초록 ▼

A read channel circuit (27) for a hard disk drive system (10) includes an analog-to-digital converter (38) having an output (39) which is supplied through a filter (41) to a detector (46) and to a band/error circuit (47). The band/error circuit extracts from the filter output a band value (48) and a

A read channel circuit (27) for a hard disk drive system (10) includes an analog-to-digital converter (38) having an output (39) which is supplied through a filter (41) to a detector (46) and to a band/error circuit (47). The band/error circuit extracts from the filter output a band value (48) and an error value (49). The band and error values are used by a timing recovery loop (51, 53) to control the operation of the analog-to-digital converter, and are used by a gain recovery loop (51, 54) to facilitate an automatic gain control function for an analog circuit (36). The band/error circuit uses targets and thresholds which are each a power of two, so that a predetermined number of the least significant bits from the output of the filter can be used as the error value, without modification. The band value is determined from the most significant bits of the output of the filter. The filter not only shapes the signal spectrum, but also performs an integer space transformation that normalizes the output of the analog-to-digital converter with respect to the predetermined targets and thresholds of the band/error circuit.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus, comprising:an analog-to-digital converter which is operable to sample an analog input signal and to output successive sample levels as respective digital values;a normalizing circuit which is operable to normalize said digital values representing the sample

[ What is claimed is:] [1.] An apparatus, comprising:an analog-to-digital converter which is operable to sample an analog input signal and to output successive sample levels as respective digital values;a normalizing circuit which is operable to normalize said digital values representing the sample levels so that selected said digital values corresponding to a predetermined sample level threshold each have a normalized digital value which is substantially a power of two; anda band/error circuit which is operable to generate a band value and an error value for each of said normalized digital values, said band/error circuit using a predetermined number of the least significant bits of each said normalized digital value as the error value therefor.