//******************************************************************************
// MSP430G2xx3 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 ~ 800kHz
// //* External watch crystal installed on XIN XOUT is required for ACLK *//
//
//
// MSP430G2xx3
// ---------------
// /|\| 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 <msp430g2553.h>
void main(void)
{
BCSCTL1 |= DIVA_2; // ACLK/4
WDTCTL = WDT_ADLY_1000; // WDT 1s/4 interval timer
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
while(1)
{
int i;
P1OUT |= 0x01; // Set P1.0 LED on
for (i = 5000; i>0; i--); // Delay
P1OUT &= ~0x01; // Reset P1.0 LED off
_BIS_SR(LPM3_bits + GIE); // Enter LPM3
}
}
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer (void)
{
_BIC_SR_IRQ(LPM3_bits); // Clear LPM3 bits from 0(SR)
}
