I-51-01E-008

ITRON Newsletter No.8
ITRON Technical Committee, TRON Association

Katsuta Building 5F, 3-39, Mita 1-chome, Minato-ku, Tokyo 108, JAPANTEL: (03) 3454-3191
FAX: (03) 3454-3224

Online Distribution of ITRON3.0
Speci cation Begins

For the Name, enter \anonymous," and for Password
enter your E-mail address. Then proceed as follows.
ftp> cd TRON/ITRON/SPEC
ftp> dir

The English-language version of the ITRON3.0 Speci cation is now available online via the Internet. Theearlier ITRON Speci cation (Ver. 2.01.00.00) andITRON2 Speci cation (Ver. 2.02.00.10) have been distributed by this means for some time, but with thecompletion recently of the ITRON3.0 Speci cation
in English, this latest version is now being made available as well.
The speci cations may be downloaded via theInternet from the directory TRON/ITRON/SPECin the machine utsun.s.u-tokyo.ac.jp (IP address:133.11.11.11), using \anonymous ftp." The method
is explained below. An alternative method is to use
a gopher, in which case the server is acrux.is.s.utokyo.ac.jp (IP address: 133.11.14.5).
Consideration is also being made to distributing
these les on a oppy disk, if there is a demand for thisservice. Those interested should contact the TRON
Association. Free distribution of ITRON speci cations applies only to the English-language editions,since the Japanese editions are sold commercially inbookstores.

Here a list of available le names will be displayed.
Enter the le name as follows.
ftp> get [ le name]
The designated le will then be downloaded to yourmachine. For more details on using ftp, refer to themanual for your particular computer model under ftpcommand.

ITRON-related Publications
Listed in another page are the publications preparedand issued by the ITRON Technical Committee as ofApril 1, 1994. The ITRON-ITRON Standard Handbook is a one-volume compilation of ITRON (Ver2.0) and ITRON2 speci cations. Each of the publications can be obtained directly from the sources indicated.
The latest version of ITRON3.0 is now Ver
3.01.00. Changes made since the ITRON3.0 Standard Handbook was released (Ver 3.00.00) are noted
in Newsletter No.5.
The ITRON Standard Guidebook '92-'93 still applies to users of ITRON (Ver 2.0) and ITRON2 speci cations, even though the dates in its title are now
past. When a new edition of the ITRON Standard
Guidebook is issued it will be targeted primarily atthe ITRON3.0 speci cation.

How to use anonymous ftp:

After connecting with the Internet, enter the following
command (this example applies to UNIX).
% ftp utsun.s.u-tokyo.ac.jp

If you get an \unknown host" or similar response, use the IP address 133.11.11.11 insteadof utsun.s.u-tokyo.ac.jp. The following message
should appear on your screen after you connect successfully.

ITRON Q&A
A selection of questions received by the ITRON Technical Committee that are of general interest to users
are taken up below.

Connected to utsun.s.u-tokyo.ac.jp.
220- utsun FTP server (Version 6.4....
220 Welcome to utsun.s.u-tokyo.ac.jp....
Name (utsun.s.u-tokyo.ac.jp: hiro):

Q. When sus tsk is issued for a running task froman interrupt handler, we should expect the stateof that task to be changed from Run to Suspend;
yet in the state transition diagram on p.23 of they This newsletter is reprinted from TRONWARE vol.27 andTRON PROJECT BIMONTHLY No.32.

1I-51-01E-008

ITRON-related Publications
NameTypePricePublisher
ISBN No.
ITRON-ITRON Standard Handbook Speci cation (Japanese)
4,800Yen Personal Media Co. 4-89362-079-7
ITRON3.0 Standard Handbook
Speci cation (Japanese)
4,000Yen Personal Media Co. 4-89362-106-8
ITRON/FILE Standard Handbook
Speci cation (Japanese)
3,000Yen Personal Media Co. 4-89362-092-4
ITRON Standard Guidebook '92-'93
Textbook (Japanese)
3,500Yen Personal Media Co. 4-89362-197-6
ITRON Speci cation Ver 2.01.00.00
Speci cation (English) 12,000Yen TRON Association{ITRON2 Speci cation Ver 2.02.00.10
Speci cation (English) 15,000Yen TRON Association{
ITRON3.0 Speci cation Ver 3.00.00
Speci cation (English){TRON Association{
NOTES:- Prices do not include consumption tax.
- The documents issued by the TRON Association are available to Association members at a special discount rate.

ITRON3.0 Standard Handbook (Japanese) nosuch state transition is indicated.

needs to be noted, however, that the de nition oftask switching time may di er from one manufacturer to another.
The following papers have been presented on thesubject of ITRON performance evaluation.

A. The diagram to which the question refers simply shows the most typical state transitions. Itis quite possible that other transitions will occur
in particular implementations. The transition occurring when sus tsk is issued for a running task
from a task-independent part is an example of astate transition not shown in the diagram.
There are other examples as well. When ter tsk
is issued for a running task, in some implementations the task will go from Run to Dormant
state (when an exit handler is implemented, direct transition to Dormant state is not an ironcladrule); but this transition is not shown.
Because of cases like these, a footnote should beadded to the state transition diagram explainingthat only the most typical transitions are indicated; and in fact this is being planned for thenext edition.

1) H. Monden et al., \A Proposal on ITRON Evaluation," Proceedings of Third TRON Realtime
OS Research Panel (IEICE, Oct. 1987), pp.2-5.
[in Japanese]2) K. Nakata et al., \Performance Evaluation ofMR7700," Proc. of TRON Technical Studies
Conference, Vol.2, No.1 (1989), pp.31-40. [inJapanese]

Free Software
The software introduced below is not sold commercially, so it is not registered with the TRON Association in the ITRON-related product registration service. Instead, it can be obtained free of charge.
Anyone wishing to have their ITRON-related freesoftware introduced in a future Newsletter should contact the ITRON Technical Committee. The committee is now thinking about changing the product registration service to allow the inclusion of free software.

Q. Is there a standard methodology or benchmark
test for evaluating the performance of an ITRONspeci cation OS? Can you suggest any referencematerial on the subject of ITRON performance
evaluation?

Sakamura Laboratory
Faculty of Science, Univ. of Tokyo
ItIs (ITRON Implementation by Sakamura Lab) isa real-time kernel developed for research and educational uses, and conforming to the ITRON speci cations. The present version, called ItIs Phase3, implements the ITRON3.0 Speci cation.

A. The ITRON Technical Committee has not madeavailable any standard methodology or benchmark test for ITRON-speci cation OS performance evaluation. A major reason is the large
di erence in performance requirements of anembedded-system OS depending on the application, making it very dicult to express performance by a uniform measure.
Much of the documentation provided by manufacturers for their ITRON-speci cation OS products
uses task switching time and maximum interrupt
latency as indicators of run-time performance. ItItIs

Outline of ItIs

ItIs implements the ITRON3.0 Speci cation for
TRON-speci cation microprocessors. The current
version implements all the ITRON3.0-speci cation2

I-51-01E-008
functions through Level E, as well as all Level X functions. It also has a number of original extended functions, and connection function support is planned forthe future.
The target systems presently supported include
Personal Media Corporation's MCUBE (Gmicro/300),
the Gmicro SBC (single-board computer) system(Gmicro/200 and Gmicro/300) o ered by the GmicroGroup manufacturers, and Aval Data Corporation's
TVME-150 CPU board (Gmicro/200). It is designed
to be ported easily to other target systems based on
TRON-speci cation microprocessors.

The intention is to have ItIs used as widely as possible so that it can be further improved in the process.
It should also serve as a useful reference for people
who are considering their own independent ITRON
development. Anyone interested in obtaining the ItIs
source code is encouraged to contact the Sakamura
Laboratory in University of Tokyo Faculty of Science.

Recent Works on ITRONThe Proceedings of the TRON Technical Studies Conference, Vol.6 No.1, includes two papers on research relating to ITRON. The rst is on \A Test Data Generator for an ITRON-speci cation OS," by T. Takeuchi
et al. of University of Tokyo. The second paper describes the \Development of an ITRON-speci cation
Real-time OS Simulator on MS-DOS," and is by N.
Kishi et al. of Musashi Institute of Technology.
Two papers on ITRON are likewise included in theproceedings of RTP'94, the 1994 Real-time Processing Workshop, which is Vol.93, No.516 of the IEICEReports. One is by H. Takada et al. of Universityof Tokyo, on \Adaptability and Standardization inthe ITRON Speci cation," which introduces the approach taken in the ITRON speci cation design toreconciling the demands for standardization and exible adaptation to applications and hardware. The
other paper is on \The Evaluation of Silicon TRON
Design," by T. Nakano (Toyota College of Technology) et al. It discusses the e ort to realize the basic
ITRON-speci cation functions as a hardware kernel.

ItIs Features

ItIs has the following features.
 Emphasizes ease of extension and maintenanceInasmuch as the main reason for developing ItIs isfor educational and research uses, the implementation allows for ready extension or alteration.
 Supports two system call interfaces

Both the software interrupt and subroutine calling methods of invoking system functions can beused in the same system.
 Provides original extended functions

Original functions are provided for automatic ID
assignment and for debugging support, etc.
 Geared to the TRON-speci cation CHIP archi-tecture
Full advantage is taken of features in the CHIP
architecture speci c to ITRON.

 Designed for exible recon guration

ItIs is provided as source code, enabling it to becon gured as needed.
 Free software

In addition to ItIs itself, the necessary development environment and tools are available as freesoftware.

Distribution and use

The beta version of ItIs based on the ITRON3.0
Speci cation is being distributed free of charge inJapan. In addition to its use for research purposes inthe Sakamura Laboratory, it is being used as course
material in the SIGBTRON course o ered by PersonalMedia Corporation, as an aid in understanding theITRON-speci cation OS design.
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