Abstract: A system uses multi-level encoding where each symbol of a plurality of symbols represents more than one bit of information in a user data symbol stream for transfer using a multilevel transmission channel. The user data symbols are represented in a digital bitwise form such that each symbol is presented as a plurality of bits and each bit is subject to a different probability of error. An error correction procedure is applied based on the different error probability that is associated with each bit in the plurality. The channel can be configured to support a mosaic tile structure, each tile containing a channel symbol such that a selected tile has a collective error probability that is different from other tiles. Customized coding can be applied to the tile structure to allocate a selected amount of error correction power to the selected tile based on an overall available correction power.

Abstract: A system uses multi-level encoding where each symbol of a plurality of symbols represents more than one bit of information in a user data symbol stream for transfer using a multilevel transmission channel. The user data symbols are represented in a digital bitwise form such that each symbol is presented as a plurality of bits and each bit is subject to a different probability of error. An error correction procedure is applied based on the different error probability that is associated with each bit in the plurality. The channel can be configured to support a mosaic tile structure, each tile containing a channel symbol such that a selected tile has a collective error probability that is different from other tiles. Customized coding can be applied to the tile structure to allocate a selected amount of error correction power to the selected tile based on an overall available correction power.

Abstract: A system uses multi-level encoding where each symbol of a plurality of symbols represents more than one bit of information in a user data symbol stream for transfer using a multilevel transmission channel. The user data symbols are represented in a digital bitwise form such that each symbol is presented as a plurality of bits and each bit is subject to a different probability of error. An error correction procedure is applied based on the different error probability that is associated with each bit in the plurality. The channel can be configured to support a mosaic tile structure, each tile containing a channel symbol such that a selected tile has a collective error probability that is different from other tiles. Customized coding can be applied to the tile structure to allocate a selected amount of error correction power to the selected tile based on an overall available correction power.

Abstract: Apparatus and methods are disclosed, including a method of programming involving determining an error rate for the memory cells, and programming the memory cells using a charge state level for a charge state that is based at least in part on the determined error rate.

Abstract: In one embodiment, an encoder reads a set of data from memory cells to obtain retrieved data influenced by one or more distortion mechanisms as a result of having been stored. A quality metric is generated responsive to the retrieved data that changes in value responsive to differences between the user data and the associated retrieved data. A quality monitor establishes a relationship between a current value of the quality metric and a threshold value and monitors the relationship as being indicative of a degradation of the quality of the retrieved data, and selectively initiates an error response. In another embodiment, a correction value is iterated through a set of values as a quality metric is monitored such that the value of the quality metric which most closely approaches the value of the quality metric immediately subsequent to an initial writing of the data can be selected.

Abstract: Apparatus and methods are disclosed, including a method of programming involving determining an error rate for the memory cells, and programming the memory cells using a charge state level for a charge state that is based at least in part on the determined error rate.

Abstract: Apparatus and methods are disclosed, including a method of programming involving determining an error rate for the memory cells, and programming the memory cells using a charge state level for a charge state that is based at least in part on the determined error rate.

Abstract: In one embodiment, an encoder reads a set of data from memory cells to obtain retrieved data influenced by one or more distortion mechanisms as a result of having been stored. A quality metric is generated responsive to the retrieved data that changes in value responsive to differences between the user data and the associated retrieved data. A quality monitor establishes a relationship between a current value of the quality metric and a threshold value and monitors the relationship as being indicative of a degradation of the quality of the retrieved data, and selectively initiates an error response. In another embodiment, a correction value is iterated through a set of values as a quality metric is monitored such that the value of the quality metric which most closely approaches the value of the quality metric immediately subsequent to an initial writing of the data can be selected.

Abstract: In one embodiment, an encoder reads a set of data from memory cells to obtain retrieved data influenced by one or more distortion mechanisms as a result of having been stored. A quality metric is generated responsive to the retrieved data that changes in value responsive to differences between the user data and the associated retrieved data. A quality monitor establishes a relationship between a current value of the quality metric and a threshold value and monitors the relationship as being indicative of a degradation of the quality of the retrieved data, and selectively initiates an error response. In another embodiment, a correction value is iterated through a set of values as a quality metric is monitored such that the value of the quality metric which most closely approaches the value of the quality metric immediately subsequent to an initial writing of the data can be selected.

Abstract: A system uses multi-level encoding where each symbol of a plurality of symbols represents more than one bit of information in a user data symbol stream for transfer using a multilevel transmission channel. The user data symbols are represented in a digital bitwise form such that each symbol is presented as a plurality of bits and each bit is subject to a different probability of error. An error correction procedure is applied based on the different error probability that is associated with each bit in the plurality. The channel can be configured to support a mosaic tile structure, each tile containing a channel symbol such that a selected tile has a collective error probability that is different from other tiles. Customized coding can be applied to the tile structure to allocate a selected amount of error correction power to the selected tile based on an overall available correction power.

Abstract: A system uses multi-level encoding where each symbol of a plurality of symbols represents more than one bit of information in a user data symbol stream for transfer using a multilevel transmission channel. The user data symbols are represented in a digital bitwise form such that each symbol is presented as a plurality of bits and each bit is subject to a different probability of error. An error correction procedure is applied based on the different error probability that is associated with each bit in the plurality. The channel can be configured to support a mosaic tile structure, each tile containing a channel symbol such that a selected tile has a collective error probability that is different from other tiles. Customized coding can be applied to the tile structure to allocate a selected amount of error correction power to the selected tile based on an overall available correction power.

Abstract: A memory system for digital data communication with a host device is described to provide data storage capacity. The system can include a controller and a plurality of modules, each module including a nonvolatile memory device wherein the module is configured to perform a management function with respect to the module at least partially based on a parameter. The parameter is provided by the controller and/or the module. The system and modules, in one feature, can support multiple forms of concurrency with respect to data accesses involving the modules.

Abstract: In one embodiment, an encoder reads a set of data from memory cells to obtain retrieved data influenced by one or more distortion mechanisms as a result of having been stored. A quality metric is generated responsive to the retrieved data that changes in value responsive to differences between the user data and the associated retrieved data. A quality monitor establishes a relationship between a current value of the quality metric and a threshold value and monitors the relationship as being indicative of a degradation of the quality of the retrieved data, and selectively initiates an error response. In another embodiment, a correction value is iterated through a set of values as a quality metric is monitored such that the value of the quality metric which most closely approaches the value of the quality metric immediately subsequent to an initial writing of the data can be selected.

Abstract: In one embodiment, an encoder reads a set of data from memory cells to obtain retrieved data influenced by one or more distortion mechanisms as a result of having been stored. A quality metric is generated responsive to the retrieved data that changes in value responsive to differences between the user data and the associated retrieved data. A quality monitor establishes a relationship between a current value of the quality metric and a threshold value and monitors the relationship as being indicative of a degradation of the quality of the retrieved data, and selectively initiates an error response. In another embodiment, a correction value is iterated through a set of values as a quality metric is monitored such that the value of the quality metric which most closely approaches the value of the quality metric immediately subsequent to an initial writing of the data can be selected.

Abstract: Apparatus and methods are disclosed, including a method of programming involving determining an error rate for the memory cells, and programming the memory cells using a charge state level for a charge state that is based at least in part on the determined error rate.

Abstract: A memory system for digital data communication with a host device is described to provide data storage capacity. The system can include a controller and a plurality of modules, each module including a nonvolatile memory device wherein the module is configured to perform a management function with respect to the module at least partially based on a parameter. The parameter is provided by the controller and/or the module. The system and modules, in one feature, can support multiple forms of concurrency with respect to data accesses involving the modules.

Abstract: In one embodiment, an encoder reads a set of data from memory cells to obtain retrieved data influenced by one or more distortion mechanisms as a result of having been stored. A quality metric is generated responsive to the retrieved data that changes in value responsive to differences between the user data and the associated retrieved data. A quality monitor establishes a relationship between a current value of the quality metric and a threshold value and monitors the relationship as being indicative of a degradation of the quality of the retrieved data, and selectively initiates an error response. In another embodiment, a correction value is iterated through a set of values as a quality metric is monitored such that the value of the quality metric which most closely approaches the value of the quality metric immediately subsequent to an initial writing of the data can be selected.

Abstract: A system uses multi-level encoding where each symbol of a plurality of symbols represents more than one bit of information in a user data symbol stream for transfer using a multilevel transmission channel. The user data symbols are represented in a digital bitwise form such that each symbol is presented as a plurality of bits and each bit is subject to a different probability of error. An error correction procedure is applied based on the different error probability that is associated with each bit in the plurality. The channel can be configured to support a mosaic tile structure, each tile containing a channel symbol such that a selected tile has a collective error probability that is different from other tiles. Customized coding can be applied to the tile structure to allocate a selected amount of error correction power to the selected tile based on an overall available correction power.

Abstract: A disk drive provides manufacture test processing of itself after it is installed and operating within a computer system. The tests include flaw mapping, embedded runout compensation and final drive verification and do not interfere with normal operations of the disk drive.

Abstract: A storage and retrieval subsystem in a data processing system includes a plurality of magnetic tape cartridges, a host computer, and a library storage module storing the plurality of magnetic tape cartridges in substantially upright positions. The library storage module includes a first cylindrical array of storage cells centered about a vertical axis, a second cylindrical array concentrically arranged about the first array, and a library tape unit including a plurality of tape drives, each of the tape drives being adapted to receive one of the magnetic tape cartridges in a substantially horizontal transducing position. A robot within the library storage module is used to transfer selected ones of the magnetic tape cartridges between their substantially upright positions and the substantially horizontal transducing positions at a selected tape drive.