摘要:
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.
摘要:
An embodiment of a non-volatile memory storage system comprises a memory controller, and a flash memory module. The memory controller manages the storage operations of the flash memory module. The memory controller is configured to assign a priority level to one or more types of house keeping operations that may be higher than a priority level of one or more types of commands received by a host coupled to the storage system, and to service all operations required of the flash memory module according to priority.
摘要:
A portion of a nonvolatile memory array that is likely to contain, partially programmed data may be identified from a high sensitivity read, by applying stricter than usual error correction code (ECC) requirements, or using pointers to programmed sectors. The last programmed data may be treated as likely to be partially programmed data. Data in the identified portion may be copied to another location, or left where it is with an indicator to prohibit further programming to the same cells. To avoid compromising previously stored data during subsequent programming, previously stored data may be backed up. Backing up may be done selectively, for example, only for nonsequential data, or only when the previously stored data contains an earlier version of data being programmed. If a backup copy already exists, another backup copy is not created. Sequential commands are treated as a single command if received within a predetermined time period.
摘要:
A method for operating a memory system is provided. In this method, a sequential update block is provided and a write command is received to write data. The write command comprises a logical address associated with the data. If the logical address is associated with a host file management data structure, then the sequential update block is converted to a chaotic update block. After the conversion, the data are written to the chaotic update block.
摘要:
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.
摘要:
A method and apparatus for storing an n-bit (for n>=2) data block in an array of non-volatile memory cells utilizes a predetermined n+k-bit (for k>=1) encoding selected to reduce the number of programmed cells required to store the n-bit data block.
摘要:
The variable latency associated with flash memory due to background data integrity operations is managed in order to allow the flash memory to be used in isochronous systems. A system processor is notified regularly of the nature and urgency of requests for time to ensure data integrity. Minimal interruptions of system processing are achieved and operation is ensured in the event of a power interruption.
摘要:
A method for operating a memory system is provided. In this method, a write command is received to write data following a previous write command. The write command and the previous write command have a discontinuity in logical addresses and the discontinuity in logical addresses defines a gap between a logical address of the write command and a logical address of the previous write command. Here, a sequential update block and preexisting data associated with the sequential update block are provided. The gap is compared with a threshold size and the data are written to the sequential update block if the gap is less than the threshold size.
摘要:
A method for phased garbage collection is provided. In this method, a write command is received to write data. The write command is allocated a timeout period to complete an execution of the write command. Thereafter, a busy signal is asserted and a portion of a garbage collection operation is performed for a garbage collection time period. The data are written to a block and the busy signal is released before the timeout period.
摘要:
A method for operating a non-volatile memory storage system is provided. In this method, a write command is received to write data. The write command is allocated a timeout period to complete an execution of the write command. Within the timeout period, a portion of a garbage collection operation is performed. The data associated with the write command are written to a buffer associated with the non-volatile memory storage system.