Efficient hardware square-root operation

Details Efficient hardware square-root operation Efficient hardware square-root operation

2005-09-08

2009-10-06

Mai, Tan V (Department: 2193)

Electrical computers: arithmetic processing and calculating

Electrical digital calculating computer

Particular function performed

Reexamination Certificate

active

07599980

ABSTRACT:
One embodiment of the present invention provides a system that uses the Newton-Raphson technique to compute a square-root. During operation, the system receives a radicand b. Next, the system calculates the square root of b, √{square root over (b)}, by first using the Newton-Raphson technique to find 1/√{square root over (b)}, and then multiplying 1/√{square root over (b)} by b to produce √{square root over (b)}. While using the Newton-Raphson technique to find 1/√{square root over (b)}, the system first obtains an initial estimate x0for 1/√{square root over (b)} and then iteratively solves the equationxi+1=xi⁢⁢(3-bxi22).Each iteration involves: (1) using a multiplier circuit twice to compute bxi2; (2) performing a bit-wise complement operation on bxi2, shifting the result, and modifying the first two bits of the result to compute3-bxi22,whereby an additional pass through an adder circuit or a multiply/add circuit is not required to perform the subtraction operation; and finally (3) using the multiplier circuit to multiply xiby3-bxi22to computexi⁢⁢(3-bxi22).

REFERENCES:
patent: 6240433 (2001-05-01), Schmookler et al.
patent: 2003/0149712 (2003-08-01), Rogenmoser et al.
Publication: “Computation of Elementary Functions on the IBM RISC System/6000 Processor”; by P.W. Markstein, IBM J. Res. Develop., vol. 34, No. 1, Jan. 1990, pp. 111-119.

Affiliated with

Also associated with

Rating

Efficient hardware square-root operation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Efficient hardware square-root operation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient hardware square-root operation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4071043