Method and system for data storage

A method of managing data storage in a memory, including:

• providing a nonvolatile memory device for storing data, the non-volatile memory device having a processor, volatile memory and non-volatile memory;
• configuring the processor for:
• interpreting a write command from a user to determine whether the write command is a first type or a second type,
• wherein the write command is of the first type when the command includes a logical address and does not include a physical address where the data is to be stored;
• and
• the write command is of the second type when the write command includes at least a physical address at which the data is stored in the nonvolatile memory;
• and,
• responsive to the write command of the first type, determining the physical address in the nonvolatile memory where data associated with the write command of the first type is to be stored in the nonvolatile memory, in accordance with a protocol, and associating the physical address with the logical address in an indirection table;
• and
• responsive to the write command of second type, determining a physical address in the nonvolatile memory where data associated with the write command of the second type is to be stored, in accordance with a protocol, and including the physical address in a response message to the user and indirection table,
• wherein the indirection table is maintained in the nonvolatile memory device.

A method of garbage collection in a memory system, comprising:

• providing a memory system, including a non-volatile memory, volatile memory and a processor;
• maintaining a first indirection table associating logical addresses with physical addresses, the memory being organized as a plurality of blocks having a plurality of physical addresses;
• characterizing each physical address as being one of valid, obsolete or free;
• selecting a block of the plurality of blocks in accordance with a protocol;
• reading the data from valid storage locations of the selected block to a buffer in the volatile memory while maintaining an association of valid data with the physical address from which it has been read;
• maintaining a cache of data to be written to the non-volatile memory;
• erasing the selected block of the plurality of blocks;
• selecting a physical address for the data in the cache from the indirection table, in accordance with a protocol;
• and
• writing data from the buffer and the data in the cache to a block selected from a pool of blocks that have been erased to provide free physical storage locations.

A device for storing data, comprising:

• a nonvolatile semiconductor memory, the memory being organized as blocks, each block comprising a plurality of physical locations where a data is storable;
• a processor having an associated buffer memory and communicating with a data interface and the nonvolatile semiconductor memory;
• wherein the processor is configured to receive commands through the data interface and to manage storage of data in the nonvolatile semiconductor memory;
• and to
• interpret a read data command from a user to determine whether the read data command is a first type of read data command or a second type of read data command, and
• wherein the read data command is of the first type when the command includes a logical address and does not include a physical address;
• and the read data command is of the second type when the command includes at least a physical address at which the data is stored in memory;
• and,
• responsive to the first type of read data command, determine the physical address of the data;
• retrieve data from the physical address in the non-volatile memory and return the data to the user;
• or
• responsive to the second type of read command, retrieve data from the physical address in the non-volatile memory and return the data to the user,
• wherein a relationship between the logical address and the physical address is maintained in an indirection table.