| 摘要 |
PURPOSE:To execute multiplication in a processing time which is half of the conventional multiplication processing time, with the small increase of a hardware by simultaneously generating two partial products and obtaining a cumulative partial product with a three-input adder. CONSTITUTION:A multiplying device equips a cumulative partial product register 9 to hold the output of a three-input adder 10 and to execute again an input to the three-input adder 10, and a high order partial product generating circuit 7 to generate a high order partial product from a multiplicand and to input the multiplicand to the three-input adder 10. A low order partial product generating circuit 8 is provided to generate a low order partial product from the multiplicand and to input the product to the three-input adder 10 and a control circuit 6 is equipped to control the high order partial product generating circuit 7 and low order partial product generating circuit 8 from a multiplier. Thus, since the two partial products are simultaneously generated and the cumulative partial product is obtained by the three-input adder 10, the two fold processing can be executed with one cycle and the high speed multiplication can be executed. |
