METHOD AND CIRCUIT FOR CLOCK RECOVERY

摘要

PURPOSE:To stably recover a source clock even when cell abort takes place in an ATM system by using N-th period frequency difference information whose reception is disable due to cell abort having been already accurately received before M-th period frequency difference information so as to obtain the M-th period frequency difference information. CONSTITUTION:On the occurrence of abort of a cell on which M-th period frequency difference information is multiplexed, a sequence number monitor section 106 detects cell abort and provides an output of a signal 107 to a frequency difference information management prediction processing section 108. The processing section 108 uses N-th period frequency difference information stored in a memory 110 before the M-th period information and received accurately to obtain a predicted value of the M-th period frequency difference information through arithmetic operation and gives the predicted value to a clock recovery section 111. The recovery section 111 recovers a source clock 113 by using the predicted value of the frequency difference information.