Abstract: Disclosed is an electronic apparatus, comprising: an electronic device, operating according to a target clock signal; and a frequency adjusting circuit, for adjusting the target clock signal before the electronic device begins to operate normally, comprising: a reference value generator, for providing at least a first reference value corresponding to an expected frequency of the target clock signal; a comparing module, coupled to the reference value generator, for comparing the reference value and an actual value corresponding to an actual frequency of the target clock signal to generate a comparing result; and an adjusting module, coupled to the comparing module and the controllable clock generator, for adjusting the controllable clock generator according to the comparing result to thereby force the actual frequency to follow the expected frequency.