Techniques are disclosed relating to self-addressing memory. In one embodiment, an apparatus includes a memory and addressing circuitry coupled to or comprised in the memory. In this embodiment, the addressing circuitry is configured to receive memory access requests corresponding to a specified sequence of memory accesses. In this embodiment, the memory access requests do not include address information. In this embodiment, the addressing circuitry is further configured to assign addresses to the memory access requests for the specified sequence of memory accesses. In some embodiments, the apparatus is configured to perform the memory access requests using the assigned addresses.

Apparatuses and methods for performing an error correction code (ECC) operation are provided. One example method can include performing a first error code correction (ECC) operation on a portion of data, performing a second ECC operation on the portion of data in response to the first ECC operation failing, and performing a third ECC operation on the portion of data in response to the second ECC operation failing.

An encoding method, decoding method, encoding device and decoding device for structured LDPC codes. The method includes: determining a basic matrix used for encoding, which includes K0 up-and-down adjacent pairs; and according to the basic matrix and an expansion factor corresponding to the basic matrix, performing an LDPC encoding operation of obtaining a codeword of Nbz bits according to source data of (NbMb)z bits, herein z is the expansion factor, and z is a positive integer which is greater than or equal to 1. The provided technical solution is applicable to the encoding and decoding of the structured LDPC, thereby realizing the encoding and decoding of LDPC at the high pipeline speed.

A decoding system for an iterative decoding of a parity check code comprises a first loop circuit adapted to store log-likelihood ratio values corresponding to a plurality of received data symbols in a memory unit; a second loop circuit adapted to compute a difference between a check-to-variable log-likelihood message at a second iteration step, and a check-to-variable log-likelihood message at a first iteration step, when the first iteration step precedes the second iteration step; and an adder unit adapted to update a log-likelihood ratio value stored on the first loop circuit by adding the difference computed in the second loop circuit; wherein the first loop circuit and the second loop circuit are synchronized such that the adder unit forwards the updated log-likelihood ratio value synchronously both to the first loop circuit and to the second loop circuit.

Certain aspects of the present disclosure generally relate to methods and apparatus for decoding low density parity check (LDPC) codes, and more particularly to early termination techniques for low-density parity-check (LDPC) decoder architecture.

According to one embodiment, in a case where a first command is received from a host, a storage device starts a first process. The storage device transmits a first response to the host in a case where a first condition is satisfied and transmits a second response and an interrupt signal to the host in a case where the first process is completed. The host, in a case where the first response is received, stops the polling and receives the second response based on reception of the interrupt signal.

Systems and methods are described for performing Layered Belief LDPC decoding on received Standard Belief LDPC encoded data bursts. In on implementation, a receiver: demodulates a signal, the demodulated signal including a noise corrupted signal derived from a codeword encoded using standard belief LDPC encoding; converts the noise corrupted signal derived from the standard belief LDPC encoded codeword to a noise corrupted signal derived from a layered belief LDPC encoded codeword; and decodes the noise corrupted signal derived from the layered belief LDPC encoded codeword using a layered belief LDPC decoder. In further implementations, systems are described for reducing collisions in Layered Belief LDPC decoders that occur when multiple parity checks need the same soft decision at the same time. In these implementations, elements in an original LBD decoder table are rearranged to increase the distance between elements specifying the same location in a RAM where soft decisions are stored.

Methods and apparatus for decoding LDPC code provide that an LDPC code may be represented as a Tanner graph comprising bit nodes and check nodes and connections between them. A configurable LDPC decoder supporting many different LDPC codes having any sub-matrix size includes several independently addressable memories which are used to store soft decision data for each bit node. The decoder further includes a number P of check node processing systems which generate updated soft decision data. The updated values are then passed back to the memories via a shuffling system. If the number of check nodes processed in parallel by the check node processing systems is P.sub.CNB (where PP.sub.CNB) and the soft decision data for a bit node is of word size q bits, the total width of the independently addressable memories is larger than P.sub.CNB*q bits.

A storage device may program data differently for different memory areas of a memory. In some embodiments, the storage device may use different codebooks for different memory areas. In other embodiments, the storage device may modify bit orders differently for different memory areas. What codebook the storage device uses or what bit order modification the storage device performs for a particular memory area may depend on the bad storage locations specific to that memory area. Where different codebooks are used, optimal codebooks may be selected from a library, or codebooks may be modified based on the bad storage locations of the memory areas.

A storage device may program data differently for different memory areas of a memory. In some embodiments, the storage device may use different codebooks for different memory areas. In other embodiments, the storage device may modify bit orders differently for different memory areas. What codebook the storage device uses or what bit order modification the storage device performs for a particular memory area may depend on the bad storage locations specific to that memory area. Where different codebooks are used, optimal codebooks may be selected from a library, or codebooks may be modified based on the bad storage locations of the memory areas.