A direct fuel injection control for an internal combustion engine includes first and second controllers. The first controller has a microprocessor and generates injection timing and duration signals on injector select lines. The second controller is a state machine including injector controls that receive the injection timing and duration signals and control injector current according to sets of injector current profile defining parameters received from the first controller on a serial bus and stored in register sets in the second controller. The second controller includes switching apparatus that can quickly change the connection of each injector control between different register sets to select different injector current profiles in successive injection pulses. Several alternative ways of providing register select signals are disclosed, and these may be incorporated in the same second controller for selection by the first controller.