77.PS接收来自PL的按键中断

本篇文章主要介绍外设（PL）产生的中断请求，在PS端进行处理。 
在PL端通过按键产生中断，PS接受到之后点亮相应的LED.

本文所使用的开发板是zedboard
PC 开发环境版本：Vivado 2015.4 Xilinx SDK 2015.4

搭建硬件工程

建好工程后，添加ZYNQ IP

双击 ZYNQ,打开Re-customize IP对话框，使能IRQ_P2P

使能UART1

点击Run Connection Automation,按照如图所示配置，点击OK

添加一个GPIO IP,按照如图所示配置，使能中断。点击Run Connection Automation

再添加一个GPIO IP，按照如图所示配置,点击OK

把axi_gpio_0的ip2intc_irpt和ZYNQ PS的 IRQ_F2P[0:0]连在一起

搭建好的硬件系统连接，如图所示

生成顶层文件，点击Generate BitStream

软件工程

新建一个Hello World工程，把以下代码添加进去

 #include <stdio.h>
 #include "platform.h"
 #include "xparameters.h"
 #include "xscugic.h"
 #include "xil_exception.h"
 #include "xgpio.h"

 //parameter definitions
 #define INTC_DEVICE_ID    XPAR_PS7_SCUGIC_0_DEVICE_ID  //DEVICE_ID用来初始化函数，索引数组元素
 #define LED_DEVICE_ID     XPAR_AXI_GPIO_1_DEVICE_ID
 #define BTNS_DEVICE_ID    XPAR_AXI_GPIO_0_DEVICE_ID
 #define INTC_GPIO_INTERRUPT_ID    XPAR_FABRIC_AXI_GPIO_0_IP2INTC_IRPT_INTR
 #define BTN_INT    XGPIO_IR_CH1_MASK
 #define DELAY 100000000

 XGpio LED;
 XGpio BTNInst;
 XScuGic    INTCInst;
 static int btn_value;

 //Function protype
 static void BTN_Intr_Handler(void *baseaddr_p);
 static int InterruptSystemSetup(XScuGic *XScuGicInstancePtr);
 static int IntcInitFunction(u16 DeviceId,XGpio *GpioInstancePtr);

 void BTN_Intr_Handler(void *InstancePtr)
 {
     unsigned char led_val=;
     //Ignore additional button presses
     if((XGpio_InterruptGetStatus(&BTNInst) & BTN_INT) != BTN_INT)
     {
         return;
         //Disable GPIO interrupts
         XGpio_InterruptDisable(&BTNInst,BTN_INT);
     }
     btn_value = XGpio_DiscreteRead(&BTNInst,);
     switch(btn_value)
     {
     case : led_val = 0x01;break;  //led[7:0]=0x01
     case :    led_val = 0x02;break;
     case :    led_val = 0x03;break; //亮1和2
     case :    led_val = 0x04;break;
     case :   led_val = 0x05;break; //亮0和2
     default:break;
     }

     XGpio_DiscreteWrite(&LED,,led_val);
     //Acknowledge GPIO interrupts
     (void)XGpio_InterruptClear(&BTNInst,BTN_INT);
     //Enable GPIO interrupts
     XGpio_InterruptEnable(&BTNInst,BTN_INT);
 }

 int main(void)
 {
     int status;

     //按键初始化
     status = XGpio_Initialize(&BTNInst,BTNS_DEVICE_ID);
     if(status != XST_SUCCESS) return XST_FAILURE;

     //初始化LED
     status = XGpio_Initialize(&LED,LED_DEVICE_ID);
     if(status != XST_SUCCESS) return XST_FAILURE;

     //设置按键IO的方向为输入
     XGpio_SetDataDirection(&BTNInst,,0xff);
     //设置LED IO 的方向为输出
     XGpio_SetDataDirection(&LED,,0X00);

     //初始化中断控制器
     status = IntcInitFunction(INTC_DEVICE_ID,&BTNInst);
     if(status != XST_SUCCESS) return XST_FAILURE;

     while(){}

     return ;
 }

 int IntcInitFunction(u16 DeviceId,XGpio *GpioInstancePtr)
 {
     XScuGic_Config *IntcConfig;
     int status;

     //Interrupt controller initialization
     IntcConfig = XScuGic_LookupConfig(DeviceId);
     status = XScuGic_CfgInitialize(&INTCInst,IntcConfig,IntcConfig->CpuBaseAddress);
     if(status != XST_SUCCESS) return XST_FAILURE;

     //Call interrupt setup function
     status = InterruptSystemSetup(&INTCInst);
     if(status != XST_SUCCESS) return XST_FAILURE;

     //Register GPIO interrupt handler
     status = XScuGic_Connect(&INTCInst,INTC_GPIO_INTERRUPT_ID,(Xil_ExceptionHandler)BTN_Intr_Handler,(void *)GpioInstancePtr);
     if(status != XST_SUCCESS) return XST_FAILURE;

     //Enable GPIO interrupts
     XGpio_InterruptEnable(GpioInstancePtr,);
     XGpio_InterruptGlobalEnable(GpioInstancePtr);

     //Enable GPIO interrupts in the controller
     XScuGic_Enable(&INTCInst,INTC_GPIO_INTERRUPT_ID);

     return XST_SUCCESS;
 }

 int InterruptSystemSetup(XScuGic *XScuGicInstancePtr)
 {
     //Register GIC interrupt handler
     Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,(Xil_ExceptionHandler)XScuGic_InterruptHandler,XScuGicInstancePtr);
     Xil_ExceptionEnable();

     return XST_SUCCESS;
 }

下载好之后，按键按下可以看到相应的LED被点亮