RAID CONTROLLER AND COMMAND PROCESSING METHOD THEREOF

PROBLEM TO BE SOLVED: To provide a RAID controller capable of increasing the degree of freedom of access from a host device to a storage device constituting the RAID.SOLUTION: The RAID controller includes: a first serial ATA interface to which a host device can be connected; a second serial ATA interface having plural ports connectable to a storage device capable of executing ATA command; and a control section that, when a significance value is written on a predetermined control register, which is specified as not-used in the ATA standard, in a control register group in which a parameter is written with respect to the type of the ATA command acquired from the host device by the first serial ATA interface, determines the value as a piece of port information for specifying the port to which a storage device for executing the ATA command is connected and controls the second serial ATA interface to transfer ATA command to the storage device through a port specified by the port information.