Data storage device and data maintenance method thereof

A data maintenance method, applied to a data storage device having a flash memory, wherein the flash memory has a plurality of SLC-spare blocks, a plurality of SLC-data blocks, a plurality of TLC-spare blocks and a plurality of TLC-data blocks, the data maintenance method comprising:

• receiving a write command arranged to write data into the flash memory;
• and
• writing the data into the SLC-spare blocks in response to a write command,
• wherein when a first predetermined condition is satisfied, the step of writing the data into the SLC-spare blocks further comprises:
• selecting a plurality of first TLC-data blocks with the least amount of valid data from the TLC-data blocks;
• writing valid data stored in the first TLC-data blocks into at least one first TLC-spare block;
• and
• releasing the first TLC-data block to increase the number of TLC-spare blocks by one.

A data maintenance method, applied to a data storage de vice having a flash memory, wherein the flash memory has a plurality of logical SLC-spare blocks, a plurality of logical SLC-data blocks, a plurality of TLC-spare blocks and a plurality of TLC-data blocks, the data maintenance method further comprising:

• writing data into one of the logical SLC-spare blocks in response to a write command from a host, wherein when a first predetermined condition is satisfied, the step of writing data into one of the logical SLC-spare blocks further comprises:
• selecting a part of the TLC-data blocks with the least amounts of valid data;
• writing valid data stored in the part of the TLC-data blocks into one of the TLC-spare block;
• and
• releasing the part of the TLC-data blocks.