//使用定時(shí)器TIM4的3通道CH3輸出占空比為25%的PWM波

#include "stm32f10x.h"

int main(void)

{

// SystemInit();

//配置IO口

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE,ENABLE);//IO口使能設(shè)置

GPIO_InitTypeDef GPIO_InitStructure; //定義結(jié)構(gòu)體

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM3的CH3連接PB8管腳

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;//復(fù)用推挽輸出

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

//定時(shí)器2

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);//配置時(shí)鐘

TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

TIM_TimeBaseStructure.TIM_Period=10000; //1s

TIM_TimeBaseStructure.TIM_Prescaler=7199; //720分頻

TIM_TimeBaseStructure.TIM_ClockDivision=0;

TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;//向上計(jì)數(shù)

TIM_TimeBaseInit(TIM4,&TIM_TimeBaseStructure);

TIM_OCInitTypeDef TIM_OCInitStructure;

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//PWM1模式1

TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//比較輸出使能

TIM_OCInitStructure.TIM_Pulse = 2500; //設(shè)置占空比

TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //輸出比較極性高

TIM_OC3Init(TIM4, & TIM_OCInitStructure); //初始化TIM4的CH3通道

TIM_OC3PreloadConfig(TIM4, TIM_OCPreload_Enable); //使能TIM4在CH3通道CCR3上的預(yù)裝載寄存器

TIM_ARRPreloadConfig(TIM4, ENABLE);//使能TIM4在CH3通道ARR3上的預(yù)裝載寄存器

TIM_Cmd(TIM4,ENABLE);//使能定時(shí)器4

while(1);

}

//以下是報(bào)錯(cuò)函數(shù)

#ifdef USE_FULL_ASSERT

void assert_failed(uint8_t* file, uint32_t line)

{

while (1)

{

}

}

#endif