A Fault Tolerant Integrated Circuit Memory

Most commercially produced integrated circuits are incapable of tolerating manufacturing defects. The area and function of the circuits is thus limited by the probability of faults occurring within the circuit. This thesis examines techniques for using redundancy in memory circuits to provide fault tolerance and to increase storage capacity. A hierarchical memory architecture using multiple Hamming codes is introduced and analysed to determine its resistance to manufacturing defects. The results of the analysis indicate that substantial yield improvement is possible with relatively modest increases in circuit area. Also, the architecture makes it possible to build larger memory circuits than is economically feasible without redundancy.