/* --COPYRIGHT--,BSD_EX
 * Copyright (c) 2012, Texas Instruments Incorporated
 * All rights reserved.
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 *    notice, this list of conditions and the following disclaimer.
 *
 * *  Redistributions in binary form must reproduce the above copyright
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 *
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 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 *******************************************************************************
 * 
 *                       MSP430 CODE EXAMPLE DISCLAIMER
 *
 * MSP430 code examples are self-contained low-level programs that typically
 * demonstrate a single peripheral function or device feature in a highly
 * concise manner. For this the code may rely on the device's power-on default
 * register values and settings such as the clock configuration and care must
 * be taken when combining code from several examples to avoid potential side
 * effects. Also see www.ti.com/grace for a GUI- and www.ti.com/msp430ware
 * for an API functional library-approach to peripheral configuration.
 *
 * --/COPYRIGHT--*/
//******************************************************************************
//  MSP430F20x1 Demo - Comp_A, Output Reference Voltages on P1.1
//
//  Description: Output Comparator_A reference levels on P1.1. Program will
//  cycle through the on-chip comparator_A reference voltages with output on
//  P1.1. Normal mode is LPM0, TA0_ISR will interrupt LPM0.
//  ACLK = n/a, MCLK = SMCLK = default DCO
//
//		  MSP430F20x1
//             -----------------
//         /|\|              XIN|-
//          | |                 |
//          --|RST          XOUT|-
//            |                 |
//            |         P1.1/CA1|--> Vref
//            |                 |			
//
//  M. Buccini / L. Westlund
//  Texas Instruments Inc.
//  December 2005
//  Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.40A
//******************************************************************************

#include <msp430.h>

void delay(void);                           // Software delay

int main (void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  CACTL2 = P2CA4;                           // CA1/P1.1 = +comp
  CCTL0 = CCIE;                             // CCR0 interrupt enabled
  TACTL = TASSEL_2 + ID_3 + MC_2;           // SMCLK/8, cont-mode
  __enable_interrupt();                     // enable interrupts

  while (1)                                 // Loop
  {
    CACTL1 = 0x00;                          // No reference voltage
    __bis_SR_register(LPM0_bits);           // Enter LPM0
    CACTL1 = CAREF0 + CAON;                 // 0.25*Vcc, Comp. on
    __bis_SR_register(LPM0_bits);           // Enter LPM0
    CACTL1 = CAREF1 + CAON;                 // 0.5*Vcc, Comp. on
    __bis_SR_register(LPM0_bits);           // Enter LPM0
    CACTL1 = CAREF1 + CAREF0 + CAON;        // 0.55V, Comp. on
    __bis_SR_register(LPM0_bits);           // Enter LPM0
  }
}

// Timer A0 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMERA0_VECTOR))) Timer_A (void)
#else
#error Compiler not supported!
#endif
{
    __bic_SR_register_on_exit(LPM0_bits);   // Clear LPM0 bits from 0(SR)
}