Patent ID: 7039730

Claim:
A storage device control apparatus, comprising: a channel controller which receives a data input/output request sent from an information processor to a storage device; a disk controller which controls data input/output operations for the storage device; and a cache memory which stores input/output data communicated between the channel controller and the disk controller, wherein the channel controller comprises: a communication interface unit which communicates with the information processor; a data transfer unit connected via a first bus to the communication interface unit for transferring the input/output data communicated between the communication interface unit and the cache memory; and a processor connected via a second bus to the data transfer unit for controlling the data transfer unit; the communication interface unit transmits a read command to the data transfer unit, the read command indicating the processor to read data; the data transfer unit sends, when the first bus conforms to a first communication protocol, a split response to the communication interface unit and sends the read command to the processor, the split response indicating that readout data corresponding to the read command is transmitted later; the data transfer unit does not send, when the first bus conforms to a second communication protocol, the split response to the communication interface unit and sends the read command to the processor; the processor receives the read command, transmits the split response to the data transfer unit, and sends the readout data corresponding to the read command to the data transfer unit; and the data transfer unit receives the readout data and sends the readout data to the communication interface unit.