Compact disc drive apparatus having an interface for transferring data and commands to and from a host controller

Claim 1

A compact disc drive apparatus for data storage, said data being organized in storage frames in a double cross-interleaved double Reed-Solomon error protection code format modulated by an eight-to-fourteen run-length-restricted channel bit format, non-redundant bytes within said storage frame format being organized in storage sectors and having per sector a sequence of synchronization information, header information, and data information comprising: electro-mechanical disc-driving means for holding and driving a data storage record; accessing means for radially accessing a data track on said record; reading means for reading an accessed data track and a sector thereon as specified by a predetermined data sector specification; demodulating means coupled to said reading means for receiving channel bits and demodulating such channel bits to a sequence of code bytes; decoding means coupled to said demodulating means for receiving said code bytes and by means of a code format represented by redundant bytes decoding said code bytes into a sequence of compact-disc user bytes; and an interface means for interfacing said drive apparatus to an external host controller, said interface means comprising: parallel-to-serial conversion means fed by said decoding means for producing bit-serially said compact-disc-user bytes as user bits; clock means fed by said parallel-to-serial conversion means for producing synchronously with said user bits a clock stream having a validating clock pulse for each of said user bits; control means having a first input for receiving host controller commands, and a recognition means for recognizing any command received as either allowable or non-allowable a first output connected to said reading means for controlling said accessing means, a second input for receiving status information regarding said electro-mechanical driving means from said accessing means and from said decoding means, and a second output for signalling drive error conditions, spin-up/non spin-up situations and non-allowable command situations for use by said controller.