//******************************************************************************
//  MSP430x47xx Demo - Timer_B, Toggle P5.1, Overflow ISR, 32kHz ACLK
//
//  Description: Toggle P5.1 using software and the Timer_B overflow ISR.
//  In this example an ISR triggers when TB overflows. Inside the ISR P5.1
//  is toggled. Toggle rate is exactly 0.5Hz.
//  Proper use of TBIV interrupt vector generator is demonstrated.
//  ACLK = LFXT1 = 32768Hz, MCLK = SMCLK = default DCO = 32 x ACLK = 1048576Hz
//  //* An external watch crystal between XIN & XOUT is required for ACLK *// 
//
//           MSP430x47xx
//         ---------------
//     /|\|            XIN|-
//      | |               | 32kHz
//      --|RST        XOUT|-
//        |               |
//        |           P5.1|-->LED
//
//  P. Thanigai / K.Venkat
//  Texas Instruments Inc.
//  November 2007
//  Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.42A
//*****************************************************************************
#include  <msp430x47x4.h>

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  FLL_CTL0 |= XCAP14PF;                     // Configure load caps
  P5DIR |= BIT1;                            // Set P5.1 to output direction
  TBCTL = TBSSEL_1 + MC_2 + TBIE;           // ACLK, contmode, interrupt

  _BIS_SR(LPM3_bits + GIE);                 // Enter LPM3 w/ interrupt
}

// Timer_B7 Interrupt Vector (TBIV) handler
#pragma vector=TIMERB1_VECTOR
__interrupt void Timer_B(void)
{
 switch( TBIV )
 {
   case  2: break;                          // CCR1 not used
   case  4: break;                          // CCR2 not used
   case 14: P5OUT ^= BIT1;                  // overflow
           break;
  }
}