Abstract: Aspects of the disclosure provide a method and an apparatus that perform a background media scan (BGMS) with improved efficiency. In particular, the disclosed BGMS processes can monitor data retention performance of a large capacity solid state drive (SSD) without significantly increasing scanning overhead by scanning only some sample pages of a memory block.

Abstract: A soft information module is coupled between one or more flash memory devices and a decoder. The soft information module receives a putative value of one or more memory cells of the one or more flash memory devices based on a read of the one or more memory cells at an initial read level, and one or more respective indicators of whether the putative value was read at one or more respective different read levels offset from the initial read level, and receives a page indicator for the read. The soft information module determines a cell program region for the read based on the putative value, the one or more respective indicators, and the page indicator, identifies a predetermined confidence value for the region, and provides the confidence value to the decoder for association with the putative value, the confidence value being representative of a likelihood that the one or more memory cells was programmed to the putative value.

Abstract: A plurality of flash memory wordlines of a flash storage device are divided into a plurality of wordline groups based on read error counts associated with the wordlines and a plurality of read level offsets. Each wordline group is associated with one of a plurality of read level offsets determined while dividing the plurality of flash memory wordlines, and associations between the plurality of read level offsets and the plurality of wordline groups are stored for use in connection with read levels to read the flash memory wordlines of the respective wordline groups.

Abstract: A device that provides for adaptive wear levelling includes at least one processor. The at least one processor utilizes sets of blocks of flash memory circuits for data storage operations, each set of blocks including a block from each flash memory circuit and at least some of the blocks being marked active for the data storage operations. The at least one processor monitors a quality metric of each block while the blocks marked active are utilized for data storage operations. The at least one processor determines when the quality metric of a block falls below a minimum level and marks the block as temporarily inactive, where the block is not utilized for the data storage operations while marked temporarily inactive. The at least one processor, when a criterion is satisfied, marks the block as active so that the block can again be utilized for the data storage operations.

Abstract: A soft information module is coupled between one or more flash memory devices and a decoder. The soft information module receives a putative value of one or more memory cells of the one or more flash memory devices based on a read of the one or more memory cells at an initial read level, and one or more respective indicators of whether the putative value was read at one or more respective different read levels offset from the initial read level, and receives a page indicator for the read. The soft information module determines a cell program region for the read based on the putative value, the one or more respective indicators, and the page indicator, identifies a predetermined confidence value for the region, and provides the confidence value to the decoder for association with the putative value, the confidence value being representative of a likelihood that the one or more memory cells was programmed to the putative value.

Abstract: A device that provides for redundancy of error correction encoded data includes at least one processor circuit. The at least one processor circuit is configured to perform error correction encoding on data items to generate corresponding codewords, where at least one of the data items may have a different length than at least one other of the data items and each of the codewords is the same length. The at least one processor circuit is further configured to generate a redundancy data item based at least in part on the codewords. The at least one processor circuit is further configured to write the codewords and the redundancy data item to separate blocks of at least one flash memory circuit.

Abstract: After a predetermined period of time in a life cycle of a flash memory device, a plurality of reliability values corresponding to a plurality of reads of one or more of the plurality of memory cells are generated; each of the reads using a variation of a predetermined read level voltage. An offset voltage is then identified, offset from the read level voltage. The offset voltage corresponds to a zero crossing point in the range of the reliability values. Once the offset voltage is identified, the read level voltage is set to a calibrated voltage based on the offset voltage.

Abstract: A table of error counts is generated based on reading wordlines of a flash memory device, the table storing an error count for each combination of wordline and respective read level voltage used to read the wordlines. A plurality of offset wordline groups are generated based on the table of error counts, with each group associating a different read level offset voltage with a plurality of wordline addresses. A storage device is configured to read memory cells using a read level offset voltage of a generated offset wordline group associated with a wordline address of the memory cells to be read. After a predetermined point in a life cycle of a respective memory block, the table is regenerated and plurality of offset wordline groups are regenerated based the regenerated table of error counts.

Abstract: A plurality of flash memory wordlines of a flash storage device are divided into a plurality of wordline groups based on read error counts associated with the wordlines and a plurality of read level offsets. Each wordline group is associated with one of a plurality of read level offsets determined while dividing the plurality of flash memory wordlines, and associations between the plurality of read level offsets and the plurality of wordline groups are stored for use in connection with read levels to read the flash memory wordlines of the respective wordline groups.

Abstract: After a predetermined period of time in a life cycle of a flash memory device, a plurality of reliability values corresponding to a plurality of reads of one or more of the plurality of memory cells are generated; each of the reads using a variation of a predetermined read level voltage. An offset voltage is then identified, offset from the read level voltage. The offset voltage corresponds to a zero crossing point in the range of the reliability values. Once the offset voltage is identified, the read level voltage is set to a calibrated voltage based on the offset voltage.

Abstract: Methods for writing multiple codewords having multiple sizes to a solid-state device are provided. In one aspect, a method includes receiving a plurality of host data units for storage in a solid-state non-volatile memory. The method includes dividing the plurality of host data units among a plurality of data payloads, wherein a first data payload comprises a first host data unit and a second data payload comprises a portion of a second host data unit. The method includes encoding the first data payload into a first codeword having a first codeword size. The method includes encoding the second data payload into a second codeword having a second codeword size, the second codeword size being different from the first codeword size. The method includes writing the first codeword and the second codeword to a first page in the solid-state non-volatile memory. Systems and machine-readable media are also provided.

Abstract: Decoding logic is provided that is operational upon a data buffer to represent a plurality of variable nodes and a plurality of check nodes. For a respective one of the variable nodes, a vector component is selected from a confidence vector associated with the variable node. Using a respective one of the check nodes, a check node return value is calculated based on one or more other vector components from one or more other vectors and one or more vector indices corresponding to the one or more other vector components. The confidence vector is then updated based on the check node return value and an index for the check node return value, and a current state of a memory cell associated with the respective one of the variable nodes is determined based on a location of a primary one of multiple vector components within the updated confidence vector.

Abstract: A plurality of flash memory wordlines of a flash storage device are divided into a plurality of wordline groups based on read error counts associated with the wordlines and a plurality of read level offsets. Each wordline group is associated with one of a plurality of read level offsets determined while dividing the plurality of flash memory wordlines, and associations between the plurality of read level offsets and the plurality of wordline groups are stored for use in connection with read levels to read the flash memory wordlines of the respective wordline groups.

Abstract: A table of error counts is generated based on reading wordlines of a flash memory device, the table storing an error count for each combination of wordline and respective read level voltage used to read the wordlines. A plurality of offset wordline groups are generated based on the table of error counts, with each group associating a different read level offset voltage with a plurality of wordline addresses. A storage device is configured to read memory cells using a read level offset voltage of a generated offset wordline group associated with a wordline address of the memory cells to be read. After a predetermined point in a life cycle of a respective memory block, the table is regenerated and plurality of offset wordline groups are regenerated based the regenerated table of error counts.

Abstract: After a predetermined period of time in a life cycle of a flash memory device, a plurality of reliability values corresponding to a plurality of reads of one or more of the plurality of memory cells are generated; each of the reads using a variation of a predetermined read level voltage. An offset voltage is then identified, offset from the read level voltage. The offset voltage corresponds to a zero crossing point in the range of the reliability values. Once the offset voltage is identified, the read level voltage is set to a calibrated voltage based on the offset voltage.

Abstract: Read signals are obtained from memory cells, and a first read signal and a second read signal are identified, from among the plurality of read signals. The first read signal is associated with a first memory cell in a first word line and the second read signal is associated with a second memory cell in a second word line, and the second word line is adjacent to the first word line. An output for the first memory cell is generated, wherein the output is based on the first and the second read signals.

Abstract: Methods for writing multiple codewords having multiple sizes to a solid-state device are provided. In one aspect, a method includes receiving a plurality of host data units for storage in a solid-state non-volatile memory. The method includes dividing the plurality of host data units among a plurality of data payloads, wherein a first data payload comprises a first host data unit and a second data payload comprises a portion of a second host data unit. The method includes encoding the first data payload into a first codeword having a first codeword size. The method includes encoding the second data payload into a second codeword having a second codeword size, the second codeword size being different from the first codeword size. The method includes writing the first codeword and the second codeword to a first page in the solid-state non-volatile memory. Systems and machine-readable media are also provided.

Abstract: A soft information module is coupled between one or more flash memory devices and a decoder. The soft information module receives a putative value of one or more memory cells of the one or more flash memory devices based on a read of the one or more memory cells at an initial read level, and one or more respective indicators of whether the putative value was read at one or more respective different read levels offset from the initial read level, and receives a page indicator for the read. The soft information module determines a cell program region for the read based on the putative value, the one or more respective indicators, and the page indicator, identifies a predetermined confidence value for the region, and provides the confidence value to the decoder for association with the putative value, the confidence value being representative of a likelihood that the one or more memory cells was programmed to the putative value.

Abstract: Read signals are obtained from memory cells, and a first read signal and a second read signal are identified, from among the plurality of read signals. The first read signal is associated with a first memory cell in a first word line and the second read signal is associated with a second memory cell in a second word line, and the second word line is adjacent to the first word line. An output for the first memory cell is generated, wherein the output is based on the first and the second read signals.

Abstract: Aspects of the subject technology relate to a method for reading information stored in a flash memory device. In some implementations, the method can include steps including, obtaining a first read signal of a first cell, wherein the first cell is located in a first word line and in a first bit line in the flash memory device, obtaining a programming level of a second cell, wherein the second cell is located in a second word line and in the first bit line, and wherein the second word line is adjacent to the first word line. In certain aspects, the method may further comprise steps for obtaining decoding information for the first cell based on the programming level of the second cell, wherein the decoding information is derived from a first set of reference voltage distributions corresponding to the obtained programming level of the second cell. A data storage system and a non-transitory machine readable storage medium are also provided.