Hardware interrupt

Your code has many flaws. The major one is, you did not use
__bic_SR_register_on_exit(LPM3_bits);
at the end of your ISR and you spend too much time inside the ISR.

You should have only do the essentials inside ISR and do those time consuming loops after it wakes up main (or whichever routing that was suspended in LPM3).

You could start a timer to determine the 5, 10, 15 seconds and use software to decide how long the switch is being pressed.

Note that the switch usually bounces for tens of msec. Your software could handle that too.

You have the right idea and a good start. But there is a long way ahead of you.

thanks for ur reply,

                                do u have any idea about the Real time Clock using I2C to interface it with Msp430F2274 I have actually posted that code in the forums

 if u have idea and knowledge then please help me out I am using RTC RX8025 sa

this is a sample code this is not exactly the full code but I am able to write this much

//******************************************************************************
#include "msp430x22x4.h"
#define _bv(n) 1<<n


  void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P1DIR |= 0x03;                            // P1.0 output
  P3SEL |= 0x36;                            // Assign I2C pins to USCI_B0
  UCB0CTL1 |= UCSWRST;                      // Enable SW reset
  UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;     // I2C Master, synchronous mode
  UCB0CTL1 = UCSSEL_2 + UCSWRST;            // Use SMCLK, keep SW reset
  UCB0BR0 = 12;                             // fSCL = SMCLK/12 = ~100kHz
  UCB0BR1 = 0;UCB0I2COA = 0x48;
 // UCB0I2CSA = 0x64;                         // Set slave address
  UCB0CTL1 &= ~UCSWRST;                     // Clear SW reset, resume operation
  IE2 |= UCB0RXIE;                          // Enable RX interrupt
  TACTL = TASSEL_2 + MC_2;                  // SMCLK, contmode
//###########################################################################################
  UCA0CTL1 |= UCSSEL_1; //CLK=32Khz
 
  UCA0BR0 = 0x3;                           // 32kHz/9600 = 3.41
  UCA0BR1 = 0x0;                           //
  UCA0MCTL = UCBRS1 + UCBRS0;
 
  UCA0CTL1 &= ~UCSWRST; 
  //IE2 |= UCA0RXIE; 
  IE2 |= UCB0RXIE;                          // Enable RX interrupt
  RXCompare = 0;                            // Used to check incoming data

  BCSCTL3 |= 0x00;                      // LFXT1 = VLO
  TACCTL0 = CCIE;                           // TACCR0 interrupt enabled
  TACCR0 = 12000;                           // ~ 1 sec
  TACTL = TASSEL_1 + MC_1;                  // ACLK, upmode
  // UCB0CTL1 |= UCTXSTT;                     // **Initialize USCI state machine**
                                            // IE2 |= UCA0RXIE;                       // sice both the USCA0RXIE n USCB0RXIE share
 //__bic_SR_register(CPUOFF);                                             //  the same vetor address this
                                            //  is not enable but check out the data
  //########################################################################################### 
  while (1)
  {
     while((UCB0CTL1&_bv(UCTXSTP)));
           // Ensure stop condition got sent
    UCB0CTL1 |= UCTXSTT;                    // I2C start condition
    while((UCB0CTL1&_bv(UCTXSTT)));
          // Start condition sent?
    UCB0CTL1 |= UCTXSTP;                    // I2C stop condition
   // __bis_SR_register(CPUOFF + GIE);        // Enter LPM0 w/ interrupts

      RXCompare++;                            // Increment correct RX value
 
   //UCB0CTL1 |=UCTR+UCTXSTT;
      UCB0I2CSA = 0x64;
     while((UCB0CTL1&_bv(UCTXSTT)));
 
     UCB0CTL1 |=UCTXSTT;
      while((UCB0CTL1&_bv(UCTXSTT)));
 
  UCB0TXBUF =0x0E;//<<4;//for(unsigned int i=0;i<60;i++);UCA0TXBUF='S';
                           // Load RX byte counter
    UCB0CTL1 |= UCTXSTT;
    UCB0CTL1 |=~UCTR;
  UCB0CTL1 |= UCTXSTT;
  UCB0I2CSA = 0x65;
  UCB0TXBUF=0x65;
  while((UCB0CTL1&_bv(UCTXSTT)));
 
  RxByteCtr--;                              // Decrement RX byte counter
  UCA0TXBUF = UCB0RXBUF;