Data accessing method for flash memory storage device having data perturbation module, and storage system and controller using the same

A controller, for a flash memory storage device having a flash memory, wherein the flash memory has a plurality of physical pages corresponding to a plurality of logical pages, the controller comprising:

• a microprocessor unit, for receiving a read command from a host, wherein the read command indicates reading data from a first logical page among the logical pages;
• a data perturbation module, electrically connected to the microprocessor unit for decoding data read from the flash memory;
• a flash memory interface, electrically connected to the microprocessor unit for accessing the flash memory;
• a buffer memory, electrically connected to the microprocessor unit for temporarily storing data;
• and
• a memory management module, electrically connected to the microprocessor unit for determining whether the first logical page or a first physical page corresponding to the first logical page among the physical pages has been written with data,
• wherein if the first logical page or the first physical page has not been written with data, the memory management module transmits a predetermined data to the host.

A flash memory storage system, comprising:

• a flash memory, for storing data, wherein the flash memory has a plurality of physical pages corresponding to a plurality of logical pages;
• a connector, for connecting to a host;
• and
• a controller, electrically connected to the flash memory and the connector, and configured to receive a read command from the host, wherein the read command indicates reading data from a first logical page among the logical pages,
• wherein the controller determines whether the first logical page or a first physical page corresponding to the first logical page among the physical pages has been written with data,
• wherein if the first logical page or the first physical page has not been written with data, the controller transmits a predetermined data to the host.