1. A machine readable storage medium having stored therein a first plurality of programming instructions defining data objects and operations on the data objects for use by a second plurality of programming instructions to enable the same second plurality of programming instructions to be compilable into a selected one of a first executable version suitable for use in a hardware/software co-simulation that effectively includes calls to hardware simulation functions that operate to generate bus cycles for a hardware simulator, and a second executable version without the effective calls, but explicitly expressed instead, suitable for use on a targeted hardware.