msp430x24x_wdt_06.c

德州仪器公司提供的msp430x24x和msp430x23x系列单片机的示例程序. 内含单片机各模块的具体程序.

//******************************************************************************
//  MSP430x24x Demo - WDT+ Failsafe Clock, 32kHz ACLK
//
//  Description; Allow WDT+ in watchdog to timeout sourced by ACLK. LPM3 is
//  entered, this example will demonstrate WDT+ feature by automatically
//  re-enabling WDT+ clock source as DCO if external XTAL fails. This can be
//  seen as a continued, though faster as clocked by DCO, watchdog timeout
//  which will toggle on P1.0 in main function.
//  ACLK = 32768, MCLK = SMCLK = default DCO ~1.045Mhz
//
//                MSP430F249
//             -----------------
//         /|\|              XIN|-
//          | |                 | 32kHz
//          --|RST          XOUT|-
//            |                 |
//            |             P1.0|-->LED
//
//  B. Nisarga
//  Texas Instruments Inc.
//  September 2007
//  Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.42A
//******************************************************************************
#include "msp430x24x.h"

void main(void)
{
  // Watchdog mode -> reset after expired time; WDT is clocked by ACLK
  WDTCTL = WDT_ARST_1000;                   // Set Watchdog Timer timeout 1s
  P1DIR |= 0x01;                            // Set P1.0 to output
  P1OUT ^= 0x01;                            // Toggle P1.0
  __bis_SR_register(LPM3_bits + GIE);       // Enter LPM3
}