Unconstrained equalization method and apparatus with gain and timing bias to control runaway for direct access storage device (DASD) data channels

摘要

An unconstrained equalization method and apparatus with gain and timing bias to control runaway are provided for a direct access storage device (DASD) data channel. A direction for moving each of a plurality of tap weights of a finite impulse response (FIR) filter is calculated. New tap weights are determined for each of a plurality of tap weights in the direction. A gain of the FIR filter for the new tap weights is compared with a set threshold gain value. A polarity of a gain bias is set to adjust a gain of a gain loop of the data channel by a preselected amount responsive to the compared gain and set threshold gain values, A phase lag of the FIR filter for the new tap weights is compared with a set threshold phase lag value. A polarity of a timing bias is set to adjust a phase lag of a timing loop of the data channel by a preselected amount responsive to the compared phase lag and set threshold phase lag values.