Memory device fail summary data reduction for improved redundancy analysis

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 per simultaneously addressable IO bit 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;
• 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 per simultaneously addressable IO bit 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 per simultaneously addressable IO bit and the second tag image indicating memory cell groups of the second set containing failures per simultaneously addressable IO bit, 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.

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, grouping simultaneously addressable IO bits of the respective memory cell groups in the first set into a plurality of first IO bit groups, keeping track of respective numbers of failures per first IO bit group 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, grouping simultaneously addressable IO bits of the respective memory cell groups in the second set into a plurality of second IO bit groups, keeping track of respective numbers of failures per second IO bit group 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.

A computer readable storage medium tangibly embodying program instructions implementing 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.

A system 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 system comprising:

• a processor which scans 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 which scans 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 which generates 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.