Provided herein may be an error correction circuit for detecting a trapping set and a method of operating the error correction circuit. The error correction circuit may include a syndrome check history manager configured to maintain a history of syndrome checks corresponding to one or more iterations of the iterative decoding scheme, and a trapping set detector configured to compare a trapping set determination policy with the history of syndrome checks to determine whether the history of syndrome checks meets criteria of the trapping set determination policy, while error correction decoding is performed, and determine that a trapping set exists when the history of syndrome checks satisfies the trapping set determination policy, wherein the trapping set determination policy is related to at least one of a change in a syndrome vector, a number of UCNs, and a change in the number of UCNs.

The present disclosure relates to an LDPC code decoder and a decoding method. A check node update processor of the LDPC code decoder includes: an AFM condition check unit which checks whether a predetermined specific condition is satisfied, and a check node determining unit which sets an approximate minimum value as a size of an entire check node output when it is determined that the specific condition is satisfied as a checking result in the AFM condition check unit and calculates a first minimum value as a true minimum value and sets a second minimum value as an approximate minimum value when it is determined that the specific condition is not satisfied to determine a size of the check node output. According to the present disclosure, a consumed hardware resource amount may be reduced by an algorithm using an approximate minimum value in a specific condition.

An error correction device includes: a plurality of variable node units each configured to: receive a hard decision bit and a channel reliability value having a first bit-precision; and perform an iteration of a decoding operation on the hard decision bit based on the channel reliability value; a plurality of check node units each configured to: receive one or more reference reliability values having a second bit-precision from one or more variable node units coupled thereto among the plurality of variable node units during the iteration; and transmit, based on the one or more reference reliability values, one or more check reliability values having the second bit-precision to the one or more variable node units coupled thereto, wherein, during the iteration, each of the plurality of variable node units further: receives one or more first check reliability values from one or more check node units coupled thereto among the plurality of check node units; and updates the hard decision bit with reference to the channel reliability value and the one or more first check reliability values by upsizing the first bit-precision of the channel reliability value and the second bit-precision of the one or more first check reliability values.

A coded signal is received via a physical channel. The coded signal is encoded by a parity check matrix. In some examples, the coded signal is low density parity check-encoded. The coded signal is decoded to determine a result signal. Said decoding alternatingly updates, for each one of a number of iterations, bit node values representing bits of the result signal and check node values representing constrains of the parity check matrix. In some examples, the decoding determines the result signal at a first precision and updates at least partly at a second precision which is lower than the first precision. In further examples, the number of iterations is dynamically adjusted.

A device includes a non-volatile memory and a low density parity check (LDPC) decoder configured to receive a representation of a codeword from the non-volatile memory. The LDPC decoder includes multiple data processing units (DPUs) and a control circuit coupled to the DPUs. The control circuit is responsive to an error metric associated with the representation of the codeword and is configured to set a message resolution at least partially based on the error metric and to selectively disable one or more components of the LDPC decoder based on the message resolution.

An error correction device includes: a plurality of variable node units each configured to: receive a hard decision bit and a channel reliability value having a first bit-precision; and perform an iteration of a decoding operation on the hard decision bit based on the channel reliability value; a plurality of check node units each configured to: receive one or more reference reliability values having a second bit-precision from one or more variable node units coupled thereto among the plurality of variable node units during the iteration; and transmit, based on the one or more reference reliability values, one or more check reliability values having the second bit-precision to the one or more variable node units coupled thereto, wherein, during the iteration, each of the plurality of variable node units further: receives one or more first check reliability values from one or more check node units coupled thereto among the plurality of check node units; and updates the hard decision bit with reference to the channel reliability value and the one or more first check reliability values by upsizing the first bit-precision of the channel reliability value and the second bit-precision of the one or more first check reliability values.

A device includes a low density parity check (LDPC) decoder that is configured to receive a representation of a codeword. The LDPC decoder includes a circuit configured to set a message length of a decoding message at least partially based on an error metric associated with the representation of the codeword. The LDPC decoder also includes a processing unit including a first group of components and a second group of components. The processing unit configured to selectively couple the first group of components to the second group of components based on the message length of the decoding message.

This invention presents a method and apparatus for vertical layered finite alphabet iterative decoding of low-density parity-check codes (LDPC) which operate on parity check matrices that consist of blocks of sub-matrices. The iterative decoding involves passing messages between variable nodes and check nodes of the Tanner graph that associated with one or more sub-matrices constitute decoding blocks, and the messages belong to a finite alphabet. Various embodiments for the method and apparatus of the invention are presented that can achieve very high throughputs with low hardware resource usage and power.

Systems and methods are disclosed for implementing a low latency decoder. In certain embodiments, an apparatus may comprise decoder configured decode a codeword of bits, including: a variable node processor configured to provide a plurality of variable-to-check (v2c) message vectors to the edge combiner in parallel, the plurality of v2c message vectors including estimates for a selected set of bits of the codeword; the edge combiner configured to generate a plurality of output message vectors for a plurality of check node vectors based on the plurality of v2c message vectors, and provide the plurality of output message vectors to the plurality of check node vectors simultaneously; a check node processor configured to update the plurality of check node vectors based on the plurality of output message vectors; and a convergence checker circuit configured to detect a valid code word based on bit value estimates from the variable node processor.

A method for operating an MS decoder and an associated memory system utilizing the MS decoder. The method determines an operation mode of the MS decoder. For each variable node, the method calculates a variable to check node V2C message. The method stores, in a check node unit CNU memory, check information associated with the calculated V2C message according to the operation mode. The check information includes full information when the operation mode is a high precision mode, and partial information when the operation mode is a low precision mode.