P1 port interrupt operation

* Function: P1.0 is used to control the on and off of the LED. The software delay is 50000 to flip P1.0. *
* *
* MSP430F2274 *
* ----------------- VCC 3.0v *
* /|\ | XIN|- ___ *
* | | XOUT|- | *
* --|RST P1.2|-->LED-----| *
* +--key-->|P1.3 P1.1|-->LED-----| *
* |---key-->|P1.4 P1.0|-->LED-----| *
* | ------------------- *
* GND *
* Author: Singel *
* Time: 2008-10-11 16:36:00 *
* Debugging environment: IAR For MSP430 Embedded Workbench v3.42A *
********************************************************************************/

#include"msp430x22x4.h"
unsigned char keybuffer;
unsigned char scanflag;
unsigned char TEMP_KEY;
void Do_Without_PORT_Register( void )
    {
      P1IE  =  0x00;
      P1IFG =  0x00; 
      P1IE  =  0x00;
    }
  
void PORT_init( void )
    {
      P1DIR |=  (BIT0+BIT1+BIT2);
      P1OUT |=  (BIT0+BIT1+BIT2); 
      P1DIR &=~ (BIT4+BIT3);            
      P1IES &=~ (BIT4+BIT3);
      P1IE  |=  (BIT4+BIT3);
      P1IFG &=~ (BIT4+BIT3);     
    }

void key_procss ( void )
    {       
      TEMP_KEY = TEMP_KEY&0X18;
      switch(TEMP_KEY)
        {
          case 0x10: P1OUT ^=  BIT0+BIT1+BIT2;break;
          case 0x08: P1OUT ^=  BIT0+BIT1+BIT2;break;
        }
      P1IE  |=  (BIT4+BIT3);      
    }
void main( void )
    {
      WDTCTL  = WDTPW + WDTHOLD; 
      BCSCTL1 = CALBC1_12MHZ;
      DCOCTL  = CALBC1_12MHZ;
      Do_Without_PORT_Register();
      PORT_init();  
      _BIS_SR(GIE+LPM4_bits);
      while(1)
        {
           if(scanflag)
            { 
              scanflag = 0;               
              key_procss();                
            } 
           _BIS_SR(GIE + LPM4_bits);
          
        }            
    }
#pragma vector = PORT1_VECTOR
__interrupt void PORT1_ISR ( void )
    {
      _BIC_SR_IRQ(LPM4_bits);
      TEMP_KEY = P1IFG;
      scanflag = 1;
      P1IE  &=~ (BIT4+BIT3);
      P1IFG &=~ (BIT4+BIT3);
    }