Evaluation Of Root Patents (Class 708/605)
  • Patent number: 6148318
    Abstract: A square root extraction circuit and a floating-point square root extraction device which simplify a circuit structure and improve an operation speed are provided. Portions for generating square root partial data (q3 to q8) include carry output prediction circuits (3 to 8), respectively. The carry output prediction circuit (i) (i equals any one of 3 to 8) receives condition flags (AHin, ALin), the most significant addition result (SUM), and square root partial data (q(i-1)) from the preceding square root partial data generating portion, and also receives a carry input (Cin) to output condition flags (AHout, ALout) for the next square root partial data generating portion, and square root partial data (q(i)). The condition flags (AHout, ALout) serve as the condition flags (AHin, ALin) for the carry output prediction circuit (i+1), respectively.
    Type: Grant
    Filed: November 5, 1997
    Date of Patent: November 14, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroyuki Kawai, Robert Streitenberger, Yoshitsugu Inoue, Hiroyuki Morinaka
  • Patent number: 6115733
    Abstract: A processor capable of efficiently evaluating constant powers of an operand such as the reciprocal and reciprocal square root is disclosed. The processor comprises a multiplier that is configured to perform iterative multiplication operations to evaluate constant powers of an operand such as the reciprocal and reciprocal square root. Intermediate products that are formed may be rounded and normalized in two paths, one assuming an overflow will occur, and then compressed and stored for use in the next iteration. The processor comprises a multiplier capable of performing signed and unsigned scalar and vector multiplication is disclosed. The multiplier may performing rounded by adding a rounding constant.
    Type: Grant
    Filed: May 8, 1998
    Date of Patent: September 5, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Stuart F. Oberman, Norbert Juffa, Fred Weber
  • Patent number: 6108682
    Abstract: An iterative division and/or iterative square root circuit 20 uses quotient digits q.sub.j+1 within the calculation that are dependent upon the input divisor D or radicand A and current partial remainder or partial radicand P.sub.j for the cycle reached. As the input divisor D or radicand A is fixed throughout the calculation, the critical path through the iterative circuit may be speeded up by preselecting and storing a subset QC of quotient digit values using a primary quotient digit selecting circuit 18, 22 operating in dependence upon the divisor D or radicand A and independently of the partial remainder or partial radicand P.sub.j. Within the iterative circuit 20, the quotient digits q.sub.j+1 to be used for each cycle can then be selected from this subset QC by a secondary quotient digit selecting circuit 24 in dependence upon the partial remainder or partial radicand P.sub.j and independent of the divisor D or radicand A.
    Type: Grant
    Filed: May 14, 1998
    Date of Patent: August 22, 2000
    Assignee: ARM Limited
    Inventor: David Terrence Matheny
  • Patent number: 6101521
    Abstract: A data processing apparatus (200) which improves the accuracy of resultant data. The data processing apparatus includes an input (220, 222) configured to receive input data. The input data includes data corresponding to an input coefficient to be multiplied by the square root of two (.sqroot.2) and input addend. The data processing apparatus further includes a first memory (202) for storing a coefficient of the square root of two, a second memory (204) for storing an addend, a summer (206, 208) which independently sums the input coefficient and the coefficient to produce a combined coefficient and sums the input addend and the addend to produce an addend sum, a multiplier (210) which multiplies the combined coefficient and an approximation of the square root of two to produce an intermediate result, and a summer (214) which sums the intermediate result and the addend sum to produce the resultant data.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: August 8, 2000
    Assignee: Motorola, Inc.
    Inventor: Jeannie Han Kosiec
  • Patent number: 6070181
    Abstract: An envelope detection method by using a peel cone approximation concept and an envelope detection circuit which implements the envelope detection method are disclosed. The envelope detection circuit includes an absolute value-determining circuit, a maximum/minimum value-determining circuit, a plurality sets of comparison circuits, an address encoder, a read only memory (ROM), and a multiplier/adder. A delaying circuit for synchronization is further included in the envelope detection circuit. With the method and the circuit for an envelope detection by using a peel cone approximation, advantages of a compact circuit structure, less operation latency, a low approximation error and a low cost are all achieved.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: May 30, 2000
    Assignee: Chun-Shan Institute of Science and Technology
    Inventor: Scott Yeh
  • Patent number: 6026423
    Abstract: A processor system apparatus and method for determining a square root of a particular value of a square of a parameter for use with an electronic circuit breaker system.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: February 15, 2000
    Assignee: Siemens Energy & Automation, Inc.
    Inventor: Michael E. McKoy