Patent ID: 6769006
Filing Date: 2004-07-27
Classification: G06F

Abstract:
A method for generating an output signal representing an output value approximating a reciprocal of input value D having a normalized mantissa M (where 1&lE;M<2) represented by an input signal, the input signal comprising a set of N0 most significant bits and the output signal approximating the reciprocal with a desired precision âˆˆ=2âˆ’N where N&lE;N0, comprising the steps of:a. for a set of P most significant bits of the input signal, generating a number n of entries in a plurality of lookup tables where n=2p, including the sub steps of: i. generating a set of input entries yi comprising a set of N significant bits in a first lookup table, where i=0, . . . , nâˆ’1; and ii. generating a set of input entries Ki comprising a set of (Nâˆ’P) significant bits in a second lookup table, where i=0, . . . , nâˆ’1; b. finding the entries yi and Ki in the lookup tables corresponding to the set of P most significant bits of the input signal; c. a multiplying K1 by a signal comprising a set of(Nâˆ’P) significant bits following the set of P most significant bits of the input signal; and d. subtracting a set of(Nâˆ’P) most significant bits from the set of N significant bits of the entry yi.