A Vlsi Circuit For Online Polynomial Computing - Application To Exponential, Trigonometric And Hyperbolic Functions

This paper presents a novel flexible architecture for the on-line computation of most real functions approximated by the first terms of their Taylor expansions. An example of a 64 digit VLSI implementation is given for some usual functions such as exponential, sh, ch, sin and cos of a real x (with [x] < 0.5, represented in a radix-two fixed point signed digit system) using a built-in coefficient table. Furthermore, the circuit universality is guaranteed by enabling the introduction of external coefficients corresponding to any polynomial of degree less than or equal to 15. The result is obtained, at up to 40 MHz frequency, with an on-line delay of 11.