Most memory test algorithms are optimized tests for a particular memory technology and a particular set of fault models, under the assumption that the memory is bit-oriented; i.e., read and write operations affect only a single bit in the memory. Traditionally, word-oriented memories have been tested by repeated application of a test for bit-oriented memories whereby a different data background (which depends on the used intra-word fault model) is used during each iteration. This results in time inefficiencies and limited fault coverage. A new approach for testing word-oriented memories is presented, distinguishing between inter-word and intra-word faults and allowing for a systematic way of converting tests for bit-oriented memories to tests for word-oriented memories. The conversion consists of concatenating the bit-oriented test for inter-word faultswith a test for intra-word faults. This approach results in more efficient tests with complete coverage of the targeted faults. Because most memories have an external data path which is wider than one bit, word-oriented memory tests are very important.

In this paper a set of fault models for coupling faults between the cells of a word has been established, together with tests for these fault models. Thereafter, a systematic way of converting tests for bit-oriented memories into tests for word-oriented memories is presented, distinguishing between inter-word and intra-word faults. This results in more efficient tests with complete coverage of the targeted faults. Because most memories have an external data path which is wider than one bit, word-oriented memory tests are very important.

Abstract-Most memory test algorithms are optimized for a particular memory technology and a particular set of fault models, under the assumption that the memory is bit-oriented, i.e., read and write operations affect only a single bit in the memory. Traditionally, word-oriented memories have been tested by repeated application of a test for bit-oriented memories, whereby a different data background is used during each application. This results in time inefficiencies and limited fault coverage. A systematic way of converting tests for bit-oriented memories into tests for word-oriented memories is presented, distinguishing between interword and intraword faults. The conversion consists of concatenating to the test for interword faults, a test for intraword faults. This approach results in more efficient tests with complete coverage of the targeted faults. Word-oriented memory tests are very important, because most memories have an external data path which is wider than one bit.

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