METHOD AND APPARATUS FOR CONTROLLING CLOCK FREQUENCY

摘要

PURPOSE: A method and an apparatus for controlling clock frequency are provided to reduce power consumption without the degradation of the response speed about the command outputted from host. CONSTITUTION: A CPU(20) generates a detection signal depending on the activation of interrupt signal. The clock signal having a first frequency or a secondary frequency higher than the first frequency in response to the detection signal which a frequency adjusting circuit(30) is outputted from the above CPU is supplied to the above CPU. When a data processing unit is a hard disk drive, the frequency adjusting circuit outputs a clock signal having the first frequency in response to the deactivated detection signal which is outputted from the above CPU to the above CPU in the idle state.