Abstract

          Introduction

     The use of embedded systems is becoming more and more widespread globally, in household appliances, in modern cars, virtually at any production enterprise [1]. This shows that a technique of writing an embedded system is currently quite important.

     This thesis will present a technique of writing an embedded system using a concept of a multilayer object-oriented architecture. Further on it will describe the main theory ideas that this technique is based on.

          Object model

     The object-oriented technique is based on an object-oriented model. Its main principles are as follows: abstraction, encapsulation, granularity and hierarchicalness.

     An object is a certain entity characterized by its behavior, state and relations with the other objects. (fig 1).

Figure 1 – object presentation

     The main components of the object-oriented model are the object-oriented analysis, object-oriented design and object-oriented programming (fig 2).

Figure 2 – software development process. The figure is an animation and contains 4 frames, repeats 7 times, has the size of 17.4 KB

     The object-oriented analysis serves as a basis for making the models required for the object-oriented design. The object-oriented design sets up a foundation for the final implementation of the system by means of the object-oriented programming.

          Multilayer architecture of the hardware-software systems

     A multilayer architecture is a division of an application into two or more levels or layers. This approach enables to divide the application into groups of subproblems with their own specific level of abstraction. Generally, it is a good practice to apply this approach for a big system. It is necessary to split the system into some number of layers and position them one relative to another. The first layer will accommodate the most low-level abstractions. This is the basis of the system. The following layers are positioned one after another on an ascending order of the abstractions.

Figure 3 – layer positioning

     Let us assume that the system is split into n layers. Figure 3 shows three layers positioned one relative to another. Layer i provides the services used by layer i + 1, and in its turn it delegates subproblems to layer i - 1. At the same time layer i interacts only with the two layers positioned close to it in the hierarchy. This concept is very convenient as in order to replace ith layer you just need to apply some insignificant changes in the two layers positioned above and lower it in the hierarchy. [3]

     Despite the fact that the splitting concept is a very good solution for the most of the complex systems but it has its drawbacks:

• The layer concept cannot encapsulate all successfully.
• Some redundant layers may occur.

     The most difficult part in implementing the layer concept for an application is an accurate assessment of the content and borders of each layer [4].

          Summary

     This master’s thesis will result in a study on the selected subject and a program written as an example according to a developed technique. The abstract presents a review material on the master’s thesis which gives theory definition and explanation of the suggested technique. It presents general concepts that will assist in developing this technique.

          Bibliography

1. Barr M., Massa A. Programming Embedded Systems. O'Reilly. 2006. - 304 p.
2. Буч Г., Максимчук, и др. Объектно-ориентированный анализ и проектирование с примерами приложений, 3-е изд. Пер.с англ. – М.:ООО “И.Д. Вильямс”, 2008 . – 720 с.: ил. – Парал. тит.англ.
3. Buschmann F., Meunier R., Rohnert H., Sommerlad P., Stal M., Sommerlad P. Pattern-Oriented Software Architecture, Volume 1: A System of Patterns. - US: John Wiley, 1996. - 634 p.
4. Фаулер М., Архитектура корпоративных программных приложений.: Пер. с англ. — М.: Издательский дом "Вильямс", 2006. — 544 с.: ил. — Парал. тит. англ.

     Important:  the master’s thesis had not been finished while writing this abstract. The expected finishing time is December 2009. The complete text of the thesis and the materials on the subject can be obtained from the author or his advisor after the specified date.

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