Support for this product is limited to customers who have already adopted these products. If adopting new products, please consider the successor, RI600V4.


This product is a real-time operating system (RTOS) conforming to the μITRON 4.0-specification, the predominant RTOS for embedded systems in Japan. Its compact resources, outstanding real-time features, and many service calls are suited for an embedded system with real-time ability and multi-tasking functions. In addition, its affinity for the Renesas C compiler package and the configurator which automatically generates startup files will help you greatly reduce development time and get to market faster.

Note: RI600/4 is not generally promoted to U.S. and European customers. Customers in U.S. and Europe who are interested in RI600/4 are requested to contact our regional marketing departments for details.

  • TRON Forum holds the copyright on the μITRON Specification.
  • TRON, ITRON, and μITRON do not refer to any specific product or products.

Release Information

Latest Ver.: V.1.01 Release 01

Released: Apr 16, 2013

Details of upgrade (See Tool News)

Operating Environment

Agreement Details

 User's Manual


  • Conforms to industry standard μITRON 4.0 specifications
    The μITRON arranges and standardizes the ITRON specifications for embedded systems. RI600/4 conforms to the μITRON 4.0 specifications, and provides service calls suitable for RX Family MCU functions.
  • Compact size for ROM
    RI600/4 enables to leverage the full performance of CPUs.
  • C user interfaces
    Using the C/C++ Compiler Package for RX Family provides the following functions :
    • Kernel direct call
      The RI600/4 kernel can be called without the C interface library. This function reduces code size and speeds up execution time.
      *Some service calls use C language interface
  • Collaboration with Renesas IDE, High-performance Embedded Workshop
    The compiler options etc. for build can be set automatically by the project generation facility for the OS of Renesas integrated development environment "High-performance Embedded Workshop" (included in the C/C++ Compiler Package for RX Family). Therefore, you can easily embed the OS to your applications.
  • Selectable OS configuration method according to development style
    You can select the method for specifying on GUI configurator or discribing on the text file.

Screen Image : Configurator



The RI600/4 kernel consists of the following modules. Each module is provided by functions (service calls) .

  • Scheduler
    Manages execution sequence of multiple tasks based on their priority levels.
  • Task management
    Manages task status such as RUNNING, READY, WAITING or SUSPENDED.
  • Task-dependent synchronization
    Changes task status from other task, and synchronizes tasks.
  • Synchronization/communication
    Carries out synchronization and communication between tasks. The following function modules are available:
    • Semaphore
      An object for exclusive control of shared devices and variables for two or more tasks.
    • Event flag
      An object to control the execution of a task according to the AND/OR condition represented by bit pattern.
    • Data queue
      An object to perform 1-word (32 bits) communication.
    • Mail box
      An object to communicate an arbitrary-length message by pointer passing.
    • Mutex
      An object to perform exclusive control, and providing support for the feature to avoid priority inversion problems.
    • Message buffer
      An object to communicate an arbitrary-length message by copying.
  • Fixed length memory pool
    An object to dynamically allocate/free memory of preassign fixed size.
  • Variable length memory pool
    An object to dynamically allocate/free memory of arbitrary size.
  • Interrupt processing
    Returns from an interrupt handler, enables/disables an interrupt for each task, and so on.
  • Time management
    Sets system timer used by RI600/4 kernel and starts user-defined alarm handler, cyclic handler and overrun handler.
  • System configuration management
    Reports information such as version number of RI600/4 kernel.
  • System state management
    Modifies and refers system status.
  • Object reset function
    Initializes the Data queue, Mail box, Message buffer, Fixed length memory pool, Variable length memory pool. This function is unique to the RI600/4 and is not defined in the μITRON4.0 specifications.

Kernel specifications

Target CPU RX Family
Maximum number of tasks 255
Number of priority levels 255
Service call number 143
(Time takes for a target task to be executed after the wup_tas is issued.)
2.5 microseconds (RX610, 100MHz)
Kernel code size From 6.2K bytes to 25.5K bytes
Kernel RAM usage per task data : 16 bytes
stack : 44 bytes



Provided items Explanation Note
Kernel source program Kernel source program Provided only with mass- production licenses which include source code.
Kernel library Kernel library for system building Compliant with big/little endian
Standard header files ・ITRON specification common definition files
・Kernel specification definition files
・Other definition files
Header files are provided both in C languages
GUI Configurator The input the construction parameters on the GUI screen allows the output of the cfg file for cfg600. -
Command Line Configurator
Generates the various definition files from a cfg file on which construction parameters are described in plain text form. -
Table generation utility
Generates the Interrupt Vector Table and Service Call Jump Table. -
Manual user's manual -


Processing Flow

Target Devices

Family Group
RX Family
  • RX210 (Supported but discontinued)
  • RX21A (Supported but discontinued)
  • RX220 (Supported but discontinued)
  • RX63N, RX631 (Supported but discontinued)
  • RX62N, RX621 (Supported but discontinued)
  • RX630 (Supported but discontinued)
  • RX610 (Supported but discontinued)
  • RX63T (Supported but discontinued)
  • RX62T (Supported but discontinued)
  • RX62G (Supported but discontinued)

Information supporting development tools

Title Description
My Renesas Create a My Renesas account to use our tool download services,
receive e-newsletter/update notifications, and take advantage of our other services.
e-learning Information for studying and learning about microcontrollers and microprocessors.
FAQ Frequently asked questions and useful hints for development.
Forum A forum and community site to share technical information,
questions and opinions with others who use Renesas MCU's.
Tool News Tool release information and other important information.
Operating Environment Information on system requirements and operating environment for the latest
version of tools.
Info on Discontinued Products A list of Renesas software and tools that have been discontinued and
are no longer being offered for new projects.