MODULATION SYSTEM CONVERTING CIRCUIT

摘要

PURPOSE:To prevent the missing clock function from being lost at the conversion of the MFM system into the 2-7RLLM system by detecting a pattern not in matching with the modulation rule of the 2-7RLLM modulation system so as to generate the MFM missing clock pattern. CONSTITUTION:When 1 byte of a post-stage part of the MFM missing clock pattern is stored in the MFM shift register 106, an MFM missing clock pattern detecting circuit 107 detects the MFM missing clock pattern. The detection circuit 107 starts immediately the 2-7RLLM modulation missing clock pattern generating circuit. The generating circuit 109 generates the 2-7RLLM modulation missing clock pattern corresponding to the MFM missing clock pattern.