IQmath Library

C-Callable ASM Interface
C-Callable ASM Interface
Declaration
Global IQ function (IQ format = GLOBAL_Q)
_iq _IQcosPU(_iq A)
Q format specific IQ function (IQ format = IQ1 to IQ30)
_iqN _IQNcosPU(_iqN A)
Input Format
Global IQ function (IQ format = GLOBAL_Q)
Input argument is in per-unit radians and represented as fixed-point
number in GLOBAL_Q format.
Q format specific IQ function (IQ format = IQ1 to IQ30)
Input argument is in per-unit radians and represented as fixed-point
number in IQN format (N=1:30).
Output Format
Global IQ function (IQ format = GLOBAL_Q)
This function returns the sine of the input argument as fixed-point
number in GLOBAL_Q format.
Example
Q format specific IQ function (IQ format = IQ1 to IQ30)
This function returns the sine of the input argument as fixed-point
number in IQN format (N=1:30)
The following sample code obtains the cos ( 0.25×π )
Q30 format in the IQmath header file.
=0.707 assuming that GLOBAL_Q is set to
Sample Code
#include /* Header file for IQmath routine */
#define PI 3.14156
_iq in1, out1;
_iq30 in2, out2
void main(void )
{
in1=_IQ(0.25*PI/PI); /* in1 =
0 .25×
π
× 2 30 = 08000000h
*/
out1=_IQcosPU(in1) /* out1== cos( 0.25 ) × 2
30 = 2D413CCCh
2π
×π */
in2=_IQ30(0.25*PI/PI); /* in2 =
0 .25×
π
× 2 30 = 08000000h
*/
out2=_IQ30cosPU(in2); /* out2== cos( 0.25 ) × 2
30 = 2D413CCCh
}
2π
×π */
©Texas Instruments Inc., June 2002 44