一个定时器为另一个定时器的预分频的问题

murennan · 发表于 2012-10-16 17:59:46

#include "stm32f10x.h"

void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
void Timer_Configuration(void);

int main(void)
{
    RCC_Configuration();
    GPIO_Configuration();
    NVIC_Configuration();
    Timer_Configuration();
    while(1);
}

void RCC_Configuration(void)
{
    ErrorStatus HSEStartUpStatus;
    RCC_DeInit();
    RCC_HSEConfig(RCC_HSE_ON);
    HSEStartUpStatus = RCC_WaitForHSEStartUp();
    if(HSEStartUpStatus == SUCCESS)
        {
           RCC_HCLKConfig(RCC_SYSCLK_Div1);
           RCC_PCLK2Config(RCC_HCLK_Div1);
           RCC_PCLK1Config(RCC_HCLK_Div2);
           RCC_ADCCLKConfig(RCC_PCLK2_Div6);
           FLASH_SetLatency(FLASH_Latency_2);
           FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
           RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);    //PLL 72M
           RCC_PLLCmd(ENABLE);
           while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);
           RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
            while(RCC_GetSYSCLKSource() != 0x08);
        }
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_DeInit(GPIOA);
    GPIO_InitStruct.GPIO_Pin=GPIO_Pin_6;
    GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_Mode=GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA,&GPIO_InitStruct);
}

void NVIC_Configuration(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

void Timer_Configuration(void)
{
    TIM_TimeBaseInitTypeDef   TIM_TimeBaseStructure;
    TIM_OCInitTypeDef          TIM_OCInitStructure;

    //配置TIMER2为主模式，更新事件作为触发输出
    TIM_DeInit(TIM2);
    TIM_TimeBaseStructure.TIM_Period=20;        //ARR的值,TIMER2的更新事件频率为100Hz
    TIM_TimeBaseStructure.TIM_Prescaler=0;
    TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; //采样分频
    TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
    TIM_PrescalerConfig(TIM2,0x8C9F,TIM_PSCReloadMode_Immediate);//时钟分频系数36000，所以定时器时钟为2K
    TIM_ARRPreloadConfig(TIM2, DISABLE);//使能ARR预装载缓冲器
    TIM_SelectOutputTrigger(TIM2,TIM_TRGOSource_Update);
    TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);

    //配置TIMER3为PWM1输出模式，输出占空比50%，周期为10S的PWM波，配置TIMER3的时钟模式为外部时钟1，选择TIMER2为触发源
    TIM_DeInit(TIM3);
    TIM_ITRxExternalClockConfig(TIM3, TIM_TS_ITR1);//外部时钟模式1，触发源为TIMER2
    TIM_SelectSlaveMode(TIM3,TIM_SlaveMode_External1);
    TIM_TimeBaseStructure.TIM_Period=1000;        //ARR的值
    TIM_TimeBaseStructure.TIM_Prescaler=0;
    TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; //采样分频
    TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse=500;                //50%占空比
    TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;
    TIM_OC1Init(TIM3, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
    TIM_ARRPreloadConfig(TIM3, ENABLE);//使能ARR预装载缓冲器

    TIM_Cmd(TIM3, ENABLE);    //开启时钟
    TIM_Cmd(TIM2, ENABLE);    //开启时钟
}

stm32f10x_it.c为

#include "stm32f10x_it.h"

void TIM2_IRQHandler(void)
{
if(TIM_GetITStatus(TIM2,TIM_IT_Update)!=RESET)
   {
    TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
   }
}

我想实现TIM2为TIM3的预分频，TIM3的CH1输出PWM，可是总是不能输出，望高手指点！