Patents Represented by Law Firm Cyrix Corporation
  • Patent number: 5307303
    Abstract: A method and apparatus for performing division is described which first comprises approximating the short reciprocal of the divisor. A reciprocal bias adjustment factor is added to the approximation and the correctly biased short reciprocal is multiplied by a predetermined number of the most significant bits of the dividend and the product is truncated to generate a first quotient digit value. The multiplication takes place in a multiplier array having a rectangular aspect ratio with the long side having a number of bits at least as large as the number of bits required for the divisor. The short side of the multiplier array has a number of bits slightly greater by several guard bits than the number of bits required for a single quotient digit value, which is also determined to be the number of bits in the short reciprocal. The quotient digit value is multiplied by the full divisor and the exact product is subtracted from the dividend to yield an exact partial remainder.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: April 26, 1994
    Assignee: Cyrix Corporation
    Inventors: Willard S. Briggs, David W. Matula
  • Patent number: 5268858
    Abstract: A multiplier system 12 is disclosed which provides for the negation of an operand stored in an operand register 14. When a negative operand must be loaded into a partial product generator 26, a carry bit is selectively generated in carry logic 44 and a selected bit or bits within the partial product is set to zero. During a subsequent pass through the multiplier system 12, a bit is added at a block 46 to provide for the addition of the required quantity for the negation of the operand.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: December 7, 1993
    Assignee: Cyrix Corporation
    Inventor: Willard S. Briggs