An apparatus (100) for providing an joint error correction code (140) for a combined data frame (254) comprising first data (112) of a first data channel and second data (122) of a second data channel comprises a first error code generator (110) configured to provide, based on a linear code, information on a first error correction code (114a, 114b) using the first data (112). The apparatus further comprises a second error code generator (120) configured to provide, based on the linear code, information on a second error correction code (124) using the second data (122). The apparatus is configured to provide the joint error correction code (140) using the information on the first error correction code (114a, 114b) and the information on the second error correction code (124).

A Reed Solomon decoder may include a syndrome calculation (SC) circuit, a key equation solver (KES) circuit, and a Chien search and error evaluation (CSEE) circuit. The SC circuit calculates a syndrome from a codeword. The KES circuit includes a plurality of sub-KES circuit and calculates an error location polynomial and an error evaluation polynomial from the syndrome. The CSEE circuit calculates an error location and an error value from the error location polynomial and the error evaluation polynomial. Each of the plurality of sub-KES circuits, the SC circuit and the CSEE circuit respectively constitute pipeline stages. The Read Solomon decoder may also include a FIFO queue that queues the codeword among a plurality of codewords sequentially received, and an error correction circuit that produces error corrected data using an output from the FIFO queue, the error location, and the error value.

Embodiments herein describe a FEC codec for generating a check byte for a message. The FEC codec includes a port encoder having a storage unit, a Galois field multiplier, and a sum unit. The storage unit stores a first staged result, which is accumulated based on previous sets of input bytes of the message for all clock cycles from a first clock cycle to a clock cycle immediately prior to the current clock cycle. The Galois field multiplier performs a Galois field multiplication of the first staged result and a power of the alpha to generate a Galois field product. The sum unit performs a Galois field addition on an internal input based on a consolidated byte for the current clock cycle and the Galois field product to generate a second staged result for subsequent use to generate the check byte. Other embodiments may be described and/or claimed.

A decoding method, a memory storage device and a memory control circuit unit are disclosed. The method includes: activating a decoding circuit which supports a plurality of decoding modes each corresponding to a threshold value, wherein a distribution of the threshold value corresponds to error correction abilities of the decoding modes; reading first data from a rewritable non-volatile memory module; performing, by the decoding circuit, a first decoding operation on the first data; obtaining a decoding parameter according to an execution result of the first decoding operation; and performing, by the decoding circuit, a second decoding operation on the first data based on a first decoding mode among the decoding modes according to a relative numerical relationship between the decoding parameter and the threshold value.

A decoding method, a memory storage device and a memory control circuit unit are disclosed. The method includes: activating a decoding circuit which supports a plurality of decoding modes each corresponding to a threshold value, wherein a distribution of the threshold value corresponds to error correction abilities of the decoding modes; reading first data from a rewritable non-volatile memory module; performing, by the decoding circuit, a first decoding operation on the first data; obtaining a decoding parameter according to an execution result of the first decoding operation; and performing, by the decoding circuit, a second decoding operation on the first data based on a first decoding mode among the decoding modes according to a relative numerical relationship between the decoding parameter and the threshold value.

A Reed Solomon decoder may include a syndrome calculation (SC) circuit configured to calculate a codeword from a syndrome ; a key equation solver (KES) circuit configured to calculate an error location polynomial and an error evaluation polynomial from the syndrome; and a Chien search and error evaluation (CSEE) circuit configured to calculate an error location and an error value from the error location polynomial and the error evaluation polynomial, wherein the KES circuit comprises a plurality of sub-KES circuit and each of the plurality of sub-KES circuit, the SC circuit and the CSEE circuit constitutes pipeline stages respectively.

A memory device includes a memory array, a processor coupled to the memory array, and a decoding apparatus. The decoding apparatus is configured to perform coarse decoding and fine decoding. In coarse decoding, the decoder decodes in parallel two or more codewords, which share a common block of bits, to determine error information. Next, the decoder corrects errors in a first codeword based on the error information. Then, it is determined if the shared common block of data bits is corrected. If the shared common data block is updated, then error correction based on the error information is prohibited in codewords sharing the common block of data bits with the first codeword. In fine decoding, a single codeword is decoded at a time for error correction.

An apparatus (100) for providing an joint error correction code (140) for a combined data frame (254) comprising first data (112) of a first data channel and second data (122) of a second data channel comprises a first error code generator (110) configured to provide, based on a linear code, information on a first error correction code (114a, 114b) using the first data (112). The apparatus further comprises a second error code generator (120) configured to provide, based on the linear code, information on a second error correction code (124) using the second data (122). The apparatus is configured to provide the joint error correction code (140) using the information on the first error correction code (114a, 114b) and the information on the second error correction code (124).

An apparatus (100) for providing an joint error correction code (140) for a combined data frame (254) comprising first data (112) of a first data channel and second data (122) of a second data channel comprises a first error code generator (110) configured to provide, based on a linear code, information on a first error correction code (114a, 114b) using the first data (112). The apparatus further comprises a second error code generator (120) configured to provide, based on the linear code, information on a second error correction code (124) using the second data (122). The apparatus is configured to provide the joint error correction code (140) using the information on the first error correction code (114a, 114b) and the information on the second error correction code (124).

A Reed-Solomon decoder circuit includes: a syndrome calculator circuit to compute syndrome values for a first codeword and a second codeword sequentially supplied to the syndrome calculator circuit, where last symbols of the first codeword overlap with first symbols of the second codeword during an overlap clock cycle between: a first plurality of non-overlap clock cycles during which the first codeword is supplied to the syndrome calculator circuit; and a second plurality of non-overlap clock cycles during which the second codeword is supplied to the syndrome calculator circuit; an error locator and error evaluator polynomial calculator circuit; an error location and error value calculator circuit; an error counter; and an error corrector circuit to correct the errors in the first codeword and the second codeword based on error counts and the error magnitudes computed by an error evaluator circuit.