To share an oscillator between a central processing unit and a receiving circuit without complicating a circuit configuration in a receiving apparatus.

A multiplier 22 of a CPU 20 receives a clock signal via a receiving circuit 11 and multiplies the clock signal to generate a clock signal. Thus, the clock signal can be recognized in a system clock 23. A local oscillation circuit 12 of the receiving circuit 11 is utilized to convert a frequency and to adjust an oscillation level, such that it is not necessary to newly provide a buffer for performing frequency conversion or the like for the CPU 20.