Abstract: A memory card includes: a plurality of memory cells; a CPU core; and an ECC unit configured to perform soft decision decoding. If decoding based on an LLR acquired from a first LLR table fails, the memory card measures a threshold voltage distribution centered on a first HB read voltage with a highest voltage. If a first shift value as a difference between a least frequent voltage of the threshold voltage distribution and the first HB read voltage is “negative”, the memory card performs decoding based on an LLR acquired from the second LLR table. If the first shift value is “positive”, the memory card performs decoding based on an LLR acquired from a third LLR table.

Abstract: A memory card decodes three bits of data stored in one memory cell and belonging to different pages, each being a unit of reading, by iterative calculation using probability based on eight threshold voltage distributions. The memory card includes a word line controlling section configured to select one required to read 1-bit data belonging to one of the pages to be read from among seven voltage sets which are composed of seven reference voltages for hard bit reading and a plurality of intermediate voltages for soft bit reading and perform control to apply the voltages of the selected voltage set as read voltages to the memory cell, a log likelihood ratio table storing section, and a decoder configured to decode read data using a log likelihood ratio.

Abstract: A memory card decodes three bits of data stored in one memory cell and belonging to different pages, each being a unit of reading, by iterative calculation using probability based on eight threshold voltage distributions. The memory card includes a word line controlling section configured to select one required to read 1-bit data belonging to one of the pages to be read from among seven voltage sets which are composed of seven reference voltages for hard bit reading and a plurality of intermediate voltages for soft bit reading and perform control to apply the voltages of the selected voltage set as read voltages to the memory cell, a log likelihood ratio table storing section, and a decoder configured to decode read data using a log likelihood ratio.

Abstract: A memory system in an embodiment having a host and a memory card, including: a plurality of semiconductor memory cells, each cell being configured to store N-bit coded data based on threshold voltage distributions; an LLR table storage section configured to store a first LLR table that consists of normal LLR data corresponding to predetermined threshold voltages and a second LLR table that consists of LLR data such that two LLRs at each location corresponding to each location in the first LLR table at which a sign is inverted between two adjacent LLRs are “0”; and a decoder configured to perform decoding processing through probability-based repeated calculations using an LLR.

Abstract: A controller includes a generation unit configured to aggregate comparison results between second threshold voltage levels held in the memory cells and predetermined third threshold voltage levels, and generate a histogram of the second threshold voltage levels, an estimation unit configured to estimate statistical parameter of a distribution of the second threshold voltage levels with respect to a first threshold voltage level according to writing data, based on the histogram, and a determination unit configured to determine a fifth threshold voltage level defining a boundary of a fourth threshold voltage level indicating a read result of the memory cells from the third threshold voltage levels based on the statistical parameter in such a manner that mutual information amount between the first threshold voltage level and the fourth threshold voltage level becomes maximum.

Abstract: A memory system in an embodiment having a host and a memory card, including: a plurality of semiconductor memory cells, each cell being configured to store N-bit coded data based on threshold voltage distributions; an LLR table storage section configured to store a first LLR table that consists of normal LLR data corresponding to predetermined threshold voltages and a second LLR table that consists of LLR data such that two LLRs at each location corresponding to each location in the first LLR table at which a sign is inverted between two adjacent LLRs are “0”; and a decoder configured to perform decoding processing through probability-based repeated calculations using an LLR.

Abstract: A controller includes a generation unit configured to aggregate comparison results between second threshold voltage levels held in the memory cells and predetermined third threshold voltage levels, and generate a histogram of the second threshold voltage levels, an estimation unit configured to estimate statistical parameter of a distribution of the second threshold voltage levels with respect to a first threshold voltage level according to writing data, based on the histogram, and a determination unit configured to determine a fifth threshold voltage level defining a boundary of a fourth threshold voltage level indicating a read result of the memory cells from the third threshold voltage levels based on the statistical parameter in such a manner that mutual information amount between the first threshold voltage level and the fourth threshold voltage level becomes maximum.

Abstract: A memory card including a word line control portion configured to perform control of applying intermediate voltages made up of a first intermediate voltage lower than a center voltage of four threshold voltage distributions and a second intermediate voltage higher than the center voltage to the memory cell, a logarithmic likelihood ratio table memory portion configured to store 9-level logarithmic likelihood ratios based on read voltages, and a decoder configured to perform decoding processing on the data read using the logarithmic likelihood ratio stored in the logarithmic likelihood ratio table memory portion.

Abstract: A pile warp tension controller for controlling the pile warp yarn tension control mechanism of a pile fabric loom controls the position of the tension roller of the pile warp yarn tension control mechanism or the torque acting on a tension lever supporting the tension roller according to the operating state of the pile fabric loom so that the tension of the pile warp yarns is regulated at an optimum value. The control mode of the pile warp tension controller is changed over from a tension control mode to a speed control mode in forming loops of the pile warp yarns to ensure the satisfactory formation of loops having a predetermined loop length and to prevent defective loops.