| 摘要 |
A method and apparatus is presented for extracting sparse failure information (72) from an error data image (30) of a memory device (20) by scanning the error data image in only two passes. During a first scan pass, the error data image (30) is scanned for failures in a first set of memory cell groups (X[1]..X[M]) organized along a first dimension (x), keeping track of failures seen in each of the respective memory cell groups in the first set, and keeping track of and designating as a must-repair memory cell group any memory cell group whose respective number of failures equals or exceeds a first maximum failure threshold. During a second scan pass, the error data image (30) is scanned for failures in a second set of memory cell groups (Y[1]..Y[N]) organized along a second dimension (y), keeping track of failures seen in each of the respective memory cell groups in the second set, and keeping track of and designating as a must-repair memory cell group any memory cell group whose respective number of failures equals or exceeds a second maximum failure threshold. Tag images (48, 58) containing sparse failure information are generated.
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