Oak Technology, Inc.

Gene E Weddle

Phil Verinsky

Robert R Griffith

Neeraj Sahejpal

Zongzhao Fei

A subcode processing circuit of an optical disc drive, and a method for processing subcode data are disclosed. The subcode processing circuit includes a shift register circuit for processing a plurality of standard subcode data bytes that are obtained from an optical disc media of the optical disc drive. The processing is configured to pack the plurality of standard subcode data bytes into a plurality of packed subcode data bytes. The plurality of packed subcode data bytes is configured to be less than the plurality of standard subcode data bytes. In one example, the shift register circuit is configured to include a plurality of shift registers and a multiplexer to assist in the processing. The subcode processing circuit is further configured to perform error correction for each byte of the plurality of packed subcode data bytes.

Compact disc subcode packing and error correction detection

An LBA/MSF converter includes a decade selector, the decade selector receiving a first input and generating a decade selector output corresponding to a decade of the first input. An operand selector receives the decade selector output and outputs an operand corresponding to the decade selector output. An adder outputs the sum of the first input and the operand, the sum being an MSF value corresponding to the first input when the first input is an LBA value, and a subtractor outputs the difference of the first input and the operand, the difference being an LBA value corresponding to the first input when the first input is an MSF value. A method of converting between an LBA and an MSF location on a data carrier includes steps of receiving a first input, determining a decade of the received first input, selecting an operand corresponding to the determined decade, adding the first input and the selected operand to generate a first output, the first output being an MSF location when the received first input is an LBA address, and subtracting the selected operand from the first input to generate a second output, the second output being an LBA address when the received first input is an MSF location. Such methods and devices allow the conversion between LBA and MSF address formats of a data carrier such as a CD-ROM without invoking the functional block(s) of the electronic design automation software predefined for that purpose.

Method and apparatus for converting between a logical block address (LBA) and a minute second frame (MSF) location on a data carrier such as a CD-ROM

A method to and apparatus for communicating formatted data from mass storage media to a host computer is disclosed. In a preferred embodiment data is received through a serial digital signal processor (DSP) from an optical compact disk. The method and apparatus separates data bytes from auxiliary bytes, and stores them into separate and specific spaces within a DRAM. Error correction is performed after each block of data has been stored. After a given block has been verified, the system controller records the block number. The method and apparatus reduces the amount of address storage required to locate valid blocks of data in the DRAM. The method of the present invention increases the effective rate of transfer of data from the DRAM to a host computer.

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San Jose, CA, United States of America

Gene E Weddle