Patent ID: 7921229

Claim:
A host device which is connected to a storage device via a bus and reads and writes data in the storage device, the storage device including a command reception unit that receives, from the host device, a command that includes host function information, indicating at least one function of said host device, and a response transmission unit that transmits a normal response to the host device only when the storage device supports all of the at least one function indicated by the host function information included in the command, the host device comprising: a command transmission unit that transmits the command including the host function information to the storage device, the host function information indicating the at least one function of the host device; a response reception unit that accepts a response from the storage device after transmission of the command from said command transmission unit; and an acceptable/unacceptable access determination unit that determines that access to the storage device is acceptable when the normal reception is identified by said response reception unit after transmission of the command from said command transmission unit and otherwise determines that access is unacceptable.