An integrated circuit chip includes: an internal circuit; a data output circuit configured to output a data packet of the internal circuit in response to a strobe signal; an oscillator configured to generate a first clock signal; a divider configured to divide the first clock signal and generate a second clock signal; and a strobe signal supply unit configured to supply the second clock signal as the strobe signal during an initial period of transmission of the data packet and supply the first clock signal as the strobe signal after the initial period.