Subcode processing apparatus having function of protecting subcode sync pattern signal in portable optical disc system and method thereof

摘要

PURPOSE: A subcode processing device having a function of protecting subcode synchronous pattern signals in a portable optical disk system is provided to selectively use the first subcode synchronous pattern signal and the second subcode synchronous pattern signal as an input signal, and to decide whether the first or the second subcode synchronous pattern signal is normally generated, to create a subcode Q error checking completion signal, thereby increasing accuracy of the subcode Q error checking completion signal in a double-speed conversion mode. CONSTITUTION: A subcode decoder(210) decodes subcode data, and outputs decoded results as multi-bit subcode data, write-in frame clock signals, and the first/the second subcode synchronous pattern signals. A subcode synchronous pattern controller(220) detects whether the first and the second subcode synchronous pattern signals are exactly generated, and outputs an error checking subcode synchronous pattern signal and a shock protect subcode synchronous pattern signal. A subcode Q error checker(230) checks an error of subcode data of a Q channel among the decoded subcode data, and outputs a checked result as an error checking completion signal. The first multiplexer(222) inputs the error checking completion signal and a shock protect control signal, and selectively outputs one of the inputted signals in response to a selection signal. An ESP(Electronic Shock Protect) unit(250) performs a shock protect function in response to the subcode synchronous pattern signal for protecting shock and the output signal of the first multiplexer.