The method of software reliability increasing for the microprocessors with multi-byte command system

Abstract

Abstract The article considers an original way of software reliability improvement of microprocessor systems with multi-byte command system in case of errors due to accidental failure while execution of the program. Program running errors (control flow errors) mean a discrepancy in the sequence of command codes executed by the microprocessor after the failure occurrence, with the working sequence of commands. The method is based on the preliminary marking of the program memory codes with the help of an additional parity/odd bit and the formation of the signal of the command code reading by microprocessor when accessing the program memory. The article proposes the analytical relations to predict the probability of detection of control flow errors for CISC-processors with any multibyte system of commands based on statistics of commands of different byteness which is contained in the code of the executable program. Along with the detection of control flow errors, all odd errors are also detected while reading the content of any program memory cell.