摘要 |
<p>A HDB3 code violation detector includes a converting part (1) for receiving positive polarity data and negative polarity data from a PCM line and for converting a HDB3 code received via the PCM line into an NRZ signal, a first judging part (2) receiving the positive polarity data, the negative polarity data and the NRZ signal, for judging whether or not a pattern of the NRZ signal received from the converting part is possible when the NRZ signal is NRZ "1" and for outputting a judgement result, a second judging part (3) receiving the positive polarity data, the negative polarity data and the NRZ signal, for judging whether or not a pattern of the NRZ signal received from the converting part is possible when the NRZ signal has a maximum of three consecutive NRZ "0"s and for outputting a judgement result, a third judging part (4) receiving the positive polarity data, the negative polarity data and the NRZ signal, for judging whether or not a pattern of the NRZ signal received from the converting part is possible when the NRZ signal has at least four consecutive NRZ "0"s and for outputting a judgement result, and a detecting part (5) for detecting a code violation of the HDB3 code based on the judgement results of the first, second and third judging parts. <IMAGE></p> |