An SRAM macro operates in a normal operation mode in which a plurality of memory-cell array blocks are accessible and in a low power mode in which bit lines in the memory-cell array blocks are left floating. When the SRAM macro returns from the low power mode to the normal operation mode, the bit lines in only memory-cell array blocks to be accessed among the plurality of memory-cell array blocks are precharged in sequence. This allows the peak of precharging current flowing into the SRAM macro to be dispersed.