使用PB12,PB13,PE14,PE15作为外部中断，PE14，PE15响应正常，但PB12,PB13无法正常进入中断，代码如下，求指点。。

void EXTI15_10_IRQHandler(void)

{

//KEY_OK

if(EXTI_GetITStatus(EXTI_Line14)==SET)

{

IO_OutputData(0x00);

delay_us(10);

EXTI_ClearITPendingBit(EXTI_Line14);

}

//KEY_UP

if(EXTI_GetITStatus(EXTI_Line15)==SET)

{

IO_OutputData(0xff);

delay_us(10);

EXTI_ClearITPendingBit(EXTI_Line15);

}

//KEY_DOWN

if(EXTI_GetITStatus(EXTI_Line12)==SET)

{

IO_OutputData(0xff);

delay_us(10);

EXTI_ClearITPendingBit(EXTI_Line12);

}

//KEY_CANCEL

if(EXTI_GetITStatus(EXTI_Line13)==SET)

{

IO_OutputData(0x00);

delay_us(10);

EXTI_ClearITPendingBit(EXTI_Line13);

}

}

----------------------------------------------------------------------

void NVIC_Configuration(void)

{

NVIC_InitTypeDef NVIC_InitStructure;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

--------------------------------------------------------------------------------------

void KEY_config(void)

{

GPIO_InitTypeDef        GPIO_InitStructure;

EXTI_InitTypeDef        EXTI_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE, ENABLE);

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;

//GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Pin = KEY_OK        |        KEY_UP;

GPIO_Init(GPIOE, &GPIO_InitStructure);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;

//GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Pin = KEY_DOWN        |        KEY_CANCEL;

GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource14);

EXTI_InitStructure.EXTI_Line = EXTI_Line14 ;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource15);

EXTI_InitStructure.EXTI_Line = EXTI_Line15 ;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource12);

EXTI_InitStructure.EXTI_Line = EXTI_Line12 ;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource13);

EXTI_InitStructure.EXTI_Line = EXTI_Line13;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

EXTI_ClearITPendingBit(EXTI_Line12);

EXTI_ClearITPendingBit(EXTI_Line13);

EXTI_ClearITPendingBit(EXTI_Line14);

EXTI_ClearITPendingBit(EXTI_Line15);

}