T. Zimmer, P. Kadionik, Y. Danto - Université Bordeaux I
Laboratoire de Microélectronique IXL, 351, cours de la Libération, 33405 TALENCE Cedex, France
Tel: (33) 5 56 84 65 40, Fax : (33) 5 56 37 15 45
zimmer@ixl.u-bordeaux.fr

Abstract

This paper proposes a new and original way to integrate training in the use of advanced measurement equipment into education at University level. It uses some features of the WWW such as the accessibility of multimedia documents, the simplicity of HTML syntax and particularly the Web's networked structure. The basic idea is that, on one side there is an instrumentation pool, i.e. a number of instruments located anywhere in the world, on the other side, a detailed description of the instrument and its front panel are available on the Web and can be accessed by any Web browser for a specific declared usergroup. This link permits students to learn how to use advanced measurement equipment and to perform real measurements with instruments not available at their University.

Introduction

The testing of devices and VLSI Systems is a fundamental step in process development, devices and system characterisation, process monitoring, reliability investigation and failure analysis. For electrical tests, a certain class of instruments is widely used, e.g. VLSI characterisation systems, semiconductor parameter analysers, network analysers, digital oscilloscopes, function generators and spectrum analysers.

Training courses in the use of this equipment for students of microelectronics would be desirable, but are not always possible because of the high cost involved. The high price of these instruments (e.g. $100 000 for a network analyser) is a huge disadvantage, because standard university training course concepts cannot be applied. Not only is the acquisition of these instruments solely for teaching purposes too expensive, the equipment would also be out of date in a matter of years. The typical lifetime of a university training course is about 10-15 years, which is not compatible with the rapid evolution of microelectronics.

Another approach is presented, based on the use of the WWW. It is addressed especially to students who need good practical expertise of advanced industrial equipment in electronics.

The new concept

In every lab advanced instruments are available and often not used at 100%. Often not all classes of instruments are available. Generally every site specialises in a well defined topic like telecommunications, ASICs, assemblies, VLSI design, etc., but students need access to a wide class of instruments to get the best possible education. To overcome this drawback we propose a new concept where measurements and instruments are geographically separated. On one side there is an instrumentation pool, i.e. a number of instruments located anywhere in the world. This pool is composed of contributions from each lab; making it as complete as possible.

The measurement instruments have to be equipped with the GPIB IEEE-488 interface (General Purpose Interface Bus) for remote control ability. In each lab the instruments are controlled by a server application executed from a workstation which is connected to the local ethernet. This application will exchange information with the official lab server. The principal instrument functions and its front panel are presented on a Web page written in HTML (HyperText Mark-up Language), the graphical part has been implemented by 'applets' written in Java (Kadionik et al, 1997).

On the other side, you will find the Internet browser which can interact with the instrument via the Web page. Only authorised persons have permission to use this Internet instrumentation service. The identification mechanism is executed by the WWW server of the lab concerned to giving access to certain special Web pages. After identification it is possible to use the instruments and to make real measurements.

Implementation

Figure 1 shows the necessary structure to add an instrument to the instrumentation pool.

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Figure 1 : Retwine (REmote World-Wide Instrumentation NEtwork) project implementation

In your lab you must have a workstation on which a local programme for measurements is installed, driving the GPIB card which is connected via the IEEE-488 interface to one or more instruments. To drive the GPIB card a special server application has to be developed. This application can be written in the C-language in an UNIX environment, which permits standard access to Internet protocols. You also need a WWW server (CERN, NSCA or Apache); this can be installed on the same workstation provided that it has access to the Internet or on a second dedicated workstation. The latter presents a better solution due to administration and security reasons. The next step is to develop the HTML pages where the principal control functions of each instrument are defined. The graphical representation of its front panel can be implemented in a Java applet. There are two possibilities for interaction between the server application and the client. You can use the HTML request << GET >> and << POST >> or you can execute the command by distance with Java applets using the Internet 'socket' mechanism. To do this you have to develop CGI (Common Gateway Interface) scripts for the user parameter control and to execute the server application concerning the instrument control.

We have chosen the UNIX environment to develop easily, in an homogenous way, all the different kinds of programmes which are necessary to build up the virtual instrument pool: the server application for the instrument control is written in the C-language, the CGI scripts are written in a UNIX 'Shell script', the applets are written in Java and the Web page are written in HTML. Figure 2 presents the interaction between the different programmes.

An identification mechanism is installed to control the access to certain special Web pages. The identification is performed through a password control. An independent database is generally available on the WWW server to manage the passwords.

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Figure 2 : Interaction between the different programmes

Examples

We are actually implementing the system described in figure 1. The instrument used is the well known HP4194A Impedance/Gain Phase analyser. Figure 3 shows the front panel of this instrument.

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Figure 3 : Front panel of HP 4194 instrument

The corresponding Web page address is http://www.ixl.u-bordeaux.fr/retwine.html, where retwine stands for REmote World-Wide Instrumentation NEtwork.

Training on the Web

This training course is designed especially for students who need good practical expertise of advanced industrial equipment in electronics. The task consists of a detailed investigation of the functionality, performances and limits of an advanced analysis system for microelectronics fields.

The work is divided into two phases :
First, an investigation is based on literature about the instrument, (i.e. user's manual, courses manuals which should be available on the net etc.) and consists in highlighting the following points :