| 摘要 |
PURPOSE:To improve the comprehensiveness of multiplication by forming a 2<n> multiplication supporting circuit in addition to a general multiplication circuit. CONSTITUTION:A processing unit is constituted of an operation control circuit 11, a general multiplication circuit 12, a 2<n> multiplication supporting circuit 13, a shifting operation circuit 15, and a selecting circuit 14 for selecting these output results. The 2<n> multiplication supporting circuit 13 forms exponential operation data and 2<n> multiplication shifting information from the 2<n> data obtained from a data line 103 and multiplication data obtained from a data line 102 by a floating point 2<n> multiplication instruction in accordance with a signal outputted from the circuit 11 and transfers the formed results to said selecting circuit 14 through a shifting operation circuit 15. In case of a fixed point 2<n> multiplication instruction, the 2<n> value data obtained from the data line 102 are shifted through the shifting operation circuit 15 and the shifted data are transferred to the circuit 14. In case of a 2<n> multiplication instruction, the multiplication data obtained from the data line 102 are shifted and transferred. These transferred results are selected by the selecting circuit 14 and outputted 112. |
