Title :
Implementation of elementary functions for logarithmic number systems
Author :
Johansson, K. ; Gustafsson, O. ; Wanhammar, L.
Author_Institution :
Dept. of Electr. Eng., Linkoping Univ., Linkoping
fDate :
7/1/2008 12:00:00 AM
Abstract :
Computations in logarithmic number systems require realisations of four different elementary functions. In the current paper the authors use a recently proposed approximation method based on weighted sums of bit-products to realise these functions. It is shown that the considered method can be used to efficiently realise the different functions. Furthermore, a transformation is proposed to improve the results for functions with logarithmic characteristics. Implementation results shows that significant savings in area and power can be obtained using optimisation techniques.
Keywords :
digital arithmetic; function approximation; optimisation; table lookup; bit-product weighted sums; elementary functions; function approximation method; logarithmic number systems; look-up tables; optimisation techniques;
Journal_Title :
Computers & Digital Techniques, IET
DOI :
10.1049/iet-cdt:20070080