This embodiment relates to a clock data recovering apparatus capable of improving consecutive identical digits (CID) resistance. The clock data recovering apparatus includes a clock generating apparatus. The clock generating apparatus includes a signal selection unit, a phase detection unit, a phase control unit, a selection unit, a phase delay unit, a time measurement unit, and a phase selection unit. The phase delay unit includes a plurality of delay elements. The phase selection unit selectively outputs an output signal of any one of the plurality of delay elements as a feedback clock. The phase detection unit detects a phase relation between an edge signal and the feedback clock. The phase control unit outputs a control signal to control a signal selection operation by the phase selection unit such that a phase difference detected by the phase detection unit decreases, to the phase selection unit.