IAR Embedded Workbench for Renesas RL78

The complete development toolchain IAR Embedded Workbench for Renesas RL78 provides one toolbox in one view, giving you one uninterrupted workflow.


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 RL78 family, example projects and code templates, and fully integrated C-STAT static analysis.


Powerful build tools

IAR C/C++ Compiler is a highly optimizing C and C++ compiler for RL78. It offers a relocating RL78 assembler and run-time libraries.


Comprehensive debugger

The C-SPY Debugger is a comprehensive debugger with RL78 simulator, support for RTOS-aware debugging on hardware and wide emulator support.


Integrated code analysis

IAR Embedded Workbench for RL78 provides integrated static code analysis through the add-on product C-STAT, ensuring code quality as well as proving alignment with standards such as MISRA C:2012.


On-demand training included

When you buy a license of IAR Embedded Workbench for Renesas RL78, 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: 5.10.3

  • The Renesas RL78/G24 Flexible Application Accelerator (FAA) co-processor is supported

    • The Renesas FAA assembler is incorporated in the IAR Embedded Workbench
    • FAA assembler-generated output is linked with the IAR linker
    • The IAR C-SPY debugger supports multicore debugging for the FAA core
  • Improved compliance with the CC-RL ABI specification

    Additional standard library functions and runtime routines have been implemented.
  • Debugging support for flash self-programming

    Debugging support while self-programming is in progress has been added for G2x and F2x devices.
  • Program corrections

    Errors have been corrected in the compiler, linker, and in IAR C-STAT.
Read complete release notes

Version: 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
  • 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. (An initial debug session with IAR Embedded Workbench is required to fill in the settings in the Hardware setup dialog box, prior to debugging in Visual Studio Code)
  • 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.
    • 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 4.21

  • RL78/G23 microcontroller group support
    The RL78/G23 group of microcontrollers is now supported.
  • IAR Build Tools for Linux
    A new product, IAR Build Tools for Renesas RL78, is available. It requires a separate product license and is distributed as a Debian package for Ubuntu containing the IAR C/C++ Compiler, IAR Assembler, Linker and library tools, C-STAT, IARBuild, and runtime libraries. Get product info
  • C-STAT enhancements
    • 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.
  • Renesas Smart Configurator included
    The Renesas RL78 Smart Configurator V1.0.1 has been included.
Read complete release notes

Version 4.20

C18 support
The default Standard C is now C18 (ISO/IEC 9899:2018).

C++17 support
The compiler now supports almost all C++17 features. The C++ library supports C++14 with no C++17 additions.

Improved Source Browser
The following improvements have been made to the Source Browser:

    • The source browser data is generated faster as it is now running as a separate thread.
    • New Source Browser Log window.
    • Status indicator in the status bar.
    • Enhanced feedback in case source browsing data cannot be generated.

EZ-CUBE2 On-Chip Debug Emulator support
The EZ-CUBE2 On-Chip Debug Emulator, primarily targeted for the Chinese market, is now supported.

E2 emulator power debugging in C-SPY
The E2 emulator allows you to measure the dynamically changing current drawn by the user system. This is visualized as a graph in the C-SPY Timeline window as well as a list of time-current value pairs in the Power Log window. It is also possible to stop execution when the current goes above or below a certain user-defined threshold value.

Documentation Comments support in the editor
The editor can distinguish comments that start with /**, /*!, /// or //! as Documentation Comments. Inside a Documentation Comment, the editor can recognize keywords that begin with \ or @. If the keyword is recognized as a doxygen keyword, the Documentation Comment will appear in tooltips and parameter hints for variables and functions. See IAR Embedded Workbench IDE Project Management and Building Guide for more information.

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

Read complete release notes

Wide support for MCU devices

Supported RL78 devices

IAR Embedded Workbench for Renesas RL78 enables you to take full advantage of the capabilities of Renesas RL78 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.

Read more about Licenses

Want to know more?

We are present worldwide to help you wherever you are, and we are happy to answer any questions you might have about our products.

Get quote

Want to use this product in your development projects? Our sales team is here to guide you to the right solution. Complete this form, and we will get back to you with a price quote tailored to your needs.

* read our Privacy policy

User guides and documentation

Hardware debugging and RTOS support

Hardware debugging support

  • Renesas E2 Emulator
  • Renesas E1 Emulator
  • Renesas E2 Emulator Lite
  • Renesas EZ-Cube
  • Renesas IECUBE
  • Renesas E20
  • Renesas TK

RTOS support

  • Micrium μC/OS-II
  • OSEK Run Time Interface (ORTI)
  • embOS
  • Express Logic
  • FreeRTOS
  • CMX

Each 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.

Try software for free

IAR Embedded Workbench for Renesas RL78 - 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
  • Limited technical support
Ladda ner

Det här innehållet finns tyvärr inte på svenska.

Vår webbplats finns främst på vårt koncernspråk engelska, förutom det innehåll för investerare som vi är lagstadgade att kommunicera på svenska. Vi rekommenderar att du besöker vår globala webbplats på engelska för att få en bättre upplevelse.

Vi stöder inte längre Internet Explorer. För att få bästa möjliga upplevelse av iar.com rekommenderar vi att du uppgraderar till en modern webbläsare som Chrome eller Edge.