International Business Machines Corporation

Charles A Keller

Timothy J Fisher

Aaron Daniel Fry

Adalberto Guillermo Yanes

Kevin E Sallese

Jason Szecheong Ma

Van Huynh

Nikolaos Papandreou

A computer-implemented method, according to one embodiment, includes: receiving a stream of data, and selecting more than one block of memory to write the stream of data to. The selected blocks of memory are in a memory that includes a plurality of blocks. Moreover, the data is written across the selected blocks of memory in parallel. The blocks of memory are also selected such that no two or more of the selected blocks of memory have an effect on a read apparent voltage of a same one of the plurality of blocks in the memory. Other systems, methods, and computer program products are described in additional embodiments.

Reducing effects of read array operations of read apparent voltage

Read Apparent Voltage (RAV) is an anomality in which an apparent threshold voltage of a storage cell transistor does not equal the actual threshold voltage of that same transistor by a large enough magnitude that the binary state of transistor is not read correctly. An infector page may cause the RAV anomality within a different infected page. To determine whether any page is an infector, each page is programmed, a page within each block is read, an acting infector page within an acting infector block is set, a possible infected page within a possible infected block is set, the acting infector page is read a predetermined plurality of instances, the possible infected page is read, a raw bit error rate (RBER) of the read of the possible infected page is determined, and the acting infector page is set as an actual infector page based upon the determined RBER.

Determining a read apparent voltage infector page and infected page

A data storage system includes a non-volatile memory array controlled by a controller that records a number of a plurality of like operations targeting a first block among a plurality of blocks in the non-volatile memory array. In response to the number of the plurality of like operations satisfying a threshold, the controller initiates a mitigation read request by recording an identifier of a second block in a high priority request in a mitigation data structure. The controller initiates other mitigation read requests by recording identifiers of other blocks of the non-volatile memory in low priority requests in the mitigation data structure. The controller preferentially services the high priority request from the mitigation data structure over the low priority requests, where servicing the high priority request includes performing a mitigation read to the second block.

Reducing read errors by performing mitigation reads to blocks of non-volatile memory

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Houston, TX, United States of America

Charles A Keller