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 which comprising at least an active memory block configured to receive data to be written in the memory device from a host device, the memory controller is coupled to the memory device and configured to access the memory device and store a first mapping table corresponding to the active memory block, and the data processing method is performed by the memory controller and comprises:

• writing data of a first logical address in the active memory block;
• and
• updating content of a sub-region bit table in response to the write operation of the active memory block, wherein the sub-region bit table comprises one or more bits, each bit is associated with one or more sub-regions and a value of each bit is initially set to a default value, and
• wherein the step of updating the content of the sub-region bit table in response to the write operation of the active memory block further comprises:
• determining which sub-region the first logical address belongs to;
• and
• setting the value of the bit associated with the sub-region that the first logical address belongs to to a predetermined value different from the default value, and
• wherein the sub-region bit table is established after content of a second mapping table has been updated based on the first mapping table,
• wherein the first mapping table comprises a plurality of fields, one field of the first mapping table is configured to record mapping information of one physical address of the active memory block, and the mapping information of the physical address is physical-to-logical mapping information regarding which logical address the data stored in the physical address of the active memory block is directed to, and
• wherein the second mapping table comprises a plurality of fields, one field of the second mapping table is configured to record mapping information of one logical address, and the mapping information of the logical address is logical-to-physical mapping information regarding which physical address of the memory device stores data of the logical address.