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STM32F0xx Standard Peripherals Firmware Library
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STM32F0xx_StdPeriph_Examples/TIM/TIM_TimeBase/main.c
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00001 /** 00002 ****************************************************************************** 00003 * @file TIM/TIM_TimeBase/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>© 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 TIM_TimeBase 00036 * @{ 00037 */ 00038 00039 /* Private typedef -----------------------------------------------------------*/ 00040 /* Private define ------------------------------------------------------------*/ 00041 /* Private macro -------------------------------------------------------------*/ 00042 /* Private variables ---------------------------------------------------------*/ 00043 __IO uint16_t CCR1_Val = 40961; 00044 __IO uint16_t CCR2_Val = 27309; 00045 __IO uint16_t CCR3_Val = 13654; 00046 __IO uint16_t CCR4_Val = 6826; 00047 uint16_t PrescalerValue = 0; 00048 00049 /* Private function prototypes -----------------------------------------------*/ 00050 static void TIM_Config(void); 00051 00052 /* Private functions ---------------------------------------------------------*/ 00053 00054 /** 00055 * @brief Main program. 00056 * @param None 00057 * @retval None 00058 */ 00059 int main(void) 00060 { 00061 /*!< At this stage the microcontroller clock setting is already configured, 00062 this is done through SystemInit() function which is called from startup 00063 file (startup_stm32f0xx.s) before to branch to application main. 00064 To reconfigure the default setting of SystemInit() function, refer to 00065 system_stm32f0xx.c file 00066 */ 00067 00068 /* TIM Configuration */ 00069 TIM_Config(); 00070 00071 /* Infinite loop */ 00072 while (1) 00073 { 00074 } 00075 } 00076 00077 /** 00078 * @brief Configure the TIM IRQ Handler. 00079 * @param None 00080 * @retval None 00081 */ 00082 static void TIM_Config(void) 00083 { 00084 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; 00085 TIM_OCInitTypeDef TIM_OCInitStructure; 00086 NVIC_InitTypeDef NVIC_InitStructure; 00087 00088 /* TIM3 clock enable */ 00089 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); 00090 00091 /* Enable the TIM3 gloabal Interrupt */ 00092 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; 00093 NVIC_InitStructure.NVIC_IRQChannelPriority = 0; 00094 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 00095 NVIC_Init(&NVIC_InitStructure); 00096 00097 /* Initialize Leds mounted on STM320518-EVAL board */ 00098 STM_EVAL_LEDInit(LED1); 00099 STM_EVAL_LEDInit(LED2); 00100 STM_EVAL_LEDInit(LED3); 00101 STM_EVAL_LEDInit(LED4); 00102 00103 /* Turn on LED1, LED2, LED3 and LED4 */ 00104 STM_EVAL_LEDOn(LED1); 00105 STM_EVAL_LEDOn(LED2); 00106 STM_EVAL_LEDOn(LED3); 00107 STM_EVAL_LEDOn(LED4); 00108 00109 /* ----------------------------------------------------------------------- 00110 TIM3 Configuration: Output Compare Timing Mode: 00111 00112 In this example TIM3 input clock (TIM3CLK) is set to APB1 clock (PCLK1), 00113 => TIM3CLK = PCLK1 = SystemCoreClock = 48 MHz 00114 00115 To get TIM3 counter clock at 6 MHz, the prescaler is computed as follows: 00116 Prescaler = (TIM3CLK / TIM3 counter clock) - 1 00117 Prescaler = (PCLK1 /6 MHz) - 1 00118 00119 CC1 update rate = TIM3 counter clock / CCR1_Val = 146.48 Hz 00120 ==> Toggling frequency = 73.24 Hz 00121 00122 C2 update rate = TIM3 counter clock / CCR2_Val = 219.7 Hz 00123 ==> Toggling frequency = 109.8 Hz 00124 00125 CC3 update rate = TIM3 counter clock / CCR3_Val = 439.4 Hz 00126 ==> Toggling frequency = 219.7 Hz 00127 00128 CC4 update rate = TIM3 counter clock / CCR4_Val = 878.9 Hz 00129 ==> Toggling frequency = 439.4 Hz 00130 00131 Note: 00132 SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f0xx.c file. 00133 Each time the core clock (HCLK) changes, user had to call SystemCoreClockUpdate() 00134 function to update SystemCoreClock variable value. Otherwise, any configuration 00135 based on this variable will be incorrect. 00136 ----------------------------------------------------------------------- */ 00137 00138 00139 /* Compute the prescaler value */ 00140 PrescalerValue = (uint16_t) (SystemCoreClock / 6000000) - 1; 00141 00142 /* Time base configuration */ 00143 TIM_TimeBaseStructure.TIM_Period = 65535; 00144 TIM_TimeBaseStructure.TIM_Prescaler = 0; 00145 TIM_TimeBaseStructure.TIM_ClockDivision = 0; 00146 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 00147 00148 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); 00149 00150 /* Prescaler configuration */ 00151 TIM_PrescalerConfig(TIM3, PrescalerValue, TIM_PSCReloadMode_Immediate); 00152 00153 /* Output Compare Timing Mode configuration: Channel1 */ 00154 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing; 00155 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; 00156 TIM_OCInitStructure.TIM_Pulse = CCR1_Val; 00157 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; 00158 00159 TIM_OC1Init(TIM3, &TIM_OCInitStructure); 00160 00161 TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable); 00162 00163 /* Output Compare Timing Mode configuration: Channel2 */ 00164 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; 00165 TIM_OCInitStructure.TIM_Pulse = CCR2_Val; 00166 00167 TIM_OC2Init(TIM3, &TIM_OCInitStructure); 00168 00169 TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable); 00170 00171 /* Output Compare Timing Mode configuration: Channel3 */ 00172 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; 00173 TIM_OCInitStructure.TIM_Pulse = CCR3_Val; 00174 00175 TIM_OC3Init(TIM3, &TIM_OCInitStructure); 00176 00177 TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Disable); 00178 00179 /* Output Compare Timing Mode configuration: Channel4 */ 00180 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; 00181 TIM_OCInitStructure.TIM_Pulse = CCR4_Val; 00182 00183 TIM_OC4Init(TIM3, &TIM_OCInitStructure); 00184 00185 TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Disable); 00186 00187 /* TIM Interrupts enable */ 00188 TIM_ITConfig(TIM3, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE); 00189 00190 /* TIM3 enable counter */ 00191 TIM_Cmd(TIM3, ENABLE); 00192 } 00193 00194 #ifdef USE_FULL_ASSERT 00195 00196 /** 00197 * @brief Reports the name of the source file and the source line number 00198 * where the assert_param error has occurred. 00199 * @param file: pointer to the source file name 00200 * @param line: assert_param error line source number 00201 * @retval None 00202 */ 00203 void assert_failed(uint8_t* file, uint32_t line) 00204 { 00205 /* User can add his own implementation to report the file name and line number, 00206 ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */ 00207 00208 /* Infinite loop */ 00209 while (1) 00210 { 00211 } 00212 } 00213 #endif 00214 00215 /** 00216 * @} 00217 */ 00218 00219 /** 00220 * @} 00221 */ 00222 00223 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/