stm32同一个定时器的输出几路不同频率的pwm信号

wh473910650 · 发表于 2016-5-6 12:23:01

想利用stm32定时器3来输出两路不同频率的pwm信号，设置如下：
void TIM3_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//3õê¼»ˉGPIO

TIM_TimeBaseStructure.TIM_Period = arr;    //（arr=7199）
TIM_TimeBaseStructure.TIM_Prescaler =psc;    //(psc=0)
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_ITConfig(TIM3,TIM_IT_CC1|TIM_IT_CC2,ENABLE );

//TIM3 Channel1
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_Pulse= CCR1;    //(CRR1=1)
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
      TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable);

//TIM3 Channel2
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_Pulse = CCR2;       //(CRR2=2)
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);

TIM_Cmd(TIM3, ENABLE);
}

void TIM3_IRQHandler(void)
{
if (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
TIM_SetCompare1(TIM3,TIM_GetCapture1(TIM3)+CCR1);
}
else if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
TIM_SetCompare2(TIM3,TIM_GetCapture2(TIM3)+CCR2);
}
}

这样理论上CH1输出频率为5000hz，CH2输出频率为2500khz，打算是为什么实际上两路的输出频率是一样的都是5000hz，这是怎么回事