void init_timer3_delay(void)
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
TIM_TimeBaseInit(TIM3, &(TIM_TimeBaseInitTypeDef) {
.TIM_Prescaler = (72-1), // 预分频器
.TIM_CounterMode = TIM_CounterMode_Down, // 向下计数
.TIM_Period = (1000-1), // 设置自动重载值
.TIM_ClockDivision = TIM_CKD_DIV1, // 时钟分频
.TIM_RepetitionCounter = 0 // 此处无意义
});
while((TIM3->SR & TIM_FLAG_Update)!=SET); // 计时到时,此处为1
TIM3->SR = (uint16_t)~TIM_FLAG_Update;
}
//
void delay_us(unsigned int us)
{
TIM3->CNT = us-1;
TIM3->CR1 |= TIM_CR1_CEN; // 使能计数器
while((TIM3->SR & TIM_FLAG_Update)!=SET);
TIM3->SR = (uint16_t)~TIM_FLAG_Update;
TIM3->CR1 &= ~TIM_CR1_CEN;
}
//