TIM1 外部脉冲计数

void TIM1_init()
{
  PC_DDR_DDR1 = 0;
  PC_CR1_C11 = 1;
  TIM1_CCMR1 = 0x9d;
  TIM1_CCER1 = 0x02;
  TIM1_SMCR = 0x57;
  TIM1_CR1 = 0x01;
}