| 摘要 |
PURPOSE: To suppress the peak value of the current consumption of the whole device small and reduce the size of the power circuit in the device by reducing the current consumption of circuits other than a motor when the current consumption becomes temporarily large at the start of motor driving. CONSTITUTION: When a user tries to save a document on an FDD 5, a CPU 2 outputs a spindle motor start instruction to an operation mode control circuit 1 first. The operation mode control circuit 1 once receiving the spindle motor start instruction stops the clock of the CPU 2 and places a DRAM 4 in self- refresh mode, and then outputs the spindle motor start signal to the FDD 5. When the power consumption becomes small after a spindle motor start current flows to the FDD 5, a mode current detecting circuit 6 detects the current state and outputs a detection signal to the operation mode control circuit 1. The operation mode control part 1 once receiving the current state detection signal resets the clock supply stop state of the CPU 2 and places the CPU 2 in operation again. |
