cordic

Simple fixed-point CORDIC function generator for C. Generates a single header file implementing the CORDIC sin/cos operation.

Usage:

gentable <n> > cordic-<n>.h

• n should be number of bits in a signed word to use for computations.

Example:

gentable 24 > cordic-24-bit.h

This will output a header file that will perform the CORDIC sin/cos operation in 24 bit signed fixed point. See cordic-test.c for an example of using the generated headerfile.

Fixed point format

Note that the generator is hardcoded to use a 2.[n-2] fixed point format, so n=16 will create code for 2.14 fixed point precision, to accept angle inputs in range [-2.0,2.0]. Angle inputs must be in the range (-pi/2, pi/2). For angle values outside of this range, wrap to [-pi, pi] then:

• a in [pi/2,pi]: a_corrected = half_pi-(theta-half_pi)
• and similarly for values -pi---pi/2

Precreated

See generated/ for a set of CORDIC headers for given a few word widths.