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A descrambler for a Digital Versatile Disk (DVD) is provided within a DVD controller to allow for real-time descrambling of DVD data from the DVD buffer. The built-in descrambler also allows the controller to interface with a Host Adapter (e.g., ATAPI Host) or MPEG II decoder. The descrambling circu

A descrambler for a Digital Versatile Disk (DVD) is provided within a DVD controller to allow for real-time descrambling of DVD data from the DVD buffer. The built-in descrambler also allows the controller to interface with a Host Adapter (e.g., ATAPI Host) or MPEG II decoder. The descrambling circuit reads four bits of an identifier portion of each sector. These four bits are used to access a look up table LUT in the descrambler for retrieving a 15 bit seed. The fifteen bit seed is used to generate a descrambling patter, which, when XORed with scrambled data, will descramble data on a byte-by-byte basis. The descrambling pattern is generated on a flash basis, by performing eight shift operations and XOR operations simultaneously, allowing for descrambling one byte per clock cycle. In the preferred embodiment, the flash descrambler may use a programmed register transfer logic (RTL) to generate sixteen bits of descrambling pattern at a time, to allow for descrambling on a word-by-word basis at the rate of one word per clock cycle.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for descrambling scrambled data comprising:a first register for receiving a first number of bits of pattern data;pattern generating means, coupled to said first register, for receiving the first number of bits of pattern data and simultaneously generating a f

[ What is claimed is:] [1.] An apparatus for descrambling scrambled data comprising:a first register for receiving a first number of bits of pattern data;pattern generating means, coupled to said first register, for receiving the first number of bits of pattern data and simultaneously generating a first number of bits of new pattern data;a second register, coupled to the pattern generating means, for storing the first number of bits of new pattern data and for transmitting the first number of bits of new pattern data to the first register to form a pattern data for generating successive new pattern data.