STM32F103C8 Trace: No Synchronization

[KHADRAOUI Ibrahim]

Hello everyone, I hope you're well and safe.

I'm working with the

• STM32F103C8T6(BluePill).

• ST-LINK V2 as programmer and hardware debugger.

• Keil µVision MDK-ARM V5.
• STM32CubeMX.

I'm trying to debug a simple application with the printf() function

• Here's the CubeMX configuration:

• Here's the code:

#include "main.h"
#include "stdio.h"
 
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
 
int main(void)
{
 
  HAL_Init();
 
  SystemClock_Config();
 
  MX_GPIO_Init();
	
	
  while (1)
  {
		printf("hello");
		ITM_SendChar('a');
		HAL_GPIO_TogglePin(LED_BUILTIN_GPIO_Port ,LED_BUILTIN_Pin);
		HAL_Delay(1000);
  }
}
 
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
 
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
 
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}
 
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
 
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
 
 
  HAL_GPIO_WritePin(LED_BUILTIN_GPIO_Port, LED_BUILTIN_Pin, GPIO_PIN_RESET);
 
 
  GPIO_InitStruct.Pin = LED_BUILTIN_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(LED_BUILTIN_GPIO_Port, &GPIO_InitStruct);
 
}
 
 
void Error_Handler(void)
{
 
}
 
#ifdef  USE_FULL_ASSERT
 
void assert_failed(uint8_t *file, uint32_t line)
{ 
 
}
#endif
 
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

• The Keil µVison configuration:

But it's not working when I start the debugger and I open the printf window it's empty and and I noticed a message below on Keil µVision "Trace: No Synchronization"

So, I hope you can help me and thank you in advance.

[Imen Ezzine · Accepted solution]

Hi KHADRAOUI Ibrahim ,

At first look at the problem seems like your code is missing:

In order to activate the ITM trace (printf) you need to add the fputc function definition just after the main function in your code as below:

/*----------------------------------------------------------------------------
  Write character to Serial Port
*----------------------------------------------------------------------------*/
int SER_PutChar (int c) {
 
                ITM_SendChar (c);
  return (c);
}
 
int fputc(int c, FILE *f) {
  return (SER_PutChar(c));
}

You can add it in the main.c file, or do it in a separate file, usually called Retarget.c for MDK-ARM.

This should work, if not make sure you use the correct "core clock" in the MDK-arm options.

Also you can ceck with the User manual in case there is a hardware modification (switch, SB etc)

PS: The SWV is not supported when using ST-LINK Shared mode, so make sure it is not checked as in the photo I attached.

I hope this help!

-Imen

[KHADRAOUI Ibrahim]

Hi @Imen Ezzine​ !

Thank you for your reply.

I tried what you advised me, but it also doesn't work, However I tried with a stm32 discovery board with an integrated ST-LINK and it worked, I deduce that the ST-LINK that I used is a cheap Chinese one (on the photo above) is not compatible with the TRACE.

Regards.

@KHADRAOUI Ibrahim​ .