Systems, methods, and apparatus related to data recovery in memory devices. In one approach, a memory device encodes stored data. The memory device reads a codeword from a storage media and determines that a number errors in the codeword exceeds an error correction capability of the memory device. The errors are due, for example, to one or more stuck bits. In response to this determination, one or more data patterns are written to the storage media at the same address from which the codeword is read. The data patterns are read to identify bit locations of the stuck bits. The identified locations are used to correct bit errors of the read codeword that correspond to the identified locations. The corrected code word is sent to a host device (e.g., which requested data from the memory device using a read command).

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 method includes: sending a first boundary bit block; sequentially sending an Ith bit block; determining a first parity check result and a second parity check result, where a check object of the first parity check result includes m consecutive bits of each bit block in the N bit blocks, a check object of the second parity check result includes n consecutive bits of each bit block in the N bit blocks, and at least one of m and n is greater than or equal to 2; and sending a second boundary bit block, the first parity check result, and the second parity check result.

Methods, systems, and devices for spare substitution in a memory system are described. A controller may, as part of a background operation, assign a spare bit to replace a bit of a code word and save an indication of the spare bit assignment in a memory array. The code word may include a set of bits that each correspond to a respective Minimum Substitution Region (MSR) within a memory medium that retains the code word. An MSR corresponding to the bit to be replaced may include a quantity of erroneous bits relative to a threshold. The controller may, during a read operation, identify the spare bit in a first portion of the code word, determine the bit to be replaced based on accessing the memory array, and replace the bit with the spare bit concurrently with receiving a second portion of the code word.

A method of correcting one or more bit errors in a memory device includes retrieving a codeword from a memory device. The codeword includes a data and an error correcting code. The method further includes determining whether the one or more bit errors are present in the retrieved codeword and correcting the retrieved codeword for the one bit error in response to determining one bit error is present in the retrieved codeword. The method also includes flipping a bit of the retrieved codeword in response to determining a plurality of bit errors is present in the retrieved codeword and correcting the retrieved codeword for the plurality of bit errors based on the bit-flipped codeword.

An error reporting system utilizes a parity checker to receive data results from execution of an original instruction and a parity bit for the data. A decoder receives an error correcting code (ECC) for data resulting from execution of a shadow instruction of the original instruction, and data error correction is initiated on the original instruction result on condition of a mismatch between the parity bit and the original instruction result, and the decoder asserting a correctable error in the original instruction result.

A memory system includes a memory device including a memory device including a plurality of blocks, each block having a plurality of pages to store data; and a controller suitable for selecting specific memory blocks among the plurality memory blocks, acquiring error bit information of the plurality of pages in each of the specific memory blocks, generating a memory block group management list of each of the specific memory blocks to classify the specific memory blocks into different memory block groups or a same memory block group based on the error bit information, and performing a test read operation on the plurality of pages in each of the plurality of memory blocks based on whether the specific memory blocks are classified into different memory block groups or the same memory block group.

Systems, methods, and apparatus related to data recovery in memory devices. In one approach, a memory device encodes stored data. The memory device reads a codeword from a storage media and determines that a number errors in the codeword exceeds an error correction capability of the memory device. The errors are due, for example, to one or more stuck bits. In response to this determination, one or more data patterns are written to the storage media at the same address from which the codeword is read. The data patterns are read to identify bit locations of the stuck bits. The identified locations are used to correct bit errors of the read codeword that correspond to the identified locations. The corrected code word is sent to a host device (e.g., which requested data from the memory device using a read command).

An error reporting system utilizes a parity checker to receive data results from execution of an original instruction and a parity bit for the data. A decoder receives an error correcting code (ECC) for data resulting from execution of a shadow instruction of the original instruction, and data error correction is initiated on the original instruction result on condition of a mismatch between the parity bit and the original instruction result, and the decoder asserting a correctable error in the original instruction result.

Methods, systems, and devices for error correction for content-addressable memory (CAM) are described. A CAM may store bit vectors as a set of subvectors, which each subvector stored in an independent aspect of the CAM, such as in a separate column or array of memory cells within the CAM. The CAM may similarly segment a queried input bit vector and identify, for each resulting input subvector, whether a matching subvector is stored by the CAM. The CAM may identify a match for the input bit vector when the number of matching subvectors satisfies a threshold. The CAM may validate a match based on comparing a stored bit vector corresponding to the identified match to the input bit vector. The stored bit vector may undergo error correction and may be stored in the CAM or another memory array, such as a dynamic random access memory (DRAM) array.