CORDIC

CORDIC (for COordinate Rotation DIgital Computer), also known as the digit-by-digit method and Volder's algorithm, is a simple and efficient algorithm to calculate hyperbolic and trigonometric functions. It is commonly used when no hardware multiplier is available (e.g., simple microcontrollers and FPGAs) as the only operations it requires are addition, subtraction, bitshift and table lookup.

Read more about CORDIC:  Origins, Mode of Operation: Rotation Mode, Mode of Operation: Vectoring Mode, Software Implementation, Hardware Implementation, Related Algorithms, History