CPC G06F 3/0604 (2013.01) [G06F 3/0616 (2013.01); G06F 3/0631 (2013.01); G06F 3/064 (2013.01); G06F 3/0656 (2013.01); G06F 3/0658 (2013.01); G06F 3/0679 (2013.01); G06F 3/0685 (2013.01); G06F 12/0246 (2013.01); G11C 11/5628 (2013.01); G06F 12/0804 (2013.01); G06F 12/0866 (2013.01); G06F 2212/7201 (2013.01); G06F 2212/7202 (2013.01); G06F 2212/7203 (2013.01); G06F 2212/7209 (2013.01)] | 20 Claims |
1. A storage device comprising:
a nonvolatile memory including a plurality of blocks, each of the plurality of blocks being a unit of data erasing and configured to store a first data of a first bit; and
a controller configured to:
allocate a first set of the plurality of blocks as a first memory area, the first set of the plurality of blocks each including a first block having a memory cell configured to store a second data of a second bit, the second bit being less than the first bit;
allocate a second set of the plurality of blocks as a second memory area, the second set of the plurality of blocks each including a second block having a memory cell configured to store the first data;
receive data from an external host apparatus;
store the received data into the first block in the first set of the plurality of blocks by a first management unit, the first management unit being less than the unit of data erasing;
copy valid data stored in the first block to the second block by a second management unit, the second management unit being corresponding to the unit of data erasing and being larger than the first management unit; and
release the first block in which no valid data is stored, after copying the valid data stored in the first block,
wherein the first block includes a pseudo block configured to be capable of storing the first data but storing the second data.
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