Asynchronous asymmetry compensation for data read from a storage medium

A computer program product, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a processing circuit to cause the processing circuit to perform a method comprising:

• detecting, by the processing circuit, positive peak amplitudes and negative peak amplitudes of an unequalized readback signal that exhibits imperfect or bi-modal waveform peaks using a peak tracking threshold module positioned at an input to an equalizer module;
• tracking, by the processing circuit, the positive peak amplitudes and the negative peak amplitudes of the unequalized readback signal in a record;
• and
• providing, by the processing circuit, as an input to an asymmetry compensator module, the record of the peak amplitudes and the negative peak amplitudes determined from the unequalized readback signal.

A computer program product, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a processing circuit to cause the processing circuit to perform a method comprising:

• detecting and tracking, by the processing circuit, positive peak amplitudes and negative peak amplitudes of a readback waveform during data reading using a first tracking threshold module positioned on an output side of an equalizer module;
• detecting and tracking, by the processing circuit, positive peak amplitudes and negative peak amplitudes of the readback waveform during the data reading at an input to the equalizer module using a second tracking threshold module in response to reading a data set separator (DSS);
• and
• performing, by the processing circuit, asymmetry compensation on data using an asymmetry compensator module based on input from the first tracking threshold module in an asymmetry compensation loop when not reading a DSS and based on input from the second tracking threshold module when reading a DSS, an output of the asymmetry compensator module being provided to the equalizer module.