Basic getting started question

Guys,

I think you have something wrong:

In the code above , the code will enter the infinite while loop and the _BIS_SR(LPM0_bits + GIE); will never be executed so that the timer will not run. This is because the time interrupt routine requires that the interrupts be set.  the code should be as follows:

#include  <msp430xG43x.h>

void main(void)
{

  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P5DIR |= 0x02;                            // P5.1 output
  CCTL0 = CCIE;                             // CCR0 interrupt enabled
  CCR0 = 20000;
  TACTL = TASSEL_2 + MC_1;                  // SMCLK, up mode

while(1)

{

  _BIS_SR(LPM0_bits + GIE);                 // Enter LPM0 w/ interrupt

}
 
}

// Timer A0 interrupt service routine
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
{
  P5OUT ^= 0x02;                            // Toggle P5.1 using exclusive-OR
}

putting the _BIS_SR(LPM0_bits + GIE);       inside the while loop or before it is an acceptable solution since it will avoid stopping if for some reason the interrupt vector causes an exit from the LPM.

Another solution, if you want to do some processing during the timer running is to use __EINT();  (check the spelling of it, it might need only one underscore).
Remember that what you need is to enable interrupts, it just so happens that you can also go to low power mode too.

Looking at the original post, the code seems ok. However, if you're afraid you're running the simulator, change the project settings to FET Debugger instead of simulator. You can sometimes notice that the simulator is executing and not the JTAG FET because when the simulator is being used, the part of the debugger where it says downloading and such runs much faster since it doesn't really do any of that.

To check the project settings in IAR right click on project name and click on settings. There is a tab for FET Debugger or something similar. A good way to start learning is with some tutorials. I have a tutorial (that still needs a lot of work but gets a lot of the basics ) at:

http://www.utdallas.edu/~gustavo.litovsky/Tutorialv0_2.pdf

There are also plenty of resources out there for the MSP430

GL