A data processing system includes one or more nodes, each node including a memory sub-system. The sub-system includes a fine-grained, memory, and a less-fine-grained (e.g., page-based) memory. The fine-grained memory optionally serves as a cache and/or as a write buffer for the page-based memory. Software executing on the system uses a node address space which enables access to the page-based memories of all nodes. Each node optionally provides ACID memory properties for at least a portion of the space. In at least a portion of the space, memory elements are mapped to locations in the page-based memory. In various embodiments, some of the elements are compressed, the compressed elements are packed into pages, the pages are written into available locations in the page-based memory, and a map maintains an association between the some of the elements and the locations.

System including a fine-grained memory and a less-fine-grained memory

A non-volatile memory system is formed of floating gate memory cells arranged in blocks as the smallest unit of memory cells that are erasable together. The system includes a number of features that may be implemented individually or in various cooperative combinations. One feature is the storage in separate blocks of the characteristics of a large number of blocks of cells in which user data is stored. These characteristics for user data blocks being accessed may, during operation of the memory system by its controller, be stored in a random access memory for ease of access and updating. According to another feature, multiple sectors of user data are stored at one time by alternately streaming chunks of data from the sectors to multiple memory blocks. Bytes of data in the stream may be shifted to avoid defective locations in the memory such as bad columns. Error correction codes may also be generated from the streaming data with a single generation circuit for the multiple sectors of data. The stream of data may further be transformed in order to tend to even out the wear among the blocks of memory. Yet another feature, for memory systems having multiple memory integrated circuit chips, provides a single system record that includes the capacity of each of the chips and assigned contiguous logical address ranges of user data blocks within the chips which the memory controller accesses when addressing a block, making it easier to manufacture a memory system with memory chips having different capacities. A typical form of the memory system is as a card that is removably connectable with a host system but may alternatively be implemented in a memory embedded in a host system. The memory cells may be operated with multiple states in order to store more than one bit of data per cell.

Flash EEPROM System with Simultaneous Multiple Data Sector Programming and Storage of Physical Block Characteristics in Other Designated Blocks

A method for operating a memory (28) that includes a plurality of analog memory cells (32) includes storing data in the memory by writing first storage values to the cells. Second storage values are read from the cells, and a Cumulative Distribution Function (CDF) of the second storage values is estimated. The estimated CDF is processed so as to compute one or more thresholds. A memory access operation is performed on the cells using the one or more thresholds.

Adaptive Estimation of Memory Cell Read Thresholds

A method for operating a memory (28) includes storing data, which is encoded with an Error Correction Code (ECC), in analog memory cells (32) of the memory by writing respective analog input values selected from a set of nominal values to the analog memory cells. The stored data is read by performing multiple read operations that compare analog output values of the analog memory cells to different, respective read thresholds so as to produce multiple comparison results for each of the analog memory cells. At least two of the read thresholds are positioned between a pair of the nominal values that are adjacent to one another in the set of the nominal values. Soft metrics are computed responsively to the multiple comparison results. The ECC is decoded using the soft metrics, so as to extract the data stored in the analog memory cells.

Reading memory cells using multiple thresholds

A memory system and method of operating the same is described, where the memory system is used to store data in a RAIDed manner. The stored data may be retrieved, including the parity data so that the stored data is recovered when the first of either the stored data without the parity data, or the stored data from all but one memory module and the parity data, has been received. The writing of data, for low write data loads, is managed such that only one of the memory modules of a RAID stripe is being written to, or erased, during a time interval.

Memory management system and method

A portion of a nonvolatile memory is partitioned from a main multi-level memory array to operate as a cache. The cache memory is configured to store at less capacity per memory cell and finer granularity of write units compared to the main memory. In a block-oriented memory architecture, the cache has multiple functions, not merely to improve access speed, but is an integral part of a sequential update block system. The cache memory has a capacity dynamically increased by allocation of blocks from the main memory in response to a demand to increase the capacity. Preferably, a block with an endurance count higher than average is allocated. The logical addresses of data are partitioned into zones to limit the size of the indices for the cache.

Non-Volatile Memory and Method With Write Cache Partition Management Methods

Data scrambling techniques implemented externally to a flash memory device are disclosed which can be used in concert with flash memory on-chip copy functionality operating internally to the flash device, thus supporting high performance copying operations. All the data stored in the flash may be scrambled, including headers and control structures. Robust file system operation may be achieved, including the capability to tolerate a power loss at any time, and yet be able to relocate data internally within the flash without having to de-scramble and then re-scramble the data. An exemplary hardware based solution has little or no impact on overall system performance, and may be implemented at very low incremental cost to increase overall system reliability. The data scrambling technique preferably uses a logical address, such as logical block address or logical page address, rather than a physical address, to determine a seed scrambling key.

System, method and memory device providing data scrambling compatible with on-chip copy operation

A portion of a nonvolatile memory is partitioned from a main multi-level memory array to operate as a cache. The cache memory is configured to store at less capacity per memory cell and finer granularity of write units compared to the main memory. In a block-oriented memory architecture, the cache has multiple functions, not merely to improve access speed, but is an integral part of a sequential update block system. Decisions to write data to the cache memory or directly to the main memory depend on the attributes and characteristics of the data to be written, the state of the blocks in the main memory portion and the state of the blocks in the cache portion.

Non-volatile memory and method with write cache partitioning

A portion of a nonvolatile memory is partitioned from a main multi-level memory array to operate as a cache. The cache memory is configured to store at less capacity per memory cell and finer granularity of write units compared to the main memory. In a block-oriented memory architecture, the cache has multiple functions, not merely to improve access speed, but is an integral part of a sequential update block system. Decisions to archive data from the cache memory to the main memory depend on the attributes of the data to be archived, the state of the blocks in the main memory portion and the state of the blocks in the cache portion.

Nonvolatile memory with write cache having flush/eviction methods

A non-volatile memory storage system is provided. The non-volatile memory storage system includes a memory configured to store a storage system firmware and a non-volatile memory cell array configured to maintain a buffer. A processor in communication with the memory and the non-volatile memory cell array also is included in the non-volatile memory storage system. Here, the processor is configured to execute the storage system firmware stored in the memory. The storage system firmware comprises program instructions for receiving a write command to write data to the non-volatile memory cell array. The write command is allocated a timeout period to complete an execution of the write command. The storage system firmware also comprises program instructions for performing a portion of a garbage collection operation within the timeout period and for storing the data in the buffer.

Shai Traister

Papers

Non-Volatile Memory and Method With Write Cache Partition Management Methods

System, method and memory device providing data scrambling compatible with on-chip copy operation

Non-volatile memory and method with write cache partitioning

Nonvolatile memory with write cache having flush/eviction methods

Non-volatile memory storage systems for phased garbage collection