Design of self-checking and fault-tolerant microprogrammed controllers

A realization of a self-checking and fail-safe programmable controller which uses a new control memory organization to give a simple and elegant implementation is described. Using this self-checking controller as an example, a new approach to fault-tolerant design referred to as Dual-Fail-Safe (DFS) is presented which utilizes two self-checking modules. The resulting fault-tolerant system is shown to be less costly and significantly more reliable than a conventional Triple-Modular-Redundancy (TMR) system.