| 摘要 |
<p>PURPOSE:To effectively reduce the current consumption by providing a clock switch control part to switch the clock frequency based on a prescribed signal. CONSTITUTION:A control part consists of a clock dividing circuit 28, a switch circuit 29, and a clock selection circuit 30. The circuit 21 outputs a 2-divided clock 31 and a 4-divided clock 32 with the basic clocks A/B 11 and 21 used as the inputs. The circuit 29 switches the clocks A/B 11 and 21, the clock 31 or the clock 32 based on the clock switch signals 33 and 34 and outputs the action clocks A/B 14 and 25. The circuit 30 uses an interface signal C22, a microinstruction d23, a microinstruction e24 or the microinstruction a12 and b13 as the inputs and outputs the signals 33 and 34. Thus the current consumption can be effectively reduced.</p> |
