Digital timing recovery in hard disk drive read channel for preamble reduction

A storage device, comprising:

• a rotating storage medium on which data is written, the data including user data preceded by a preamble occupying storage area whose size is derived from a preamble tone;
• at least one read head;
• a respective timing buffer configured to store respective digitized data samples from each respective read head of the at least one read head in a respective timing buffer, the respective digitize samples having the preamble with a preamble length derived from the preamble tone;
• zero-phase start circuitry configured to determine a zero-phase start phase angle from the preamble of the digitized data samples;
• interpolator circuitry, output of the zero-phase start circuitry being fed forward to the interpolator circuitry, the interpolator circuitry including an interpolation filter configured to be selected based on the zero-phase start phase angle;
• wherein:
• the respective digitized data is released from the respective timing buffer after a duration sufficient for completion of operation of the zero-phase start circuitry and the interpolator circuitry;
• and
• the interpolator circuitry is configured to interpolate samples of the digitized data released from the respective timing buffer.

A storage device, comprising:

• rotating storage means on which data is written, the data including user data preceded by a preamble occupying a storage area having a size derived from a preamble tone;
• at least one read head means;
• a respective timing buffer means configured to store respective digitized data samples from each respective read head of the at least one read head in a respective timing buffer, the respective digitize samples having the preamble with a preamble length derived from the preamble tone;
• zero-phase start means configured to determine a zero-phase start phase angle from the preamble of the digitized data samples;
• interpolator means, output of the zero-phase start means being fed forward to the interpolator means, the interpolator means including interpolation filter means configured to be selected based on the zero-phase start phase angle;
• wherein:
• the respective digitized data is released from the respective timing buffer means after a duration sufficient for completion of operation of the zero-phase start means and the interpolator means;
• and
• the interpolator means is configured to interpolate samples of the digitized data released from the respective timing buffer means.