pwm输出不为方波

alenyue · 发表于 2019-3-21 15:11:58

求助！！！采用定时器3 CH3完全重映射PC8输出PWM方波，但输出波形不正常
主函数：
PWM_Init(99,7199);
TIM_SetCompare3(TIM3,50);
while(1)
{
;
}
pwm初始化函数：
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeInitStructure;

TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO|RCC_APB2Periph_GPIOC,ENABLE);
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE);
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_8;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);
TIM_TimeInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeInitStructure.TIM_CounterMode=TIM_CounterMode_Up;
TIM_TimeInitStructure.TIM_Period=LoadValue;
TIM_TimeInitStructure.TIM_Prescaler=prer;
TIM_TimeBaseInit(TIM3, &TIM_TimeInitStructure);
//TIM_OCInitStructure.TIM_OCIdleState=
TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM2;
//TIM_OCInitStructure.TIM_OCNIdleState=
//TIM_OCInitStructure.TIM_OCNPolarity=
TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;
//TIM_OCInitStructure.TIM_OutputNState=
TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable;
//TIM_OCInitStructure.TIM_Pulse=;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_Cmd(TIM3, ENABLE);

pwm输出如图