Compatible CORDIC and CCM algorithms for small area realization

In this paper, new compatible CORDIC and CCM (Convergence Computing Method) algorithms are proposed. The algorithms are based on new convergence sets of {tan^-12^-2i; i=0,1,2,...,[n/2]} and {ln(1+2^-2i); i=1,2,...,[n/2]} for CORDIC and CCM respectively, other than the existing sets of {tan^-1 2^-i; i=0,1,2,...,n} and {ln(1+2^-i); i=0,1,2,...,n}. Based on the new convergence sets, adaptive double and quadruple rotation and convergence schemes are developed. The new rotation sequences and schemes make CORDIC and CCM algorithms highly compatible in hardware implementation. Besides, cos^-1 and sin ^-1 functions can also be realized with the new algorithm, which is hard for conventional algorithms. Moreover, this new rotation sequence can be applied to both trigonometric and hyperbolic functions. In implementation, the new algorithm results in smaller ROM size, smaller barrel shifters, simpler scaling factor compensation, and richer functional capabilities than conventional CORDIC processors. Layout design of the combined CORDIC/CCM processor has been accomplished and sent to foundry for chip realization