Patent ID: 8792197

Claim:
An apparatus comprising: control circuitry adapted for coupling to a write head of a storage device; wherein the control circuitry comprises: a write driver configured to generate a write signal comprising a plurality of write pulses responsive to write data; and a driver controller associated with the write driver and configured to adjust overshoot amplitudes of respective ones of the write pulses utilizing a segmented digital-to-analog converter; wherein the driver controller comprises: a pattern detector configured to detect patterns in the write data; and pattern-dependent write circuitry comprising the segmented digital-to-analog converter; wherein the segmented digital-to-analog converter comprises: a first segment decoder configured to decode a first portion of a base overshoot value to identify a corresponding number of base overshoot segments; a combiner configured to form a combination of the base overshoot value and a differential overshoot value; a second segment decoder configured to decode a first portion of the combination of the base overshoot value and the differential overshoot value to identify a corresponding number of enhanced overshoot segments; and switching circuitry coupled to the first and second segment decoders and configured to select between the number of base overshoot segments and the number of enhanced overshoot segments responsive to detection of a particular pattern by the pattern detector; wherein the overshoot amplitude for a given one of the write pulses is determined at least in part as a function of the selected one of the number of base overshoot segments and the number of enhanced overshoot segments.