Микропроцессорная техника / MSP430G2xx2_Code_Examples / msp430g2xx2_wdt_02

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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.
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//******************************************************************************
//  MSP430G2xx2 Demo - WDT, Toggle P1.0, Interval Overflow ISR, 32kHz ACLK
//
//  Description: Toggle P1.0 using software timed by WDT ISR. Toggle rate is
//  exactly 250ms based on 32kHz ACLK WDT clock source.  In this example the
//  WDT is configured to divide 32768 watch-crystal(2^15) by 2^13 with an ISR
//  triggered @ 4Hz.
//  ACLK = LFXT1 = 32768Hz, MCLK = SMCLK = default DCO
//  //* External watch crystal installed on XIN XOUT is required for ACLK *//	
//
//		  MSP430G2xx2
//             -----------------
//         /|\|              XIN|-
//          | |                 | 32kHz
//          --|RST          XOUT|-
//            |                 |
//            |             P1.0|-->LED
//
//  D. Dang
//  Texas Instruments Inc.
//  December 2010
//  Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************

#include <msp430.h>


int main(void)
{
  WDTCTL = WDT_ADLY_250;                    // WDT 250ms, ACLK, interval timer
  IE1 |= WDTIE;                             // Enable WDT interrupt
  P1DIR |= 0x01;                            // Set P1.0 to output direction

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

// Watchdog Timer interrupt service routine
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
{
  P1OUT ^= 0x01;                            // Toggle P1.0 using exclusive-OR
}