(一) 先贴出能工作的PWM初始化程序,如下
void
tiM14_Init()
{
RCC->AHBENR|=1<<17; //使能PORTA时钟
GPIOA->MODER = 0X68AAA6F5 ; //PA4/TIM14-CH1复用功能输出
GPIOA->OTYPER = 0X00000000;
GPIOA->OSPEEDR = 0X00000000;
GPIOA->PUPDR = 0X25000000;
GPIOA->AFR[0] =0XFFF0FFFF;; //清除PA4原来的设置
GPIOA->AFR[0] |=1<<18; //设置PA4为AF4
RCC->APB1ENR|=1<<8; //TIM14时钟使能
TIM14->PSC=0; //预分频器1分频
TIM14->ARR=240; //设置频率(200K)
TIM14->CCR1 =72; //设置占空比
TIM14->EGR |= 1; //产生一次更新事件
TIM14->CCMR1|=6<<4; //CH1 PWM1模式
TIM14->CCMR1|=1<<3; //CH1预装载使能
TIM14->CCER|=1<<0; //OC1输出使?高电平有效有效
TIM14->CR1=0x0080; //ARPE使能
TIM14->CR1|=0x01; //使能定时器14
}
(二) 不能工作的第1路PWM(TIMI-CH1/PA8)初始化程序,如下
void TIM1_Init()
{
RCC->AHBENR|=1<<17; //使能PORTA时钟
GPIOA->MODER = 0X68AAA6F5 ;
GPIOA->OTYPER = 0X00000000;
GPIOA->OSPEEDR = 0X00000000;
GPIOA->PUPDR = 0X25000000;
GPIOA->AFR[0] =0XFFFFF0FF;; //清除PA8原来的设置
GPIOA->AFR[0] |=1<<9; //设置PA8为AF2
RCC->APB2ENR|=1<<11; //TIM1时钟使能
TIM1->PSC=47; //预分频器48分频
TIM1->ARR=1000; //设置频率
TIM1->CCR1 =500; //设置占空比
TIM1->CCMR1|=7<<4; //CH1 PWM2模式
TIM1->CCMR1|=1<<3; //CH1预装载使能
TIM1->CCER|=1<<0; //OC1输出使能
TIM1->CR1|=1<<7; //ARPE使能
TIM1->EGR |= 1; //产生一次更新事件
TIM1->CR1|=0x01; //使能定时器1
TIM1->BDTR |=1<<15;
}
(三) 不能工作的第2路PWM(TIM3-CH1/PB4)初始化程序,如下
void TIM3_Init()
{
RCC->APB1ENR|=1<<1; //TIM3时钟使能
RCC->AHBENR|=1<<18; //使能PORTB时钟
GPIOB->MODER = 0X55551655; //PB4复用功能输出
GPIOB->OTYPER = 0X00000000; //推挽输出
GPIOB->OSPEEDR = 0X00000000; //低速
GPIOB->PUPDR = 0X00004000; //除了PB7带上拉，其它脚则无上拉/下拉
GPIOB->AFR[0] =0XFFFFFF0F; //清除PB4原来的设置
GPIOB->AFR[0] |=1<<4; //设置PB4为AF1
TIM3->PSC=47; //预分频器48分频
TIM3->ARR=1000; //设置频率
TIM3->EGR |= 1; //产生一次更新事件
TIM3->CCR1 =500; //设置占空比
TIM3->CCMR1|=7<<4; //CH1 PWM2模式
TIM3->CCMR1|=1<<3; //CH1预装载使能
TIM3->CCER|=1<<0; //OC1输出使能,高电平有效
TIM3->CR1|=1<<7; //ARPE使能
TIM3->CR1|=0x01; //使能定时器3
}
(三) 不能工作的第3路PWM(TIM16-CH1/PA6)初始化程序,如下
void TIM16_Init()
{
RCC->AHBENR|=1<<17; //使能PORTA时钟
GPIOA->MODER = 0X68AAA6F5 ; //PA6复用功能输出
GPIOA->OTYPER = 0X00000000;
GPIOA->OSPEEDR = 0X00000000;
GPIOA->PUPDR = 0X25000000;
GPIOA->AFR[0] =0XFF0FFFFF;; //清除PA6原来的设置
GPIOA->AFR[0] |=1<<20; //设置PA6为AF5
GPIOA->AFR[0] |=1<<22;
RCC->APB2ENR|=1<<17; //TIM16时钟使能
TIM16->PSC=47; //预分频器48分频
TIM16->ARR=1000; //设置频率
TIM16->CCR1 =170; //设置占空比
TIM16->EGR |= 1; //产生一次更新事件
TIM16->CCMR1|=6<<4; //CH1 PWM1模式
TIM16->CCMR1|=1<<3; //CH1预装载使能
TIM16->CCER|=1<<0; //OC1输出使能
TIM16->CR1=0x0080; //ARPE使能
TIM16->CR1|=0x01; //使能定时器16
}
PCLK=HCLK=48MHZ.
查了很久，上面4路PWM设置内容几乎一样的，为何只有1路能功作，而其他3路则一直是低电平，没PWM波形输出,难道还有别的开关控制?
举报
