TMS320F280040-Q1: Where to find the details about the C standard function calls for CCS?

Crane Shao

Part Number: TMS320F280040-Q1

Hello,

I am using CCS12.0 and C2000 microcontrollers. It looks some C standard function call like sprintf() behave differently from C standard ones. For example, when "%f" is applied as a format, the program goes nowhere. When "%d" is applied, it has no problem.

char newMsg[MAX_UART_PRINTF_LEN] = {""};

sprintf(newMsg, "\r\nabcdefghijklmn %f.\n\0", abc);

Does any one know why it behaves like this?

Thanks!

Crane

over 3 years ago

0 George Mock over 3 years ago

TI__Guru**** 250710 points

Make sure you #include <stdio.h>.

Maybe the stack overflowed. Make the stack bigger with the linker option --stack=number.

If that doesn't help, please review these Tips for using printf.

Please let me if these suggestions resolve the problem.

Thanks and regards,

-George

0 Crane Shao over 3 years ago in reply to George Mock

Intellectual 910 points

Thanks George!

Yes I did include stdio.h.

--stack_size=0x3F8. I think it is big enough considering that I am just testing something in an empty project.

I didn't review the tips in detail as sprintf() need less from printf(). enable CIO ... is enabled.

I wrote my own function to convert integer and float to a string, not using sprintf any more.

Thanks!

Crane

0 Crane Shao over 3 years ago in reply to Crane Shao

Intellectual 910 points

Just wondering where to find the details of the definitions of these functions as their behaviors might be different in different compilers. I think CCS is different from standard C library. Is my understanding right?

0 George Mock over 3 years ago in reply to Crane Shao

TI__Guru**** 250710 points

Crane Shao said:
where to find the details of the definitions of these functions

Please search the C28x compiler manual for the chapter titled Using Run-Time-Support Functions and Building Libraries.

Thanks and regards,

-George

0 Crane Shao over 3 years ago in reply to George Mock

Intellectual 910 points

Got it. I see it mentions ANSI/ISO C/C++ standard library. So it means that the functions in CCS are completely same as they are in C/C++ standard library. I can just refer any documentation for C/C++ standard library. Is my understanding right?

0 George Mock over 3 years ago in reply to Crane Shao

TI__Guru**** 250710 points

Crane Shao said:
I can just refer any documentation for C/C++ standard library.

Yes. That said, C I/O functions (printf, etc.) are always odd on embedded systems. In this specific case, they only work when running under control of CCS.

Thanks and regards,

-George

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F280040-Q1: Where to find the details about the C standard function calls for CCS?