Abstract: Decoding associated with a second error correction code and a first error correction code is performed. Ns first and second-corrected segments of data, first sets of parity information, and second sets of parity information are intersegment interleaved to obtain intersegment interleaved data, where the Ns segments of data, the Ns first sets of parity information, and the Ns second sets of parity information have had decoding associated with the first and the second error correction code performed on them (Ns is the number of segments interleaved together). Decoding associated with a third error correction code is performed on the intersegment interleaved data and interleaved parity information to obtain at least third-corrected interleaved data. The third-corrected interleaved data is de-interleaved.

Abstract: A plurality of partially-decoded codewords that have been processed at least once by a first and a second error correction decoder is stored. A plurality of metrics associated with how close a corresponding partially-decoded codeword is to being successfully decoded is stored. From the plurality of partially-decoded codewords, a codeword having a metric indicating that that codeword is the closest to being successfully decoded by the first error correction decoder and the second error correction decoder is selected. The selected codeword is output to the first error correction decoder.

Abstract: A starting read threshold is received. A first offset and a second offset is determined. A first read is performed at the starting read threshold offset by the first offset to obtain a first hard read value and a second read is performed at the starting read threshold offset by the second offset to obtain a second hard read value. A soft read value is generated based at least in part on the first hard read value and the second hard read value.

Abstract: A first bit position of a cell in solid state storage is read where a sorting bit is obtained using the read of the first bit position. A second bit position of the cell is read for a first time, including by setting a first read threshold associated with the second bit position to a first value and setting a second read threshold associated with the second bit position to a second value. The second bit position of the cell is read for a second time, including by setting the first read threshold to a third value and setting the second read threshold to a fourth value. A new value for the first read threshold and for the second read threshold is generated using the sorting bit, the first read, and the second read.

Abstract: A system and method for determining soft read data for a group of cells in a nonvolatile flash memory are disclosed. An expected value representative of a plurality of stored values in a group of cells is obtained. A measured value representative of the plurality of stored values in the group of cells is obtained, based on a single read to the group of cells. A soft read data for the group of cells is determined based at least in part on the expected value and the measured value. The expected and measured values may include at least one of a number of 0s, a number of 1s, a ratio of 0s to 1s or a ratio of 1s to 0s. A reliability for a bit i may be obtained using a one-step majority logic decoder, and a threshold reliability may be used when determining the soft read data.

Abstract: A first message, associated with going from one of a plurality of variable nodes to one of a plurality of check nodes is computed, wherein: (1) one or more connections between the plurality of variable nodes and the plurality of check nodes are specified by an LDPC parity check matrix and (2) a scaling constant is used to compute the first message. A second message, associated with going from one of the plurality of check nodes to one of a plurality of variable nodes, is computed, wherein the scaling constant is not used to compute the second message.

Abstract: It is determined that a read count has reached one of a set of read count thresholds. An initial test page which corresponds to the read count threshold that has been reached is selected from a set of initial test pages. There is at least one page that is not in the set of initial test pages and is victimized by an offending page that also victimizes a page in the set of initial test pages. A test read is performed on the selected test page and the results of the test read of the selected test page are evaluated for read disturb noise.

Abstract: Turbo equalization is performing by using a soft output detector to perform decoding. At least a portion of a local iteration of decoding is performed using a soft output decoder. A metric associated with decoding progress is generated and it is determined whether to perform another local iteration of decoding based at least in part on the metric.

Abstract: A victim group of one or more cells is read using a first read threshold to obtain a first raw read which includes one or more values. The victim group of cells is read using a second read threshold to obtain a second raw read which includes one or more values. A neighboring read, corresponding to a neighboring group of one or more cells associated with the victim group of cells, is obtained. A composite read is generated, including by selecting from at least the first raw read and the second raw read based at least in part on the neighboring read.

Abstract: A read back bit sequence and charge constraint information are obtained. A lower bound on a number of bit errors associated with the read back bit sequence is determined based at least in part on the read back bit sequence and the charge constraint information. The lower bound and an error correction capability threshold associated with an error correction decoder are compared. In the event the lower bound is greater than or equal to the error correction capability threshold, an error correction decoding failure is predicted and in response to the prediction a component is configured to save power.

Abstract: A first read threshold associated with a first page in a block and a second read threshold associated with a second page in the block are received, where the first page has a first page number and the second page has a second page number. A slope and a y intercept are determined based at least in part on the first read threshold, the second read threshold, the first page number, and the second page number. The slope and the y intercept are stored with a block identifier associated with the block.

Abstract: It is decided whether to adjust data associated with a decoder. In the event it is decided to adjust the data associated with the decoder, the data is adjusted to obtain adjusted data and decoding is performed on the adjusted data. In the event it is decided to not adjust the data associated with the decoder, decoding is performed on the data associated with the decoder.

Abstract: A read is performed using a first iteration of a read threshold voltage that is set to a default voltage to obtain a first characteristic. A second iteration of the read threshold voltage is generated using the default voltage and an offset. A read is performed using the second iteration of the read threshold voltage to obtain a second characteristic. A third iteration of the read threshold voltage is generated using the first and second characteristics. A read is performed using the third iteration of the read threshold voltage to obtain a third characteristic. It is determined if the third characteristic is one of the two characteristics closest to a stored characteristic. If so, a fourth iteration of the read threshold voltage is generated using the two closest characteristics.

Abstract: A method for detecting a defect in a portion of a storage device is disclosed. Reference data and data read from the portion are compared to determine a number of error bits and a number of error symbols. An error ratio is computed, wherein the error ratio comprises a ratio of the number of error bits to the number of error symbols. A defect is detected based on whether the error ratio exceeds a threshold. In some embodiments, the reference data and the read data are compared to determine an error vector, wherein a bit in the error vector with a value one indicates a bit error in the read data. For each of a plurality of windows of the error vector, a corresponding number of error bits is determined. A defect is detected based on whether any of the numbers of error bits exceeds a threshold.

Abstract: A first read threshold associated with a first page in a block and a second read threshold associated with a second page in the block are received, where the first page has a first page number and the second page has a second page number. A slope and a y intercept are determined based at least in part on the first read threshold, the second read threshold, the first page number, and the second page number. The slope and the y intercept are stored with a block identifier associated with the block.

Abstract: A first bit position of a cell in solid state storage is read where a sorting bit is obtained using the read of the first bit position. A second bit position of the cell is read for a first time, including by setting a first read threshold associated with the second bit position to a first value and setting a second read threshold associated with the second bit position to a second value. The second bit position of the cell is read for a second time, including by setting the first read threshold to a third value and setting the second read threshold to a fourth value. A new value for the first read threshold and for the second read threshold is generated using the sorting bit, the first read, and the second read.

Abstract: Second interleaved data is de-interleaved using a second interleaving mapping to obtain encoded data. The second interleaved data includes a copy of constrained data in the same sequence and having the same values as the constrained data. Also, the portion of the second interleaved data that includes the copy of the constrained data satisfies a modulation constraint associated with limiting a number of consecutive events to a maximum number of consecutive events. The encoded data is decoded to obtain first interleaved data and the first interleaved data is de-interleaved using a first interleaving mapping to obtain the constrained data, a copy of which is included in the second interleaved data, where the constrained data satisfies the modulation constraint.

Abstract: A method for preparing high purity ammonia is provided, which comprises the following three steps of: (1) obtaining the required feed gases (i.e., hydrogen-nitrogen gas mixture) by catalytic cracking ammonia; (2) purifying the hydrogen-nitrogen gas mixture; and (3) synthesizing high purity ammonia by using the hydrogen- nitrogen gas mixture with high purity. In the provided method, the obtained ammonia with undesired purity is fed back to an ammonia catalytic cracking unit. The whole production system is a closed system without any discharging of ammonia and thus is environment friendly. Each step of the method can reduce cost.

Abstract: A soft output detector is programmed with a first set of parameters. Soft information is generated according to the first set of parameters, including likelihood information that spans a maximum likelihood range. Error correction decoding is performed on the soft information generated according to the first set of parameters. In the event decoding is unsuccessful, the soft output detector is programmed with a second set of parameters, soft information according is generated to the second set of parameters (including likelihood information that is scaled down from the maximum likelihood range), and error correction decoding is performed on the soft information generated according to the second set of parameters.

Abstract: A plurality of partially-decoded codewords that have been processed at least once by a first and a second error correction decoder is stored. A plurality of metrics associated with how close a corresponding partially-decoded codeword is to being successfully decoded is stored. From the plurality of partially-decoded codewords, a codeword having a metric indicating that that codeword is the closest to being successfully decoded by the first error correction decoder and the second error correction decoder is selected. The selected codeword is output to the first error correction decoder.