Usb storage device and control device

摘要

A controller (21) to be installed in a USB storage device (17) stores format type information of a first area and a second area defined in a flash memory (25) of the USB storage device (17) in order to make a USB mass storage class driver (13) recognize the first area as a disk device to and from which reading, writing and deleting of data can be executed and the second area as a CD-ROM device for which only reading of data can be executed. The controller (21) sends the format type information of the first area and the second area to the USB mass storage class driver (13) in response to a command from a disk drive driver (14) so that the USB mass storage class driver (13) recognizes the USB storage device (17) as two kind of devices including the disk device and the CD-ROM device and an operation system recognizes format of the first area and the second area and limits issuance of either of a command to write to and a command to delete from the second area. The controller (21), in accordance with a command received from an external device (11) and the format type information of the first area and the second area, further on executes reading, writing and deleting of data to and from the first area and executes only reading of data from the second area even if the controller (21) receives either of a command to write to or delete from the second area.