STM32CubeWL/Projects/NUCLEO-WL55JC/Examples/TIM/TIM_TimeBase/Inc/main.h

101 lines
3.2 KiB
C

/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file TIM/TIM_TimeBase/Inc/main.h
* @author MCD Application Team
* @brief Header for main.c module
******************************************************************************
* @attention
*
* Copyright (c) 2020 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __MAIN_H
#define __MAIN_H
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "stm32wlxx_hal.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stm32wlxx_nucleo.h"
/* USER CODE END Includes */
/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */
/* USER CODE END ET */
/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */
/* USER CODE END EC */
/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */
/* USER CODE END EM */
/* Exported functions prototypes ---------------------------------------------*/
void Error_Handler(void);
/* USER CODE BEGIN EFP */
/* USER CODE END EFP */
/* Private defines -----------------------------------------------------------*/
/* USER CODE BEGIN Private defines */
/*
In this example TIM2 input clock (TIM2CLK) is set to APB1 clock (PCLK1),
since APB1 prescaler is equal to 1.
TIM2CLK = PCLK1
PCLK1 = HCLK
=> TIM2CLK = HCLK = SystemCoreClock
To get TIM2 counter clock at 10 KHz, the Prescaler is computed as following:
Prescaler = (TIM2CLK / TIM2 counter clock) - 1
Prescaler = (SystemCoreClock /10 KHz) - 1
Note:
SystemCoreClock variable holds HCLK frequency and is defined in system_stm32wlxx.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 */
#define PRESCALER_VALUE (uint32_t)(((SystemCoreClock) / (10000)) - 1)
/* Initialize TIMx peripheral as follows:
+ Period = 10000 - 1
+ Prescaler = (SystemCoreClock/10000) - 1
+ ClockDivision = 0
+ Counter direction = Up
*/
#define PERIOD_VALUE (10000 - 1);
/* USER CODE END Private defines */
#ifdef __cplusplus
}
#endif
#endif /* __MAIN_H */