Evaluation of Applicability of Highly reliable Duplex Systems that employ Fault-tolerant Microprocessors.
We evaluated the functions and the performance of a highly reliable system which is the tightly-coupled duplex system made up of two microprocessors, the GMICRO/100 and the G100FTS (GMICRO/100 for Fault-Tolerant System) which is a fault tolerant microprocessor.During normal operation mode, normal processing of data transfer and further more, processing for recovery from a transient fault and a permanent fault as well as maintenance of processing continuity have been confirmed.It has been demonstrated that this system enables us to obtain high reliability. On the other hand, it was revealed that the average performance of numerical calculation and data transfer of this system was 69 to 75 % that of a simplex system. From this result, it was found that when the duplex system is to be applied to an application system that requires real time operations, it is necessary to recognize in advance the relationship between the tolerable maximum response time and the feasible fault-tolerant function of the application system.