exp,log and other math functions using CW for MCU Development Studio v10.6 and an MC9S08PA8

[efthymioskondos]

Dear community,

I am transfering a part of code from one MCU vendor (Atmel xmega32E5) to Freescale/NXP MC9S08PA8 MCU ,

and when I use the log function from math.h (i hope like other IDEs does)  the MCU "hits" endless restarts.

If i comment this line, MCU does its supposed job without any issue and i can see an ADC result on debugger crystal clear.

unsigned int temp;

double ftemp;

void main(void)

{

  System_Init();                                            //Initialise system hardware/software modules

  for(;;)

  {

  temp=ADC_Get_Sample(CH11);              //Read current channel ADC value (54us@8MHz)

  ftemp=log(((10240000/temp) - 10000));   //Endless restart occurs - CRITICAL point

  }

}

1) How /When do i  update/include the "math.h" or similar (?) library header ?

2) Does this IDE support floats and doubles for "small ones" like the PA16 MCU?

(I have chosen at the beggining bareboard project with IIEE 64bit float support)

Best Regards,

Tim

[efthymioskondos]

FIY ,

SOLVED according to Edward Karpicz and Stanislav suggestion.

So to use logx,log , exp functions , include your <math.h> on your project and also go to

Project Settings->Linker_Files->Project.prm , open file with double click

and edit  STACKSIZE from 0x80 (128bytes default size), to a bigger numer.
But beware, not to kill the entire RAM area by entering exotic hex number (For me it worked for 256bytes (0x100).

Cheers,

Ef

[efthymioskondos]

Thank you Edward & Stanislav for your fast response ,

I will look into it as for math.h and modify(increase) the stack size of S08.

See how it goes, and get you feedback as soon as possible.

Cheers,

Tim

[kef2]

Default stack size set in PRM file is too short for S08 math functions.

[Stano]

Hello Efthymios,

it is possible to use the math functions in CW10.6. You need just include it:

#include <math.h>

It adds the math.h file from the installed CW package.

I hope this helps you.

Best Regards,

Stano.