Issue No. 06 - June (1978 vol. 27)
D. Davies , Digital Systems Laboratory, Stanford University
Most of the published work on massive redundancy makes one crucial assumption: the redundant modules are synchronized. There are three ways of achieving synchronization in redundant systems-independent accurate clocks, a common external reference, and mutual feedback. The use of a common external reference is currently the most widely used technique, but suffers from vulnerability to common-point failures. We introduce a novel mutual feedback technique, called "synchronization voting," that does not have this drawback. A practical application of synchronization voting is described in the appendix?a fault-tolerant crystal-controlled clock.
voters, Asynchronous networks, clocks, fault-tolerant computing, microcomputers, N-modular redundancy (NMR), signal selection, synchronization, triple modular redundancy (TMR)
D. Davies and J. Wakerly, "Synchronization and Matching in Redundant Systems," in IEEE Transactions on Computers, vol. 27, no. , pp. 531-539, 1978.