The internal timer A of the MSP430F149 microcontroller is set to flash the LED for 1 second-EEWORLD

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#include "msp430x14x.h"

//********************Function declaration******************

void InitClock();

//********************Main function************************

void main(void)

{

WDTCTL = WDTPW + WDTHOLD; // Turn off the watchdog

InitClock(); // Initialize the clock

P1DIR |= BIT0; // Set P1.0 as output

CCTL0 = CCIE; // Enable CCR0 interrupt

CCR0 = 500;

TACTL = TASSEL_2 + MC_1; // Subsystem clock, up counting mode

_BIS_SR(LPM0_bits + GIE); // Low power mode 0/ open general interrupt

}

//******************************************

Function name: InitClock

Function : Initialize the clock function

Parameters : None

Return value : None

//************************************************

void InitClock()

{

unsigned int oscdly;

BCSCTL1 &= ~XT2OFF; // Clear OSCOFF/XT2 to enable XT2 oscillator

{

IFG1 &=~OFIFG; //Clear OFIFG

oscdly=255;

while(oscdly--); //delay waiting

}

while(IFG1 & OFIFG); //Until OFIFG=0

DCOCTL |= DCO0 + DCO1 + DCO2; // Max DCO

BCSCTL1 |= RSEL0 + RSEL1 + RSEL2; // XT2on, max RSEL

//These two sentences set DCOCTL and BCSCTL1, set the frequency of DCO

// Generally speaking, after the PUC is reset, if the system clock MCLK is not set specifically, the MCU will default to

//Recognize the frequency generated by the DCO oscillator as the system clock, but if you set BCSCTL2 to select

//If the clock source of MCLK is (such as: BCSCTL2 |= SELM_2+SELS;), the system clock is

//XT2 oscillates.

//------------------------------------------------ -------------

BCSCTL2 |= SELM_2+SELS; //SMCLK and MCLK uses XT2

//This sentence sets BCSCTL2 and selects the clock sources of MCLK and SMCLK

//Note: ACLK can only come from LFXT1. The frequency division of ACLK can be set in BCSCTL1.

//------------------------------------------------ -------------

}

//******************************************

Function name: Timer_A

Function : Timer A interrupt service subroutine

Parameters : None

Return value : None

//************************************************

#pragma vector=TIMERA0_VECTOR

__interrupt void Timer_A (void)

{

P1OUT ^= BIT0; // Invert P1.0

}

Keywords：MSP430F149 Reference address：The internal timer A of the MSP430F149 microcontroller is set to flash the LED for 1 second

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