TQ2440 key interrupt

1. It is necessary to call the MMU function to implement memory mapping;

2. After the interrupt is triggered and the interrupt processing function is entered, the corresponding bits of SRCPND and INTPND must be cleared first. If the secondary interrupt source is used, such as EINT4 in EINT4_7, the corresponding bit of EINTPEND must be cleared. Generally speaking, the corresponding bit of the secondary interrupt source should be cleared first, and then the interrupt source, otherwise the interrupt source will cause multiple interrupts. After the clearing is completed, specific processing can be performed.

#include "def.h"
#include "option.h"
#include "2440addr.h"
#include "2440lib.h"
#include "2440slib.h"
#include "mmu.h"

#define LED1 (1<<5) //must be "()"
#define LED2 (1<<6)
#define LED3 (1<<7)
#define LED4 (1<<8)
 
#define KEY1   (1< <1)   //GPF1
#define KEY2   (1<<4)   //GPF4
#define KEY3   (1<<2)   //GPF2
#define KEY4   (1<<0)   //GPF0

//void delay_ms(U32 i);
void init_irq(void);
void MMU_Init(void);

int Main(void)
{
    rGPBCON=0x15400;
    rGPBDAT=0x7ff;
    MMU_Init();    //MMU is required to implement address mapping
    init_irq();        //Initialize interrupt registers
    while(1);
   
}

void delay_ms(U32 i)
{
   int j;
   for(;i>0;i--)
       for(j=65535;j>0;j--);
}

void key_per(void)    //Key processing
{
    if(!(rGPFDAT&KEY1))
        rGPBDAT=~LED1;
       
    else if(!(rGPFDAT&KEY2))
        rGPBDAT=~LED2;
       
    else if(!(rGPFDAT&KEY3))
     rGPBDAT=~LED3;
     
    else if (!(rGPFDAT&KEY4))
        rGPBDAT=~LED4;
       
}

void __irq key1_3_4(void)
{
   //When a key is pressed, jump to this function. In each branch corresponding to the following keys, you should call before jumping to key_per()

  //ChearPending() clears the corresponding bits of SCRPND and INTPND
    if(rINTPND &KEY3)           
    {                                  
      ClearPending(BIT_EINT2);
      key_per();
    }
    else if(rINTPND &KEY4)
    {                               
      ClearPending(BIT_EINT0);
      key_per();
    }
  
    else if(rINTPND&KEY1)            
    {                
      ClearPending(BIT_EINT1);
      key_per();
    }
   

}

void __irq key2(void) 

{
 //if(rEINTPEND &KEY2)             //10000
 //{      
      rEINTPEND = (1<<4);            //CLEAR   rEINTPEND
      ClearPending(BIT_EINT4_7);
      key_per();
 //} 
}

//Since key2 corresponds to GPF4 in the circuit diagram, the corresponding interrupt function is EINT4, which is specifically determined by the secondary interrupt register

//EINTMASK is used to enable it. In init_irq(), since the interrupt processing function needs to be mapped, key2 is written separately here to make the program clear.

void init_irq(void)
{
    rGPFCON&=(~((3<<0)|(3<<2)|(3<<4)|(3<<8)));
    rGPFCON|=((2<<0 )|(2<<2)|(2<<4)|(2<<8));   //configure GPF0,1,2,4 to EINT0,1,2,4
    //rGPFCON=0xfeea;
    rPRIORITY= 0x00000000;     //deafult priority configure
    rINTMOD=0x0;                     //IRQ
    EnableIrq(BIT_EINT0|BIT_EINT1|BIT_EINT2|BIT_EINT4_7); //enable EINT0, 1, 2, 4_7 with INTMSK register
    //rINTMSK&=(~((1<<0 )|(1<<1)|(1<<2)|(1<<4)));
    rEINTMASK&=~(1<<4);                               //enbale EINT4 with EINTMASK register

//The following is to map the addresses of key1_3_4 and key2 functions to the interrupt vector table, so that when the interrupt is triggered, it jumps to the address of the corresponding function to execute

//Execute this function. If the EINT0 interrupt is triggered, the function key1_3_4 will be executed.

    pISR_EINT0= (unsigned int)key1_3_4;     

    pISR_EINT1= (unsigned int)key1_3_4;
    pISR_EINT2= (unsigned int)key1_3_4;
    pISR_EINT4_7= (unsigned int)key2;
  
}