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CS269: HW/SW Engineering of Embedded Systems, Winter02
An Embedded System Application
compute
air flow
compute
injection
time
drive
actuators
air
flow
injection
time
air temperature
engine temperature
engine speed
throttle position
look-up table
PWM signals
air pressure
Engine Control Unit
Let’s go through an example of designing an embedded system using programmable and non-programmable IPs.  Here is a typical embedded application, that of engine control for an automobile to achieve low emission and fuel efficiency.  The operation of the engine controller can be partitioned into three different processes.  The first process computes air flow from throttle position, engine speed, air temperature, and air pressure.  The second process takes the air flow and the engine temperature, go through some table look-up to arrive at the injection time.  The third process compute the pulse width modulation signal from the injection time and actually control the fuel injection.