| 摘要 |
PURPOSE:To modulate and demodulate a digital signal which is suitable for write and readout of a magnetic recording device, by generating not only a binary signal of ''0'' and ''1'' but also a ternary signal by adding ''2'', and writing a signal expressed by ''2'' as a rectangular pulse without making it an NRZI signal, at the time of write. CONSTITUTION:A digital signal inputted from an input terminal 1 is converted to an 8 BC code by a 4-8 bit code converting circuit 2, and it is inputted to a connecting part correcting circuit 3. In this circuit, for instance, an 8 BC code 101 is converted in accordance with a conversion table as a code 020. In case of reading out data recorded in a magnetic recording device 6, a zero crossing point of a signal is detected by zero crossing detecting circuits 9, 10, a clock signal is extracted, a demodulating signal is obtained, and it is converted to a digital signal by an 8-4 bit code converting circuit 12. In this way, the clock signal is extracted easily, and generation of a bit error can be prevented exactly. |
