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cordic

Table of Contents:

Functions

cordic

cordic

hyp_cordic

Examples

Examples

Function cordic

template <int SIZE, int MODE>
void cordic(ap_fixpt<unsigned int W_IN, int IW_IN> angle, ap_fixpt<unsigned int W_IN, int IW_IN> x, ap_fixpt<unsigned int W_IN, int IW_IN> y)

Runs the CORDIC algorithm using the circular coordinate system. See hls_sincos and hls_atan for examples of usage.

Template Parameters:

  • int SIZE: number of desired CORDIC iterations. If SIZE is larger than the depth of the angle table, the depth of the angle table will be used for number of iterations instead.
  • int MODE: variable to indicate vectoring mode (e.g. y -> 0) or rotating mode (e.g. angle -> 0). See hls_common.hpp for modes.

Function Arguments:

  • ap_fixpt<unsigned int W_IN, int IW_IN> angle: input argument in radians
  • ap_fixpt<unsigned int W_IN, int IW_IN> x: x-coordinate, will hold the resulting x-coordinate after CORDIC executes
  • ap_fixpt<unsigned int W_IN, int IW_IN> y: y-coordinate, will hold the resulting y-coordinate after CORDIC executes

Returns:

No return.

Function cordic

template <int SIZE>
void cordic(ap_fixpt<unsigned int W_IN, int IW_IN> angle, ap_fixpt<unsigned int W_IN, int IW_IN> x, ap_fixpt<unsigned int W_IN, int IW_IN> y, ap_fixpt<unsigned int W_IN, int IW_IN> desired_val)

Runs the CORDIC algorithm using the circular coordinate system. This version of CORDIC drives y to the fourth parameter, desired_val.See hls_asin for an example of usage.

Template Parameters:

  • int SIZE: number of desired CORDIC iterations. If SIZE is larger than the depth of the angle table, the depth of the angle table will be used for number of iterations instead.

Function Arguments:

  • ap_fixpt<unsigned int W_IN, int IW_IN> angle: input argument in radians
  • ap_fixpt<unsigned int W_IN, int IW_IN> x: x-coordinate, will hold the resulting x-coordinate after CORDIC executes
  • ap_fixpt<unsigned int W_IN, int IW_IN> y: y-coordinate, will hold the resulting y-coordinate after CORDIC executes
  • ap_fixpt<unsigned int W_IN, int IW_IN> desired_val: value to drive y to

Returns:

No return.

Function hyp_cordic

template <int SIZE, int MODE>
void hyp_cordic(ap_fixpt<unsigned int W_IN, int IW_IN> angle, ap_fixpt<unsigned int W_IN, int IW_IN> x, ap_fixpt<unsigned int W_IN, int IW_IN> y)

Runs the CORDIC algorithm. See hls_exp for an example of usage.NOTE: We use a gain of 0.82816, and a max angle of 1.11817.

Template Parameters:

  • int SIZE: number of desired CORDIC iterations. If SIZE is larger than the depth of the angle table, the depth of the angle table will be used for number of iterations instead.
  • int MODE: variable to indicate vectoring mode (e.g. y -> 0) or rotating mode (e.g. angle -> 0). See hls_common.hpp for modes.

Function Arguments:

  • ap_fixpt<unsigned int W_IN, int IW_IN> angle: input argument in radians
  • ap_fixpt<unsigned int W_IN, int IW_IN> x: x-coordinate, will hold the resulting x-coordinate after CORDIC executes
  • ap_fixpt<unsigned int W_IN, int IW_IN> y: y-coordinate, will hold the resulting y-coordinate after CORDIC executes

Returns:

No return.

Examples

  hls::ap_fixpt<32, 16> x = 0.60725293500888125616;

  hls::ap_fixpt<32, 16> y = 0;

  hls::ap_fixpt<32, 16> r = 3.14;

  hls::math::cordic<16, ROTATING>(r, x, y); 

  hls::math::cordic<16, VECTORING>(r, x, y);

  hls::ap_fixpt<32, 16> x = 0.60725293500888125616;

  hls::ap_fixpt<32, 16> y = 0;

  hls::ap_fixpt<32, 16> r = 3.14;

  hls::ap_fixpt<32, 16> dv = 3.14;

  hls::math::cordic<16>(r, x, y, dv);

  hls::ap_fixpt<32, 16> x = 0.82816;

  hls::ap_fixpt<32, 16> y = 0;

  hls::ap_fixpt<32, 16> r = 3.14;

  hls::math::cordic_hyp<16, ROTATING>(r, x, y);

  hls::math::cordic_hyp<16, VECTORING>(r, x, y);