Data storage device transmitting delta servo control value over serial interface

A data storage device comprising:

• a disk comprising servo data;
• a head;
• a first actuator configured to actuate the head radially over the disk;
• and
• control circuitry configured to:
• compute a first initial digital control value based on the servo data;
• transmit the first initial digital control value over a serial interface to a driver circuit configured to control the first actuator based on the first initial digital control value;
• compute a first delta digital control value based on the servo data, wherein the first delta digital control value for adjusting the first initial digital control value;
• transmit the first delta digital control value over the serial interface to the driver circuit, wherein the first initial digital control value consists of a first number of bits and the first delta digital control value consists of a second number of bits less than the first number of bits.

Control circuitry comprising:

• a serial interface configured to receive digital control values;
• a first accumulator;
• and
• a first digital-to-analog converter configured to generate a first analog control signal for controlling a first actuator based on an output of the first accumulator, wherein the first actuator is configured to actuate a head radially over a disk,
• wherein the control circuitry is configured to:
• initialize the first accumulator based on a first digital control value received over the serial interface;
• and
• adjust the first accumulator based on a second digital control value received over the serial interface.