Digital modulation apparatus used with dvd-ram and dvd-r/rw for increasing margin of operation of external device and method thereof

Abstract

A digital modulation apparatus and method used for a DVD-RAM and a DVD-R/RW and for increasing the margin of an operation of an external device is provided. The digital modulation apparatus includes a 4-stage pipeline and includes a mode selection unit, a field enabling signal generation unit, a data fetch and sync code generating unit, an eight-to-fourteen modulation plus (EFMplus) conversion unit, and a non-return-to-zero inverted (NRZI) conversion unit. The mode selection unit generates a mode selection signal for selecting one from a DVD-RAM operation mode and a DVD-R/RW operation mode in response to a control signal. The field enabling signal generation unit selectively generates recording field enabling signals related to a DVD-RAM, or selectively generates recording field enabling signals related to a DVD-R/RW, in response to a start signal and the mode selection signal and provides the recording field enabling signals to the data fetch and sync code generation unit. The data fetch and sync code generation unit fetches 8-bit data words, generates sync codes, and performs an operation for fetching the data words and an operation for generating first sync codes in parallel. The EFMplus conversion unit converts the 8-bit data words output from the data fetch and sync code generation unit into M-bit (where M is an integer) first code words and then, converts the converted first code words into 16-bit second code words. The NRZI conversion unit converts the second code words into a NRZI signal.