Multiplierless Piecewise Linear Approximation of Elementary Functions

In this work a multiplierless architecture for piecewise linear approximation of elementary functions is discussed. By limiting the slope coefficient to a given number of signed-power-of-two (SPT) terms the general multiplier can be replaced by configurable shifts and a multi-input adder. The considered architecture was proposed in an earlier work for use in direct digital frequency synthesizers (DDFS). We extend it to arbitrary functions and propose some techniques to reduce the complexity.