system_stm32f0xx.c File Reference

CMSIS Cortex-M0 Device Peripheral Access Layer System Source File. More...

#include "stm32f0xx.h"

Functions
void	SystemInit (void)
	Setup the microcontroller system.
void	SystemCoreClockUpdate (void)
	Update SystemCoreClock variable according to Clock Register Values.

Variables
uint32_t	SystemCoreClock = 8000000
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-M0 Device Peripheral Access Layer System Source File.

Author

MCD Application Team

1. 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_stm32f0xx.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.
2. After each device reset the HSI (8 MHz) is used as system clock source. Then SystemInit() function is called, in "startup_stm32f0xx.s" file, to configure the system clock before to branch to main program.

3. This file configures the system clock as follows:

Supported STM32F0xx device

System Clock source | HSI

SYSCLK(Hz) | 8000000

HCLK(Hz) | 8000000

AHB Prescaler | 1

APB1 Prescaler | 1

=============================================================================

Attention

Copyright (c) 2016 STMicroelectronics. All rights reserved.

This software component is licensed by ST under BSD 3-Clause license, the "License"; You may not use this file except in compliance with the License. You may obtain a copy of the License at: opensource.org/licenses/BSD-3-Clause