| 摘要 |
<p>PURPOSE:To heighten processing speed of a system as a whole by making switching control of a switching circuit by signals of a microcomputer according to operation speed of an IC device selected by the microcomputer. CONSTITUTION:A microcomputer 3 controls a switching circuit 14 according to operation speed of an IC device to be selected by signals of software. If an IC device of high operation speed is selected, the microcomputer selects a clock signal, and if an IC device of low operation speed is selected, selects a frequency dividing clock signal of low frequency. At the time of the microcomputer 3 makes internal processing at high speed, the switching circuit 14 is switched to the clock signal and controlled. In case of a microcomputer of CMOS type, etc., and a low power consumption mode is to be set, the switching circuit 14 is switched to one of frequency dividing signals to slow down processing speed and reduce power consumption.</p> |
