外部中断开启LED灯的例程

我想用PB的IO口输入外部中断，而不是按键的PORTA0 ，但是我B口中断返回一直是failed 无法开启，是什么问题呢

代码

gpio_pin_config_t sw_config = {
kGPIO_DigitalInput, 0,
};
gpio_pin_config_t sw3_config = {
kGPIO_DigitalInput, 0,
};
/* Define the init structure for the output LED pin 灯 */
gpio_pin_config_t led_config = {
kGPIO_DigitalOutput, 0,
};

BOARD_InitPins();
BOARD_BootClockRUN(); //时钟
BOARD_InitDebugConsole(); //串口
//a= GPIO_ReadPinInput(GPIOB,17u);
/* Print a note to terminal. */
PRINTF(“\r\n GPIO Driver example\r\n”);
PRINTF(“\r\n Press %s to turn on/off a LED \r\n”, BOARD_SW_NAME);
PRINTF(“\r\n %d”,a);
/* Init input switch GPIO. */

// EnableIRQ(BOARD_SW_IRQ);

PORT_SetPinInterruptConfig(BOARD_SW_PORT, BOARD_SW_GPIO_PIN, kPORT_InterruptFallingEdge);

PORT_SetPinInterruptConfig(BOARD_SW3_PORT, BOARD_SW3_GPIO_PIN, kPORT_InterruptFallingEdge);
PRINTF(“%d \n”,EnableIRQ(BOARD_SW3_IRQ));//portb
PRINTF(“%d \n”,EnableIRQ(BOARD_SW_IRQ));
//DisableIRQ(BOARD_SW_IRQ);

GPIO_PinInit(BOARD_SW_GPIO, BOARD_SW_GPIO_PIN, &sw_config);
GPIO_PinInit(BOARD_SW3_GPIO, BOARD_SW3_GPIO_PIN, &sw3_config);

/* Init output LED GPIO. */
GPIO_PinInit(BOARD_LED_GPIO, BOARD_LED_GPIO_PIN, &led_config);

这个sw3就是我自己设置的IO口