Want help error message IAR+launch pad

Pradeep Wijayasene said:

what does this mean ? does it says about stack over flow?

Sort of.

It means that after putting all your variables into ram, there is not enough unused ram available for a stack of the size you defien din the project settings (80 bytes is the default I think)

Keep in mind that this setting is just a hint that causes a linker error. It does not in any way define or limit the stack usage of your program. If your code uses local variables or recursion, the stack will grow to any size, overwriting all variables and finally growing into the void (crashing the system).

Pradeep Wijayasene said:

How can i fix this

Use less variables, use char isntead of int where it is appropriate. Don't use float/double if not really necessary (it usually isn't, even if people think it is).
Declare constant values as constants and not as normal variables. Especially if it are arrays.

You may reduce the stack size setting in the project. But this will only remove the linker error. But it doesn't change the resulting binary and will not influence the stack usage of your program.