a method and a data transfer apparatus capable of handling dma block transfer interruptions are provided . the data transfer apparatus includes a plurality of direct memory access channels each having different priorities and at least one backup channel information memory for saving control information necessary for a restart of an interrupted dma transfer through one of the dma channels . the data transfer apparatus further includes a control means responsive to transfer commands which command dma transfers through the dma channels . in addition , the control means executes various interrupt handling steps when a transfer command interrupts an execution of a dma transfer through one of the dma channels having a lower priority than the priority of the dma channel used by the interrupting transfer command , so that an interruption of an important data transfer can be prevented .