Providing space-efficient storage for dynamic random access memory (DRAM) cache tags is provided. In one aspect, a DRAM cache management circuit provides a plurality of cache entries, each of which contains a tag storage region, a data storage region, and an error protection region. The DRAM cache management circuit is configured to store data to be cached in the data storage region of each cache entry. The DRAM cache management circuit is also configured to use an error detection code (EDC) instead of an error correcting code (ECC), and to store a tag and the EDC for each cache entry in the error protection region of the cache entry. In this manner, the capacity of a DRAM cache can be increased by avoiding the need for the tag storage region for each cache entry, while still providing error detection for the cache entry.

Providing memory bandwidth compression using compression indicator (CI) hint directories in a central processing unit (CPU)-based system is disclosed. In this regard, a compressed memory controller provides a CI hint directory comprising a plurality of CI hint directory entries, each providing a plurality of CI hints. The compressed memory controller is configured to receive a memory read request comprising a physical address of a memory line, and initiate a memory read transaction comprising a requested read length value. The compressed memory controller is further configured to, in parallel with initiating the memory read transaction, determine whether the physical address corresponds to a CI hint directory entry in the CI hint directory. If so, the compressed memory controller reads a CI hint from the CI hint directory entry of the CI hint directory, and modifies the requested read length value of the memory read transaction based on the CI hint.

A device includes a memory and a controller including a data shaping engine. The data shaping engine is configured to apply a mapping to input data that includes one or more m-tuples of bits to generate transformed data. The transformed data includes one or more n-tuples of bits, and n is greater than m. A relationship of a gray coding of m-tuples to a gray coding of n-tuples is indicated by the mapping. The input data includes a first number of bit values that represent a particular logical state, and the transformed data includes a second number of bit values that represent the particular logical state, the second number of bit values being less than the first number of bit values.

According to one embodiment, when the first command is received from a host, a controller translates a first address designated by a first command into a second address representing a real address of the nonvolatile memory based on a first mapping and accesses the translated second address of the nonvolatile memory. The controller determines whether or not the first mapping is changed based on a degree of wear of the nonvolatile memory and changes some of all the correspondence relations in a case where the first mapping is changed.

A memory system having an interconnect configured to receive commands from a system to read data from and/or write data to a memory device. The memory system also has a bridge configured to receive the commands from the interconnect, to manage ECC data and to perform address translation between system addresses and physical memory device addresses by calculating a first ECC memory address for a first ECC data block that is after and adjacent to a first data block having a first data address, calculating a second ECC memory address that is after and adjacent to the first ECC block, and calculating a second data address that is after and adjacent to the second ECC block. The bridge may also check and calculate ECC data for a complete burst of data, and/or cache ECC data for a complete burst of data that includes read and/or write data.

An apparatus is disclosed having a parity buffer having a plurality of parity pages and one or more dies, each die having a plurality of layers in which data may be written. The apparatus also includes a storage controller configured to write a stripe of data across two or more layers of the one or more dies, the stripe having one or more data values and a parity value. When a first data value of the stripe is written, it is stored as a current value in a parity page of the parity buffer, the parity page corresponding to the stripe. For each subsequent data value that is written, an XOR operation is performed with the subsequent data value and the current value of the corresponding parity page and the result of the XOR operation is stored as the current value of the corresponding parity page.

A method and apparatus for determining the sector size and concomitant host metadata size to determine the difference between total size of the data block to be stored, and using the difference for parity data. This allows an increase in parity bits available for smaller sector sizes and/or data with smaller host metadata sizes. Because the amount of space available for additional parity bits is known, data with lower numbers of parity bits may be assigned to higher quality portions a memory array written with longer programming trim times, and/or written to memory dies with good redundant columns, further increasing performance and reliability.

Memory controllers, devices, modules, systems and associated methods are disclosed. In one embodiment, a memory module includes a pin interface for coupling to a bus. The bus has a first width. The module includes at least one storage class memory (SCM) component and at least one DRAM component. The memory module operates in a first mode that utilizes all of the first width, and in a second mode that utilizes less than all of the first width.

A system includes a memory device having blocks of memory cells. A processing device is operatively coupled to the memory device, the processing device to detect an error event triggered within a source block of the memory cells. In response to detection of the error event, the processing device is to read data from the source block; write the data into a mitigation block that is different than the source block; and replace, in a block set map data structure, a first identifier of the source block with a second identifier of the mitigation block. The block set map data structure includes block location metadata for a data group, of the memory device, that includes the data.

Systems and methods for recovering corrupted data or missing data from a cache are provided. When a data corruption is discovered in a storage system, the cache may be searched to determine if a valid copy of the corrupted data can be recovered from the cache.