A storage device includes a controller including first and second pins and configured to output a multi-level chip enable signal through the second pin, and a memory device. The memory device includes third and fourth pins respectively connected to the first and second pins, and a plurality of memory chips commonly connected to the fourth pin. The plurality of memory chips respectively include a plurality of resistors connected to one another in a daisy-chain structure between the third pin and a first voltage terminal. The plurality of memory chips are configured to respectively generate a plurality of reference voltage periods that divide between a voltage level of the third pin and a voltage level of the first voltage terminal based on the plurality of resistors.