A device which may be configured to generate delayed clock signals by a specified phase difference, which may include a clock generator circuit for generating at least one clock signal, a delayed clock signal generator for delaying the at least one clock signal, a phase detect circuit for generating a selecting signal based on the amount of phase delay detected according to a half-cycle (π), and in comparison with the clock signal, a phase interpolation circuit for controlling the delay time of the delayed clock signals and interpolating the delayed clock signals, and a selecting circuit which outputs the delayed clock signal delayed by a specified phase difference.