stm32 微秒定延时问题

Posted 2021-03-15 cxianren

problem: 如果想用计时器定时微秒级,不要使能自动重载:代码如下:

static uint16_t counter;
void Delay_us(uint32_t us){
    counter=0xffff-us-5;
        __HAL_TIM_SetCounter(&htim14,counter);
    HAL_TIM_Base_Start(&htim14);
    while(counter<0xffff-6){
        counter=__HAL_TIM_GetCounter(&htim14);
    }
    HAL_TIM_Base_Stop(&htim14);
}

否则会出现不能退出的异常
fix code

static uint16_t counter;
void Delay_us(uint32_t us){//max time 1500us(1.5ms)
    counter=0xffff-us-99;
        __HAL_TIM_SetCounter(&htim14,counter);
    HAL_TIM_Base_Start(&htim14);
    while(counter<0xffff-100&&counter>0xffff-1500){
        counter=__HAL_TIM_GetCounter(&htim14);
    }
    HAL_TIM_Base_Stop(&htim14);
}