| 摘要 |
PROBLEM TO BE SOLVED: To automatically switch a defective memory block to a preliminary memory block by outputting only the data of the memory block at normal operation time, outputting a non-matching signal or a matching signal of correspondent bits for two sets of data at repair operation, generating a fail signal at the non-matching signal output time and counting the number of times of occurrence. SOLUTION: A storage device 50 is provided with a repair terminal 65, and the repair terminal 65 is pulled up by a resistor R0 at non-connection. A memory part of 2N×Q bits is divided to 2N-L pieces of plural memory blocks 11K (k=1-2N-L), and further is provided with two or more preliminary memory blocks 17 m (m=1-2). Non-matching detection circuits 20h, 21 inputting the data from two memory blocks, outputting only the data of a specified address at normal operation times and outputting a signal of whether or not correspondent bit signals of two data are non-matching at repair operation time are arranged.
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