SMCLK provides clock source for TACLK.. CPU is normally off and // used only during TA_ISR.. Proper use of the TAIV interrupt vector generator // is demonstrated.. Dang // Texas Instrume
Trang 1//****************************************************************************** // MSP430G2xx1 Demo - Timer_A, Toggle P1.0, CCR1 Cont Mode ISR, DCO SMCLK //
// Description: Toggle P1.0 using software and TA_1 ISR Toggles every
// 50000 SMCLK cycles SMCLK provides clock source for TACLK
// During the TA_1 ISR, P1.0 is toggled and 50000 clock cycles are added to // CCR0 TA_1 ISR is triggered every 50000 cycles CPU is normally off and // used only during TA_ISR Proper use of the TAIV interrupt vector generator // is demonstrated
// ACLK = n/a, MCLK = SMCLK = TACLK = default DCO
//
// MSP430G2xx1
//
-// /|\|
XIN|-// | | |
// |RST
XOUT|-// | |
// | P1.0| >LED
//
// D Dang
// Texas Instruments Inc
// October 2010
// Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************
#include <msp430g2231.h>
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1DIR |= 0x01; // P1.0 output
CCTL1 = CCIE; // CCR1 interrupt enabled
CCR1 = 50000;
TACTL = TASSEL_2 + MC_2; // SMCLK, Contmode
_BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}
// Timer_A3 Interrupt Vector (TAIV) handler
#pragma vector=TIMERA1_VECTOR
interrupt void Timer_A(void)
{
switch( TAIV )
{
case 2: // CCR1
{
P1OUT ^= 0x01; // Toggle P1.0
CCR1 += 50000; // Add Offset to CCR1
}
break;
case 4: break; // CCR2 not used
case 10: break; // overflow not used
}
}