as C11
    • ANSI X3.159-1989, known as C89

    The ISO/ANSI C/C++ Compliance level varies between the different compilers. For complete information, please refer to the IAR C/C++ Compiler user documentation in your chosen product.

    IEEE 754 standard

    IAR Embedded Workbench supports the IEEE 754 standard for floating-point arithmetic.


    MISRA C is a software development standard for the C programming language developed by MISRA, The Motor Industry Software Reliability Association. Its aims are to facilitate code safety, portability and reliability in the context of embedded systems, specifically those systems programmed in ISO C.

    The first edition of the MISRA C standard, "Guidelines for the use of the C language in vehicle based software", was produced in 1998. In 2004, a second edition was produced with many substantial changes to the guidelines, including a complete renumbering of the rules. Additionally MISRA C:2012 with extended support and MISRA C++:2008 for identifying unsafe code constructs in the C++ standard have also been added to the standards.

    IAR Embedded Workbench features an add-on product C-STAT so you can check compliance with rules as defined by MISRA C:2004, MISRA C++:2008 and MISRA C:2012.

    Test validation

    We use the following commercial test suites to test conformance of our tools to the standards:

    • Plum Hall Validation test suite for ISO/IEC C conformance
    • Perennial EC++ Validation Suite for C++ conformance
    • Dinkum C++ Proofer to test how our libraries conform to the C and C++ standard as well as test our STL implementation against the C++ standard.

    In addition to the commercial suites, we use several in-house test suites for testing new features, regression testing, corrected errors, etc.

Renesas FIT support

  • Renesas FIT simplifies development for the RX family. The technology is supported by IAR Embedded Workbench for RX.

    Renesas FIT consists of a Board Support Package (BSP), peripheral function modules, middleware modules, and interface modules and these can be used with IAR Embedded Workbench for RX.

    The tool Renesas Smart Configurator, supplied with IAR Embedded Workbench for RX, supports the following three functions related to embedding Renesas drivers in your systems:

    • importing FIT modules
    • generating driver code
    • generating device configuration code

    The generated modules are incorporated via the IAR Project Connection mechanism.