The described embodiments provide an efficient mechanism for performing hardware and software co-simulation that greatly simplifies system implementation, and improves the user controllability and ease-of-use. The mechanism includes the hardware and software co-simulators synchronizing at finite and predetermined synchronization points (e.g., five synchronization points) without using polling or busy-wait techniques. The hardware and software co-simulators run freely and independently from each other until one of the synchronization points is reached. At such point the simulators can communicate and/or control other simulation states, thereby reducing the amount of communication and control between the simulators.