Abstract: Nonlinear functions are essential in multimedia systems, but they are difficult to be implemented in fixed point SOC. In this paper, a method combining a lookup table and Taylor series is proposed to approximate nonlinear functions by considering the ability of fixed point SOC and the limitation of memory. In addition, a fast convergent method is presented to improve precision by only taking sixth order Taylor series. Experiments show that the proposed method needs less memory compared with the full lookup table method, and can greatly improve precision compared to the method proposed by Tsung Han Tsai [1]

Key words: SOC, fixed point, conversion, Taylor series