TIMx_ETR外部时钟源模式2配置方法

由于stm32中的时钟源对应的GPIO口都是ST原厂已经分配好的，可以查看数据手册了解，所以我们要将外部触发信号连接到对应的时钟源GPIO pin口，这样才能起到外部时钟源的作用。

例如:TIM3_ETR外部时钟源是接在PD2口的，如果你连接其他GPIO_Pin口，此时不会进入中断函数，也就没有起到外部时钟源的作用。

 

Timer.c

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#include "stm32f10x.h" extern uint16_t Num;   void Timer_Init(void) {     RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);           //配置GPIO     GPIO_InitTypeDef    GPIO_InitStructure;     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;     GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;     GPIO_Init(GPIOD,&GPIO_InitStructure);           TIM_ETRClockMode2Config(TIM3, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_Inverted,0x00);       //  TIM_InternalClockConfig(TIM2);  //单片机上电自动默认TMI2，可不写     TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;     TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;     TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;     TIM_TimeBaseInitStructure.TIM_Period = 10 -1;   // 0~65535     TIM_TimeBaseInitStructure.TIM_Prescaler = 1 -1; // 0~65535     TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;     TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStructure);           TIM_ClearFlag(TIM3, TIM_FLAG_Update);   //避免刚好初始化就进入中断     TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);       TIM_Cmd(TIM3,ENABLE);           NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);           NVIC_InitTypeDef    NVIC_InitStructure;     NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;     NVIC_Init(&NVIC_InitStructure);         }     uint16_t Timer_GetCounter(void) {     return TIM_GetCounter(TIM3); }   void TIM2_IRQHandler(void) {     if(TIM_GetITStatus(TIM3, TIM_IT_Update) == SET)     {         Num++;         TIM_ClearITPendingBit(TIM3, TIM_IT_Update);     } }

　Timer.h

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#ifndef __TIMER_H #define __TIMER_H   void Timer_Init(void); uint16_t Timer_GetCounter(void);   #endif

main.c

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#include "stm32f10x.h" #include "Delay.h" #include "OLED.h" #include "Timer.h"   uint16_t Num;   int main(void) {     OLED_Init();     Timer_Init();     OLED_ShowString(1, 1, "Num:");     OLED_ShowString(2, 1, "CNT:");       while(1)     {               OLED_ShowNum(1, 5, Num, 5);         OLED_ShowNum(2, 5, Timer_GetCounter(), 5);     } }