产生一个2K 占空比50%的pwm波形
// PWM输出 PB1
void PwmPhyConfig()
{
//此部分需手动修改 IO 口设置
RCC->APB1ENR |= 1<<1; //TIM3 时钟使能
RCC->AHB1ENR |= 1<<1; //使能 PORTB 时钟
GPIOB->MODER |= (2<<1*2); //复用模式
GPIOB->OTYPER &= ~(1<<1); //推挽
GPIOB->PUPDR |= (1<<1*2); //上拉
GPIOB->OSPEEDR |= (1<<1*2); //高速
GPIOB->AFR[0] |= (2<<1*4); //GPIO_AF2_TIM3
TIM3->ARR = pwm_arr; //设定计数器自动重装值
TIM3->PSC = pwm_psc; //预分频器不分频
TIM3->CCMR2 |= 6<<12; //CH4 PWM1 模式
TIM3->CCMR2 |= 1<<11; //CH4 预装载使能
TIM3->CCER |= 1<<12; //OC4 输出使能
TIM3->CCER |= 1<<13; //OC4 低电平有效
TIM3->CR1 |= 1<<7; //ARPE 使能
TIM3->CR1 |= 1<<0; //使能定时器 3
TIM3->CCR4 = 250;
}
/******************************pwm*************************************/
#define pwm_arr (500-1) //2K
#define pwm_psc (108-1) //1M
void PwmPhyConfig(void);
/**********************************************************************/
标签：TIM3,arr,void,1CR1,STM32F7xx,pwm,外设 From： https://www.cnblogs.com/lum0126/p/16892972.html