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2. TRON project
Summary
In 1980, Ken Sakamura proposed the basic concept of TRON (The Real-time Operating system Nucleus) at the committee of JEIDA (Japan Electronic Industry Development Association.) After four years of discussion in the committee, the TRON project started in 1984. The basis of the project was the ITRON (Industrial TRON) sub-project, where new operating system interface specifications with superior real-time characteristics for embedded systems was discussed, decided and made available as "open architecture" for anyone who wanted them.
The development cycle, which consisted of specification planning, implementation to various kinds of processors, and specification refining, was repeated. In this cycle, the specifications and implementation results were made open in order to gather the wisdom of many people. This process led ITRON specifications to become the standard accepted by many people.
In this standardization process, the balance between unification and optimization ability was stressed. For adaptability to a wide-range of processors, from 8 bit to 32 bit, Sakamura carefully conducted the project on the "weak standardization" principle to avoid the over-specification, which degrades the performance in different hardware architecture processors.
In 1988, TRON association was founded in Japan and accelerated the promotion of ITRON specification. Microprocessor manufacturers and other companies moved to implement the embedded-system oriented operating systems based on the decided ITRON specification(1),(2) into various kinds of microprocessors.
Using this ITRON specification, standardization in application software programming has been developed for embedded systems. This standardization has been applied in home electronic products, cellular phones, automobiles, facsimiles and digital cameras and other products.
The TRON association North America Liaison Office has been founded in the United States, and the Korea TRON association was founded in August 2000. These associations are spreading the TRON specification internationally.
TRON project progress
The first version of ITRON specification was distributed in 1987. After considering the results of the implementation of the first version, and views expressed by many people, the next version was divided to two kinds of specifications and both were distributed. One was the ƒÊITRON2.0 specification that was restricted in functionality for smaller microprocessors, and the other was the ITRON2 specification that was designed for larger-scale microprocessors.
The ƒÊITRON3.0 specification that was made available in 1993 was developed to be uniformly applicable to a wide variety of hardware from 8 bit to 32 bit processors, which further accelerated application standardization. Additionally, that version included new specifications for network-linked distributed systems, which enabled ITRON specification to be responsible to the network development.
Utilizing the results of ITRON, other TRON sub-projects(3) have progressed; BTRON for operating systems and related specifications for human-machine interface in PCs or workstations; CTRON for operating systems for communication equipment; and HMI for human-machine interface guidelines applicable to all kinds of embedded systems.
Recently, in 1997, the JTRON specification was made available, which combines ITRON with the Java execution environment that is superior in portability and network transparency. In 1999, the ƒÊITRON4.0 specification was made available, and raises the program compatibility by the "standard profile definition."
Results of TRON implementation
ITRON specification operating systems are available for most kinds of microprocessors in the world. ITRON OS has the largest share in the embedded system in Japan(4), according to the results of the questionnaire to Japanese users by TRON association. From 30% to 40% of embedded systems use ITRON(5). Especially, for home electronic products, 80% of systems in Japan used ITRON in 1999. Recent typical examples of ITRON implementation are the cellular phone by NTT Docomo and the automobile by TOYOTA.
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