188 lines
5.2 KiB
Plaintext
188 lines
5.2 KiB
Plaintext
//#############################################################################
|
|
// \file atan.cla
|
|
//
|
|
// \brief Arc Tangent Example
|
|
//
|
|
//#############################################################################
|
|
// $Copyright:
|
|
// Copyright (C) 2014-2023 Texas Instruments Incorporated - http://www.ti.com/
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions
|
|
// are met:
|
|
//
|
|
// Redistributions of source code must retain the above copyright
|
|
// notice, this list of conditions and the following disclaimer.
|
|
//
|
|
// Redistributions in binary form must reproduce the above copyright
|
|
// notice, this list of conditions and the following disclaimer in the
|
|
// documentation and/or other materials provided with the
|
|
// distribution.
|
|
//
|
|
// Neither the name of Texas Instruments Incorporated nor the names of
|
|
// its contributors may be used to endorse or promote products derived
|
|
// from this software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
// $
|
|
//#############################################################################
|
|
|
|
//
|
|
// Included Files
|
|
//
|
|
#include "cla_ex2_atan_shared.h"
|
|
|
|
//
|
|
// Defines
|
|
//
|
|
|
|
//
|
|
// Globals
|
|
//
|
|
// Note that the globals defined in the .cla source are global to the cla source
|
|
// file. i.e. they may be shared across tasks. All of the data shared between
|
|
// the CLA and the C28x CPU must be defined in the C (or C++) code, and not the
|
|
// CLA code.
|
|
//
|
|
|
|
//
|
|
// Function Definitions
|
|
//
|
|
//Task 1 : Calculate atan(Y)
|
|
// Description:
|
|
// Step(1): if( 1.0 >= abs(Y) )
|
|
// Numerator = abs(Y)
|
|
// Denominator = 1.0
|
|
// else
|
|
// Numerator = 1.0
|
|
// Denominator = abs(Y)
|
|
//
|
|
// Step(2): Ratio = Numerator/Denominator
|
|
//
|
|
// Note: Ratio range = 0.0 to 1.0
|
|
//
|
|
// Step(3): Use the upper 6-bits of the "Ratio" value as an
|
|
// index into the table to obtain the coefficients
|
|
// for a second order equation:
|
|
//
|
|
// _FPUatan2Table:
|
|
// CoeffA0[0]
|
|
// CoeffA1[0]
|
|
// CoeffA2[0]
|
|
// .
|
|
// .
|
|
// CoeffA0[63]
|
|
// CoeffA1[63]
|
|
// CoeffA2[63]
|
|
//
|
|
// Step(4): Calculate the angle using the following equation:
|
|
//
|
|
// arctan(Ratio) = A0 + A1*Ratio + A2*Ratio*Ratio
|
|
// arctan(Ratio) = A0 + Ratio(A1 + A2*Ratio)
|
|
//
|
|
// Step(5): The final angle is determined as follows:
|
|
//
|
|
// if( Y >= 0 and 1.0 >= abs(Y) )
|
|
// Angle = arctan(abs(Y)/1.0)
|
|
// if( Y >= 0 and 1.0 < abs(Y) )
|
|
// Angle = PI/2 - arctan(1.0/abs(Y))
|
|
// if( Y < 0 )
|
|
// Angle = -Angle
|
|
__interrupt void Cla1Task1 ( void )
|
|
{
|
|
//
|
|
//Local Variables
|
|
//
|
|
unsigned int uxTblIdx; //unsigned integer valued Table index
|
|
float ratio;
|
|
float num,den;
|
|
float A0,A1,A2; //Table coefficients
|
|
float *base;
|
|
float result;
|
|
|
|
//
|
|
//Preprocessing
|
|
//
|
|
__mdebugstop();
|
|
num = __mminf32(fabsf(fVal),1.0f);
|
|
den = __mmaxf32(fabsf(fVal),1.0f);
|
|
|
|
ratio = (num/den); //Expected the newton raphson algo for better
|
|
//accuracy on the divide
|
|
uxTblIdx = ratio * TABLE_SIZE_M_1 * 3; //convert table index to u16-bits
|
|
uxTblIdx = uxTblIdx * 3; //Table is ordered as 3 32-bit coefficients, the
|
|
//index points to these triplets, hence the *3*sizeof(float)
|
|
|
|
base = &CLAatan2Table[uxTblIdx];
|
|
A0 = *base++;
|
|
A1 = *base++;
|
|
A2 = *base;
|
|
|
|
result = A0 + ratio*(A1 + A2*ratio);
|
|
|
|
//
|
|
//Post processing
|
|
//
|
|
if(fabsf(fVal) > 1.0f)
|
|
{
|
|
result = PIBYTWO - result;
|
|
}
|
|
|
|
if(fVal < 0.0f)
|
|
{
|
|
result = -result;
|
|
}
|
|
|
|
fResult = result;
|
|
}
|
|
|
|
interrupt void Cla1Task2 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
interrupt void Cla1Task3 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
interrupt void Cla1Task4 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
interrupt void Cla1Task5 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
interrupt void Cla1Task6 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
interrupt void Cla1Task7 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
interrupt void Cla1Task8 ( void )
|
|
{
|
|
|
|
}
|
|
|
|
//
|
|
// End of file
|
|
//
|
|
|