Method and apparatus for interpolating peak detection of servo stripe pulses
View Patent ↗A method and device for detecting a peak which is substantially the same as the actual peak are disclosed. In one embodiment, the device includes a filter, a shift register, a controller and a digital interpolator. The filter is configured to receive a plurality of signal samples and the shift register, which is coupled with the filter, has multiple registers. The shift register is configured to receive the plurality of signal samples and to shift the plurality of signal samples through the registers. The controller is coupled with the shifter register and is configured to detect a zero-crossing event in the signal samples. The digital interpolator is coupled with the controller and configured to perform a binary search to identify a peak substantially the same as the actual peak.
1. A device for identifying a peak comprising:
a filter configured to receive a plurality of signal samples, wherein said filter is a quadrature filter that converts a peak event to a zero-crossing event;
a shift register, coupled with said filter, comprising a plurality of registers, said shift register configured to receive said plurality of filtered signal samples and to shift said plurality of filtered signal samples through said plurality of registers, wherein said plurality of registers includes center pair registers;
a controller coupled with said shift register and configured to detect a zero-crossing event in response to said plurality of filtered signal samples, wherein said controller is further configured to save at least a portion of said plurality of said filtered signal samples in response to sign changes between said center pair registers; and
a binary interpolator coupled with said controller and configured to perform a binary search on said saved filtered signal samples to identify a peak substantially the same as an actual peak.
2. The device of claim 1 further comprising a digitizer coupled to said filter, wherein said digitizer is capable of converting data from analog format to digital format.
3. The device of claim 2 , wherein said digitizer is an analog to digital converter that converts analog signals detected over a plurality of stripes on a magnetic type to digital signals.
4. The device of claim 1 , wherein said shift register comprises a plurality of 16, 32, 64, 128, 256, or 512 registers.
5. The device of claim 1 , wherein said binary interpolator further includes:
a set of look-up tables containing a plurality of predetermined coefficients; and
a set of multipliers coupled to said look-up tables to perform a multiply function between saved filtered signal sample data and selected coefficients from said look-up tables.
6. The device of claim 1 , wherein said binary interpolator further includes a set of adders that is coupled to said set of multipliers for adding at least two successive results from said multipliers.
7. A method for identifying a peak. comprising:
receiving a plurality of signal samples in response to detecting of servo stripe Pulse;
detecting peaks in said plurality of signal samples;
converting said peaks to zero-crossing events, by applying a quadrature filter;
identifying sign change between two successive filtered signal samples, by utilizing center pair registers in a plurality of registers in a shift register;
saving at least a portion of said plurality of filtered signal samples in response to said sign change; and
performing a binary search on said saved portion of said plurality of filtered signal samples to reconstruct a peak, which is substantially the same as an actual peak.
8. The method of claim 7 , further comprising digitizing analog signal samples generated from said stripe pulse to digital signals samples.
9. The method of claim 7 , wherein said performing a binary search further includes identifying a set of coefficients from look-up tables in response to number of iterations.
10. The method of claim 9 , wherein said performing a binary search further includes multiplying at least one saved filtered sample and a selected coefficient.
11. The method of claim 10 , wherein said performing a binary search further includes performing an add function between two outputs from multipliers.
12. An apparatus of identifying a peak, comprising:
means for receiving a plurality of signal samples in response to detecting of servo stripe pulse;
means for detecting peaks in said plurality of signal samples;
means for converting said peaks to zero-crossing event, by applying quadrature filter;
means for identifying sign change between two successive filtered signal samples, by utilizing center pair registers in a plurality of registers in a shift register;
means for saving at least a portion of said plurality of filtered signal samples in response to said sign change; and
means for performing a binary search on said saved portion of said plurality of filtered signal samples to reconstruct a peak, which is substantially the same as an actual peak.
13. The apparatus of claim 12 , wherein said means for performing a binary search further includes means for multiplying at least one saved filtered sample and a selected coefficient.