//******************************************************************************
//  MSP430F20x2 Demo - ADC10, DTC Sample A1 32x, 1.5V, Repeat Single, DCO
//
//  Description: Use DTC to sample A1 32 times with reference to internal 1.5v.
//  Vref Software writes to ADC10SC to trigger sample burst. In Mainloop MSP430
//  waits in LPM0 to save power until ADC10 conversion complete, ADC10_ISR(DTC)
//  will force exit from any LPMx in Mainloop on reti. ADC10 internal
//  oscillator times sample period (16x) and conversion (13x). DTC transfers
//  conversion code to RAM 200h - 240h. P1.0 set at start of conversion burst,
//  reset on completion.
//
//                MSP430F20x2
//             -----------------
//         /|\|              XIN|-
//          | |                 |
//          --|RST          XOUT|-
//            |                 |
//        >---|P1.1/A1      P1.0|-->LED
//
//   P.Thanigai
//  Texas Instruments Inc.
//  May 2007
//  Built with Code Composer Essentials Version: 2.0
//******************************************************************************
#include  "msp430x20x2.h"

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  ADC10CTL1 = CONSEQ_2+INCH_1;              // Repeat single channel
  ADC10CTL0 = SREF_1 + ADC10SHT_2 + MSC + REFON + ADC10ON + ADC10IE;
  __enable_interrupt();                     // Enable interrupts.
  TACCR0 = 30;                              // Delay to allow Ref to settle
  TACCTL0 |= CCIE;                          // Compare-mode interrupt.
  TACTL = TASSEL_2 + MC_1;                  // TACLK = SMCLK, Up mode.
  LPM0;                                     // Wait for delay.
  TACCTL0 &= ~CCIE;                         // Disable timer Interrupt
  __disable_interrupt();
  ADC10DTC1 = 0x20;                         // 32 conversions
  ADC10AE0 |= 0x02;                         // P1.1 ADC option select
  P1DIR |= 0x01;                            // Set P1.0 output

  for (;;)
  {
    ADC10CTL0 &= ~ENC;
    while (ADC10CTL1 & BUSY);               // Wait if ADC10 core is active
    ADC10SA = 0x200;                        // Data buffer start
    P1OUT |= 0x01;                          // Set P1.0 LED on
    ADC10CTL0 |= ENC + ADC10SC;             // Sampling and conversion start
    __bis_SR_register(CPUOFF + GIE);        // LPM0, ADC10_ISR will force exit
    P1OUT &= ~0x01;                         // Clear P1.0 LED off
  }
}

// ADC10 interrupt service routine
__interrupt void ADC_ISR (void);
ADC10_ISR(ADC_ISR)
__interrupt void ADC_ISR (void)
{
  __bic_SR_register_on_exit(CPUOFF);        // Clear CPUOFF bit from 0(SR)
}

__interrupt void Timer_A(void);
TIMERA0_ISR(Timer_A)
__interrupt void Timer_A(void)
{
  TACTL = 0;
  LPM0_EXIT;                                // Exit LPM0 on return
}