POWER CALCULATOR AND MULTIPLIER

摘要

PURPOSE: To decrease the frequency of arithmetic. ;CONSTITUTION: Respective bits of an exponent (n) in binary notation are obtained to find a combination which minimizes Σ_i0^a(n)|Ti| among T_i combinations which provide n=2^a(n)+Σ_i0^a(n)T_i.2ⁱ, (T_iE{-1, 0, 1}, a(n)=[log₂n]). In an X register 14, (x) is stored as an initial value and in a register 13, T is stored; and switches 15 and 16 are switched with the least significant digit bit T₀ of the T register 13, and the value of the X register 14 is squared by a multiplier 21 each time the T register 13 is shifted to the right by one bit and then stored in the X register 14. A multiplier 17 multiplies the value of the X register 13 and the value of a Y register 19 (initial value 1) when T₀=1 and stores the result in the Y register 19, and multiplies the value of the X register 14 and the value of a Z register 18 when T₀=-1 and stores the result in the Z register 18. Lastly, both the values of the X register 14 and Y register 19 are multiplied by a multiplier 22 and the result is multiplied by the value of the Z register 18 to obtain xn.;COPYRIGHT: (C)1993,JPO&Japio