A semiconductor memory device having a plurality of banks

(57) ABSTRACT A flash memory includes a data bank having a plurality of banks, a merge bank, and an update data bank. A file System using the flash memory includes a unit Storing update data corresponding to a data rewrite command into the update data bank, a unit Selecting the latest update data for each block from update data Stored in the update data bank when the update data bank becomes full, and a processing unit processing the latest update data. The processing unit includes a unit Storing latest update data into a merge bank, a unit Selecting data associated with the latest update data from the data bank to Store the Selected data into the merge bank, and a unit Setting the merge bank as a new data bank.