Off target test benchs and cross compiled code, to check more complex algorithms, can be useful for cases where the program unit(s) under test do not have a direct relationship to the embedded environment or the target microcontroller characteristics. I have often even done this for the "design phase prototyping stage" of a project using differing languages such as Visual Basic on the PC and Embedded C or Assembler on the target MCU!!

Whenever the testing function falls into the category of being dependent on the embedded MCU environment and its companion peripherals / hardware then I think it is a waste of time trying to do testing off target. Just doctoring up the dependencies to get code to run on an alien platform can introduce its own set of errors and the work to do it can often take as long or longer than it took to develop the original code in the first place.

It may also depend to some degree upon the work environment. If you are an independent developer / consultant or working at a small lean and mean company your choices could be much different than those you would make working at a fat rich big company. For example the culture at the big company may place a high value on the idea of embedded software validation using some type of standalone behavioral model that is wrapped around the code that is under test.

Michael Karas