Apparatus for controlling reading and writing in a disk drive

An apparatus for controlling the reading and writing of data to and from the data fields of a sector-servo fixed-block-architecture disk drive, the disk drive having a data disk with some servo sectors located within the data fields and splitting their associated data fields into at least two portions of unequal length, the apparatus comprising:

• means for clocking write data to and read data from the data fields;
• means for storing a first value representing the location of a servo sector within a data field;
• a counter for counting dat clock cycles;
• a comparator coupled to the counter and the servo sector location value storing means for generating a signal when the value in the counter matches the stored servo sector location value;
• means coupled to the clocking means and responsive to the comparator signal for interrupting the reading or writing of data for a fixed time period;
• and
• means for updating the storing means with a second value, different from the first value, representing the location of the next servo sector within its associated data field.

An apparatus for controlling the reading and writing of a data stream to and from the data fields in a sector-servo fixed-block-architecture disk drive, the disk drive having an encoder/decoder for encoding and decoding data in the disk stream, a voltage-controlled oscillator for clocking dat in the data stream during read mode, and a data disk with some servo sectors located within the data fields and splitting their associated data fields into at least two portions, the apparatus comprising:

• a data clock generator for clocking data in the data stream during write mode;
• a disk data controller for controlling the data stream to and from the encoder/decoder, the disk dat controller being coupled to the data clock generator and having means for receipt of a clocking signal from the voltage-controlled oscillator;
• means for storing a first value representing the location of a servo sector within a data field;
• a counter coupled to the data clock generator and having means for receipt of a clocking signal from the voltage-controlled oscillator for counting data clock cycles during read and write modes;
• a comparator coupled to the counter and the servo sector location value storing means for generating a signal when the value in the counter matches the stored servo sector location value;
• data timing and control circuitry coupled to the disk data controller and the comparator for interrupting the data stream for a fixed time period in response to the comparator signal, whereby data in the data stream in not read from or written to the data fields during said time period;
• and
• means for updating the storing means with a second value representing the location of the next servo sector within its associated data field.