Patent ID: 7697233

Claim:
A disk drive comprising: a disk; a head; an actuator for actuating the head over the disk; a state variable memory for storing a plurality of state variable sets, wherein each state variable set comprises a plurality of state variables and each state variable set corresponds to a task object; a coefficient memory for storing a plurality of coefficient sets, wherein each coefficient set comprises a plurality of coefficients and each coefficient set corresponds to a task object; and control circuitry operable to execute one of the task objects to generate an actuator control signal by: initializing a base state register to address a selected one of the state variable sets in the state variable memory; initializing a base coefficient register to address a selected one of the coefficient sets in the coefficient memory; using the base state register to read a first state variable from the selected state variable set; using the base coefficient register to read a first coefficient from the selected coefficient set; and using a multiply/accumulate circuit to multiply the first state variable by the first coefficient.