Abstract: Trigonometric functions are extensively used in digital signal processing. A suitable method to calculate theses functions for each arbitrary angel is Cordic Algorithm. But, the biggest problem of this method is the rotation iteration for result achievement. Most common fractions such as 2 10 have not any exact presentation in the binary computations; because of this and many other reasons, today, designing decimal computational units is considered. Designing the Cordic decimal algorithm has very high delay so, in this study, changing the control system of algorithm, convergence rate and, finally, its responding rate was increased. Algorithm`s hardware basis would not be changed because a little hardware would be added to control unit.