Patent ID: 8635379

Claim:
A data storage device comprising: a data storage device controller configured to control a storage medium and to receive a frame from an initiator; and a tag duplicate check unit to determine the initiator, tag information, and a type of the frame according to the received frame, and to provide an interrupt to the data storage device controller if a same frame type and same tag information are received from the initiator, the tag duplicate check unit comprising: a tag analysis logic to generate tag check data of the received frame, a tag buffer set to store tag check data corresponding to a command not being completed, a tag comparator to check a duplicate of tag check data, and a priority encoder to select an empty tag buffer of the tag buffer set, wherein the tag duplicate check unit is configured to determine whether the received frame is a command frame or a task frame, the tag comparator compares the generated tag check data with tag check data stored in the tag buffer set, when the generated tag check data is different from tag check data stored in the tag buffer set, the tag analysis logic stores the generated tag check data in the tag buffer set, and the tag analysis logic invalidates a valid bit of tag check data being completed and stored in the tag buffer set in synchronization with completion notification which the data storage device controller sends to the initiator.