A storage device includes a host interface configured to communicate with a host device according to a first protocol through an input terminal, an output terminal, and a clock terminal. The input terminal is configured to receive an input signal from the host device according to the first protocol. The output terminal is configured to output an output signal to the host device according to the first protocol. The clock terminal configured to receive a clock signal from the host device according to the first protocol. The host interface is configured to communicate with the host device according to a second protocol through the clock terminal, the second protocol being different from the first protocol.