摘要:
An apparatus for providing dynamic equalizer optimization is disclosed. The present invention solves the above-described problems by providing equalizer coefficient updates that converge towards the same solution as the direct method without having to first write a known pattern to the disk or requiring any prior knowledge of the data already written on the disk. The adaptive cosine function may be used to modify only a DFIR tap set, only the j and k parameters of a cosine equalizer or to modify both the tap set for a DFIR filter and the j and k parameters of the cosine equalizer. Another algorithm, such as the LMS algorithm, may be used to modify parameters not modified by the cosine algorithm.
摘要:
A noise-predictive data detection method and apparatus are provided for enhanced noise-predictive maximum-likelihood (NPML) data detection in a direct access storage device. A data signal from a data channel in the direct access storage device is applied to a maximum-likelihood detector that provides an estimated sequence signal. A noise bleacher filter having a frequency response of (1+.alpha.D)/1-.beta.D.sup.2) receives a combined estimated sequence signal and data signal and provides a noise filtered signal. A matching and error event filter receives the noise filtered signal and provides an error event filtered signal. An error correction unit receives the estimated sequence signal from the maximum-likelihood detector and receives the error event filtered signal and provides an error corrected estimated sequence signal.
摘要:
Apparatus and method for providing equalization adjustment for a filter are provided in a PRML data channel. A first predetermined test pattern is written. Relative error is measured in both magnitude and phase for predetermined frequencies. A relative magnitude ratio for the predetermined frequencies and a phase delay between the predetermined frequencies are identified. A tap set is generated having predefined frequency responses at a plurality of predefined discrete frequencies.
摘要:
A method of correcting repeatable run out (RRO) errors for a HDD in which RRO data is instead stored in consolidated form within the reserved area of the disk, instead of storing RRO data in the servo patterns for each HDD track or sector. RRO data is preferably stored in the reserved area of a hard disk drive in compressed form. The compressed RRO data is subsequently read into DRAM in compressed form and then decompressed for use. Predictive techniques determine what compressed RRO data is needed for upcoming read/write operations.
摘要:
A method of correcting repeatable run out (RRO) errors for a HDD in which RRO data is instead stored in consolidated form within the reserved area of the disk, instead of storing RRO data in the servo patterns for each HDD track or sector. RRO data is preferably stored in the reserved area of a hard disk drive in compressed form. The compressed RRO data is subsequently read into DRAM in compressed form and then decompressed for use. Predictive techniques determine what compressed RRO data is needed for upcoming read/write operations.