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          STM32通用定時器TIMx

          作者: 時間:2016-11-13 來源:網(wǎng)絡(luò) 收藏
          STM32計數(shù)器時鐘可由下列四種時鐘源提供:

          (1)內(nèi)部時鐘(CK_INT)

          本文引用地址:http://cafeforensic.com/article/201611/316145.htm

          (2)外部時鐘模式1:外部輸入腳(TIx)

          (3)外部時鐘模式2:外部觸發(fā)輸入(ETR)

          (4)內(nèi)部觸發(fā)輸入(ITRx)

          時鐘源(CK_INT)經(jīng)預(yù)分頻(PSC)后得到定時時鐘(CK_CNT),每個定時時鐘計數(shù)寄存器計數(shù)(可設(shè)向上/向下/中央對齊模式),計數(shù)寄存器計數(shù)至捕獲比較寄存器(CCR),則產(chǎn)生CC中斷;計數(shù)寄存器計數(shù)至預(yù)裝載值(ARR),則產(chǎn)生UPDATE中斷,并重裝預(yù)載值。

          舉個例子:(以向上計數(shù)為例,每40us中斷一次)

            例程:
          (省略RCC設(shè)置部分)


          void TIM2_Configuration(void)
          {
          TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
          TIM_OCInitTypeDef TIM_OCInitStructure;

          RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);// for 36MHz


          TIM_DeInit(TIM2);
          TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
          TIM_TimeBaseStructure.TIM_Period = 1200;// 預(yù)裝初值
          TIM_TimeBaseStructure.TIM_Prescaler = 36-1;// 預(yù)分頻
          TIM_TimeBaseStructure.TIM_ClockDivision = 0x00; // 時鐘分頻因子(用于ETR,TIX)
          TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; // 向上計數(shù)
          TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; // 重復(fù)計數(shù)
          TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);


          /*-------------------*/
          TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
          TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
          TIM_OCInitStructure.TIM_Pulse = 40; //40us中斷一次
          TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
          TIM_OC1Init(TIM2, &TIM_OCInitStructure);
          TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);

          /*-------------------*/
          TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
          TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
          TIM_OCInitStructure.TIM_Pulse = 800;//PWM 800/1200
          TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
          TIM_OC2Init(TIM2, &TIM_OCInitStructure);
          TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Disable);

          /*-------------------*/
          //TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Gated);
          //TIM_SelectInputTrigger(TIM2, TIM_TS_ITR0);

          TIM_ARRPreloadConfig(TIM2, DISABLE);

          TIM_ITConfig(TIM2, TIM_IT_CC1|TIM_IT_CC2|TIM_IT_Update, ENABLE);
          TIM_Cmd(TIM2, ENABLE);
          }


          /*--------------中斷程序-------------------*/
          void TIM2_IRQHandler(void)
          {

          uint16_t capture = 0;

          if(TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)

          {

          if((timer_cnt1++)>49)

          {

          timer_cnt1 = 0;

          f_2ms = 1;

          }

          TIM_ClearITPendingBit(TIM2, TIM_IT_CC1);

          capture = TIM_GetCapture1(TIM2);

          if(capture==1200)

          TIM_SetCompare1(TIM2, 40);

          else

          TIM_SetCompare1(TIM2, capture + 40);

          }

          if(TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)

          {

          GPIO_SetBits(P_LCDBK, LCDBK);

          }

          if(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)

          GPIO_ResetBits(P_LCDBK, LCDBK);

          TIM2->SR = 0x00;
          }



          關(guān)鍵詞: STM32通用定時器TIM

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