Clock supply apparatus reducing consumption of power

摘要

A clock supply apparatus includes a low-rate source clock generating unit for generating a low-rate source clock signal, a frequency multiplication/division unit for performing frequency multiplication/division processing for the low-rate source clock signal to generate a high-rate clock signal to be utilized in signal processing only during a period in which a sleep signal remains nonactive, a sleep time measuring unit for measuring a sleep time duration from the moment the sleep signal becomes active and issuing a sleep end signal upon measurement of a predetermined time period, and a sleep control unit for controlling whether the signal processing block is placed in a sleep or non-sleep mode. The sleep control unit decides the end of the sleep period upon detection of the sleep end signal.