| 摘要 |
<p>PURPOSE:To prevent a substancial stuff discrimination frequency from fluctuating with the capacity of a buffer memory or the insertion information amount excepting for an input signal to a synchronization signal. CONSTITUTION:With writing/reading signals 13 and 14 from writing/reading counters 2 and 3 which N(the capacity bit number of the buffer memory 1)- frequency-dividing writing/reading clock signals 12 and 17,a digital input signal 11 is written, temporarily stored, read out and transmitted as a digital synchronization signal 15 by the buffer memory 1. From a phase comparison signal 16 outputted by discriminating the lead/delay of a phase in accordance with whether the writing/reading counters 2 and 3 are larger or smaller than the respective binary number values of the writing/reading signals 13 and 14 of the whole stage by a phase comparator 4. A stuff controller 5 discriminates whether the insertion of a stuff bit is necessary or not and if it is necessary, stuff operation is controlled to generate a reading clock signal 17. Consequently, in the stuff discrimination system by counting whole stage phase comparison. the writing/reading signal of the whole stage is phase-compared by one clock and the substancial stuff discrimination frequency is not made to fluctuate so that a reception part can reduce destuff jitter.</p> |
