Data processing method for improving access performance of memory device and data storage device utilizing the same

A data processing method for a data storage device, wherein the data storage device comprises a memory device and a memory controller, the memory device comprises a plurality of memory blocks, the memory blocks correspond to a plurality of logical units, each logical unit corresponds to a plurality of logical addresses, the logical addresses corresponding to each logical unit are divided into a plurality of regions, and each region is further divided into a plurality of sub-regions and each sub-region corresponds to multiple continuous logical addresses, the memory controller is coupled to the memory device and configured to access the memory device, and the data processing method is performed by the memory controller and comprises:

• establishing a read count table and updating content of the read count table in response to a read command issued by a host device with a transfer length greater than 1 for designating more than one logical address to be read, wherein the read count table comprises a plurality of fields and each field is configured to record a read count associated with one sub-region, and the content of the read count table is updated by increasing the read count(s) associated with the sub-region(s) that logical addresses designated in the read command belong to;
• selecting at least one sub-region to be rearranged according to the content of the read count table;
• and
• performing a data rearrangement procedure to move data of the logical addresses belonging to the selected at least one sub-region to a first memory space of the memory device having continuous physical addresses, wherein the first memory space is a first memory block.