Flash memory controller and data storage device and flash memory control method

A flash memory controller, operating a flash memory in accordance with commands issued from a host, comprising:

• a first volatile storage area, storing logical-to-physical address mapping data between the host and the flash memory as well as error detection codes encoded from the logical-to-physical address mapping data;
• and
• a microcontroller, configured to perform an error detection procedure based on the error detection codes when reading from the first volatile storage area,
• wherein when the error detection procedure shows that logical-to-physical address mapping data retrieved from the first volatile storage area is incorrect, the microcontroller is configured to restore the logical-to-physical address mapping data in the first volatile storage area based on a backup of the logical-to-physical address mapping data.