Codesign-extended applications.

ABSTRACTWe challenge the widespread assumption that an embedded system's functionality can be captured in a single specification and then partitioned among software and custom hardware processors. The specification of some functions in software is very different from the specification of the same function in hardware - too different to conceive of automatically deriving one from the other. We illustrate this concept using a digital camera example. We introduce the idea of codesign-extended applications to deal with the situation, wherein critical functions are written in multiple versions, and integrated such that simple compiler/synthesis flags instantiate a particular version along with the necessary control and communication behavior. By capturing a specification as a codesign-extended application, a designer enables smooth migration among platforms with increasing amounts of on-chip configurable logic.