A controller, a flash memory device and method for writing data to a flash memory device

A controller, a flash memory device and method for writing data to the flash memory device, wherein the controller is applied to the storage system, the storage system comprises a flash memory device and said controller, said flash memory device comprises a flash memory chip, the flash chip containing block, said block comprising a plurality of pages, wherein said at least one of the plurality of pages in the bad page is page, the controller comprising a processor and a communication interface; the communication interface for communicating with the flash memory device communicates; the processor for receiving the capacity information of the block of the flash memory device transmits; obtaining the effective capacity of the block according to the capacity information of the block, the effective capacity does not contain the said bad page capacity; reading target data, said target data size for the effective capacity of the blocks; transmitting said target data to the flash memory device. You can improve the utilization of the block, to save storage space of the SSD.