Memory management system and method
View Patent ↗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.
1. A method of operating a memory system, the method comprising:
providing a memory system having a plurality of FLASH memory modules;
providing a memory controller communicating with the plurality of memory modules;
storing data as a stripe of data blocks and an error correcting code data block for the stripe of data blocks, on memory modules of the plurality of memory modules;
configuring the memory controller and the memory modules such that at least one of write or erase operations of each of the memory modules where the stripe of data is stored occurs during a substantially non-overlapping time interval with respect to at least one of write or erase operations of each of the other memory modules where the stripe of data is stored;
requesting data of the stored stripe of data blocks and the error correcting code data block, from the memory modules; and
configuring the memory controller to use the earliest of:
(a) the data in the stored stripe of data blocks, or
(b) less than all of the data in the stored stripe of data blocks and the error correcting code data block,
received by the memory controller to represent the data, without waiting for the other of either (a) or (b) to be received by the memory controller; and
outputting the data,
wherein, when using the step of (b) to represent the data, the step includes using the less than all of the data in stored stripe of data blocks and the error correcting code data block to reconstruct missing data in the stripe of stored data blocks; and, wherein the missing data is data that is in (a) and that is not in (b),
wherein the requesting step provides the requested data to the output step in a time interval of less than or equal to approximately an erase time of a NAND FLASH memory circuit of a memory module of the plurality of memory modules.
2. The method of claim 1 , further comprising:
providing a communications interface adapted to connect to an external source of data or requests for retrieving data.
3. The method of claim 1 , wherein the error correcting code data is parity data.
4. The method of claim 3 , wherein the missing data of the stripe of data blocks is computed as an exclusive-OR (XOR) of less than all of the stored data blocks of the stripe of data blocks and the parity data.
5. The method of claim 1 , wherein the memory module is at least one of an electronic circuit or a physical address range.
6. A method of operating a memory system, the method comprising:
providing a memory system having a plurality of memory modules comprising FLASH memory circuits;
providing a memory controller communicating with the plurality of memory modules;
storing data as a stripe of data blocks and an error correcting code data block for the stripe of data blocks, on memory modules of the plurality of memory modules;
requesting data of the stored stripe of data blocks and the error correcting code data block, from the memory modules; and
configuring the memory controller to use the earliest of:
(a) the data in the stored stripe of data blocks, or
(b) less than all of the data in the stored stripe of data blocks and the error correcting code data block,
received by the memory controller to represent the data, without waiting for the other of either (a) or (b) to be received by the memory controller; and
outputting the data,
wherein, when using the step of (b) to represent the data, the step includes using the less than all of the data in stored stripe of data blocks and the error correcting code data block to reconstruct missing data in the stripe of stored data blocks; and, wherein the missing data is data that is in (a) and that is not in (b),
wherein the memory controller and the memory modules are configured such that the step of outputting the data is performed in a time period of less than an erase time period of a data block of the plurality of data blocks from the time of performing the step of requesting.
7. The method of claim 6 , wherein the step of outputting the data is performed while another data block is being written to a memory module of the memory modules on which the data being read has been stored.
8. The method of claim 6 , wherein the step of outputting the data is performed while an erase operation is being performed.