PURPOSE: To facilitate processing and program generation, and to increase an arithmetic speed by providing an arithmetic processing part which processes a tag and data independently when processing such information that the tag is added to the data.

CONSTITUTION: An arithmetic circuit 4-1 extracts only tags from pieces of information sent out to A-Bus and B-Bus to perform specific arithmetic processing, and outputs the result to Y-Bus and also stores a flag in a flag register 7-1. In this case, the information of only the 1st byte is only fetched in the arithmetic circuit 4-1 so as to fetch only the tag from the A-Bus or B-Bus. An arithmetic circuit 4-2 extracts only data from the pieces of information sent out to the A- Bus and B-Bus to perform specific arithmetic processing, and outputs the result to the Y-Bus and also stores a flag in a flag register 7-2.