system_stm32f4xx.c File Reference

CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. More...

#include "stm32f4xx.h"

Macros
#define	HSE_VALUE   ((uint32_t)25000000)
#define	HSI_VALUE   ((uint32_t)16000000)

Functions
void	SystemInit (void)
	Setup the microcontroller system Initialize the FPU setting, vector table location and External memory configuration.
void	SystemCoreClockUpdate (void)
	Update SystemCoreClock variable according to Clock Register Values. The SystemCoreClock variable contains the core clock (HCLK), it can be used by the user application to setup the SysTick timer or configure other parameters.

Variables
uint32_t	SystemCoreClock = 16000000
const uint8_t	AHBPrescTable [16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}
const uint8_t	APBPrescTable [8] = {0, 0, 0, 0, 1, 2, 3, 4}

Detailed Description

CMSIS Cortex-M4 Device Peripheral Access Layer System Source File.

Author

MCD Application Team

This file provides two functions and one global variable to be called from user application:

• SystemInit(): This function is called at startup just after reset and before branch to main program. This call is made inside the "startup_stm32f4xx.s" file.
• SystemCoreClock variable: Contains the core clock (HCLK), it can be used by the user application to setup the SysTick timer or configure other parameters.
• SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must be called whenever the core clock is changed during program execution.

Attention

Copyright (c) 2017 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.