STM32通用定時器TIMx
(1)內(nèi)部時鐘(CK_INT)
本文引用地址:http://m.butianyuan.cn/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)至預裝載值(ARR),則產(chǎn)生UPDATE中斷,并重裝預載值。
舉個例子:(以向上計數(shù)為例,每40us中斷一次)
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;// 預裝初值
TIM_TimeBaseStructure.TIM_Prescaler = 36-1;// 預分頻
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;
}
評論