Oct. 13, 1998
ITRON Technical Committee, TRON Association

JTRON2.0 Specification Released

The ITRON Technical Committee of the TRON Association has released the JTRON2.0 specification, as a standard interface specification for implementing Java runtime environments on an ITRON-specification real-time OS.

The JTRON2.0 specification defines interfaces that make it possible to build application systems taking advantage of both Java and ITRON, in which Java runtime environments are implemented on an ITRON-specification OS, now an industry standard in the embedded systems field. Although this specification is intended mainly for use with an ITRON-specification OS, much of it is usable with other real-time OS architectures as well.

Background and Outline

The field of embedded systems is one more area where Java technology is attracting attention of late. In a Java runtime environment, programs downloaded on a network can be run safely; and Java lends itself readily to creating a graphical user interface (GUI). Despite advantages like these, the overhead for byte code processing and the need for garbage collection make Java less than ideal for real-time systems. An effective approach is to combine the advantages of both, by implementing the Java runtime environment on top of an ITRON-specification kernel. Application systems can then be built by implementing the parts for which Java is best suited as Java programs, and implementing as ITRON tasks the parts that take advantage of the ITRON-specification kernel strengths.

A key issue here is the interface for communication between Java programs and ITRON tasks. These interfaces need to be standardized, or else Java's highly touted portability will be nullified. The JTRON2.0 specification released at this time defines these interface standards. Three interfaces are specified here. The first is the interface by which a Java program accesses ITRON-specification kernel resources (Type 1). The second is the interface for sharing Java objects between a Java program and ITRON task (Type 2), and the third is for stream communication between a Java program and ITRON task (Type 3). Of these, Type 1 is defined in the initial JTRON specification (JTRON1.0 specification) released in December 1997 and is not included in the JTRON2.0 Specification.

As with other ITRON specifications, the JTRON2.0 specification is a fully open specification, which anyone can use freely to develop and market products based on the specification, without paying licensing fees. The entire specification can be downloaded from the URL below (currently available only in Japanese, with an English-language version to be issued in a few months).


Features of the JTRON2.0 Specification

The features of the JTRON2.0 specification can be summarized as follows.

Comments by People related to the Development

Kiichiro Tamaru, who chairs the ITRON Technical Committee: "With the release of the JTRON2.0 specification, a framework has been made available for combining the respective advantages of the ITRON-specification OS and Java runtime environment. I expect this will further the spread and development of both the ITRON specification and Java technology. I'm proud to note that the JTRON2.0 specification is a pioneering step even from an international standpoint, and that the ITRON Technical Committee intends to actively pursue international standardization in this area based on JTRON2.0."

Ryu Koriyama, President of Aplix Corporation, which developed and markets the JBlend OS implementing the JTRON1.0 specification and has broad experience applying Java technology to embedded systems: "Our company has completed development work for implementing the JTRON2.0 specification, and we plan to market this product at the same time as we release our µITRON4.0-specification OS. As a leader in JTRON-specification OS development, we are eager to promote an active marketplace by being the first to put a JTRON-specification OS on the market."

Hiroshi Monden, General Manager of the NEC Software Design Laboratories (NEC is producing the NetJacs industrial network computer which runs a combination of an ITRON-specification OS and Java application environments): "The JTRON2.0 specification gives us a standard method for merging ITRON applications with Java applications, which up to now had to be done on an ad hoc basis. This should lead to greater reusability of Java programs in embedded systems and expand the use of Java in the embedded field."

Future Plans and Promotional Efforts

Minor adjustments to the JTRON2.0 Specification will be made when the next-generation µITRON4.0 kernel specification, now under study by the ITRON Technical Committee, reaches a fixed state. At the same time the Type 1 interface, not included in the present release, will be revised to conform to the µITRON4.0 specification and then incorporated in JTRON2.0.

At the ITRON Specification Seminar held October 14 in Tokyo, the ITRON Technical Committee will give a detailed presentation on the JTRON2.0 specification. Then on November 4 in San Jose, California, the specification will be introduced at an ITRON International Meeting. At these and other seminars and trade fairs in Japan and overseas, a major promotional effort is being aimed at gaining broad acceptance for the JTRON2.0 specification.

For more information, please contact:

Toru Takeuchi
ITRON Technical Committee Secretariat, TRON Association
TEL: 03-3454-3191
FAX: 03-3454-3224
Email: torutake@sepia.ocn.ne.jp

Hiroaki Takada (Lecturer, Toyohashi Univ. of Technology)
Secretary, ITRON Technical Committee
TEL: 0532-44-6752
FAX: 0532-44-6781
Email: hiro@ertl.ics.tut.ac.jp

What Is ITRON?

The ITRON project is dedicated to providing real-time OS specifications for embedded systems, as well as related standard specifications. The µITRON real-time kernel specification, designed for small-scale embedded systems, has been adopted in numerous embedded products, becoming an industry standard in this field. ITRON is a subproject of the TRON Project, and is promoted by the ITRON Technical Committee under the TRON Association. To find out more about ITRON, please visit the ITRON home page at the following URL.


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