State-of-the-Art Assessment of Testing and Testability of Custom LSI/VLSI Circuits. Volume VI. Redundancy, Testing Circuits, and Codes.

The demands for higher system reliability and self checking required by the new fault tolerant computers have put new emphais on the use of the redundant circuits. Types of redundancy include parallel, triple modular redundancy, Quadd, standby, hybrid and software. Various computers employing one or more of these types are discussed. Generally, hardware, software and time redundancy required for error detection and correltion, are interrelated. Mathematical modleing, when applied to fault tolerant systems, can be used to measure the system reliability.