Abstract:
Methods and systems involve collecting memory device parameters and using memory device parameters to determine memory wear information. A set of first parameters associated with wear of the memory device is monitored for at least one memory unit of the memory device. The first parameters are compared to respective trigger criterion. If the comparison reveals that one or more of the first parameters are beyond their trigger criterion, then collection of a second set of parameters is triggered. The second parameters are also indicative of the wear of the memory device. The set of first parameters may overlap the set of second parameters. The set of second parameters are used to develop memory wear information. In some implementations, the memory wear information may be configuration information used to configure the read/write channel to compensate for wear of the memory device. In some implementations, the memory wear information may be used to predict or estimate the lifetime of the device.
Abstract:
A nominal reference read operation compares analog voltages of the memory cells to at least one nominal reference voltage. A shifted reference read operation compares the analog voltages of the memory cells to at least one shifted reference voltage that is shifted from the nominal reference voltage to compensate for an expected change in the analog voltages of the memory cells. Data stored in the memory cells is decoded by a first decoding process that uses the information from either the nominal reference read operation or the shifted reference read operation. The data stored in the memory cells is decoded by a second decoding process that uses the information from both the nominal reference read operation and the shifted reference read operation.
Abstract:
Methods and systems involve collecting memory device parameters and using memory device parameters to determine memory wear information. A set of first parameters associated with wear of the memory device is monitored for at least one memory unit of the memory device. The first parameters are compared to respective trigger criterion. If the comparison reveals that one or more of the first parameters are beyond their trigger criterion, then collection of a second set of parameters is triggered. The second parameters are also indicative of the wear of the memory device. The set of first parameters may overlap the set of second parameters. The set of second parameters are used to develop memory wear information. In some implementations, the memory wear information may be configuration information used to configure the read/write channel to compensate for wear of the memory device. In some implementations, the memory wear information may be used to predict or estimate the lifetime of the device.
Abstract:
Approaches for decoding data read from memory cells of a nonvolatile, solid state memory involve attempting to decode hard data using a hard decoding process prior to a time that soft data is available to the decoder. The hard data includes information about the digital symbols stored in the memory cells without data confidence information. The soft data includes information about the digital symbols stored in the memory cells and data confidence information. In response to the hard decoding process failing to achieve convergence, after the soft data becomes available to the decoder, the soft data is decoded using a soft decoding process. The decoder generates an output of the decoded data after the hard decoding process or the soft decoding process achieves convergence.
Abstract:
Approaches for decoding data read from memory cells of a nonvolatile, solid state memory involve attempting to decode hard data using a hard decoding process prior to a time that soft data is available to the decoder. The hard data includes information about the digital symbols stored in the memory cells without data confidence information. The soft data includes information about the digital symbols stored in the memory cells and data confidence information. In response to the hard decoding process failing to achieve convergence, after the soft data becomes available to the decoder, the soft data is decoded using a soft decoding process. The decoder generates an output of the decoded data after the hard decoding process or the soft decoding process achieves convergence.
Abstract:
Outer code words can span multiple data blocks, multiple die, or multiple chips of a memory device to protect against errors in the data stored in the blocks, die and/or chips. A solid state memory device is arranged in multiple data blocks, each block including an array of memory cells arranged in a plurality of pages. The data is encoded into inner code words and symbol-based outer code words. The inner code words and the symbol-based outer code words are stored in the memory cells of the multiple blocks. One or more inner code words are stored in each page of each block and one or more symbols of each outer code word are stored in at least one page of each block. The inner code words and the outer code words are read from the memory device and are used to correct the errors in the data.
Abstract:
A storage medium includes at least one data unit defining a plurality of symbol-based inner code words and a plurality of symbol-based outer code words. Each symbol included in one of the inner code words is also included in one of the outer code words. A processor is configured to perform a first iteration of inner code error correction on the plurality of symbol-based inner code words, a first iteration of outer code error correction on the plurality of symbol-based outer code words and a second iteration of inner code error correction on the plurality of symbol-based inner code words. In the first iteration of outer code error corrections, at least one of the outer code words is correctable. In the second iteration of inner code error correction, at least one of the inner code words is correctable.
Abstract:
This disclosure is related to systems and methods for low wear operation of solid state memory, such as a flash memory. In one example, a controller is coupled to a memory and adapted to dynamically adjust programming thresholds over the course of usage of the data storage device such that a signal-to-noise ratio from reading data stored in the data storage cells is no less than a minimum amount needed to recover the data using an enhanced error detection capability.
Abstract:
Outer code words can span multiple data blocks, multiple die, or multiple chips of a memory device to protect against errors in the data stored in the blocks, die and/or chips. A solid state memory device is arranged in multiple data blocks, each block including an array of memory cells arranged in a plurality of pages. The data is encoded into inner code words and symbol-based outer code words. The inner code words and the symbol-based outer code words are stored in the memory cells of the multiple blocks. One or more inner code words are stored in each page of each block and one or more symbols of each outer code word are stored in at least one page of each block. The inner code words and the outer code words are read from the memory device and are used to correct the errors in the data.
Abstract:
A storage medium includes at least one data unit defining a plurality of symbol-based inner code words and a plurality of symbol-based outer code words. Each symbol included in one of the inner code words is also included in one of the outer code words. A processor is configured to perform a first iteration of inner code error correction on the plurality of symbol-based inner code words, a first iteration of outer code error correction on the plurality of symbol-based outer code words and a second iteration of inner code error correction on the plurality of symbol-based inner code words. In the first iteration of outer code error corrections, at least one of the outer code words is correctable. In the second iteration of inner code error correction, at least one of the inner code words is correctable.