Moving reference channel quality monitor for read channels
US6014768A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1997 |
| Grant date | Jan 11, 2000 |
| Priority date | — |
| Expiry date | Feb 4, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/41
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method and apparatus for monitoring a read channel in a disk drive system and calibrating the disk drive system. In one embodiment, a comparator circuit is provided to detect the data samples, that fall within a pre-programmed, variable-width distribution window. The output of the comparator circuit is digitized and sent to a logic block to qualify the valid samples. A relative counter or histogram of the detected data samples is obtained. The valid sample count is fed to a counter that can be accessed via a serial port. The channel parameters can be adjusted based upon a relative figure of merit read off the serial port that reflects the distribution of the samples with respect to the target value after processing a statistically valid number of samples. An embodiment of the invention provides a slicer circuit which generates an ideal waveform that tracks the input signal. The ideal waveform constitutes a moving reference for comparison with the sampled signal in a channel quality monitor. The moving reference signal reduces hardware requirements in the comparing circuitry of the channel quality monitor. Further, hardware utility is optimized in an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.