Patent ID: 7185040

Claim:
An apparatus providing a square root of a radicand by a iterative operation the apparatus comprising: a root digit selector for selecting an (i−1)'th root digit from an (i−2)'th partial remainder; a first correction term generator for creating a first correction term by means of an (i−2)'th partial square root and the (i−1)'th root digit; a second correction term generator for creating a second correction term by means of an (i−1)'th partial square root; a third correction term generator for creating a third correction term by means of the (i−1)'th partial square root; a first subtractor for deducting the first and second correction terms from a left-shifted value of an (i−2)'th partial remainder; a second subtractor for deducting the first and second correction terms from the left-shifted value of the (i−2)'th partial remainder; a carry propagation detector for determining whether there is a borrow or a carry-in while calculating an (i−i )'th partial remainder; root digit prediction means for predicting an i'th root digit in response to an (i−1)'th root digit, the (i−2)'th partial remainder, and an output of the carry propagation detector; and selection means for selecting an alternative one of outputs of the first and second subtractors as an i'th partial remainder in response to the i'th root digit.