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seagull3010
seagull3010
Associate
June 11, 2015
Question

Getting printf on STM32F407 Discovery board

  • June 11, 2015
  • 2 replies
  • 2409 views
Posted on June 11, 2015 at 13:14

Hi i am new to embedded system programming and stumbled upon this basic problem of re-directing output to the ITM Port0. I read multiple posts on the same but sadly I cant get it to work. I shall try to be as descriptive as possible. I am following the lab mentioned here http://www.keil.com/appnotes/files/apnt_230.pdf Page 15 Section 19. 

Board : STM32F407 Discovery board

Keil 5.15 MDK 

/*----------------------------------------------------------------------------

 * CMSIS-RTOS 'main' function template

 *---------------------------------------------------------------------------*/

&sharpdefine osObjectsPublic                     // define objects in main module

&sharpinclude ''osObjects.h''                      // RTOS object definitions

&sharpdefine ITM_Port8(n) (*((volatile unsigned char *)(0xE0000000+4*n)))

/*

 * main: initialize and start the system

 */

int main (void) {

int value = 1;

  osKernelInitialize ();                    // initialize CMSIS-RTOS

  // initialize peripherals here

  // create 'thread' functions that start executing,

  // example: tid_name = osThreadCreate (osThread(name), NULL);

ITM_Port8(0) = value ;

while(ITM_Port8(0) == 0);

ITM_Port8(0) = 0x0D;

while(ITM_Port8(0) == 0);

ITM_Port8(0) = 0x0A;

osKernelStart ();                         // start thread execution 

}

 I know the settings for the core clock speed are important so i set it correctly to 168MHz . Here is the snapshot to be sure. http://imgur.com/jSiUY2a,bqdc5c9&sharp1

What am i missing here ? Seems my debug view gets nothing . Any help for me ?

#stm32f-printf
    This topic has been closed for replies.

    2 replies

    Tesla DeLorean
    Tesla DeLorean
    Guru
    June 11, 2015
    Posted on June 11, 2015 at 15:04

    I'd probably check the 'Port 0..7' option, and use the ITM_SendChar() function.Posted some non RTX examples of using the SWV and Keil to the forum.

    https://community.st.com/0D50X00009XkgG8SAJ

     Might want to update the ST-LINK firmware, looks rather dated.

    Edit: Fixed DEAD LINK, original post from 11-Jun-2015

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    Tesla DeLorean
    Tesla DeLorean
    Guru
    June 11, 2015
    Posted on June 11, 2015 at 21:32

    0690X00000603KXQAY.jpg

    0690X0000060MoHQAU.gif 

    // STM32F4-DISCO SWV DEMO - sourcer32@gmail.com
// Make sure SB12 is make, and trace speed matches core frequency as built
#include <
stdio.h
>
#include ''stm32f4_discovery.h''
//****************************************************************************
void ITM_SendString(char *s)
{
while(*s)
ITM_SendChar(*s++);
}
//****************************************************************************
int main(void)
{
int i;
volatile int j;
ITM_SendString(''SWD Testing

'');
printf(''Hello World!

'');
i = 0;
while(1) /* Infinite loop */
{
ITM_SendString(''0123456789 '');
if ((i++ & 0x07) == 0x07)
ITM_SendString(''

'');
for(j=0; j<
10000000
; j++);
}
}
//******************************************************************************
// Hosting of stdio functionality through SWV - Serial Wire Viewer
//******************************************************************************
#include <rt_misc.h>
#pragma import(__use_no_semihosting_swi)
struct __FILE { int handle; /* Add whatever you need here */ };
FILE __stdout;
FILE __stdin;
int fputc(int ch, FILE *f)
{
ITM_SendChar(ch);
return(ch);
}
int fgetc(FILE *f)
{
char ch;
ch = '?';
return((int)ch);
}
int ferror(FILE *f)
{
/* Your implementation of ferror */
return EOF;
}
void _ttywrch(int ch)
{
ITM_SendChar(ch);
}
void _sys_exit(int return_code)
{
label: goto label; /* endless loop */
}
//****************************************************************************
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d

'', file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
//******************************************************************************

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