THE RELIABILITY IMPROVING OF COMPUTER SYSTEM ELEMENTS WITH USING MODULAR ENCODING
Authors: Freyman V. I. 
Published: April 2022

Context. Computing systems are implemented in many industries and economies of the modern world. The quality indicators of the systems in which they are used depend on the reliability of their work. The reliability of a computing system consists of the reliability of the construction and functioning of its elements. It is not always possible to ensure reliability in the design by choosing a high-quality element base, structural redundancy, or other well-known methods. Therefore, important and critical elements of computing systems are protected by built-in control schemes. They allow you to detect errors that occur when performing basic data operations. An effective way of constructing such circuits is to use actions on the remainder of the division of the operands by a selected module or by several modules (modular coding). Especially the task of choosing the most accurate and least redundant means of control is relevant for a wide range of basic elements of modern computing systems.

Objective. The aim of the work is research and development of recommendations on the use of modular coding to improve the reliability of the functioning of elements of modern computing systems in various hardware and software basis.

Methods. A method for numerical control of the correctness of performing basic arithmetic and logical operations by computing devices is selected and analyzed. On its basis, a schematic model of a computing system was built and verified in the MatLab Simulink environment, which uses modular coding as a means of ensuring the reliability of the functioning of elements. The analysis of the probabilistic characteristics of decision-making is carried out, estimates of the probability of an erroneous decision-making are given. A software implementation of the simulation algorithm in the Visual Basic for Applications environment has been created, which made it possible to plot the dependence of reliability indicators on coding parameters.

Results. A schematic model of a computing system has been developed. It allows study various combinations of faults in the functioning of elements and errors in their operations. An algorithm for simulating all kinds of malfunctions and errors in the functioning of elements of computing systems when they perform basic operations is implemented in software. The qualitative dependences of the probabilistic characteristics of reliability on the coding parameters are determined. Based on the analysis of the characteristics obtained, conclusions are drawn and practical recommendations are given on the use of modular coding in the elements of computing systems in order to achieve the specified reliability indicators.

Conclusions. To improve the reliability of the functioning of the elements of computing systems, it is effective to use built-in control schemes using modular coding. Taking into account the recommendations for choosing the parameters of the codes will ensure the required reliability with minimal redundancy of circuits and the computational complexity of the calculation algorithms.