stm32 系统时钟配置

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);

}