STM32F0xx Standard Peripherals Firmware Library: main.c Source File

00001 /**
00002   ******************************************************************************
00003   * @file    IWDG/IWDG_Reset/main.c  
00004   * @author  MCD Application Team
00005   * @version V1.4.0
00006   * @date    24-July-2014
00007   * @brief   Main program body
00008   ******************************************************************************
00009   * @attention
00010   *
00011   * <h2><center>&copy; COPYRIGHT 2014 STMicroelectronics</center></h2>
00012   *
00013   * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
00014   * You may not use this file except in compliance with the License.
00015   * You may obtain a copy of the License at:
00016   *
00017   *        http://www.st.com/software_license_agreement_liberty_v2
00018   *
00019   * Unless required by applicable law or agreed to in writing, software 
00020   * distributed under the License is distributed on an "AS IS" BASIS, 
00021   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00022   * See the License for the specific language governing permissions and
00023   * limitations under the License.
00024   *
00025   ******************************************************************************
00026   */
00027 
00028 /* Includes ------------------------------------------------------------------*/
00029 #include "main.h"
00030 
00031 /** @addtogroup STM32F0xx_StdPeriph_Examples
00032   * @{
00033   */
00034 
00035 /** @addtogroup IWDG_Reset
00036   * @{
00037   */
00038 
00039 /* Private typedef -----------------------------------------------------------*/
00040 /* Private define ------------------------------------------------------------*/
00041 /* Private macro -------------------------------------------------------------*/
00042 /* Private variables ---------------------------------------------------------*/
00043 __IO uint32_t TimingDelay = 0;
00044 __IO uint32_t LsiFreq = 40000;
00045 extern __IO uint16_t CaptureNumber;
00046 
00047 /* Private function prototypes -----------------------------------------------*/
00048 static void TIM14_ConfigForLSI(void);
00049 void Delay(__IO uint32_t nTime);
00050 
00051 /* Private functions ---------------------------------------------------------*/
00052 
00053 /**
00054   * @brief  Main program.
00055   * @param  None
00056   * @retval None
00057   */
00058 int main(void)
00059 {
00060   /*!< At this stage the microcontroller clock setting is already configured, 
00061        this is done through SystemInit() function which is called from startup
00062        file (startup_stm32f0xx.s) before to branch to application main.
00063        To reconfigure the default setting of SystemInit() function, refer to
00064        system_stm32f0xx.c file
00065      */ 
00066 /* Initialize LED and Tamper Button mounted on the Eval board */       
00067   STM_EVAL_LEDInit(LED1);
00068   STM_EVAL_LEDInit(LED2);
00069   STM_EVAL_PBInit(BUTTON_TAMPER, BUTTON_MODE_EXTI);
00070 
00071   /* Setup SysTick Timer for 1 msec interrupts  */
00072   if (SysTick_Config(SystemCoreClock / 1000))
00073   { 
00074     /* Capture error */ 
00075     while (1);
00076   }
00077 
00078 
00079   /* Check if the system has resumed from IWDG reset */
00080   if (RCC_GetFlagStatus(RCC_FLAG_IWDGRST) != RESET)
00081   {
00082     /* IWDGRST flag set */
00083     /* Turn on LED1 */
00084     STM_EVAL_LEDOn(LED1);
00085 
00086     /* Clear reset flags */
00087     RCC_ClearFlag();
00088   }
00089   else
00090   {
00091     /* IWDGRST flag is not set */
00092     /* Turn off LED1 */
00093     STM_EVAL_LEDOff(LED1);
00094   }
00095 
00096 #ifdef LSI_TIM_MEASURE
00097   /* TIM Configuration -------------------------------------------------------*/
00098   TIM14_ConfigForLSI();
00099   
00100   /* Wait until the TIM14 get 2 LSI edges */
00101   while(CaptureNumber != 2)
00102   {
00103   }
00104 
00105   /* Disable TIM14 CC1 Interrupt Request */
00106   TIM_ITConfig(TIM14, TIM_IT_CC1, DISABLE);
00107 #endif /* LSI_TIM_MEASURE */
00108   
00109   /* IWDG timeout equal to 250 ms (the timeout may varies due to LSI frequency
00110      dispersion) */
00111   /* Enable write access to IWDG_PR and IWDG_RLR registers */
00112   IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
00113 
00114   /* IWDG counter clock: LSI/32 */
00115   IWDG_SetPrescaler(IWDG_Prescaler_32);
00116 
00117   /* Set counter reload value to obtain 250ms IWDG TimeOut.
00118      Counter Reload Value = 250ms/IWDG counter clock period
00119                           = 250ms / (LSI/32)
00120                           = 0.25s / (LsiFreq/32)
00121                           = LsiFreq/(32 * 4)
00122                           = LsiFreq/128
00123    */
00124   IWDG_SetReload(LsiFreq/128);
00125 
00126   /* Reload IWDG counter */
00127   IWDG_ReloadCounter();
00128 
00129   /* Enable IWDG (the LSI oscillator will be enabled by hardware) */
00130   IWDG_Enable();
00131 
00132   while (1)
00133   {
00134     /* Toggle LED2 */
00135     STM_EVAL_LEDToggle(LED2);
00136 
00137     /* Insert 220 ms delay */
00138     Delay(220);
00139 
00140     /* Reload IWDG counter */
00141     IWDG_ReloadCounter();  
00142   }
00143 }
00144 
00145 #ifdef LSI_TIM_MEASURE
00146 /**
00147   * @brief  Configures TIM14 to measure the LSI oscillator frequency.
00148   * @param  None
00149   * @retval None
00150   */
00151 static void TIM14_ConfigForLSI(void)
00152 {
00153   NVIC_InitTypeDef NVIC_InitStructure;
00154   TIM_ICInitTypeDef  TIM_ICInitStructure;
00155   
00156   /* Enable peripheral clocks ------------------------------------------------*/
00157   RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
00158 
00159   /* Allow access to the RTC */
00160   PWR_BackupAccessCmd(ENABLE);
00161 
00162   /* Reset RTC Domain */
00163   RCC_BackupResetCmd(ENABLE);
00164   RCC_BackupResetCmd(DISABLE);
00165   
00166   /*!< LSI Enable */
00167   RCC_LSICmd(ENABLE);
00168   
00169   /*!< Wait till LSI is ready */
00170   while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)
00171   {}
00172   
00173   /* Select the RTC Clock Source */
00174   RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);
00175    
00176   /* Enable the RTC Clock */
00177   RCC_RTCCLKCmd(ENABLE);
00178 
00179   /* Wait for RTC APB registers synchronisation */
00180   RTC_WaitForSynchro();
00181   
00182   /* Enable TIM14 clocks */
00183   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14, ENABLE);  
00184   
00185   /* Enable the TIM14 Interrupt */
00186   NVIC_InitStructure.NVIC_IRQChannel = TIM14_IRQn;
00187   NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
00188   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
00189   NVIC_Init(&NVIC_InitStructure);
00190   
00191   /* Configure TIM14 prescaler */
00192   TIM_PrescalerConfig(TIM14, 0, TIM_PSCReloadMode_Immediate);
00193   
00194   /* Connect internally the TM14_CH1 Input Capture to the LSI clock output */
00195   TIM_RemapConfig(TIM14, TIM14_RTC_CLK);
00196   
00197   /* TIM14 configuration: Input Capture mode ---------------------
00198      The LSI oscillator is connected to TIM14 CH1
00199      The Rising edge is used as active edge,
00200      The TIM14 CCR1 is used to compute the frequency value 
00201   ------------------------------------------------------------ */
00202   TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
00203   TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
00204   TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
00205   TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV8;
00206   TIM_ICInitStructure.TIM_ICFilter = 0;
00207   TIM_ICInit(TIM14, &TIM_ICInitStructure);
00208   
00209   /* TIM14 Counter Enable */
00210   TIM_Cmd(TIM14, ENABLE);
00211 
00212   /* Reset the flags */
00213   TIM14->SR = 0;
00214     
00215   /* Enable the CC1 Interrupt Request */  
00216   TIM_ITConfig(TIM14, TIM_IT_CC1, ENABLE);  
00217 }
00218 #endif /* LSI_TIM_MEASURE */
00219 
00220 /**
00221   * @brief  Inserts a delay time.
00222   * @param  nTime: specifies the delay time length, in 10 ms.
00223   * @retval None
00224   */
00225 void Delay(__IO uint32_t nTime)
00226 {
00227   TimingDelay = nTime;
00228 
00229   while(TimingDelay != 0);
00230 }
00231 
00232 /**
00233   * @brief  Decrements the TimingDelay variable.
00234   * @param  None
00235   * @retval None
00236   */
00237 void TimingDelay_Decrement(void)
00238 {
00239   if (TimingDelay != 0x00)
00240   { 
00241     TimingDelay--;
00242   }
00243 }
00244 
00245 #ifdef  USE_FULL_ASSERT
00246 
00247 /**
00248   * @brief  Reports the name of the source file and the source line number
00249   *         where the assert_param error has occurred.
00250   * @param  file: pointer to the source file name
00251   * @param  line: assert_param error line source number
00252   * @retval None
00253   */
00254 void assert_failed(uint8_t* file, uint32_t line)
00255 { 
00256   /* User can add his own implementation to report the file name and line number,
00257      ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
00258 
00259   /* Infinite loop */
00260   while (1)
00261   {
00262   }
00263 }
00264 #endif
00265 
00266 /**
00267   * @}
00268   */
00269 
00270 /**
00271   * @}
00272   */
00273 
00274 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/