/**
******************************************************************************
* [url=home.php?mod=space&uid=288409]@file[/url] TIM/TIM_TimeBase/Src/main.c
* [url=home.php?mod=space&uid=187600]@author[/url] MCD Application Team
* [url=home.php?mod=space&uid=247401]@brief[/url] This sample code shows how to use STM32F1xx 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 is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/** @addtogroup STM32F1xx_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);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/* STM32F103xB HAL library initialization:
- Configure the Flash prefetch
- 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 64 MHz */
SystemClock_Config();
/* Configure LED2 */
BSP_LED_Init(LED2);
/*##-1- Configure the TIM peripheral #######################################*/
/* -----------------------------------------------------------------------
In this example TIM3 input clock (TIM3CLK) is set to APB1 clock (PCLK1) x2,
since APB1 prescaler is set to 4 (0x100).
TIM3CLK = PCLK1*2
PCLK1 = HCLK/2
=> TIM3CLK = PCLK1*2 = (HCLK/2)*2 = HCLK = SystemCoreClock
To get TIM3 counter clock at 10 KHz, the Prescaler is computed as following:
Prescaler = (TIM3CLK / TIM3 counter clock) - 1
Prescaler = (SystemCoreClock /10 KHz) - 1
Note:
SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f1xx.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 / 10000) - 1;
/* Set TIMx instance */
TimHandle.Instance = TIMx;
/* Initialize TIMx peripheral as follows:
+ Period = 10000 - 1
+ Prescaler = (SystemCoreClock/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(LED2);
}
/**
* @brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSI)
* SYSCLK(Hz) = 64000000
* HCLK(Hz) = 64000000
* AHB Prescaler = 1
* APB1 Prescaler = 2
* APB2 Prescaler = 1
* PLLMUL = 16
* Flash Latency(WS) = 2
* @param None
* @retval None
*/
void SystemClock_Config(void)
{
RCC_ClkInitTypeDef clkinitstruct = {0};
RCC_OscInitTypeDef oscinitstruct = {0};
/* Configure PLL ------------------------------------------------------*/
/* PLL configuration: PLLCLK = (HSI / 2) * PLLMUL = (8 / 2) * 16 = 64 MHz */
/* PREDIV1 configuration: PREDIV1CLK = PLLCLK / HSEPredivValue = 64 / 1 = 64 MHz */
/* Enable HSI and activate PLL with HSi_DIV2 as source */
oscinitstruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
oscinitstruct.HSEState = RCC_HSE_OFF;
oscinitstruct.LSEState = RCC_LSE_OFF;
oscinitstruct.HSIState = RCC_HSI_ON;
oscinitstruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
oscinitstruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
oscinitstruct.PLL.PLLState = RCC_PLL_ON;
oscinitstruct.PLL.PLLSource = RCC_PLLSOURCE_HSI_DIV2;
oscinitstruct.PLL.PLLMUL = RCC_PLL_MUL16;
if (HAL_RCC_OscConfig(&oscinitstruct)!= HAL_OK)
{
/* Initialization Error */
while(1);
}
/* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
clocks dividers */
clkinitstruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
clkinitstruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
clkinitstruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
clkinitstruct.APB2CLKDivider = RCC_HCLK_DIV1;
clkinitstruct.APB1CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&clkinitstruct, FLASH_LATENCY_2)!= HAL_OK)
{
/* Initialization Error */
while(1);
}
}
/**
* @brief This function is executed in case of error occurrence.
* @param None
* @retval None
*/
static void Error_Handler(void)
{
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
/**
* @}
*/
/**
* @}
*/
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