4 Emulation Definition --Imitating the function of (another system), as by modifications to hardware or software that allow the imitating system to accept the same data, execute the same programs, and achieve the same results as the imitated system Advantage --Can check design in real environment --Faster than simulation Disadvantage --Hard to make the whole system --Needs to fix environment --Hard to debug Simulation or emulation--based testing can reveal the presence of bugs but can never assure the absence of bugs.