| 摘要 |
<p>PURPOSE:To obtain a microcomputer possible for always stable operation with low power consumption by operating the microcomputer with a high speed clock normally and with a low speed clock at low power consumption respectively. CONSTITUTION:The high speed clock 16 from an oscillating section 15 and the low speed clock 18 from an oscillation section 17 are selected by a clock section 14 and the result is fed to a CPU 11 via a clock control section 110. When the CPU 11 is operated synchronously with the low speed clock 18, the oscillation of the oscillating section 15 is stopped by a clock stop signal 111 to attain low power consumption. When the low speed clock is changed into the high speed clock, the stop signal 111 is released to activate the oscillating section 15. Then a counter section 112 counts the high speed clock 16 and when the count reaches a prescribed value, an overflow signal 113 is generated. The CPU 11 receiving the signal 113 uses the high speed clock 16 switchingly.</p> |
