A semiconductor memory integrated circuit for controlling a refresh operation includes: a first period generating unit that generates a first periodic signal having an uniformed period; a second period generating unit that generates a second periodic signal according to a first control signal; a period generation control unit that generates a timing signal for every predetermined period; a frequency dividing unit that divides the frequency of the first periodic signal into at least one frequency-divided periodic signals; and a period selection control unit that controls the operation of the second period generating unit according to the at least one frequency-divided periodic signals and the second periodic signal, determines temperature, and outputs one of the frequency-divided periodic signals corresponding to the determined temperature as a refresh signal.