Apparatuses and techniques are described for periodically refreshing word line voltages in a memory device. A decision to perform a refresh operation is made based on the temperature and number of program-erase (P-E) cycles. In one approach, the refresh operation is not performed if the number of P-E cycles is below a threshold number and/or the temperature is below a threshold temperature. When the temperature and number of P-E cycles indicate that a refresh operation should be performed, a timer counts an elapsed time until the elapsed time reaches an allowed discharge time. The allowed discharge time can be based on the temperature, number of P-E cycles, and other factors which affect an expected number of fail bits. The allowed discharge time can also change as the temperature changes during the counting of the elapsed time.

Apparatuses and techniques are described for periodically refreshing word line voltages in a memory device. A decision to perform a refresh operation is made based on the temperature and number of program-erase (P-E) cycles. In one approach, the refresh operation is not performed if the number of P-E cycles is below a threshold number and/or the temperature is below a threshold temperature. When the temperature and number of P-E cycles indicate that a refresh operation should be performed, a timer counts an elapsed time until the elapsed time reaches an allowed discharge time. The allowed discharge time can be based on the temperature, number of P-E cycles, and other factors which affect an expected number of fail bits. The allowed discharge time can also change as the temperature changes during the counting of the elapsed time.

A storage system and method for smart folding are provided. In one example, the storage system has a memory with a plurality of single level cell (SLC) blocks and a multi-level cell (MLC) block. The MLC block has a plurality of pages, each with a different sense time. The storage system tracks a read count of each of the plurality of SLC blocks and determines how to fold the plurality of SLC blocks into the plurality of pages based on the read count of each of the plurality of SLC blocks and the sense time of each of the plurality of pages. In this way, SLC blocks with higher read counts can be folded into pages that have faster sense times.

A storage device and an operating method thereof are provided. The storage device includes a non-volatile memory and a memory controller. The non-volatile memory includes memory blocks each including a word lines. The memory controller determines a word line strength of each of the word lines, adjusts a state count of each of the word lines based on the word line strengths, and adjust a program parameter of each of the word lines to decrease a program time variation between the word lines.

Method and apparatus for managing data in a non-volatile memory (NVM) of a storage device, such as a solid-state drive (SSD). In some embodiments, first data are read from the NVM using an initial set of read voltages over a selected range of cross-temperature differential (CTD) values comprising a difference between a programming temperature at which the first data are programmed to the NVM cells and a reading temperature at which the first data are subsequently read from the NVM cells. A master set of read voltages is thereafter selected that provides a lowest acceptable error rate performance level over the entirety of the CTD range, and the master set of read voltages is thereafter used irrespective of NVM temperature. In some cases, the master set of read voltages may be further adjusted for different word line addresses, program/erase counts, read counts, data aging, etc.

Adaptive write operations for non-volatile memories select programming parameters according to monitored programming performance of individual memory cells. In one embodiment of the invention, programming voltage for a memory cell increases by an amount that depends on the time required to reach a predetermined voltage and then a jump in the programming voltage is added to the programming voltage required to reach the next predetermined voltage. The adaptive programming method is applied to the gate voltage of memory cells; alternatively, it can be applied to the drain voltage of memory cells along a common word line. A circuit combines the function of a program switch and drain voltage regulator, allowing independent control of drain voltage of selected memory cells for parallel and adaptive programming. Verify and adaptive read operations use variable word line voltages to provide optimal biasing of memory and reference cells during sensing.

There may be provided a controller including an erase count monitor and a command generator. The erase count monitor may store and update an erase count value for the memory block. The erase count value may indicate a number of times an erase operation is performed for the memory block. The command generator may be configured to generate, based on the erase count value, a set command for setting a first select transistor among the select transistors to which an erase operation voltage is to be applied during the erase operation of the memory block, and a second select transistor among the select transistors to be floated when the erase operation voltage is to be applied to the first select transistor.

Error correction coding (ECC) mis-corrected reads, if undetected, result in silent data corruption of a non-volatile memory device. Overcoming ECC mis-corrected reads is based on a read signature of a result of reading a page in the non-volatile memory device. An ECC mis-correct logic counts the number of bits in the end-most buckets into which the bits of the result is divided. End-most buckets that are overpopulated or starved reveal a tell-tale read signature of an ECC mis-correct. The ECC mis-correct is likely to occur when the read reference voltage level used to read the page is shifted in one direction or another to an extreme amount that risks reading data from a different page. Detecting ECC mis-corrected reads can be used to overcome the ECC mis-corrects and mitigate silent data corruption.

A memory system and method for storing data in one or more storage chips includes: one or more memory cards each having a plurality of storage chips, and each chip having a plurality of dies having a plurality of memory cells; a memory controller comprising a translation module, the translation module further comprising: a logical to virtual translation table (LVT) having a plurality of entries, each entry in the LVT configured to map a logical address to a virtual block address (VBA), where the VBA corresponds to a group of the memory cells on the one or more memory cards, wherein each entry in the LVT further includes a write wear level count to track the number of writing operations to the VBA, and a read wear level count to track the number of read operations for the VBA mapped to that LVT entry.

A nonvolatile semiconductor memory includes a plurality of memory cells, a plurality of bit lines connected to the plurality of memory cells, a first circuit which controls the plurality of bit lines according to first data, a source line commonly connected to first ends of the plurality of bit lines, and a second circuit which is connected to the source line and which detects second data according to a current amount in the source line.