Western Digital Technologies, Inc.

Hgst Technologies Santa Ana, Inc.

S-Tec Corporation

Majid Nemati Anaraki

Richard David Barndt

Anthony Dwayne Weathers

Seyhan Karakulak

Scott Kayser

Xinde Hu

Anantha Raman Krishnan

Kasra Vakilinia

Mai Ghaly

Aldo Giovanni Cometti

Daniel Lee Helmick

Chandan Mishra

Dillip Kumar Dash

Amir Hossein Gholamipour

Jake Bear

The subject technology provides for scanning blocks of a flash memory device for erased pages. A first codeword read from a page of a block in a flash memory device is received and provided to a first decoder for decoding. In response to receiving a first success indicator from the first decoder indicating that the first codeword was successfully decoded, first decoded data is provided from the first decoder to a second decoder for verification of the first decoded data. In response to receiving a first failure indicator from the second decoder indicating that the first decoded data was not verified, the page of the block is identified as being in an erased state based on the first success indicator received from the first decoder and the first failure indicator received from the second decoder.

Method and system for identifying erased memory areas

A system for hierarchical variable code rate error correction coding may include at least one circuit that is configured to identify a row of a hierarchical portion of a generator matrix that corresponds to a determined code rate, determine a number of information bits to apply to the hierarchical portion based at least on the identified row, and apply the determined number of information bits to the identified row. The circuit may be further configured to apply an output of the identified row to a subsequent row of the hierarchical portion, when the hierarchical portion includes a subsequent row, and apply an output of a last row of the hierarchical portion to a base portion of the generator matrix. The circuit may be further configured to provide a codeword output by the base portion of the generator matrix.

Hierarchical variable code rate error correction coding

Method and system for scanning for erased flash memory pages

Systems, apparatuses, methods, and computer program products are disclosed for updating data of write-in-place storage devices. One system includes a write-in-place memory device including a redundant storage structure and a controller for the memory device. A memory device is configured to store data across a set of stripes of a redundant storage structure. A controller is configured to receive updated data for a dataset stored across a first stripe, generate a new parity for the dataset based on the updated data, overwrite the dataset across the first stripe with the updated data, and/or write the new parity to the set of stripes.

Updating write-in-place storage devices

A storage system is provided comprising a memory and a controller. The controller is configured to receive a write command, data, and a logical address; determine a physical address associated with the logical address; generate protection information for the data using the data and at least one of the logical address and physical address; and store the data and the protection information in the memory without storing the at least one of the logical address and physical address in the memory.

Storage system and method for improved generation and storage of data protection information

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.

Reduced complexity non-binary LDPC decoding algorithm

The subject technology provides a decoding solution that conserves variable node memory in Low Density Parity Check decoding operations, while supporting multiple choices of code rates. A decoder includes a plurality of variable node memories, with each of the variable node memories having a predetermined memory capacity based on a position of a respective variable node associated with the variable node memory relative to a first variable node in a series of variable nodes. The code rate determines how many of the variable node memories are used, and the size of the data stored in each memory. The capacity of the memories is predetermined so that, as the code rate and number of memories utilized by the decoder increases or decreases, utilization of the memory capacity of each variable node memory is maximized.

Tapered variable node memory

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.

Redundancy of error correction encoded data in a storage system

In one embodiment, an electronic system includes a decoder configured to decode an encoded data unit using multiple variable nodes and multiple check nodes to perform a low-density parity check (LDPC) decoding process. The encoded data unit can be received from a solid-state memory array. As part of performing the LDPC decoding process, the decoder can (i) convert reliability information representing first non-binary values to reliability information representing first binary values, (ii) determine reliability information representing second binary values using the reliability information representing first binary values, and (iii) convert the reliability information representing the second binary values to reliability information representing second non-binary values.

Non-binary LDPC decoder using binary subgroup processing

Systems and methods are disclosed for decoding solid-state memory cells using one-read soft decision decoding. A controller of a data storage device is configured to perform a first decoding of a first code word based at least in part on data associated with a reading of the first code word, and to detect a decoding failure associated with the first decoding. The controller determines reliability information for decoding the first code word in response to the decoding failure based at least in part on data associated with a successful decoding of a second code word and performs a second decoding of the first code word based at least in part on the reliability information.

Method and system for soft decoding through single read

Data storage systems may include a solid-state memory array configured to store encoded data units and a controller configured to decode the encoded data units. Decoding the encoded data units may include updating a check node of a plurality of check nodes associated with a parity check matrix by identifying first and second sets of variable nodes in a plurality of variable nodes associated in the parity check matrix with the check node and constructing a trellis based on the second set of variable nodes. The trellis may be used to determine a message and, based at least in part on the message, a first set of messages to be sent from the check node to the first set of variable nodes may be determined. A second set of messages to be sent from the check node to each variable node in the second set of variable nodes also may be determined.

Growing community of inventors

San Diego, CA, United States of America

Majid Nemati Anaraki