Each coordinate rotation digital computer iteration selects the rotation direction by analyzing the results of the previous iteration. In this paper, we introduce two arctangent radices and show that about 2/3 of the rotation directions can be derived in parallel without any error. Some architectures exploiting these strategies are proposed.

The CORDIC algorithm is a powerful tool for computing trigonometric functions (sine and cosine) and some transcendental functions (hyperbolic sine and cosine) at a circuit complexity suited for physical implementation by using VLSI technologies. In this paper, we propose a family of architectures for high-throughput applications based on computation pipelining. The granularity of pipelining can be varied to increase the throughput at a cost of increased circuit complexity. The wide variety of solutions allows optimizing the trade-off between performance and circuit complexity, by taking into account the specific requirements and constraints of the application. The evaluations and the designer guidelines an also given.

The COordinate Rotation DIgital Computer (CORDIC) algorithm is an iterative procedure to evaluate various elementary functions. It usually consists of one scaling multiplication and n+1 elementary shift-add iterations in an n bit processor. These iterations can be paired off to form double iterations to lower the hardware complexity while the computational complexity stays the same. With this structure, the shifter size is reduced to 1/2 (1+9/n+1). In this paper, we present this merged algorithm, its error analysis, and software simulation results.