关于stm32L476的TIM2 输出PWM波形
我配置TIM2的通道输出PWM波形，用寄存器操作的，但是怎么输出一直是个高电平，求高手指点，谢谢！配置程序如下：void PWM_Timer2_Init(void)
{
GPIO_Pin_Init(PORTA，GPIO_Pin_3，GPIO_MODE_AF_PP，GPIO_PULLUP, GPIO_SPEED_HIGH,AF1);
TIM_TypeDef *Timer = TIM2;
/* Enable the Low Speed APB (APB1) peripheral clock*/
RCC->APB1ENR1 |= RCC_APB1ENR1_TIM2EN; //__TIM2_CLK_ENABLE()
/* Timer2 control register 1 (TIMx_CR1) */
Timer->CR1 &= ~(TIM_CR1_DIR | TIM_CR1_CMS); // Clear direcion and center aligned mode bits
Timer->CR1 |= TIM_COUNTERMODE_CENTERALIGNED1;
Timer->CR1 &= ~TIM_CR1_CKD; // clesr clock division bits
Timer->CR1 |= TIM_CLOCKDIVISION_DIV1; // division = 1
// Timer2 prescaler (TIMx_PSC)
Timer->PSC = TIM2_PRESCALER_VALUE; // initialize Timer2 prescale value = 1
// TIM2 capture/compare mode register 4(TIMx_CCMR2)
Timer->CCMR2 &= ~TIM_CCMR2_CC4S; // Capture/Compare Channel4 is configured as output
// Timer->CCMR2 &= ~TIM_CCMR2_OC4PE; // Output Compare Channel4 Preload disabled, TIMx_CCR1 can be written at anytime
Timer->CCMR2 |=TIM_CCMR2_OC4PE; // Output Compare 4 preload enable
Timer->CCMR2 &= ~TIM_CCMR2_OC4M; // clear Output compare 4 mode
Timer->CCMR2 |=TIM_CCMR2_OC4M_1; // OC1M: Output compare 4 mode = 6, PWM mode 1
Timer->CCMR2 |=TIM_CCMR2_OC4M_2;
Timer->CCER|=TIM_CCER_CC4P;
Timer->CCMR2 &=~TIM_CCMR2_OC4FE;
Timer->CR2&=~TIM_CR2_OIS1;
Timer->CCMR2 |=TIM_CCMR2_OC4CE; // Output Compare Ch4 Clear Enable
// TIM2 auto-reload register (TIM2_ARR) // initialize PWM frequency
Timer->ARR = 699; // initialize Timer2 Auto Reload Register
// TIM2 capture/compare register 4 (TIM2_CCR4) // initialize duty cycle
Timer->CCR4 = 200; // initialize Timer2 Capture/Compare Register 4
// TIM2 control register 1 (TIMx_CR1)
Timer->CR1 |= TIM_CR1_CEN; // Timer2 enable
// TIM2 capture/compare enable register (TIMx_CCER)
Timer->CCER = Timer->CCER |=TIM_CCER_CC4E;
}
调好了，问题已经解决，配置程序没问题，程序里面的标志位没有使能导致的！谢谢各位关注！
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