Row/column pattern sensitive fault detection in RAMs via built-in self-test

Abstract

Row-pattern-sensitive and column-pattern-sensitive faults in random-access memories (RAMs) are the class of faults in which the contents of a cell are assumed to be sensitive to the contents of the row and column containing the cell. Although the existence of such faults has been argued in the literature, tests to detect such faults have been proposed. The authors formally define a fault model based on the row and column pattern sensitivity. They establish a lower bound on the length of a test sequence required to detect such faults and propose algorithms that generate test sequences of the required length. Although the length of the test sequence is O(N/sup 3/2/), where N is the number of bits in the RAM, the authors believe that the algorithm can be used to test RAMs in built-in self-test environments.<>