Abstract: A register controlled delay locked loop (DLL), including: a coarse delay line for generating a delayed input clock signal by delaying an external clock signal; a fine delay line unit for receiving the delayed input clock signal in order to generate a first fine delayed clock signal and a second fine delayed clock signal; a phase detector for comparing phases of the external clock signal and a feed-backed clock signal in order to generate a phase detection signal based on the comparison result; a phase mixer for generating a mixed clock signal by mixing phases of the first fine delayed clock signal and the second fine delayed clock signal based on a weight value; and a mixer controller for generating the weight value based on the phase detection signal.