A storage device includes a first memory device, a second memory device, and a controller. The first memory device and the second memory device share the same channel to communicate with the controller. Communication between the first memory device and the controller and communication between the second memory device and the controller are mutually exclusive. When the controller receives a read request directed to the second memory device while the controller processes a direct memory access (DMA) operation directed to the first memory device, the controller suspends the DMA operation and transmits a read command associated with the read request to the second memory device.