TIMING CONTROL SYSTEM FOR TIME DIVISION CHANNEL PART

PURPOSE:To improve the reliability of a time division channel part by providing the titled system with a doubled Clock distribution circuit to discribute clocks into the time division channel part. CONSTITUTION:when either one, e.g. a clock distribution circuit(CKD) 130, out of CKDs 130, 131 is failed, the CKD 130 informs its fault to the CKD 131 through control lines 160, 161, stops clock output and sends a clock sending permission signal. Receiving the fault information, the CKD 131 receives the clock sending permission signal and distributes the clocks. When the CKD 131 is failed, clocks are similarly distributed from from the CKD 130. Since the connection of the time division channel part can be secured by one CKD at the time of failure in the other CKD, the reliability of the time division channel part 200 can be improved.