#include <stm32f10x_map.h>
#include "main.h"
由于学习初没有找到中文资料,翻译了点,不管好坏,贴上来和大家分享吧!!!
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/
/*******************************************************************************
* Function Name : RCC_DeInit
* Description : Deinitializes the RCC peripheral registers to their default
* reset values.
* - The HSITRIM[4:0] bits in RCC_CR register are not modified
* by this function.
* - The RCC_BDCR and RCC_CSR registers are not reset by this
* function.
* Input : None
* Output : None
* Return : None
*******************************************************************************/
void RCC_DeInit(void)
{
// Disable APB2 Peripheral Reset
RCC->APB2RSTR = 0x00000000;
// Disable APB1 Peripheral Reset
RCC->APB1RSTR = 0x00000000;
// FLITF and SRAM Clock ON
RCC->AHBENR = 0x00000014;
//Disable APB2 Peripheral Clock
RCC->APB2ENR = 0x00000000;
// Disable APB1 Peripheral Clock
RCC->APB1ENR = 0x00000000;
// Set HSION bit
RCC->CR |= (u32)0x00000001;
// Reset SW[1:0], HPRE[3:0], PPRE1[2:0], PPRE2[2:0], ADCPRE[1:0] and MCO[2:0] bits
RCC->CFGR &= 0xF8FF0000;
// Reset HSEON, CSSON and PLLON bits
RCC->CR &= 0xFEF6FFFF;
// Reset HSEBYP bit
RCC->CR &= 0xFFFBFFFF;
// Reset PLLSRC, PLLXTPRE, PLLMUL[3:0] and USBPRE bits
RCC->CFGR &= 0xFF80FFFF;
//Disable all interrupts
RCC->CIR = 0x00000000;
}
void SetupClock(void)
{
/* Reset HSEON and HSEBYP bits before configuring the HSE ------------------*/
/* Reset HSEON bit */
RCC->CR &= 0xfffeffff; //HSEON清零
/* Reset HSEBYP bit */
RCC->CR &= 0xfffbffff; //清除HSEBYP
/* Set HSEON bit */
RCC->CR |= 0x00010000; //置位HSEON
/* Wait till HSE is ready */
while ((RCC->CR&0x00020000)== 0);
//清除HPRE AHB precxaler
RCC->CFGR&=0xffffff0f;
//SYSCLK not divided HCLK = SYSCLK
RCC->CFGR|=0;
//清除PPRE2 APB high speed precxaler
RCC->CFGR&=0xffffc7ff;
//HCLK not divided PCLK2=HCLK
RCC->CFGR|=0;
//清除PPRE1 APB low speed precxaler
RCC->CFGR&=0xfffff8ff;
//HCLK divided by 2 PCLK1=HCLK/2
RCC->CFGR|=0x00000400;
*(vu32 *)0x40022000 = 0x01; /* Flash 2 wait state */
/* PLLCLK = 8MHz * 9 = 72 MHz */
/* Clear PLLSRC, PLLXTPRE and PLLMUL[21:18] bits */
RCC->CFGR&= 0xffc0ffff;
//选择HSE作为PLL时钟输入 PLLMUL选择9倍频
RCC->CFGR|=0x00010000|0x001c0000;
RCC->CR|=0X01000000; //置位PLLON位
while((RCC->CR&0x02000000)== 0); //wait till PLL is ready
//清除 SW System clock Switch
RCC->CFGR&=0xfffffffc;
//选择 PLL作为系统时钟
RCC->CFGR|=0x00000002;
//等待 PLL作为系统时钟标志置位
while((RCC->CFGR&0x0000000c)!=0x08);
// SysTick event each 10 ms with input clock equal to 9MHz (HCLK/8)
//SysTick->LOAD=90000;
//SysTick->CTRL |= 0x00000002;
}
void delay(void)
{
uint i,j;
for(i=0;i<10;i++)
for(j=0;j<30000;j++);
}
int main(void)
{
RCC_DeInit();
SetupClock();
RCC->APB2ENR|=0X08;
GPIOB->CRH=0X33333333;
GPIOB->BRR|=0XFFFF;
/**********MCO******************/
RCC->APB2ENR|=0X04;
GPIOA->CRH&=0xf0;
GPIOA->CRH|=0x0b;
RCC->CFGR|=0X07000000;
//RCC->APB2ENR|=0x01;
while(1)
{
//GPIOB->BSRR=0X80000000;
//GPIOB->BSRR=0X00008000;
GPIOB->ODR|=0X8000;
//delay();
GPIOB->ODR&=0X7FFF;
// delay();
}
//while(1);
}
#ifndef MAIN_H
#define MAIN_H
//#define _RCC
/*#include <stm32f10x_lib.h> */
#define uchar unsigned char
#define uint unsigned int
void RCC_DeInit(void);
void SetupClock(void);
#endif
相关链接:https://bbs.21ic.com/upfiles/img/200710/20071024165215319.pdf |
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