The quality of embedded software is important, especially for life-critical and mission-critical embedded systems. And software testing is a key activity to ensure the quality of embedded software. Both system testing and unit testing are vital to test embedded software. Unit testing is probably more important to ensure there are no latent faults. System testing is almost invariably done on a target system, but unit testing is normally done on a host system, as standard test frameworks generally don’t support the execution of unit tests on a target system. This paper analyzes the significant quality benefits to run unit testing on a target system. Also, it presents a performance model for evaluating the test execution cost, discusses the experimental results, and identifies the factors which influence the experiment