| 摘要 |
PROBLEM TO BE SOLVED: To perform multiplication for binary four-fold word length format by dividing a mantissa part through an original method so as to require just four times of multiplication. SOLUTION: A process is divided into four parallel routes. The code bits of two operands are mutually processed by a code calculation block step 16 and two 16-bit binary indexes are processed by a binary index 16-adic conversion block step 100. The multiplicand mantissa of 113 bits is divided into two sections of a high-order 56-bit part designated as XH and a low-order 60-bit part designated as XL while using binary shift quantity information by a block step 101. The mantissa of 113 bits of a multiplier operand is inputted to a division block step 102 and divided into a clear value '1', a high-order 56-bit part designated as YH and a low-order 56-bit part designated as YL. The outputs of the division block steps 101 and 102, X, XL, '1', YH and YL are inputted to a calculation block step 103. Calculating processing includes the execution of four times of multiplication and four times of addition. |
