| 摘要 |
PURPOSE:To form a clock switching part with a low-speed process switching circuit by providing a dividing circuit and a multiplying circuit before and after the clock switching part respectively. CONSTITUTION:An input clock is usually selected within a clock switching part 2 and supplied to a data processing part 1 to be synchronous with the input data. When this information produces a no-input state or a frame step-out state, a switch control part signal is sent to a clock processing part 2 from the part 1 and a clock is selected out of a local oscillation part 4. This switching action forms a frame within an intermediate repeating installation and delivers data. Then an input clock dividing circuit 5 and a multiplying circuit 3b having the same value as the dividing ratio of the circuit 5 are added to a clock switching circuit at the front and back sides of the part 2 respectively. As a result, the switching actions of high frequency clocks can be minimized and a clock switching action is carried out through a low-speed processing action. |
