| 摘要 |
PURPOSE:To execute the subtraction of an expanded input at the time of expansion only by a multiplier by dividing the expanded input into two high-order and low-order bits to process the expanded input. CONSTITUTION:In case of executing subtraction by using an nXn bit multiplier to expand an NXN (N>n) bits multipler, logic adding expansion inputs Mi, Mj independently as they are or after inversion by two inputs ADD/SUB, Kc is formed. The multiplier is constituted by adding logic 0 to Kc at the use of a unit, executing addition, i.e. directly inputting the Mi, Mj, when ADD/SUB=0, and executing subtraction, i.e. inverting and inputting the Mi, Mj when ADD/ SUB=1. Consequently, the Mi, Mj are added to products Xi, Yi directly or after inversion by the ADD/SUB and Kc values as shown in the figure. |
