Micron Technology Incorporated

Matthew D Jenkinson

Nathaniel J Meier

Dennis G Montierth

Christopher Gordon Wieduwilt

Jiyun Li

Seth A Eichmeyer

Timothy B Cowles

Michael Amiel Shore

Beau D Barry

Adam J Grenzebach

Matthew Alan Prather

A memory device includes a plurality of fuse banks for a memory region. Each fuse bank stores bit information that relates to at least one of a default address for the plurality of fuse banks or an address of a memory cell that is defective. A default address protection circuit is configured to provide a default address status signal indicating whether a fuse bank in the plurality of fuse banks is storing bit information that corresponds to both the default address and an address of a memory cell that is defective. The memory device include a no_match circuit that overrides a repair of the external memory address if the external address matches the default address and if the default address status signal indicates that no fuse bank is storing bit information that corresponds to both the default address and an address of a memory cell that is defective.

Unused redundant enable disturb protection circuit

Methods, systems, and devices for indicating a blocked repair operation are described. A first indication of whether an address of a memory device is valid may be stored. After the first indication is stored, a command for accessing the address may be processed. Based on processing the command, a second indication of whether the address is valid may be obtained, and a determination of whether to perform or prevent a repair operation for repairing the address may be made based on the first indication and the second indication. A third indication of whether the repair operation was performed or prevented may be stored.

Indicating a blocked repair operation

Methods, systems, and devices for error evaluation for a memory system are described. A memory device may be configured to monitor access errors of the memory device to evaluate a likelihood that such errors are related to a failure of the memory device itself or to a failure outside the memory device. For example, a memory device may monitor a respective quantity of errors for each of a set of banks and, if the memory device detects that multiple banks are associated with a threshold quantity of access errors, the memory device may infer the presence of a failure outside the memory device. The memory device may store an indication of such a detection, which may be used to support failure diagnosis or resolution efforts, such as refraining from replacing a memory device when access errors are more likely to be the result of a system failure.

Error evaluation for a memory system

An apparatus may include a refresh control circuit with multiple timing circuits. The timing circuits may be used to control steal rates, e.g., the rate of refresh time slots dedicated to healing victim word lines of row hammers. The timing circuits may be controlled to allow independent adjustment of the steal rates for different victim word lines. Thus, different victim word lines may be refreshed at different rates and the different rates may be independent of one another.

Apparatuses and methods for controlling steal rates

Embodiments of the disclosure are drawn to apparatuses, systems, and methods for dynamic refresh allocation. Memories may be subject to row hammer attacks, where one or more wordlines are repeatedly accessed to cause data degradation in victim rows nearby to the hammered wordlines. A memory may perform background auto-refresh operations, and targeted refresh operations where victim wordlines are refreshed. The memory may monitor access patterns to the memory in order to dynamically allocate the number of targeted refresh operations and auto-refresh operations in a set of refresh operations based on if a hammer attack is occurring and the type of hammer attack which is occurring.

Apparatuses and methods for dynamic refresh allocation

Embodiments of the disclosure are drawn to apparatuses, systems, and methods for lossy row access counting. Row addresses along a to address bus may be sampled. When the row address is sampled it may be compared to a plurality of stored addresses in a data storage unit. If the sampled address matches one of the stored addresses, a count value associated with that address may be updated in a first direction (such as being increased). Periodically, all of the count values may also be updated in a second direction (for example, decreased).

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Boise, ID, United States of America

Matthew D Jenkinson