How to Use C28x C/C++ Intrinsic Functions

Louis Zhu

Other Parts Discussed in Thread: CONTROLSUITE

I use F28069M FPU for my motor control application. I want to use intrinsic functions such as __sin(), __cos(), what library and header files should be referenced? Anything special should be done in a linker command file?

Thanks!

over 10 years ago

0 David M. Alter over 10 years ago

TI__Guru 61235 points

Louis,

There are no header/include files for intrinsics, and no function prototypes. Intrinsics are not really functions. You do not need to do anything special in the linker .cmd file. Intrinsic code will appear in the same section as the rest of the code it is being used in.

Regards,

- David

0 Louis Zhu over 10 years ago in reply to David M. Alter

Expert 1685 points

But I have the following errors and warnings. Please advise how to resolve them.

0 David M. Alter over 10 years ago in reply to Louis Zhu

TI__Guru 61235 points

Louis,

You are trying to use intrinsics that require the TMU (trigonometric math unit) on the device. TMU is only on TMS320F2837x devices so far. Are you using one of these devices? Do you have TMU0 selected in the project options?

If you do not have TMU0 selected, you will get the errors you cited. But remember, you cannot just select TMU0 unless you are using a F2837x device or the code will not work.

Regards,

David

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Edit: I just re-read your original post. You are using F2806x. You cannot use the intrinsics you've referenced on that device.

0 Louis Zhu over 10 years ago in reply to David M. Alter

Expert 1685 points

Thanks, that reminds me of the <math.h> functions.

0 David M. Alter over 10 years ago in reply to Louis Zhu

TI__Guru 61235 points

Louis,

You should look at the 'fast RTS library' in ControlSuite. It will give much better performance on things like sin and cos than the regular compiler RTS lib. It is located in ControlSuite here: C:\TI\controlSUITE\libs\math\FPUfastRTS.

- David

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How to Use C28x C/C++ Intrinsic Functions