A peripheral device for use in a system including a storage unit coupled to a local bus. The peripheral device has a shared bus interface provided for interfacing with the storage unit and the local bus. The peripheral device also includes core logic coupled to the shared bus interface. When the core logic receives a read/write command with respect to the storage unit through the local bus, it causes the local bus to enter at least a wait state and performs a corresponding data transfer between the peripheral device and the storage unit through the shared bus interface during the wait state. In particular, the peripheral device shares the shared bus interface with the storage unit so as to transfer data.