STM8S003F3计数不管用是怎么回事？

void tim1_count_init(void){    GPIOC->DDR  = ~GPIO_PIN_6;//输入    GPIOC->CR1 |= GPIO_PIN_6;//上拉输入    GPIOC->CR2  = ~GPIO_PIN_6;//禁止外部中断功能    GPIOC->DDR  = ~GPIO_PIN_7;//输入    GPIOC->CR1 |= GPIO_PIN_7;//上拉输入    GPIOC->CR2  = ~GPIO_PIN_7;//禁止外部中断功能    //CLK->PCKENR1 |= CLK_PCKENR1_TIM1;    TIM1->CCMR1 = 0x31;    //TIM1->CCMR2 = BIT0;//CC1通道被配置为输入，IC1映射在TI1FP1上；    //TIM1->CR2 |= BIT7;//使能计数器    TIM1->CCER1 |= 0x02;    //TIM1->CCMR2 = _OC2M=0x00;//无滤波器，以fMASTER采样    //TIM1->CCER1_CC2P=0;//捕获发生在TI2F的上升沿    //TIM1->CCMR2_OC2PE=0x00;//无预分频器，捕获输入口上检测到的每一个边沿都触发一次捕获    TIM1->SMCR |= 0x50;//选定TI2作为输入源    TIM1->SMCR |= 0x07;//TIM1_SMCR_SMS;//选中的触发输入(TRGI)的上升沿驱动计数器。    TIM1->CR1 |= 0x01;//TIM1_CR1_CEN;//使能计数器}uint16_t time1_get_num(void){    uint32_t d32;        d32 = TIM1->CNTRH;        d32 <<= 8;        d32 |= TIM1->CNTRL;    return d32;}