江科大學(xué)習(xí)筆記 _4.定時(shí)器中斷配置
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內(nèi)部時(shí)鐘計(jì)數(shù)：
1.?RCC時(shí)鐘開(kāi)啟
Timer2掛載在APB1總線上
RCC_APB1PeriphClockCmd(RCC_APB1ENR_TIM2EN, ENABLE);
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2.?選擇時(shí)基單元的時(shí)鐘源
TIM_InternalClockConfig(TIM2);
//Configures the TIMx internal Clock ?使用內(nèi)部時(shí)鐘源
如果不調(diào)用這個(gè)函數(shù)，使用的也是內(nèi)部時(shí)鐘
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3.?配置時(shí)基單元
????TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
????TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;//濾波分頻
????TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;
????TIM_TimeBaseInitStruct.TIM_Period = 10000 - 1;
????TIM_TimeBaseInitStruct.TIM_Prescaler = 7200 - 1;
????TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStruct);
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?TIM_ClearFlag(TIM2, TIM_FLAG_Update);//防止初始化完就進(jìn)中斷的問(wèn)題
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4.?配置輸出中斷控制，允許更新中斷到輸出NVIC
TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
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5.?配置NVIC，打開(kāi)定時(shí)器同通道，優(yōu)先級(jí)
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
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????NVIC_InitTypeDef NVIC_InitStruct;
????NVIC_InitStruct.NVIC_IRQChannel = ?TIM2_IRQn;
????NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
????NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 2;
????NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;
NVIC_Init(&NVIC_InitStruct);
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6.?運(yùn)行控制
TIM_Cmd(TIM2,ENABLE);
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中斷服務(wù)函數(shù)
void TIM2_IRQHandler(void)
{
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????if(TIM_GetITStatus(TIM2, TIM_IT_Update) == SET)
????{
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????????Num++;
????????
????????TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
????}
}
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