Patent ID: 8423819

Claim:
A data storage device, coupled to a host, comprising: a downgrade memory, comprising a plurality of blocks, wherein each of the blocks comprises a plurality of pages, and each of the pages comprises a plurality of sectors, wherein some of the sectors are defect sectors; and a controller, generating a defect table for recording a plurality of defect addresses of the defect sectors in the blocks, receiving a plurality of data sectors to be written to the downgrade memory from the host, determining a plurality of first physical sector addresses for storing the data sectors according to the defect table, and sending write commands to the downgrade memory to direct the downgrade memory to write the data sectors according to the first physical sector addresses; wherein the write commands respectively comprise an identifier of the write command, a physical page address of a target page, a series of random write commands and physical sector addresses of the target page to be written with the data sectors, and a program command, and wherein the identifier of the write command is different from a hex-decimal value representing the random write commands.