A frequency generator, includes a
control unit, configured to receive an input
signal to generate a divisor
signal, a phase
signal and a circulation signal; a
frequency divider, configured to receive the input signal and perform an integer division to the input signal according to the divisor signal, so as to generate a frequency division signal; a circulating
delay circuit, coupled to the
frequency divider and configured to perform at least one circulating operation to the frequency division signal, and for each circulating operation, generate at least one phase
delay signal; a first
multiplexer, coupled to the circulating
delay circuit and configured to select one signal from the frequency division signal and the at least one phase delay signal according to the phase signal, so as to generate a multiplexed signal; and a retimer, coupled to the first
multiplexer and configured to generate an output signal.