/*
* Register the switch_gpio interrupt handler in the vector table
*/
XIntc_RegisterHandler(XPAR_OPB_INTC_0_BASEADDR,
XPAR_OPB_INTC_0_DIP_SWITCHES_4BIT_IP2INTC_IRPT_INTR,
(XInterruptHandler)switch_int_handler,
(void *)XPAR_DIP_SWITCHES_4BIT_BASEADDR); //感觉这个之前要先进行中断初始化，就是xintc_inint...的一个命令 | 
