SEMICONDUCTOR MEMORY DEVICE FOR PERFORMING REMAINING BANK REFRESH OPERATION AND REFRESH METHOD THEREOF

Disclosed is a semiconductor memory device that includes a memory cell array including a plurality of memory banks, a command decoder configured to decode a per-bank refresh command and a remaining bank refresh command received from an external source, and a refresh controller configured to control the cell array to perform a per-bank refresh operation for refreshing one memory bank among the plurality of memory banks that is based on a decoding result of the per-bank refresh command of the command decoder, wherein the refresh controller is configured to perform a remaining bank refresh operation for refreshing remaining memory banks other than the one memory bank among the plurality of memory banks, in response to the remaining bank refresh command during one refresh cycle.