Patent ID: 7596166

Claim:
A control circuit comprising: an integrated circuit comprising a plurality of circuit blocks and a CPU (central processing unit), which operate based on clock signals; a quartz oscillation circuit that outputs a first clock signal; a spectrum spread clock generator that outputs a second clock signal having a frequency that is spread, for the plurality of circuit blocks, by inputting the first clock signal; a selection circuit for inputting the first clock signal output from the quartz oscillation circuit and the second clock signal output from the spectrum spread clock generator, and for selecting a clock signal to be output for the plurality of circuit blocks and the CPU based on a first signal, wherein the spectrum spread clock generator is provided with a switch for changing on and off of a power source of the spectrum spread clock generator based on a second signal, and wherein the first signal and the second signal are output from the CPU in a case that the CPU shifts to a low-power-consumption mode, and the selection of the first clock signal by the selection circuit and turning off of the power source of the spectrum spread clock generator by changing the switch are performed, and wherein the integrated circuit comprises a frequency conversion circuit for outputting a third clock signal by dividing the frequency of the first clock signal, and the frequency conversion circuit outputs the third clock signal for a predetermined circuit block of the plurality of circuit blocks.