| 摘要 |
<p>PURPOSE: To calculate a direct current value without any increase or decrease of the number of bits of a code word mapping-processed to an information word by providing each storage means for each positive and negative code word for enabling selection suitable to recording and reproduction and controlling code conversion. CONSTITUTION: The negative/positive code words of an information word are read by first/second look-up tables 10/20, mutually synchronized by first/second latches 30/40, and outputted to a selecting means(SW) 1. An output selected by this SW 1 is temporarily stored by a third latch 50, and an outputted parallel signal is converted into serial data and outputted by a serial/parallel converting part 60. This output is inputted to a CDS calculating circuit 70, and a CDS value is calculated by a load pulse generator 71, counting means 72, fourth and fifth latches 73 and 75, detector 74, and comparator 76 by using a master lock CLK1. The SW 1 is controlled by the circuit 70 for this calculated result. Thus, the CDS value can be calculated without any increase or decrease of the number of bits of the code word.</p> |
