CHOICE OF CODE FOR DETECTING ERRORS IN BACKUP CHANNELS OF A DUPLICATED COMPUTER

Abstract

An analysis of operation and selection of reliability indicators for specialized computers (SEVMs) of aerospace equipment was carried out. The requirements for the methods of redundant computer systems are formulated. A comparative evaluation of the detecting ability and hardware costs in the implementation of the majority method of redundancy, the method of duplication and the use of corrective codes is carried out. The expediency of using the duplication method to increase the probability of failure-free operation and survivability of self-healing digital computers, using algebraic linear codes, to identify a faulty backup channel is substantiated. Unlike the known codes, it is proposed to use an algebraic linear code, in which the values of the check bits correspond to the direct and inverse values of the information bits, which makes it possible to detect errors when reading information from the inverse outputs of the memory, correct single errors, detect double errors and control the logical operation of inverting required to represent a negative number in an additional code, which makes it possible to adapt the code to control the arithmetic and logical operations of the computer processor. The evaluation of the probability of failure-free operation of a duplicated computer, with its general redundancy, with the detection and correction of single errors in the backup memory channels and the detection of errors in the backup channels of the processor ALU based on the proposed code, and the assessment of the probability of failure-free operation of the computer, with its separate redundancy, with error detection in the backup channels of the duplicated memory based on the Hamming code and error correction in the backup channels of the processor ALU based on the majority method. As a result of comparing the probabilities of failure-free operation, it has been established that the total reservation of the computer based on the proposed code, in comparison with the separate reservation of the memory and ALU of the processor of the computer, makes it possible to provide a gain in the probability of failure-free operation of the computer and its functional units throughout the entire period of operation.