| 摘要 |
PURPOSE: To send prescribed information to a low-order device by selecting a clock signal from a high-order device or a clock signal generated by an oscillator by an in-use/standby switching device according to high-order information. CONSTITUTION: When a clock select signal 64 shows that Q=1, a system-selected input clock is OFF or excellent and the clock precision mode state of the high- order device is a self-running state. At this time, an alarm transmitting circuit 34 sets some bits of a down in-operation communication information signal 55 to 1 and sends the signal to the low-order device, which performs processing for the stop of service, etc. A selection processing circuit 37 selects an internal clock signal connected to the oscillator 36 and outputs a signal 60 to a reference clock signal 66. The signal 66 is connected to a clock signal generator 39. The generator 39 has a function for clock signal generation, etc., and supplies a clock signal to the low-order device. Consequently, specific frequency accuracy is satisfied and information can be sent to the low-order device. |
