A simulation system, method, and article of manufacture. A simulation system has a discrete and a continuous portion. The discrete portion further has a peripheral emulator in communication with the continuous portion of the simulation system. A portion of a peripheral emulator is separated and is caused to operate in a thread of a continuous system. The continuous system and the peripheral are in loose synchronization and therefore sparsely communicate with each other. The configuration significantly reduces the frequency of inter-thread communications between the continuous system and the discrete system that are performed in response to a continuous clock in a simulation system including the continuous system and the discrete system, thereby reducing communication cost. Accordingly, the operation speed of the simulation system can be increased.