stm32关于利用定时器计数脉冲个数的问题，请大家帮助!

代码如下：
void DJ_GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;


RCC_ClocksTypeDef RCC_ClockFreq;
SystemInit();
RCC_GetClocksFreq(&RCC_ClockFreq);


RCC_APB1PeriphClockCmd(RCC_APB1Periph_tiM2,


ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|


RCC_APB2Periph_GPIOB, ENABLE);


GPIO_InitStructure.GPIO_Pin=GPIO_Pin_0;



GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);


GPIO_InitStructure.GPIO_Pin=GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOB,&GPIO_InitStructure);
}


void DJ_BH_MODE_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_ICInitTypeDef TIM_ICInitStructure;


TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
TIM_TimeBaseStructure.TIM_Prescaler = 0x00;
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
TIM_TimeBaseStructure.TIM_CounterMode =


TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);


TIM_ICInitStructure.TIM_Channel=TIM_Channel_1;



TIM_ICInitStructure.TIM_ICPolarity=TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICPrescaler=TIM_ICPSC_DIV1


;



TIM_ICInitStructure.TIM_ICSelection=TIM_ICSelection_Direct


TI;
TIM_ICInitStructure.TIM_ICFilter=0x0;
TIM_ICInit(TIM2,&TIM_ICInitStructure);


TIM_ETRClockMode2Config(TIM2, TIM_ExtTRGPSC_OFF,


TIM_ExtTRGPolarity_NonInverted, 0);
TIM_SetCounter(TIM2,0);
TIM_Cmd(TIM2, ENABLE);
}
小弟想利用编码器进行电机测速，定时器设置成外部时钟源，然后用计数器对编码器输出的脉冲进行计数，计数到334，电机就转动一圈。不过貌似程序有点问题，电机怎么也停不下来，求帮助啊。万分感谢！