Reliability analysis and architecture of a hybrid-redundant digital system: generalized triple modular redundancy with self-repair

The objective to attain fault-tolerant computing has been gaining an increasing amount of attention in the past several years. A digital computer is said to be fault-tolerant when it can carry out its programs correctly in the presence of logic faults, which are defined as any deviations of the logic variables in a computer from the design values. Faults can be either of transient or permanent duration. Their principal causes are: (1) component failures (either permanent or intermitent) in the circuits of the computer, and (2) external interference with the functioning of the computer, such as electric noise or transient variations in power supplies, electromagnetic interference, etc.