Difficulty with creating two Interrupt Service Routines at Port 1 and Port2

Niloofar, next time when inserting code, please use the syntax highlighter in rich formatting so it is easier to read - it then looks like this:

#include <msp430.h>
#include <stdio.h>
#include <math.h>

int Period = 1000-1;

//#pragma LOCATION( DC, 0x2400 );

int DC = 100;

int main( void )
{
  WDTCTL = WDTPW + WDTHOLD; // Stop WDT

  for(;;)
  {
    //push-buttons update
    P1REN |= BIT1; // Enable resistor on P1.1
    P1OUT  = BIT1; // set p1.1 resistor to pull-up
    P2REN |= BIT1; // Enable resistor on P2.1
    P2OUT  = BIT1; // set p2.1 resistor to pull-up
   
    if( ((P1IN & 0x02) != 0x02) && (DC < Period) ) // if Push-Button1 is pressed and DC<Period
    {
      P1IE  |=  0x02; // enable P1.1 interrupt
      P1IES |=  0x02; // select high to low edge
      P1IFG &= ~0x02; // clear P1.1 flag
  
      __bis_SR_register( LPM0_bits + GIE );
      __no_operation();
    }
  
    if( ((P2IN & 0x02) != 0x02) && (DC > 0) ) // if Push-button2 is pressed and DC<0
    {
      P2IE  |=  0x02; // enable P2.1 interrupt
      P2IES |=  0x02; // select hight to low sensitivity
      P2IFG &= ~0x02; // clear P2.1 flag
      
      __bis_SR_register( LPM0_bits + GIE );
      __no_operation();
    }

    //pwm update
    P1DIR   |= BIT3;
    P1SEL   |= BIT3;

    TA0CCR0  = Period;
    TA0CCTL2 = OUTMOD_7;
    TA0CCR2  = DC;
    TA0CTL   = TASSEL_2 + MC_1; // SMCLK, up mode
    
    __bis_SR_register( LPM0_bits );
    __no_operation();
  } //for loop end
} //main end

#pragma vector = PORT1_VECTOR
__interrupt void Port_1( void )
{
  DC = DC + round( 0.1 * Period ); // DC is increased by 10% of the Period
  P1IFG &= ~0x02;
  P1IES ^= 0x02;
}

#pragma vector = PORT2_VECTOR
__interrupt void Port_2( void )
{
  DC = DC - round( 0.1 * Period ); // DC is decreased by 10% of the Period
  P2IFG &= ~0x02;
  P2IES ^= 0x02;
}

So let's see what is wrong with your code...

just a vie thoughts on first sight:

Dennis Eichmann said:

P2IES ^= 0x02;

why do you toggle the edges? doesnt make sense to me,

Dennis Eichmann said:

round( 0.1 * Period );

in a real program never use dificult math in an IRQ, it costs too much time and resources, always do this in your normal code not in th eIRQ, although for testing it is ok, it wont hurt you.

you sure you need pull ups not pull downs?

next step I would debug , do you enter the IRQs at all?

your code seems pretty simple with a simple debug in code composer you should be able to find where it is not doing the things you want it to do.

Good luck.

When you configure the pins or the timer you do not need to do it over and over again in your for(;;)-loop, so you can put all the configuration before the loop:

int Period = (1000 - 1);
int DC     = 100;

void main( void )
{
  WDTCTL = WDTPW | WDTHOLD; // Stop WDT

  P1SEL |=  BIT3;
  P1DIR |=  BIT3;

  P1REN |=  BIT1; // enable resistor on P1.1
  P1OUT  =  BIT1; // set p1.1 resistor to pull-up
  P1IES |=  BIT1; // select high to low edge
  P1IFG &= ~BIT1; // clear P1.1 flag
  P1IE  |=  BIT1; // enable P1.1 interrupt
  
  P2REN |=  BIT1; // enable resistor on P2.1
  P2OUT  =  BIT1; // set p2.1 resistor to pull-up
  P2IES |=  BIT1; // select hight to low sensitivity
  P2IFG &= ~BIT1; // clear P2.1 flag
  P2IE  |=  BIT1; // enable P2.1 interrupt

  TA0CCR0  = Period;
  TA0CCR2  = DC;
  TA0CCTL2 = OUTMOD_7;
  TA0CTL   = TASSEL_2 | MC_1; // SMCLK, up mode

  __bis_SR_register( GIE );

  for(;;)
  {
    ...
  }
}

seb is right with his comment - using a floating point operation on this processor inside an ISR isn't the best idea in general. If your program will not do anything else, then this might be OK. But I think a floating point operation isn't necessary here. You have a fixed period of 1000, so in-/decrementing 100 does the same. If it will change later to a variable period, then better go for (period / 10), which is still an integer. Or you could also set a new period in your main in combination with another variable that holds the new in-/decrement value which will be calculated at the same time the new period is set.

Then you will run into the typical button problem: bouncing

You always have to debounce buttons with a delay (bad way) or a timer. The timer method is more complex, of course. If you want to use interrupts for the input buttons, you could start a timer inside the button-ISR and check the button's state in the timer interrupt again. If it is still pressed, do the desired action.

But you could also read your buttons in periodic intervals controlled by a timer.

And to seb's other statement: Why do you change the PxIES? I also don't get why you handle the buttons inside the main and inside the ISR. Maybe you describe what you originally had planned.

Hi Dennis, thank you so much for reviewing the code. I make sure to use the syntax highlighter in rich formatting in future.

Thank you very much for your valuable comments.
Regarding the duty cycle, is there anyway that I can store this value in RAM and update it as it changes? From the datasheet I see the address of 4 sectors of RAM, but I am not sure which one I can use.

Sorry that my posted program does not make good sense, but following your comments I am updating it. I'll post the new program in a few days and would greatly appreciate if you review it.

What exactly are you talking about witht he 4 secot of RAM?

MSP430F only has flash and RAM, maybe you should be aware of how your program code works first?!

Almost everything you write in code in C-language will be stored in RAM during runtime, only const will be stored in Flash. And flash is not easily changed during runtime, since it is not easily eraseable.

So your Duty cycles will be in RAM. But i am not sure yet how that would make your whole Code work or not work.