| 摘要 |
PURPOSE:To execute a multiplication with a double efficiency in a short time without increasing a circuit scale at all by adding a selection circuit at the periphery of a multiplier of conventional type. CONSTITUTION:A multiplier 1 has the same performance as a conventional type of multiplier which performs multiplication between multipliers K1KN and multiplicands L1-LN and outputs multiplication results M1-M2N-1. A selector 2 is a selector provided at the multiplicand input side of the multiplier 1, and outputs an input A to an output Y when a select input S is 0, and an input B to the output Y when the select input S is 1. 0 is always inputted to the MSB input A of the selector 2, and multiplicands l1-lN are inputted to the input terminal of the selector 2. A selector 3 is a selector provided at the multiplication result output side of the multiplier 1, and similarly as the selector 2, it outputs the input A to the output Y when the select input S is '0', and the input B to the output Y when the select input S is '1'. 0 is always inputted to the LSB input A of the selector 3. |
