Hardware/software co-simulation is generally performed withseparate simulation models.This makes trade-off evaluationdifficult, because the models must be re-compiled wheneversome architectural choice is changed.We propose a techniqueto simulate hardware and software that is almost cycle-accurate,and uses the same model for both types of components.Only the timing information used for synchronizationneeds to be changed to modify the processor choice, the implementationchoice, or the scheduling policy.We show howthis technique can be used to decide the implementation of areal-life example, a car dashboard controller.