Unformatted text preview: Introduction 21 can be influenced by the contents of its neighboring cells, referred to as a pattern sensitivity fault . A coupling fault results when a transition in one cell causes the content of another cell to change. Therefore, it is necessary when testing memories to add tests for pattern sensitivity and coupling faults in addition to stuck-at faults. Extensive work has been done on memory testing and many memory test algorithms have been proposed [van de Goor 1991] [Bushnell 2000]. One of the most efficient RAM test algorithms, in terms of test time and fault detection capability, currently in use is the March LR algorithm illustrated in Table 1.4. This algorithm has a test time on the order of 16 N , where N is the number of address locations, and is capable of detecting pattern sensitivity faults, intra-word coupling faults, and bridging faults in the RAM. For word-oriented memories, a background data sequence (BDS) must be added to detect faults within each word of the memory. The March LRmust be added to detect faults within each word of the memory....
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- Spring '08