Patent ID: 7971007

Claim:
A method for accessing a downgrade memory including a plurality of blocks, each block having a plurality of pages, and each page having a plurality of sectors, the downgrade memory having a plurality of non-accessible sectors, the method comprising the steps of: programming an initial write command to the blocks; generating status information by programming an initial read command to the blocks after the blocks have been written; marking at least one block as a special block having at least one of the non-accessible sectors in response to the status information for a follow-up accessing, wherein the status information indicates the at least one of the non-accessible sectors of the at least one block; parsing a write command corresponding to the at least one special block; selecting accessible sectors according to the status information; and programming the write command to the accessible sectors, wherein the write command comprises: a head portion, indicating the beginning of the write command; a first addressing portion next to the head portion, indicating page address for being written with data; at least one list portion, being adjacent to the first addressing portion; and a tail portion next to the at least one list portion, indicating end of the write command, wherein each of the at least one list portion stores sector address and data.