S3C2440 development board uses external interrupts to implement button switching of different functions

#include "def.h"

#include "option.h"

#include "2440addr.h"

#include "mmu.h" 

#include "stdio.h"

/*Interrupt processing function Press different buttons to enter the interrupt processing, and start different functions according to the different buttons pressed to realize the button functions of the function control panel*/

void __irq Eint_Isr(void)

{

  switch(rEINTPEND)

  {

    case 1<<13: //Function 1 starts and function 2 is turned off at the same time

         rGPBDAT=0<<6|1<<7;

         rEINTPEND=1<<13; //Wait for the next interrupt to enter

         break;

    case 1<<14: //Function 2 starts and function 1 is turned off at the same time

         rGPBDAT=1<<6|0<<7;

         rEINTPEND=1<<14; //Wait for the next interrupt to enter

         break;

    case 1<<8: //Close functions 1 and 2

         rGPBDAT=1<<6|1<<7;

         rEINTPEND=1<<8; //Wait for the next interrupt to enter

         break;

    default:

         rGPBDAT=1<<6|1<<7;

         break;

  }

  ClearPending(BIT_EINT8_23); //Wait for the next interrupt in this interrupt vector to arrive

}

/*Set the default function after startup*/

void Led_on()

{

     //Set up the LED light

   rGPBCON=0x155555; //Set GPB to output 

   rGPBDAT=(0x1<<6)|(0x1<<7); //GPB7 pin is set, LED is off

}

/*Set button trigger mode*/

void Eint_func()

{

   //Key interrupt source settings

   rGPGCON=(rGPGCON&~((0x3<<0)|(0x3<<10)|(0x3<<12)))|(0x1<<1)|(0x1<<11)|(0x1<<13); //Set GPG0, 5, 6 pins to EINT8, 13, 14

   rGPGUP|=(0x1<<0)|(0x1<<5)|(0x1<<6); //Pin uses the second function

   rEXTINT1=rEXTINT1&~(0x7<<0);//|(0x1<<2); //Button 1 is set to low level edge trigger

   rEXTINT1=rEXTINT1&~(0x7<<20);//|(0x1<<22); //Button 2 is set to low level edge trigger

   rEXTINT1=rEXTINT1&~(0x7<<24);//|(0x1<<26); //Button 3 is set to low level edge trigger

}

/*Interrupt initialization*/

void Eint_init()

{

   rEINTMASK=rEINTMASK&~((0x1<<8)|(0x1<<13)|(0x1<<14)); // Enable external interrupt mask, do not mask interrupt when it is 0

   /*Set up interrupt controller*/

   rINTMOD&=~BIT_EINT8_23; //Set the interrupt mode to IRQ

   rINTMSK&=~BIT_EINT8_23; //Start interrupt enable

}

/*Interrupt pending, waiting for interrupt*/

void Eint_wait()

{

   rSRCPND=rSRCPND; //Interrupt pending register clear

   rINTPND=rINTPND; //Interrupt source pending register clear

   rEINTPEND|=(0x1<<8)|(0x1<<13)|(0x1<<14); //External interrupt suspend register, Eint13 suspends waiting for interrupt

   rSRCPND=BIT_EINT8_23; //Interrupt source pending register corresponding position 1 waiting for interrupt

   rINTPND=BIT_EINT8_23; //Interrupt pending register corresponding position 1 waiting for interrupt

}

/*Set interrupt pointer*/

void Eint_p()

{

   pISR_EINT8_23 =(U32)Eint_Isr; //Set interrupt to Eint11 response

}

/*Main program starts*/

void Main()

{

// isr_asm(); // Enable the I bit of the CPSR register

   Led_on(); //Turn off the LED at startup

   Eint_init(); //Interrupt initialization

   Eint_func(); //Interrupt trigger status initialization

   Eint_wait(); //Wait for interrupt

   Eint_p(); //Interrupt pointer

}