Patent attributes
A USB storage device having the function of preventing stored software from being deleted by mistake achieved with as simple a structure as possible. In the USB storage device, the storage area is divided into an area in which execution of reading, writing and deleting is allowed and an area in which only execution of reading is allowed. Information to make a USB mass storage class driver recognize these areas as areas corresponding, respectively, to logical unit numbers defined in the SCSI command set of the USB mass storage class driver owned by the host is stored in the USB storage device. The information includes logical unit numbers, formats, writing/deleting allowed/not allowed flag, logical block numbers and physical block numbers. By this, the USB mass storage class driver recognizes the USB storage device as a SCSI device having two logical units.
