File content as of revision 0:86b437ce0d0f:

// ST_401_84MHZ
// https://os.mbed.com/users/dreschpe/code/ST_401_84MHZ/
// If you want to use a different crystal or frequency : the STM32CubeMX tool is your friend :-)
// use the STM32CubeMX Tool to calculate the register settings 
// www.st.com/stm32cube‎ 
// 

//#include "stm32f4xx_hal.h"
//#include "ST_F401_84MHZ.h"
// 
//F401_init84::F401_init84(unsigned int external){
//    if(external == 1){
//        SystemClock_Config_84MHz_external();
//        }
//    else {
//        SystemClock_Config_84MHz_internal(); 
//        }
//    }
//
//void F401_init84::SystemClock_Config_84MHz_internal(void)
//{
//  HAL_RCC_DeInit();  // we have to reset the clock settings !
//  RCC_ClkInitTypeDef RCC_ClkInitStruct;
//  RCC_OscInitTypeDef RCC_OscInitStruct;
//
//  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;                // internal 16MHz RC 
//  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
//  RCC_OscInitStruct.HSICalibrationValue = 6;
//  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;                              // PLL on
//  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
//  RCC_OscInitStruct.PLL.PLLM = 16;                                          // setup PLL divider
//  RCC_OscInitStruct.PLL.PLLN = 336;
//  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
//  RCC_OscInitStruct.PLL.PLLQ = 4;
//  HAL_RCC_OscConfig(&RCC_OscInitStruct);                                    
//
//  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1;
//  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
//  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
//  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);
//  SystemCoreClockUpdate();                                                  // update SystemCoreClock var
//}
//
//
//// use a external 8 MHz crystal to generate the CPU clock
//// You have to add X3 8MHz 
//// C33,C34 18pF 0603
//// R35,R37 0R 0603 or use wire
//
//
//void F401_init84::SystemClock_Config_84MHz_external(void)
//{
//  HAL_RCC_DeInit();  // we have to reset the clock settings !
//  RCC_ClkInitTypeDef RCC_ClkInitStruct;
//  RCC_OscInitTypeDef RCC_OscInitStruct;
//
//  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_HSE;
//  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
//  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
//  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
//  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
//  RCC_OscInitStruct.PLL.PLLM = 8;
//  RCC_OscInitStruct.PLL.PLLN = 336;
//  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
//  RCC_OscInitStruct.PLL.PLLQ = 4;
//  HAL_RCC_OscConfig(&RCC_OscInitStruct);
//
//  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1;
//  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
//  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
//  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2);
//  SystemCoreClockUpdate();                                                 // update SystemCoreClock var
//
//}