ΜITRON

The ITRON project is the first of several sub-architectures of the TRON project.

Originally undertaken in 1984, ITRON is a Japanese open standard for a real-time operating system (RTOS) initiated under guidance of Ken Sakamura. This project aims to standardize the RTOS and related specifications for embedded systems, particularly small-scale embedded systems. The ITRON RTOS is targeted for consumer electronic devices, such as mobile phones and fax machines. Various vendors sell their own implementations of the RTOS.

ITRON, and µITRON (sometimes also spelled uITRON or microITRON) are the name of RTOS specifications coming out of ITRON projects. 'µ' means that the particular specification is meant for the smaller 8-bit or 16-bit CPU targets. Specifications are available for free. Commercial implementations are available, and offered under many different licenses.

A few sample sources exist, and there are many commercial source offerings, too.

Examples of open source RTOSes incorporating an API based on µITRON specification are eCos and RTEMS.

ITRON specification is meant for hard real-time embedded RTOS.

It is very popular in the embedded market, as there are many applications for it, i.e., devices with the OS embedded inside.

For example, there is an ACM Queue interview with Jim Ready, founder of MontaVista (realtime linux company), "Interview with Jim Reddy", April 2003, ACM Queue [1]. He says in the interview, "The single, most successful RTOS in Japan historically is µITRON. This is an indigenous open specification led by Dr. Ken Sakamura of the University of Tokyo. It is an industry standard there." Many Japanese digital cameras, for example, have use ITRON specification OS. Toyota automobile has used ITRON specification OS for engine control.

Supported CPUs are numerous. ARM, MIPS, x86, FR-V and many others including CPUs supported by open source RTOS eCos and RTEMS, both of which include the support for µITRON compatible APIs.

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