A semiconductor memory device having an efficient core structure for multi-writing includes a data input/output line, a plurality of memory banks each comprising a plurality of memory cells, a first global bit line and a second global bit line which are shared by the plurality of memory banks, and a first write driver and a second write driver which are connected with the data input/output line and provide a program current to the plurality of memory banks through the first and second global bit lines, respectively. Each memory bank includes a first cell area connected with the first global bit line and a second cell area connected with the second global bit line. In a multi-write mode, the first cell area in a first memory bank among the plurality of memory banks and the second cell area in a second memory bank among the plurality of memory banks are simultaneously selected and data is written to memory cells in the selected first and second cell areas, so that data writing time is reduced under the same conditions as a normal write mode.