CCS/TMS320F28035: IQasin or IQacos in IQmathLib

dfde jiems

Intellectual 510 points

Part Number: TMS320F28035
Other Parts Discussed in Thread: C2000WARE

Tool/software: Code Composer Studio

hi,

everyone,

my question is：

in1 =_IQ(0.70710678L);
out1 =_IQasin(in1);

in theory：

out1 = 0.25 * 3.14156

but when I use CCS V6 debug the formula ：IQasin，it results ：

out1 = -0.3131141663

why？

over 5 years ago

0 Shanty over 5 years ago

TI__Expert 5410 points

Hello,

Can you try the following and let me know what the result is:

Value of in1

The return value is supposed to be in IQ format. Can you adjust for that and get back to me?

-Shantanu

0 dfde jiems over 5 years ago in reply to Shanty

Intellectual 510 points

Thanks，

Shantanu，

#define GLOBAL_Q 24

in1 =_IQ(1.0);
out1 =_IQasin(in1);

debug value：

out1 = 2.309521794

0 Shanty over 5 years ago in reply to dfde jiems

TI__Expert 5410 points

I am assuming in1 is 16777216 ?

out1 is expected to be in Q24 format right?

0 Sira Rao80 over 5 years ago in reply to Shanty

TI__Mastermind 26430 points

I ran the test on the F2837x using the project at C2000Ware_3_02_00_00\libraries\math\IQmath\c28\examples\C\2837xd

and it works fine. See attached. The default Global Q is 24, so in1 corresponds to round(0.707.. x 2^24) and out1 corresponds to round(pi/4 x 2^24).

0 dfde jiems over 5 years ago in reply to Sira Rao80

Intellectual 510 points

Hi，

thanks for your answer！！

I have found the problem ，because of “F28035.CMD” file（I need to add IQmathTablesRam SECTIONS） ,

1、but i donnot know the relationship between IQmath_coff.lib and IQmath.lib?

2、following is the cmd，and I donnot know Uncomment or not uncommented ?

/* Allocate IQ math areas: */
   IQmath            : > FLASHA      PAGE = 0                  /* Math Code */
   IQmathTables      : > IQTABLES    PAGE = 0, TYPE = NOLOAD   /* Math Tables In ROM */
   IQmathTablesRam   : > IQTABLES3   PAGE = 0, TYPE = NOLOAD   /* Math Tables In ROM 林华俤新增*/

Cla1ToCpuMsgRAM : > CLA_CPU_MSGRAM PAGE = 1
CpuToCla1MsgRAM : > CPU_CLA_MSGRAM PAGE = 1

.reset : > RESET, PAGE = 0, TYPE = DSECT
vectors : > VECTORS PAGE = 0, TYPE = DSECT

/* Uncomment the section below if calling the IQNexp() or IQexp()
      functions from the IQMath.lib library in order to utilize the
      relevant IQ Math table in Boot ROM (This saves space and Boot ROM
      is 1 wait-state). If this section is not uncommented, IQmathTables2
      will be loaded into other memory (SARAM, Flash, etc.) and will take
      up space, but 0 wait-state is possible.
   */
/*
   IQmathTables2    : > IQTABLES2, PAGE = 0, TYPE = NOLOAD
   {

IQmath.lib<IQNexpTable.obj> (IQmathTablesRam)

   }
*/
   /* Uncomment the section below if calling the IQNasin() or IQasin()
      functions from the IQMath.lib library in order to utilize the
      relevant IQ Math table in Boot ROM (This saves space and Boot ROM
      is 1 wait-state). If this section is not uncommented, IQmathTables2
      will be loaded into other memory (SARAM, Flash, etc.) and will take
      up space, but 0 wait-state is possible.
   */

IQmathTables3 : > IQTABLES3, PAGE = 0, TYPE = NOLOAD
{

IQmath.lib<IQNasinTable.obj> (IQmathTablesRam)

}

thanks！！

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CCS/TMS320F28035: IQasin or IQacos in IQmathLib