STM32F1 läuft nur mit angeschlossenem ST-Link

// ----------------------------------------------------------------------------

#include <stdio.h>

#include <stdlib.h>

#include "diag/Trace.h"

#include "stm32f10x.h"

// ----- main() ---------------------------------------------------------------

// Sample pragmas to cope with warnings. Please note the related line at

// the end of this function, used to pop the compiler diagnostics status.

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-parameter"

#pragma GCC diagnostic ignored "-Wmissing-declarations"

#pragma GCC diagnostic ignored "-Wreturn-type"

int main(int argc, char* argv[])

{

  GPIO_InitTypeDef GPIO_InitStructure;

  TIM_TimeBaseInitTypeDef TIM_TimeBase_InitStructure;

  NVIC_InitTypeDef NVIC_InitStructure;

  SystemInit();

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE, ENABLE);

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_Init(GPIOE, &GPIO_InitStructure);

  TIM_TimeBase_InitStructure.TIM_ClockDivision = TIM_CKD_DIV1;

  TIM_TimeBase_InitStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBase_InitStructure.TIM_Period = 1999;

  TIM_TimeBase_InitStructure.TIM_Prescaler = 17999;

  TIM_TimeBaseInit(TIM2, &TIM_TimeBase_InitStructure);

  TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

  NVIC_Init(&NVIC_InitStructure);

  TIM_Cmd(TIM2, ENABLE);

  // Short loop.

  while (1)

  {

  }

  return 0;

}

extern "C" void TIM2_IRQHandler(void)

{

  TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

  if (GPIO_ReadOutputDataBit(GPIOE, GPIO_Pin_5))

  {

    GPIO_WriteBit(GPIOE, GPIO_Pin_5, Bit_RESET);

  }

  else

  {

    GPIO_WriteBit(GPIOE, GPIO_Pin_5, Bit_SET);

  }

}

#pragma GCC diagnostic pop

// ----------------------------------------------------------------------------

GPIO_WriteBit(GPIOE, GPIO_Pin_5, GPIO_ReadOutputDataBit(GPIOE, GPIO_Pin_5) ? BIT_RESET : BIT_SET);