[求助]最近再用stm32f407调试tim3输出相位180的pwm，但是现在就出来一路是怎么回事

zhangsxa · 发表于 2019-9-27 16:38:31

float Duty = 0.48;
u16 ARR = 0,PSC = 0,CH1Ccr = 0,CH2Ccr = 0,DT = 500;
u32 Frequence = 100000;

TIM_TimeBaseInitTypeDef  TIM_TimeBaseInitStruct;
GPIO_InitTypeDef  GPIO_InitStruct;
TIM_OCInitTypeDef TIM_OCInitStruct;

Frequence = 100000;  //频率，单位：Hz
Duty = 0.48;       //占空比
DT = 500;          //死区时间，单位：ns

//中央对齐模式，只在CNT计数到CCR翻转一次，频率较PWM模式减半，且ARR不需要-1
ARR = 36000000/(PSC+1)/Frequence;          //设置成100KHz
CH1Ccr = ARR*Duty - DT/2/((PSC+1)*13.89f);  //TIM 72M下约13.89ns一个周期
CH2Ccr = ARR - CH1Ccr;                   //CH4与CH3和为ARR

GPIO_PinAFConfig(GPIOA,GPIO_PinSource6|GPIO_PinSource7,GPIO_AF_TIM3); //PA6\7复用为TIM3

/**********************TIM3 GPIO配置*****************************/
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;       //上拉

GPIO_Init(GPIOA,&GPIO_InitStruct);

/**********************初始化TimBase结构体*************************/
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);
TIM_InternalClockConfig(TIM3);

TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_CenterAligned1;
TIM_TimeBaseInitStruct.TIM_Period = ARR;
TIM_TimeBaseInitStruct.TIM_Prescaler = PSC;
TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseInitStruct);

  //  TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStruct);
/**********************初始化TIM3 OC结构体*************************/
TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStruct.TIM_Pulse = CH1Ccr;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;

TIM_OC1Init(TIM3,&TIM_OCInitStruct);
TIM_OCInitStruct.TIM_Pulse = CH2Ccr;
TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;

TIM_OC2Init(TIM3,&TIM_OCInitStruct);

TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能TIMx在CCR1上的预装载寄存器
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM3, ENABLE); //使能TIMx在ARR上的预装载寄存器

TIM_Cmd(TIM3, ENABLE);
TIM_CtrlPWMOutputs(TIM3, ENABLE);