/** ****************************************************************************** * @file TIM/TIM_TimeBase/Src/main.c * @author MCD Application Team * @brief This sample code shows how to use STM32F7xx TIM HAL API to generate * a time base of one second with the corresponding Interrupt request. ****************************************************************************** * @attention * *

© Copyright (c) 2016 STMicroelectronics. * All rights reserved.

* * This software component is licensed by ST under BSD 3-Clause license, * the "License"; You may not use this file except in compliance with the * License. You may obtain a copy of the License at: * opensource.org/licenses/BSD-3-Clause * ****************************************************************************** */ /* Includes ------------------------------------------------------------------*/ #include "main.h" /** @addtogroup STM32F7xx_HAL_Examples * @{ */ /** @addtogroup TIM_TimeBase * @{ */ /* Private typedef -----------------------------------------------------------*/ /* Private define ------------------------------------------------------------*/ /* Private macro -------------------------------------------------------------*/ /* Private variables ---------------------------------------------------------*/ /* TIM handle declaration */ TIM_HandleTypeDef TimHandle; /* Prescaler declaration */ uint32_t uwPrescalerValue = 0; /* Private function prototypes -----------------------------------------------*/ void SystemClock_Config(void); static void Error_Handler(void); static void CPU_CACHE_Enable(void); /* Private functions ---------------------------------------------------------*/ /** * @brief Main program * @param None * @retval None */ int main(void) { /* Enable the CPU Cache */ CPU_CACHE_Enable(); /* STM32F7xx HAL library initialization: - Configure the Flash ART accelerator on ITCM interface - Systick timer is configured by default as source of time base, but user can eventually implement his proper time base source (a general purpose timer for example or other time source), keeping in mind that Time base duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and handled in milliseconds basis. - Set NVIC Group Priority to 4 - Low Level Initialization */ HAL_Init(); /* Configure the system clock to 216 MHz */ SystemClock_Config(); /* Configure LED1 & LED3 */ BSP_LED_Init(LED1); BSP_LED_Init(LED3); /*##-1- Configure the TIM peripheral #######################################*/ /* ----------------------------------------------------------------------- In this example TIM3 input clock (TIM3CLK) is set to APB1 clock (PCLK1) x2, since APB1 prescaler is equal to 4. TIM3CLK = PCLK1*2 PCLK1 = HCLK/4 => TIM3CLK = HCLK/2 = SystemCoreClock/2 To get TIM3 counter clock at 10 KHz, the Prescaler is computed as follows: Prescaler = (TIM3CLK / TIM3 counter clock) - 1 Prescaler = ((SystemCoreClock/2) /10 KHz) - 1 Note: SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f7xx.c file. Each time the core clock (HCLK) changes, user had to update SystemCoreClock variable value. Otherwise, any configuration based on this variable will be incorrect. This variable is updated in three ways: 1) by calling CMSIS function SystemCoreClockUpdate() 2) by calling HAL API function HAL_RCC_GetSysClockFreq() 3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency ----------------------------------------------------------------------- */ /* Compute the prescaler value to have TIMx counter clock equal to 10000 Hz */ uwPrescalerValue = (uint32_t)((SystemCoreClock / 2) / 10000) - 1; /* Set TIMx instance */ TimHandle.Instance = TIMx; /* Initialize TIMx peripheral as follows: + Period = 10000 - 1 + Prescaler = ((SystemCoreClock / 2)/10000) - 1 + ClockDivision = 0 + Counter direction = Up */ TimHandle.Init.Period = 10000 - 1; TimHandle.Init.Prescaler = uwPrescalerValue; TimHandle.Init.ClockDivision = 0; TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP; TimHandle.Init.RepetitionCounter = 0; TimHandle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE; if (HAL_TIM_Base_Init(&TimHandle) != HAL_OK) { /* Initialization Error */ Error_Handler(); } /*##-2- Start the TIM Base generation in interrupt mode ####################*/ /* Start Channel1 */ if (HAL_TIM_Base_Start_IT(&TimHandle) != HAL_OK) { /* Starting Error */ Error_Handler(); } while (1) { } } /** * @brief Period elapsed callback in non blocking mode * @param htim : TIM handle * @retval None */ void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) { BSP_LED_Toggle(LED1); } /** * @brief System Clock Configuration * The system Clock is configured as follow : * System Clock source = PLL (HSE) * SYSCLK(Hz) = 216000000 * HCLK(Hz) = 216000000 * AHB Prescaler = 1 * APB1 Prescaler = 4 * APB2 Prescaler = 2 * HSE Frequency(Hz) = 25000000 * PLL_M = 25 * PLL_N = 432 * PLL_P = 2 * PLL_Q = 9 * VDD(V) = 3.3 * Main regulator output voltage = Scale1 mode * Flash Latency(WS) = 7 * @param None * @retval None */ void SystemClock_Config(void) { RCC_ClkInitTypeDef RCC_ClkInitStruct; RCC_OscInitTypeDef RCC_OscInitStruct; HAL_StatusTypeDef ret = HAL_OK; /* Enable HSE Oscillator and activate PLL with HSE as source */ RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE; RCC_OscInitStruct.HSEState = RCC_HSE_ON; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE; RCC_OscInitStruct.PLL.PLLM = 25; RCC_OscInitStruct.PLL.PLLN = 432; RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; RCC_OscInitStruct.PLL.PLLQ = 9; ret = HAL_RCC_OscConfig(&RCC_OscInitStruct); if(ret != HAL_OK) { while(1) { ; } } /* Activate the OverDrive to reach the 216 MHz Frequency */ ret = HAL_PWREx_EnableOverDrive(); if(ret != HAL_OK) { while(1) { ; } } /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */ RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2); RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2; ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_7); if(ret != HAL_OK) { while(1) { ; } } } /** * @brief This function is executed in case of error occurrence. * @param None * @retval None */ static void Error_Handler(void) { /* Turn LED3 on */ BSP_LED_On(LED3); while (1) { } } #ifdef USE_FULL_ASSERT /** * @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None */ void assert_failed(uint8_t *file, uint32_t line) { /* User can add his own implementation to report the file name and line number, ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */ /* Infinite loop */ while (1) { } } #endif /** * @brief CPU L1-Cache enable. * @param None * @retval None */ static void CPU_CACHE_Enable(void) { /* Enable I-Cache */ SCB_EnableICache(); /* Enable D-Cache */ SCB_EnableDCache(); } /** * @} */ /** * @} */ /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/