//******************************************************************************
// MSP-FET430P140 Demo - Basic Clock, LPM3 Using WDT ISR, 32kHz ACLK
//
// Description: This program operates MSP430 normally in LPM3, pulsing P1.0
// at 4 second intervals. WDT ISR used to wake-up system. All I/O configured
// as low outputs to eliminate floating inputs. Current consumption does
// increase when LED is powered on P1.0. Demo for measuring LPM3 current.
// ACLK= LFXT1/4= 32768/4, MCLK= SMCLK= default DCO
// //* External watch crystal on XIN XOUT is required for ACLK *//
//
//
// MSP430F149
// ---------------
// /|\| XIN|-
// | | | 32kHz
// --|RST XOUT|-
// | |
// | P1.0|-->LED
//
// M. Buccini
// Texas Instruments Inc.
// Feb 2005
// Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.21A
//******************************************************************************
#include <msp430x14x.h>
void main(void)
{
BCSCTL1 |= DIVA_2; // ACLK/4 ACLK来自LX1=32 KHz
WDTCTL = WDT_ADLY_1000; // WDT 1s/4 interval timer用作间隔定时器1000ms(1s)*4,看门狗功能不用,而用作定时器功能,可以产生中断
IE1 |= WDTIE; // Enable WDT interrupt
P1DIR = 0xFF; // All P1.x outputs
P1OUT = 0; // All P1.x reset
P2DIR = 0xFF; // All P2.x outputs
P2OUT = 0; // All P2.x reset
P3DIR = 0xFF; // All P3.x outputs
P3OUT = 0; // All P3.x reset
P4DIR = 0xFF; // All P4.x outputs
P4OUT = 0; // All P4.x reset
P5DIR = 0xFF; // All P5.x outputs
P5OUT = 0; // All P5.x reset
P6DIR = 0xFF; // All P6.x outputs
P6OUT = 0; // All P6.x reset
while(1)
{
int i;
_EINT();
LPM3; // Enter LPM3 低功耗3开启中断 cpu停止了(以下程序不能进行,等待激活,但是ACLK继续活跃,看门狗定时器继续工作
P1OUT &= ~0x01; // Set P1.0 LED off
for (i = 5000; i>0; i--); // Delay
P1OUT |= 0x01; // Clear P1.0 LED on
}
}
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer (void)
{
LPM3_EXIT; // Clear LPM3 bits from 0(SR)
}