ARITHMETIC UNIT APPLYING LOGARITHM EXPRESSING NUMERICAL COMPUTING METHOD HAVING SCALING FUNCTION

摘要

PURPOSE:To use the conversion tables and the addition/subtraction tables as they are and to widen the range of the handling numerical value by providing an input adder between an input conversion tables and a computing element and an output adder between a computing element and an output conversion table respectively. CONSTITUTION:The input data X1,...,Xn on the fixed decimal points are converted into the logarithms via an input conversion table 1 to calculate fj (X1,...,Xn). At the same time, an input adder 2 adds together -K1,...,-Kn and a computing element 3 applying a logarithm expressing numerical computing method performs the due calculation. An output adder 4 adds the proper value, e.g., gj (K1,...,Kn) to the calculation result of the element 3. Then this addition value is converted into the number of fixed decimal points via an output conver sion table 5. Thus, the original output result fj (K1,...,Kn) can be obtained.