(EN) A method and apparatus for synchronizing a delay line to a reference clock includes a delay line that receives a clock input signal based on a reference clock and outputs a delay edge signal according to a control adjustment. An injector receives a first rise edge of the reference clock and in response to a first trigger sends the clock input signal to the delay line. A synchronizer determines that the rise edge has passed through the delay line and in response sends the injector a second trigger to send a next single fall edge of the clock input signal to the delay line. A charge pump determines a timing difference between the delay edge signal and a reference edge signal sent from the injector. The charge pump sends the control signal to the delay line to adjust the delay setting of the delay line based on the timing difference.