Patent ID: 7831044

Claim:
A data processing apparatus for scrambling data which are under being transferred or de-scrambling scrambled data which are under being transferred, comprising: an ID storing section which stores an ID information relating to a sector which is a scrambling block unit of data under being transferred, which ID information is set by a central processing unit; a sector counter section which counts the number of the sectors in the data under being transferred; an operation section which adds the ID information from the ID storing section and the sector number information from the sector counter section; a scramble seed value table conversion section which converts the addition result which is inputted from the operation section into a scrambling seed value; a scramble filter of at least one byte which, making a period during which data of a predetermined length is transferred one cycle, produces a next cycle scramble seed value from the present cycle scramble seed value; a selector which selects a scramble seed value which is outputted from the scramble seed table conversion section when the data under being transferred is a top of a sector and selects the scramble seed value which is outputted from the scramble filter section otherwise, to output the selected result to the scramble filter; wherein the data under being transferred being scrambled or the scrambled data under being transferred being de-scrambled using the scramble seed value which is outputted from the selector.