Patent ID: 7444566

Claim:
A method for extracting repair information from an error data image of a memory device, the error data image comprising corresponding error data for each of a plurality of memory cells organized into a plurality of memory cell groups along a plurality of dimensions of the memory device, each memory cell group addressable by one of a plurality of address components corresponding to one of the plurality of dimensions, the error data image comprising a plurality of bits each bit corresponding to a different one of the memory cells in the memory device and having a value indicating whether or not the corresponding memory cell is defective, the method comprising: scanning the error data image for failures in a first set of memory cell groups organized along a first dimension between a selected set of addresses, keeping track of respective numbers 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; and scanning the error data image for failures in a second set of memory cell groups organized along a second dimension between the selected set of addresses, keeping track of respective numbers 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; and generating one or both of a first tag image associated with memory cell groups of the first set and a second tag image associated with memory cell groups of the second set, the first tag image indicating memory cells of the first set containing failures and the second tag image indicating memory cell groups of the second set containing failures, wherein at least one of the first tag image and the second tag image exclude indication of failures in designated must-repair memory cell groups of the corresponding set.