Note this demo has been modified to compile on the msp430-gcc compiler.
//******************************************************************************
// MSP430F20xx Demo - Timer_A, Toggle P1.0, CCR0 Cont. Mode ISR, DCO SMCLK
//
// Description: Toggle P1.0 using software and TA_0 ISR. Toggles every
// 50000 SMCLK cycles. SMCLK provides clock source for TACLK.
// During the TA_0 ISR, P1.0 is toggled and 50000 clock cycles are added to
// CCR0. TA_0 ISR is triggered every 50000 cycles. CPU is normally off and
// used only during TA_ISR.
// ACLK = n/a, MCLK = SMCLK = TACLK = default DCO
//
// MSP430F20xx
// ---------------
// /|\| XIN|-
// | | |
// --|RST XOUT|-
// | |
// | P1.0|-->LED
//
// M. Buccini / L. Westlund
// Texas Instruments Inc.
// October 2005
// Built with CCE Version: 3.2.0 and IAR Embedded Workbench Version: 3.40A
//******************************************************************************
#include <msp430x20x3.h>
#include <signal.h>
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1DIR |= 0x01; // P1.0 output
CCTL0 = CCIE; // CCR0 interrupt enabled
CCR0 = 50000;
TACTL = TASSEL_2 + MC_2; // SMCLK, contmode
_BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}
// Timer A0 interrupt service routine
// vector=TIMERA0_VECTOR
interrupt (TIMERA0_VECTOR) Timer_A (void)
{
P1OUT ^= 0x01; // Toggle P1.0
CCR0 += 50000; // Add Offset to CCR0
}