stm32 系统时钟配置

版权声明：本文为博主原创文章，转载请注明出处。 https://blog.csdn.net/lee_xuwei/article/details/82771992

HSE：72M，HSE：64M，HSI：64M

代码实现：

// 时钟设置
//#define MAINCLOCK_72M  		   // HSE,外部时钟
//#define MAINCLOCK_64M_EXTERN     // HSE
#define MAINCLOCK_64M_INTERAL      // HSI

/** System Clock Configuration
*/
void SystemClock_Config(void)
{
    RCC_OSCInitTypeDef RCC_OscInitStruct;
    RCC_ClkInitTypeDef RCC_ClkInitStruct;

    /**Initializes the CPU, AHB and APB busses clocks 
	*/
	#ifdef MAINCLOCK_72M
		RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
		RCC_OscInitStruct.HSEState = RCC_HSE_ON;
		RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;	
		//RCC_OscInitStruct.HSIState = RCC_HSI_ON;	
		RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;	
		RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
		RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;   // 72M
	#else
		#ifdef MAINCLOCK_64M_EXTERN
			RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
			RCC_OscInitStruct.HSEState = RCC_HSE_ON;
			RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
			RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
			RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
			RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL8;  	// 64M
		#else
			// MAINCLOCK_64M_INTERAL
			RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
			RCC_OscInitStruct.HSICalibrationValue = 16;
			RCC_OscInitStruct.HSIState = RCC_HSI_ON;
			RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
			RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI_DIV2;
			RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;  	// 64M
		#endif
	#endif


	if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
	{
		Error_Handler();
	} 

	/**Initializes the CPU, AHB and APB busses clocks 
	*/
	RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
									|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
	RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
	RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; 		// 72M/64M 
	#ifdef MAINCLOCK_72M
		RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV8; 	// 72 / 8 = 9M
		RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV4; 	// 72 / 4 = 18M
	#else
		RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV8;	// 64 / 8 = 8M
		RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV4;	// 64 / 4 = 16M
	#endif

	if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
	{
		Error_Handler();
	}

	/**Configure the Systick interrupt time 
	*/
	HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

	/**Configure the Systick 
	*/
	HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

	/* SysTick_IRQn interrupt configuration */
	HAL_NVIC_SetPriority(SysTick_IRQn, SysTick_IRQn_PP, 0);
}