stm32 TIM3 工作于PWM1,向上计数,我想在匹配中断函数里更改CCR1的值,然后再软件设置UG位产生更新,将CCR1的值更新到影子寄存器,但是现在发现更新不到影子寄存器,请教下什么原因:
void TM3_PWM_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure; //比较捕获模式初始化
//基本的初始化
TIM_TimeBaseStructure.TIM_Prescaler=0; //PSC预分频 不分频72MHZ
TIM_TimeBaseStructure.TIM_Period=900; //自动重载寄存器 0到999 1000次一个周期
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1 ; //不分频 见TIMx_CR1寄存器位9 位8
TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM1 ;
TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse=CCR1_Val; //设定比较值
TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;
TIM_OC1Init(TIM3,&TIM_OCInitStructure); //初始化了通道1
TIM_OC1PreloadConfig(TIM3,TIM_OCPreload_Enable);
TIM_ITConfig(TIM3,TIM_IT_CC1,ENABLE); //使能匹配中断
//使能TM3重载寄存器ARR
TIM_ARRPreloadConfig(TIM3,ENABLE);
//使能TM3
TIM_Cmd(TIM3,ENABLE);
}
void TIM3_IRQHandler(void)
{
if(TIM_GetITStatus(TIM3,TIM_IT_CC1)==SET)
{
TIM_ClearITPendingBit(TIM3,TIM_IT_CC1); //软件清0
CCR1_Val++;
TIM_SetCompare1(TIM3,CCR1_Val);
TIM_ClearFlag(TIM3,TIM_FLAG_Update);
TIM_GenerateEvent(TIM3,TIM_EventSource_Update);
if(CCR1_Val==998)
CCR1_Val=500;
}
}
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