| 摘要 |
<p>PURPOSE:To reproduce digitally a prescribed clock of a bipolar code even when a code error takes place in part of data by using a clock having a frequency four times that of the prescribed clock so as to obtain a rising position of a positive code and a negative code in a unipolar code and generating a differentiating pulse. CONSTITUTION:A rising position of a positive code AMI+ and a negative code AMI- in a unipolar code U converted by a B/U conversion section 10 is obtained by a clock 4phi CLK having a frequency four times that of the prescribed clock and a pulse is generated by rising differentiating circuits 11, 12 and an OR circuit 3 ORs a ripple carry RC being a carry output of a 1/4 frequency division counter 2 and differentiating pulses P1, P2 outputted from the rising differentiating circuits 11, 12, a value C given in advance is loaded to the 1/4 frequency division counter 2 to start count and the decoder 4 decodes a count of the 1/4 frequency division counter 2 and the falling position of the decoded value is obtained by a falling differentiating circuit 5, from which a differentiating pulse P is generated, A required transmission line clock CLK1 is obtained by generating a repetivive pulse in matching with the period of the differentiating pulse P.</p> |
