fet440_wdt_01.c

来自「MSP430F43x, MSP430F44x.zip c语言 例程」· C语言 代码 · 共 41 行

//******************************************************************************
//  MSP-FET430P440 Demo - WDT, Toggle P5.1, Interval Overflow ISR, DCO SMCLK
//
//  Description: Toggle P5.1 using WDT configured for Interval Timer mode.
//  Interrupt toggles LED every 31ms when using default FLL+ register
//  settings and an external 32kHz watch crystal.
//  ACLK = LFXT1 = 32768Hz, MCLK = SMCLK = default DCO = 32 x ACLK = 1048576Hz
//  //* An external watch crystal between XIN & XOUT is required for ACLK *//	
//
//                 MSP430F449
//             -----------------
//         /|\|              XIN|-
//          | |                 | 32kHz
//          --|RST          XOUT|-
//            |                 |
//            |             P5.1|-->LED
//
//  M. Buccini
//  Texas Instruments Inc.
//  Feb 2005
//  Built with IAR Embedded Workbench Version: 3.21A
//*****************************************************************************
#include <msp430x44x.h>

void main(void)
{
  WDTCTL = WDT_MDLY_32;                     // ~31ms interval timer
  IE1 |= WDTIE;                             // Enable WDT interrupt
  P5DIR |= 0x02;                            // Set P5.1 to output direction

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

// Watchdog Timer interrupt service routine
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
{
  P5OUT ^= 0x02;                            // Toggle P5.1 using exclusive-OR
}