stm32 debugging with interrupt enabled

Development Boards MicroMod
1

Hi, in my application I use TIMER 2 to generate an interrupt every 20 ms.

If I try to debug my application step by step the debugger stops at the beginning of the timer ISR (all breakpoints are removed).

The only way to debug step by step is by placing a breakpoint at the address of the next instruction and give the “continue” command.

This behavior seems strange to me, how can I can resolve this situation ?

2

You need to lookup the register MCUDBG in the ref manual.

This will show you how to turn off certain peripherals in debug mode.

Cheers

Spen

3

Hi nagio,

Would you mind sharing your code with us?

I’m having another problem but also with TIMER2. As soon as I enable the timer2, the PC goes to FaultISR. I’m not sure what I do wrong.

Here is the timer config I use.

void RCC_Configuration(void)
{
  /* RCC system reset(for debug purpose) */
  RCC_DeInit();

  /* Enable HSE */
  RCC_HSEConfig(RCC_HSE_ON);

  /* Wait till HSE is ready */
  HSEStartUpStatus = RCC_WaitForHSEStartUp();

  if (HSEStartUpStatus == SUCCESS)
  {
    /* Enable Prefetch Buffer */
    FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

    /* Flash 2 wait state */
    FLASH_SetLatency(FLASH_Latency_2);

    /* HCLK = SYSCLK */
    RCC_HCLKConfig(RCC_SYSCLK_Div1);

    /* PCLK2 = HCLK */
    RCC_PCLK2Config(RCC_HCLK_Div1);

    /* PCLK1 = HCLK/4 */
    RCC_PCLK1Config(RCC_HCLK_Div4);

    /* PLLCLK = 8MHz * 9 = 72 MHz */
    RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

    /* Enable PLL */
    RCC_PLLCmd(ENABLE);

    /* Wait till PLL is ready */
    while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
    {}

    /* Select PLL as system clock source */
    RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

    /* Wait till PLL is used as system clock source */
    while (RCC_GetSYSCLKSource() != 0x08)
    {}
  }

  /* TIM2 clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

  /* GPIOC clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
}

void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;

#ifdef  VECT_TAB_RAM
  /* Set the Vector Table base location at 0x20000000 */
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif

  /* Enable the TIM2 gloabal Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure); 
}


...

 /* Peripherals InitStructure define */
  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
  TIM_OCInitTypeDef TIM_OCInitStructure;
  
  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = 1000; // auto reaload register
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
  
  /* Prescaler configuration */
  TIM_PrescalerConfig(TIM2, 35999, TIM_PSCReloadMode_Immediate);
  
  /* Output Compare Active Mode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing ;
  TIM_OCInitStructure.TIM_OutputState = TIM_Channel_1;
  TIM_OCInitStructure.TIM_Pulse = 0;
  TIM_OC1Init(TIM2, &TIM_OCInitStructure);
  TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);
  
  /* Output Compare Active Mode configuration: Channel2 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing ;
  TIM_OCInitStructure.TIM_OutputState = TIM_Channel_2;
  TIM_OCInitStructure.TIM_Pulse = 0;
  TIM_OC2Init(TIM2, &TIM_OCInitStructure);
  TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Disable);


  /* TIM IT enable */
  TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
  
  /* TIMW counter stopped when core is halted */
  //DBGMCU_Config (DBGMCU_TIM2_STOP, ENABLE); // does not link!
  
  /* TIM2 enable counter */
  TIM_Cmd(TIM2, ENABLE);

  while(1);

void TIM2_IRQHandler(void)
{
  if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)
  {
    TIM_ClearITPendingBit(TIM2, TIM_IT_CC1);

    /* Pin PC.06 toggling with frequency = 73.24 Hz */
    GPIO_WriteBit(GPIOC, GPIO_Pin_6, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_6)));

  }
  else if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)
  {
    TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);

    /* Pin PC.07 toggling with frequency = 109.8 Hz */
    GPIO_WriteBit(GPIOC, GPIO_Pin_7, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_7)));


  }

If anyone sees something wrong, could you let me know? Appreciated, Thanks

4

sorry for my late answer, my code is identical to the example “TimeBase” that comes with the stm32 firmware library (version 2.0 23/05/08) and it works fine. There are 2 differences, I only use one channel of timer 2 and the APB1 clock is 18MHz instead of 36MHz

5

Thanks for answering.

I have it working now.

I forgot to include the vector.c file, hence the interrupt was pointing nowhere.