//******************************************************************************
//  MSP430F23x0 Demo - Timer_A, Toggle P1.0, Overflow ISR, DCO SMCLK
//
//  Description: Toggle P1.0 using software and Timer_A overflow ISR.
//  In this example an ISR triggers when TA overflows. Inside the TA
//  overflow ISR P1.0 is toggled. Toggle rate is approximately 18Hz.
//  Proper use of the TAIV interrupt vector generator is demonstrated.
//  ACLK = n/a, MCLK = SMCLK = TACLK = default DCO ~1.2MHz
//
//               MSP430F23x0
//            -----------------
//        /|\|              XIN|-
//         | |                 |
//         --|RST          XOUT|-
//           |                 |
//           |             P1.0|-->LED
//
//  A. Dannenberg
//  Texas Instruments Inc.
//  January 2007
//  Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.41A
//******************************************************************************
#include "msp430x23x0.h"

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P1DIR |= 0x01;                            // P1.0 output
  TACTL = TASSEL_2 + MC_2 + TAIE;           // SMCLK, contmode, interrupt

  __bis_SR_register(LPM0_bits + GIE);       // Enter LPM0 w/ interrupt
}

// Timer_A3 Interrupt Vector (TAIV) handler
#pragma vector=TIMERA1_VECTOR
__interrupt void Timer_A(void)
{
  switch  (__even_in_range(TAIV, 10))       // Efficient switch-implementation
  {
    case  2: break;                         // TACCR1 not used
    case  4: break;                         // TACCR2 not used
    case 10: P1OUT ^= 0x01;                 // overflow
             break;
  }
}