A delay locked loop includes a main delay circuit including a plurality of unit delay lines that generate a plurality of internal clocks by delaying an input clock, delay amounts of the plurality of unit delay lines being adjusted in response to code signals; a sub-delay circuit including a plurality of sub-delay lines that generate a plurality of phase clocks by respectively delaying the input clock and the plurality of internal clocks; a phase detector configured to compare phases of the plurality of phase clocks and provide a phase detection signal according to a result of the comparison; and a digital circuit configured to update the code signals corresponding to the plurality of unit delay lines one by one at a time when the phase detection signal is provided to the digital circuit.