A Decision-Based CORDIC Hardware for Arc Tangent Calculation

The COordinate Rotation DIgital Computer (CORDIC) simplifies the elementary function using bit-shift operation and addition. However, the iteration increases with the accuracy and causes a long latency. In this paper, we propose a decision-based CORDIC hardware for arc tangent calculation, which introduce a comparator to determine the necessity of the rotation in every iteration. By bypassing the redundant processes, the proposed CORDIC achieve a higher accuracy. Besides, the regular structure is also friendly for folding implementation. Experiments show that compare with the conventional CORDIC, the decision-based CORDIC hardware has an improvement of 28.1% in accuracy. Synthesis results in 65nm technology shows that the proposed unfolding hardware consumes an area of 0.774mm
²
and a power of 0.644mW under 65nm technology, which has an improvement of about 13.7% and 3% in comparison with the conventional CORDIC, and the folding structure has an area of 0.164mm
²
and a power of 0.243mW .