Determining a reference waveform used by a correlator in a servo channel
AssigneeInternational Business Machines Corporation
InventorsGiovanni Cherubini, Robert Allen Hutchins, Jens Jelitto
Life of this patent
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Abstract
Provided are a method, servo channel, and tape drive for determining a reference waveform used by a correlator in a servo channel. Sequences of servo signal samples are provided from read servo signals read from a servo pattern on a recording medium. A determination is made of a reference waveform based on the sequences of servo signal samples and the reference waveform is forwarded. Interpolated servo signals are generated. The interpolated servo signal samples and the forwarded reference waveform are received to generate correlation output samples. Position and velocity information are calculated from the correlation output samples.
Claims22
A servo channel for a tape drive coupled to a servo reader reading a servo pattern encoded on a recording medium, comprising:
- an analog-to-digital converter (ADC) receiving read servo signals from the servo pattern read by servo reader and providing sequences of servo signal samples;
- a monitoring and control unit coupled to the ADC operable to determine a reference waveform based on the sequences of servo signal samples and forward the determined reference waveform;
- an interpolator coupled to the ADC operable to generate interpolated servo signal samples:
- a correlator coupled to receive the interpolated servo signal samples from the interpolator and the forwarded reference waveform from the monitoring and control unit, and operable to generate correlation output samples;
- computational units coupled to the correlator to receive the correlation output samples and operable to calculate position and velocity information from the correlation output samples.
A method implemented in a servo channel, comprising:
- providing sequences of servo signal samples from read servo signals read from a servo pattern on a recording medium;
- determine a reference waveform based on the sequences of servo signal samples;
- forwarding the reference waveform;
- generating interpolated servo signal samples:
- receiving the interpolated servo signal samples and the forwarded reference waveform to generate correlation output samples;
- calculating position and velocity information from the correlation output samples.
A tape drive coupled to a recording medium, comprising:
- a servo reader for reading a servo pattern encoded on the recording medium;
- and
- a servo channel coupled to the servo reader to receive read servo signals from the servo reader and operable to perform:
- processing the received read servo signals read from the servo reader;
- determine a reference waveform based on the sequences of servo signal samples;
- forwarding the reference waveform;
- generating interpolated servo signal samples:
- receiving the interpolated servo signal samples and the forwarded reference waveform to generate correlation output samples;
- and
- calculating position and velocity information from the correlation output samples.
Dependencies are inferred from the claim text.