Method for accessing flash module, associated flash controller and electronic device

A flash controller, arranged to access a flash module, and the flash controller comprising:

• a read only memory (ROM), arranged to store a code;
• a microprocessor, arranged to execute the code to control the access of the flash module;
• and
• a memory, arranged to store a logical address group table corresponding to a block in the flash module, wherein the logical address group table marks states of a plurality of logical address groups, and the state of each of the logical address groups indicates whether data written into the block has any logical address located in the logical address group;
• wherein when the block requires a garbage collection operation, the microprocessor refers to the logical address group table to read at least one logical address to physical address (L2P) mapping table from the flash module, and refers to the at least one L2P mapping table to determine valid pages and invalid pages in the block, for performing the garbage collection operation.

An electronic device, comprising:

• a flash module;
• and
• a flash controller, arranged to access the flash module, wherein the flash controller creates a logical address group table corresponding to a block in the flash module;
• wherein the logical address group table marks states of a plurality of logical address groups, and the state of each of the logical address groups indicates whether data written into the block has any logical address located in the logical address group;
• and when the block requires a garbage collection operation, the flash controller refers to the logical address group table to read at least one L2P mapping table from the flash module, and refers to the at least one L2P mapping table to determine valid pages and invalid pages in the block, for performing the garbage collection operation.