Patent ID: 7577894

Claim:
A judgment apparatus which judges legitimacy of data included in each data block using a check code included in each data block when each of a plurality of data blocks is divided into a plurality of frames and divided frames are received from a host computer via a fiber channel of a communication network outside the judgment apparatus, comprising: a group identifier storage device storing a group identifier of a data block corresponding to a frame received among a plurality of group identifiers allocated to the plurality of data blocks; an interim result storage device having a plurality of entries which store interim calculation results of check codes of the data blocks in accordance with the respective group identifiers; a data length storage device storing a data length of data stored in the frame received; a buffer device storing the data stored in the frame received; a buffer length update device updating the data length stored in the data length storage device when the data is read from the buffer device; a production device producing an interim calculation result of a check code using an interim calculation result stored in an entry of the interim result storage device which corresponds to the group identifier stored in the group identifier storage device and the data stored in the buffer device, and updating the interim calculation result stored in the entry until the data length stored in the data length storage device reaches a prescribed value; and a comparison device comparing a final calculation result with a check code of a data block and outputting a comparison result when a last frame of the data block is received from the host computer via the fiber channel of the communication network outside the judgment apparatus and the production device produces the final calculation result of the check code of the data block using data of the last frame.