Partitioning disc drive read/write electronics to improve data transfer performance

A disc drive, comprising:

• an actuator assembly which supports a head adjacent a rotatable disc;
• an analog pre-processor integrated circuit, mounted to the actuator assembly to electrically interface with the head, comprising:
• a write current driver circuit to apply write currents to the head to write data in the form of a series of magnetic flux transitions to a recording disc;
• a readback signal amplification circuit to apply preamplification to an analog readback signal having peaks corresponding to previously written magnetic flux transitions transduced from the disc;
• a prewrite compensation circuit, coupled to the write current driver circuit, which applies prewrite compensation to bits in an input write data stream to adjust timing of magnetic flux transitions written in response to the bits in the input write data stream so that peaks in a subsequent analog readback signal are provided with nominally a same temporal spacing as a temporal spacing of the bits in the input write data stream;
• an automatic gain control circuit, responsive to the readback signal amplification circuit, which normalizes the subsequent analog readback signal to a desired amplitude range;
• and
• an equalizer circuit, responsive to the automatic gain control circuit, which equalizes the normalized subsequent analog readback signal;
• and
• a digital post-processor integrated circuit device, comprising:
• a detector circuit, responsive to the equalizer circuit, which outputs a readback data stream having a series of bits nominally corresponding to the bits in the input data stream;
• an error correction code circuit, responsive to the equalizer circuit, which detects and corrects erroneous bits in the readback data stream;
• a buffer, responsive to the error correction code circuit, which temporarily stores the bits of the readback data stream as a set of output data;
• and
• a host interface, responsive to the buffer, which controls transfer of the output data to a host computer in which the disc drive is mountable.