A method of operation in an integrated circuit (IC) memory device is disclosed. The method includes refreshing a first group of storage rows in the IC memory device at a first refresh rate. A retention time for each of the rows is tested. The testing for a given row under test includes refreshing at a second refresh rate that is slower than the first refresh rate. The testing is interruptible based on an access request for data stored in the given row under test.

A memory control method for a rewritable non-volatile memory module including a plurality of physical units is provided according to an exemplary embodiment of the disclosure. The method includes: reading first data from a first physical unit of a rewritable non-volatile memory module; decoding the first data by a decoding circuit; updating reliability information according to the decoded first data; reading second data from a second physical unit of the rewritable non-volatile memory module; and decoding the second data by the decoding circuit according to the updated reliability information.

An apparatus includes an interface and a control circuit. The interface may be configured to process transfers to/from a medium. The control circuit may be configured to generate a trapping set list of trapping sets of a low-density parity check code, classify bit positions of the trapping sets as belonging to either a user bits field or a parity bits field of a codeword, encode data using the low-density parity check code to generate the codeword, and present the codeword to the interface to transfer the codeword to the medium. The generation of the codeword may include at least one of a shortening or a puncturing of bit locations in the codeword in response to the classifying of the bit positions of the trapping sets. All of the data may be held in the bit locations of the codeword other than the bit locations that are shortened or punctured.

Memory controllers, devices and associated methods are disclosed. In one embodiment, a memory controller includes write circuitry to transmit write data to a memory device, the write circuitry includes a write error detection correction (EDC) encoder to generate first error information associated with the write data. Data bus inversion (DBI) circuitry conditionally inverts data bits associated with each of the write data words based on threshold criteria. Read circuitry receives read data from the memory device. The read circuitry includes a read EDC encoder to generate second error information associated with the received read data. Logic evaluates the first and second error information and conditionally reverse-inverts at least a portion of the read data based on the decoding.

A method of operating a memory controller includes classifying a plurality of memory cells in an erase state into a plurality of groups, based on erase state information about the plurality of memory cells in the erase state; setting at least one target program state for at least some memory cells from among memory cells included in at least one of the plurality of groups; and programming the at least some memory cells for which the at least one target program state has been set, to a program state other than the at least one target program state from among the plurality of program states.

In various embodiments, an apparatus, system, and method may increase data integrity in a redundant storage system. In one embodiment, a request is received for data stored at a storage system having a plurality of storage elements, where one or more of the plurality of storage elements include parity information. A determination is made that one of the plurality of storage elements is unavailable, the unavailable storage element being a functional storage element and including at least a portion of the data. Responsive to the determination, the data is reconstructed based on at least a portion of the parity information and data from one or more of the plurality of storage elements other than the unavailable storage element; a response is provided to the request such that the response includes the reconstructed data.

An apparatus 2 comprises at least three processing circuits 4 to perform redundant processing of a common thread of program instructions. Error detection circuitry 16 is provided comprising a number of comparators 22 for detecting a mismatch between signals on corresponding signal nodes 20 in the processing circuits 4. When a comparator 22 detects a mismatch, this triggers a recovery process. The error detection circuitry 16 generates an unresolvable error signal 36 indicating that a detected area is unresolvable by the recovery process when, during the recovery process, a mismatch is detected by one of the proper subset 34 of the comparators 22. By considering fewer comparators 22 during the recovery process than during normal operation, the chances of unrecoverable errors being detected can be reduced, increasing system availability.

Implementations of Data Bus Inversion (DBI) techniques within a memory system are disclosed. In one embodiment, a set of random access memory (RAM) integrated circuits (ICs) is separated from a logic system by a bus. The logic system can contain many of the logic functions traditionally performed on conventional RAM ICs, and accordingly the RAM ICs can be modified to not include such logic functions. The logic system, which can be a logic integrated circuit intervening between the modified RAM ICs and a traditional memory controller, additionally contains DBI encoding and decoding circuitry. In such a system, data is DBI encoded and at least one DBI bit issued when writing to the modified RAM ICs. The RAM ICs in turn store the DBI bit(s) with the encoded data. When the encoded data is read from the modified RAM ICs, it is transmitted across the bus in its encoded state along with the DBI bit(s). The logic integrated circuit then decodes the data using the DBI bit(s) to return it to its original state.

An indirection mapping data structure can maintain a mapping between logical block addresses used by a host computer and physical data storage locations on a solid state drive. Changes to the indirection mapping data structure can be stored in journals. When a journal is full, the journal can be stored to a predetermined location on the cluster block determined based on the number of entries stored by the journal, leading to a number of journals scattered throughout the cluster block at predetermined locations. Each physical chunk of media, whether written with data or marked as defective is journaled. Such a journaling scheme, where the journal locations are predetermined and each physical chunk of media is journaled is referred to as physical media-aware spatially coupled journaling. During replay the spatially coupled journals can be retrieved from the predefined locations within cluster blocks and used to rebuild the indirection mapping data structure.

Techniques are provided for storing a row address of a defective row of memory cells to a bank of non-volatile storage elements (e.g., fuses or anti-fuses). After a memory device has been packaged, one or more rows of memory cells may become defective. In order to repair (e.g., replace) the rows, a post-package repair (PPR) operation may occur to replace the defective row with a redundant row of the memory array. To replace the defective row with a redundant row, an address of the defective row may be stored (e.g., mapped) to an available bank of non-volatile storage elements that is associated with a redundant row. Based on the bank of non-volatile storage elements the address of the defective row, subsequent access operations may utilize the redundant row and not the defective row.