IQmath function error ---- Urgent

Hi Frank,

Can you try the following and see if it builds? Im assming you're GLOBAL_Q is 2.

voltageRMS= _IQ2sqrt(_IQdiv(sum,_IQ(counter)));

Hi Vishal,

I tried, but it is still not working.

it built only when I changed it to

voltageRMS = _IQ2( sqrt(sum / counter) );

Frank

Frank,

I tried the following code and it worked fine:

#include "DSP28x_Project.h"

//Global Definitions
#define  GLOBAL_Q       2
#include "IQmathLib.h"

//Function Prototypes

//ISR Prototypes

//Global Variables

//Main Function
void main( void )
{    
    //Local Variables
    _iq2 var1,var2;
    _iq2 counter;
    
    //! Step 1: Setup the system clock
    InitSysCtrl();

    //! Step 2: Initialize PIE control
    DINT;
    InitPieCtrl();
    IER = 0x00000000;
    IFR = 0x00000000;
    InitPieVectTable();
 
    //Test 1: _IQ2sqrt() test, sqrt(4/2) = 1.1412
    //Expected iq2 answer is 0x5 = 0.11 (0.75, round toward zero?)
    counter = _IQ2(2); //IQ->8
    var1    = _IQ2(4); //IQ->16
    var2    = _IQ2sqrt(var1/counter);//IQ->3


    while(1)
    {
    
    }       
    asm(" NOP");
}

Hi Vishal,

Thank you for your reply,

I tried your code and it worked in a sample program, but still not in my project program.

Then, I realized I forgot to mention that I also used Sine table in my program.

#pragma DATA_SECTION(sine_table,"IQmathTables");
_iq30 sine_table[512];

Every time, I tried to use both "sine_table" and  "_IQ2sqrt " , and it gave me error message #10099-D.  ( It could build if I only use one of them)

If I click on the message, it says

I am using TMS320F28035 Experimental Kit.

Thank you,

Frank

I really want to know how to use this on-chip look-up table without causing issues with _IQsqrt.

Have anyone used this before?

Thank you,

Frank

Hi Vishal,

Thank you very much for your help. It is working now.

Frank