Raghunathan,

Five or six years ago I toured a Motorola electronics design and manufacturing facility in Illinois that did a considerable amount of automotive electronics - mostly engine control modules. At the time Motorola was incorporating some innovative methods of packaging to move heat from the high current components used to drive electronic fuel injectors through the pc board and into the case where, in a vehicle, heat would be passed to the chassis.
As the facility was owned and operated by Motorola, Motorola's sixteen bit microprocessors were used - the 683XX family.

During a trip a few months later, I visited an Allied Signal plant that did a number of things including design and manufacture of engine control modules. Like Motorola, Allied Signal did some innovative packaging and incorporated the Motorola 683XX family for driving fuel injectors.

Caterpillar has its own line of engine and machinery controls, though I don't recall the processor.

Cummins used to manufacture its own ECMs but turned over the job to a third party about five years ago.

I suggest you take a look at the Motorola 68332 microprocessor and delve into its TPU (time processing unit) to understand the capability it has for sequencing drive circuits of fuel injectors, even as the engine speed accelerates and deccelerates between cylinder firings.

Bruce