With the fast development of semiconductor technology, more and more Intellectual Property (IP cores) can be integrated into one chip under the Globally Asynchronous and Locally Synchronous (GALS) architecture. Power becomes the main restriction of the System-on-Chip (SOC) performance especially when the chip is used in a portable device. Many low power technologies have been proposed and studied for IP core's design. However, there is a shortage of system level power management schemes (policies) for the GALS architecture. In particular, the area of using Dynamic Power Management (DPM) to optimize SOC power dissipation under latency restriction ains relatively unexplored. This thesis describes the work of modelling and design of an asynchronous event coprocessor to control the operations of an IP core in the GALS architecture.