This product is a real-time operating system (Real-time OS) conforming to the µITRON4.0 Specification, the predominant Real-time OS 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 IDE CS+ and e2 studio, and the configurator which automatically generates startup files will help you greatly reduce development time and get to market faster.

Note: RI600V4 is not generally promoted to U.S. and European customers. Customers in U.S. and Europe who are interested in RI600V4 are requested to contact our regional marketing departments for details.

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  • TRON, ITRON, and μITRON do not refer to any specific product or products.
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Sample projects (CS+ edition) for Firmware Integration Technology (FIT) have been added for RX65N and RX651. Learn More (Tool News) >>

Release Information


Latest Ver.: V1.04.00

Released: Oct 1, 2014

Details of upgrade (See Tool News)

Operating Environment

Agreement Details

CS+ interface plug-ins (Real-time OS Common plug-in)

Latest Ver.: V3.03.00

Released: Jul 1, 2016

CS+ interface plug-ins (Plug-in for RI600V4)

Latest Ver.: V3.01.00

Released: Jul 1, 2016

Integrated Tools

  • Compiler: CC-RX
  • Integrated development environment: CS+e2 studio


  • Compliant with µITRON4.0 SpecificationThe design conforms to the µITRON4.0 Specification, the representative OS architecture for embedded control.
  • ROM-based implementation:
    Since the system is a real-time/multi-tasking OS assumed to be used embedded in the execution environment, it was designed to be compact and ready for ROM-based implementations. Also, because the system can be configured linking only the service calls used in the system by the user (rather than all the service calls provided by the RI600V4), a real-time/multi-tasking OS can be configured which is compact and optimized for the user's needs.
  • Interface with CS+ and e2 studio, the Renesas Electronics Integrated Development Environment
    The RI600V4 OS interfaces with CS+ and e2 studio to support the following functions:
    • Auto-settings for options required in OS build
    • Displays state of OS control object for tasks, semaphore, etc. (Resource Information)
    • Graphical display of task operation logs and service call issue logs (Task Analyzer).

  • Sample Projects (CS+ edition) Provided for FIT Sample projects (CS+ edition) for the use of Firmware Integration Technology (FIT) with the RI600V4 real-time operating systems (Real-time OS) for the RX family are supplied.
    Download the sample project for FIT from Downloads Tab.


The RI600V4 kernel consists of the following modules. Each module is provided by functions (service calls) .

Task management functions
Provided by the RI600V4 include a function to reference task statuses such as priorities and detailed task information, in addition to a function to manipulate task statuses such as activation and termination of tasks.
Task dependent synchronization functions
Changes task status from other task, and synchronizes tasks.
Synchronization and communication functions
The synchronization and communication functions of the RI600V4 consist of Semaphores, Eventflags, Data Queues, Mailboxes, Mutex, and Message buffer that are provided as means for realizing exclusive control, queuing, and communication among tasks.
  • Semaphores:In the RI600V4, semaphores are provided as a means (exclusive control function) for preventing contention for limited resources (hardware devices, library function, etc.) arising from the required conditions of simultaneously running tasks.
  • Eventflags:Provides 32-bit eventflags as a queuing function for tasks.Data Queues:
    Provides the data queues that have the data queue area in which data read/write is enabled for transferring the prescribed size(4 bytes) of data.
  • Mailboxes:Provides a mailbox, as a communication function between tasks, that hands over the execution result of a given processing program to another processing program.
  • MutexAn object to perform exclusive control, and providing support for the feature to avoid priority inversion problems.
  • Message bufferAn object to communicate an arbitrary-length message by copying.
Fixed-sized memory pool
A function to dynamically allocate/free memory of preassign fixed size.
Variable-sized memory pool
A function to dynamically allocate/free memory of arbitrary size.
Time management functions
Provides methods to implement time-related processing (Timer Operations: Delayed task wakeup, Timeout, Cyclic handlers, and Alarm handlers) by using base clock timer interrupts that occur at constant intervals, as well as a function to manipulate and reference the system time. When using the time management function, it is necessary to specify the timer template file corresponding to the target device in the system configuration file.
System state management
Provides functions for referencing the system status such as the context type and CPU lock status, as well as functions for manipulating the system status such as ready queue rotation, scheduler activation, or the like.
Interrupt processing
Provides functions about interrupt handler that is called when an interrupt is occurred.
System configuration management
Reports information such as version number of RI600V4 kernel.
Object reset function
Initializes the Data queue, Mail box, Message buffer, Fixed-sized memory pool, Variable-sized memory pool. This function is unique to the RI600V4 and is not defined in the µITRON4.0 specifications.